WO2013181159A1 - Power trigger sprayer - Google Patents

Abstract

A power trigger sprayer comprising an integrated nozzle and pump assembly. The pump may comprise one or more pistons. Each piston feeds an input port of a swirl chamber spray nozzle. The nozzle is pulsed at a high rate, producing a predetermined spray pattern. In a further embodiment, the sprayer may be configured for handheld application of liquids and may comprise a tank for holding the liquid, a power source and control actuator together with the spray pump and nozzle in a hand operable unit. The sprayer may comprise a drip guard for directing drip flow away from the trigger and hand grip portion of the sprayer. The sprayer may include a battery within the hand grip portion. The battery may be in a battery module with grip/latch tabs allowing easy removal and replacement of the battery.

Description

Liquid Delivery System

Related Applications

This application is a continuation in part of application 13/482,331 titled "Liquid Delivery System", filed May 29, 2012 by Harwood, which claims the benefit under 35 USC 119(e) of provisional application Serial No. 61/580,650, Titled "Liquid Delivery System", filed 27 December 2011 by Harwood. This application is also a continuation in part of application 13740190, titled: "Wobble Drive Mechanism" filed 12 January 2013 by Harwood et al., which claims the benefit of provisional application 61708592 titled: "Wobble Drive Mechanism" filed October 1, 2012 by Harwood; this application also claims the benefit of provisional application 61806862 titled: "Liquid Delivery System", filed March 30, 2013 by Harwood. All of the above listed US Patent and Patent Applications are hereby incorporated herein by reference in their entirety.

Field of the Invention

The present invention pertains generally to the field of liquid delivery systems, more particularly to devices for powered airless spray delivery of liquids.

Background of the Invention

Typical spray delivery systems include aerosol bottles, hand sprayers, and motorized and air driven paint sprayers. Aerosol bottles require special propellants and have environmental issues. Hand sprayers are typically limited to light liquids such as cleaning fluids that have a similar viscosity to water. Paint sprayers typically require a compressed air source or electric cord, making them too large and awkward for many applications. The aerosols and paint sprayers typically produce small droplet sizes that contribute to mists that degrade air purity and settle on undesired surfaces.

Prior art methods of spray delivery of viscous fluids may involve a high pressure gas to dropletize the flow. The gas flow turbulence acts to break up a low pressure liquid stream. Alternatively, two high pressure streams may be directed to impinge on one another from substantially opposite directions to break up the flow into droplets. These and other techniques for spraying viscous liquids typically result in a fine mist or undesired spray patterns. The fine mist may be desired in some paint spray operations, but can cause problems in other applications where the delivery must be confined to a target area and mists that may be carried by ambient air currents must be minimized.

Thus, there is a need for improvements in the art of spray delivery of high viscosity liquids.

Brief Description of the Invention

Briefly, the invention relates to a power trigger sprayer comprising an integrated nozzle and pump assembly. The pump may comprise one or more pistons. Each piston feeds an input port of a swirl chamber spray nozzle. The nozzle is pulsed at a high rate, producing a predetermined spray pattern. In a further embodiment, the sprayer may be configured for handheld application of liquids and may comprise a tank for holding the liquid, a power source and control actuator together with the spray pump and nozzle in a hand operable unit. The sprayer may comprise a drip guard for directing drip flow away from the trigger and hand grip portion of the sprayer. The sprayer may include a battery within the hand grip portion. The battery may be in a battery module with grip/latch tabs allowing easy removal and replacement of the battery. In one variation, the sprayer pistons have a top cap for contact interface with the intermediate plate. The piston top cap may have a flat surface for contact with the intermediate plate to minimize contact pressure and resulting wear. The underside of the piston cap may have a spherical contact with the piston. One or more sliding interfaces between parts including the wobble plate hub, intermediate plate, piston cap, piston, and/or cylinder block may comprise two different materials, for example, two different plastics, for example nylon and acetyl, for example, DELRIN^®. In one variation, a corrosion resistant metal, for example stainless steel, in particular, for example NITRONIC-60^®, may be used for elements in contact with corrosive fluids.

In another variation, the pump may include a freely rotating contact member for coupling the pistons to the wobble plate. The contact member may be allowed to freely rotate coaxially with an associated piston to minimize friction and wear at the contact point with the wobble plate. The contact member may have a conical contact end for contacting the wobble plate. In a further variation, the contact member may be rigidly coupled to the piston and the piston may also be freely rotatable to minimize friction at the wobble plate contact point.

The contact member may be disposed within a non-rotating sleeve of TEFLON® or other low friction material and may be spring loaded against the wobble plate by spring force acting through the non-rotating sleeve.

In a further variation, the pump delivers a pulsating flow to the spray nozzle to better fill the interior of the coverage area of the spray pattern than traditional constant flow swirl nozzles.

In a further variation the sprayer may have an intermediate plate between the wobble plate and the pistons. The intermediate plate may be rotationally mounted on the wobble plate and allowed to rotate freely relative to the wobble plate.

In a further variation, the system may be configured for handheld application of liquids and may comprise a tank for holding the liquid, a power source and control actuator together with the spray pump and nozzle in a hand operable package.

In one application, the system may be configured for application of high viscosity liquids, such as vegetable cooking oils in a food preparation operation by matching the nozzle configuration and flow rate to produce a wide spray pattern with large enough droplet size to avoid undesirable mist formation. In one embodiment, the system meets a mist free criterion, for example: 90% of the flow volume comprises droplets that are large enough to settle in still air at 6 inches per second (15 cm/sec), or preferably one foot per second (30 cm/sec.) or faster.

In one variation, the system delivers a filled circular spray pattern. The pattern may be measured at, for example 20 cm. The full width of the spray may be for example, 20 degrees for 90% containment. The fluid delivery may be for example from 1 ml/sec to 3 ml/sec for a fluid having an exemplary kinematic viscosity of 15 centiStokes or more.

The filled circular pattern may be achieved, at least in part, by operating the swirl nozzle at multiple flow rates. In one embodiment, the pump delivers pulses of flow distributed over a range of flow rates. For example, the pulse flow characteristic may be characterized as a half sine function delivering flow rates from zero to a maximum value. The flow characteristic may include at least two different non-zero flow rates. The width of the spray pattern may be a function of the flow rate. Thus the pattern distribution may be controlled by varying the flow rate.

In one variation, the flow is pulsed at a pulse repetition rate sufficient for an average high velocity flow from a following pulse to overtake an average low velocity flow from a preceding pulse before reaching a spray target. In one variation, the spray target may be at a distance of, for example, at least 20, or at least 30 centimeters. Average high velocity and average low velocity being the average flow above and below a 50% velocity. In one variation, the pulse repetition rate is preferably between 2000 and 30,000 pulses per minute, preferably 14000 pulses per minute.

In one variation, the swirl chamber has a height to width ratio preferably between 0.4 and 0.6.

The swirl chamber output nozzle opening may be located in a recess and the nozzle initial cone angle may be greater than the spray initial cone angle to minimize drips.

In a further variation the sprayer may be configured in a hand held unit. The hand held unit may include a spray bottle source for the fluid. The hand held unit may further include a drip guard for directing any fluid drip in front of a space to be occupied by the hand in an operating configuration for the device. The space being within 2.5 cm or preferably within 2 cm of a trigger for operating the sprayer. The drip guard may form a lowest local point directly below the nozzle. The trigger guard satisfies several, self -conflicting constraints: (a) the guard forms the lowest point, (b) does not block access to the trigger, and hence, interfere with grapping the trigger during operation, and (c) remains close enough to the nozzle that the oil does not flow around the guard.

In a further variation of a hand held unit, the sprayer may include a battery configured to fit within a grip handle of the device and the unit may achieve a total spray "on" time of greater than one hour. The battery is contained within a plug-in battery module that may be removed and placed in a charger with a single continuous grip and place motion without releasing the grip until completed, and without removing the sprayer from the liquid source bottle.

In a further variation of a hand held unit, the sprayer may achieve a total spray volume of 1 liter or more, preferably greater than three liters on a single charge from the power source.

The invention further includes methods related to the features of the device including a method of spraying a viscous fluid.

The present disclosure also pertains to a wobble drive mechanism for coupling a rotary motion to a reciprocating motion comprising a diagonal plate coupled to a rotary motion axis driving a wobble carrier having a flat side in sliding contact with the diagonal plate and a spherical side in contact with a spherical bearing recess. The wobble carrier has a bore containing at least one reciprocating drive shoe. The reciprocating drive shoe may be coupled to a piston operating within a cylinder. The reciprocating drive shoe may be free to move in the bore linearly and/or rotationally. In various embodiments, the reciprocating drive shoe comprises two or more components. In various embodiments the piston is coupled to the shoe via a fixed rod section and the fixed rod section terminates in a double cylindrical bearing T section or a spherical bearing. The reciprocating drive may operate various devices, for example, pump or motor devices.

In a further variation, the reciprocating drive shoe comprises a shuttle and an end cap.

In a further variation, the wobble carrier is restrained from rotating around the rotary axis by lateral restraint of the connecting rod.

In a further variation, the reciprocating drive shoe is partitioned into two or more components; the two or more components collectively include a top bearing portion proximal to the wobble hub for coupling axial extension motion of the reciprocating motion, and further include a bottom bearing portion for coupling axial retracting motion of the reciprocating motion and further include an aperture for passing a connecting rod for coupling the reciprocating motion.

In a further variation, the two or more components of the reciprocating drive shoe are held in place for operation by walls of the wobble carrier bore and the coupling rod end coupling; wherein the walls of the wobble carrier bore prevent separation of the two or more components and the connecting rod end coupling prevents relative sliding of at least two of the two or more components.

In a further variation, the reciprocating drive shoe comprises two half shoe components.

In a further variation, the reciprocating drive shoe comprises a shuttle and an end cap.

In a further variation, the shuttle forms a through hole in the shuttle, the shuttle capturing the end cap within a portion of the through hole, the shuttle having a bearing surface for coupling to a coupling rod end coupling within the through hole, the shuttle forming an aperture portion of the through hole for receiving a coupling rod.

In a further variation, further including a piston coupled to the reciprocating drive shoe, the piston is coupled to the reciprocating drive shoe via a fixed rod section, the fixed rod section fixedly attached to the piston, and the fixed rod section terminating in a double cylindrical bearing T section.

In a further variation, further including a piston coupled to the reciprocating drive shoe, the piston is coupled to the reciprocating drive shoe via a fixed rod section, the fixed rod section fixedly attached to the piston, and the fixed rod section terminating in a spherical ball end coupling.

In a further variation, the spherical surface of the wobble carrier is based on a sphere having a center along the center axis of the wobble carrier bore.

In a further variation, the spherical surface of the wobble carrier is based on a sphere having a radius sufficient to include within the sphere the reciprocating drive shoe at a maximum travel range for the reciprocating drive shoe within the wobble carrier bore.

In a further variation, the spherical surface of the wobble carrier is interrupted to allow passage of the coupling rod through the spherical surface.

In a further variation, a spherical surface of the spherical recess allows passage of the coupling rod through the spherical surface of the spherical recess.

In a further variation, the spherical surface of the wobble carrier is based on a sphere having a radius greater than a radius or a width of the wobble carrier bore.

In a further variation, the sliding contact with the diagonal plate includes an anti friction pad.

Embodiments using the drive section for a fluid pump are disclosed. The drive may be used for pump or motor embodiments.

The mechanism is capable of coupling the rotary motion to both push and pull of the reciprocating motion without having return springs that apply a continuous preload. In a pump application, this may eliminate the need for return springs to retract the pistons and eliminates the forces and friction forces related to the return springs.

The wobble carrier is not attached by a typical shaft and bearing, but rather "floats" within the space between the diagonal drive and the spherical bearing seat. The arrangement allows for simple assembly, wide tolerances in the parts and permits significant wear. These and further benefits and features of the present invention are herein described in detail with reference to exemplary embodiments in accordance with the invention.

Brief Description of the Figures

The present invention is described with reference to the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar elements. Additionally, the left-most digit(s) of a reference number identifies the drawing in which the reference number first appears.

Fig. 1 A- Fig 1C illustrate an exemplary liquid delivery system in accordance with the present invention.

Fig. ID is a magnified view of a portion of the cross section view of Fig. IB.

Fig. 2 A is a side view of a second embodiment of the invention.

Fig. 2B is a cross section view of the embodiment of Fig. 2A.

Fig. 2C is a magnified view of a portion of the cross section of Fig. 2B.

Fig. 3A, Fig. 3B, and Fig. 3C are outline drawings showing the features of the nozzle structure.

Fig. 4A-Fig. 4H illustrate various spray pattern effects.

Fig. 41 - Fig. 4L depict a three piston embodiment.

Fig. 5 illustrates a side cross section view of an exemplary sprayer having an intermediate plate between the wobble plate and the pistons.

Fig. 6 illustrates a 90 degree rotated side view of the sprayer of Fig. 5.

Fig. 7 illustrates a side cross sectional view of an exemplary sprayer wherein the pistons have a top cap for contact interface with the intermediate plate.

Fig. 8 illustrates a 90 degree rotated side cross sectional view of the sprayer of Fig. 7.

Fig. 9 illustrates a side cross sectional view of the sprayer of Fig. 7 showing assembly screws.

Fig. 10 illustrates an alternative embodiment of Fig. 9.

Fig. 11 illustrates a side cross sectional view of the sprayer of Fig. 7 showing the rotational mounting of the intermediate plate.

Fig. 12 illustrates a side cross sectional view of the sprayer of Fig. 7 showing an alternative ball bearing mounting of the intermediate plate to the wobble plate.

Fig. 13 illustrates a side cross sectional view of an exemplary sprayer in accordance with the present invention. Fig. 14 shows the integrated pump and nozzle section of the sprayer of Fig. 13.

Fig. 15 and Fig. 16 illustrate cross sections of the exemplary pump of Fig. 13 from planes perpendicular to the plane of Fig. 13.

Fig. 17 is an exploded view of the sprayer of Fig. 13 - Fig. 16.

Fig. 18 illustrates a perspective view of an exemplary sprayer head assembly in accordance with the present invention.

Fig. 19 is a left side elevational view of the exemplary sprayer head assembly of Fig. 18.

Fig. 20 is a front cross section view of the exemplary sprayer head assembly as indicated in Fig. 19.

Fig. 21A is a front elevational view of the exemplary sprayer head assembly of Fig. 18.

Fig. 21B is a cross section view as indicated in Fig. 21 A.

Fig. 22 is a left side cross section view of the exemplary sprayer head assembly as indicated in Fig. 21.

Fig. 23 is a left side view of the exemplary sprayer of Fig. 18 with the left shell and battery pack removed. Fig. 24 is a detail drawing of a portion of the cross section of Fig. 22A showing an exemplary vent check valve embedded in a bottle interface cap.

Fig. 25 is an exploded view of the exemplary sprayer head assembly of Fig. 18.

Fig. 26 is a right side elevational view of the exemplary sprayer head with a spray bottle.

Fig. 27 is a front elevational view of the exemplary sprayer head with a spray bottle of Fig. 26.

Fig. 28 is a right side elevational view of the exemplary sprayer head with a pickup tube installed.

Fig. 29 is a schematic diagram of an exemplary control circuit for the sprayer of Fig. 18.

Fig. 30 shows the operational capability for two usage profiles. Fig. 31A and Fig. 31B are two different isometric views illustrating an exemplary integrated sprayer pump, nozzle, motor in accordance with the present invention.

Fig. 32A and Fig. 32B are a side and front view, respectively of the sprayer of Fig. 31 A.

Fig. 33 is a cross section view of the exemplary sprayer as shown in Fig. 32A.

Fig. 34 is a cross section view as indicated for Fig. 33 in Fig. 32B, however the diagonal drive 3204 is rotated 90 degrees showing the pistons 3212 at half travel.

Fig. 35 is a cross section view of the exemplary sprayer as shown in Fig. 32B.

Fig. 36 shows a center cross section parallel to the cross section as indicated in Fig 32B..

Fig. 37 is a cross section as indicated for Fig. 35 in Fig. 32B, but with the diagonal drive rotated 90 degrees.

Fig. 38 is a cross section as indicated in Fig. 32B parallel to the cross section of Fig. 37, but showing the opposite piston.

Fig. 39 is the same cross section as Fig. 36, but with the diagonal drive rotated 90 degrees.

Fig. 40A and Fig. 40B show two isometric views of the wobble carrier.

Fig. 41 A and Fig. 41B show an isometric view of a left and right piston shoe bearing.

Fig. 41C and Fig. 41D illustrate a different isometric view of the piston shoe bearings of Fig. 41 A and Fig. 41B. Fig. 42 A and Fig. 42B illustrate an exemplary cylinder top section.

Fig. 43A and Fig. 43B show an exemplary diagonal drive plate.

Fig. 44 shows an exemplary piston assembly.

Fig. 45 illustrates a second exemplary embodiment in accordance with the present invention.

Fig. 46 illustrates the system of Fig. 45 with the diagonal drive plate rotated.

Fig. 47 illustrates the system of Fig. 45 at a center section.

Fig. 48 shows the system of Fig. 45 at a section through one piston with the piston at maximum upward position. Fig. 49 shows the system of Fig. 48 with the diagonal drive rotated to show the piston at maximum downward travel.

Fig. 50 shows the wobble carrier of the system of Fig. 45.

Fig. 51 shows the piston shoes for the wobble carrier of Fig. 45.

Fig. 52 shows the top cylinder section for the system of Fig. 45.

Fig. 53 shows the diagonal drive plate of the system of Fig. 45.

Fig. 54 shows the piston of the system of Fig. 45.

Fig. 55 is a cross section view of an alternative exemplary embodiment related to the exemplary embodiment of Fig. 45.

Fig. 56 shows a section view of the exemplary pump of Fig. 55 at a section rotated 90 degrees. Fig. 57 shows a section view of the exemplary pump of Fig. 55 with the input wobble hub rotated 90 degrees.

Fig. 58 shows a section view the exemplary pump of Fig. 57 at a section rotated 90 degrees.

Fig. 59A and Fig. 59B show a top front right, and bottom back left view the exemplary coupling shuttle of Fig. 55.

Fig. 60A and Fig. 60B show a top, front, right view and bottom, back, left view of the exemplary cap plug of Fig. 55.

Fig. 61 illustrates an exemplary overmold alternative having a dual divergence nozzle cone.

Fig. 62 is a cross section of the exemplary structure of Fig. 61.

Fig. 63 is a cross section view of the nozzle structure portion of the assembly of Fig. 61.

Fig. 64 shows the metal component 6102 of Fig. 63 at a 90 degree cross section.

Fig. 65 shows a detail view of the nozzle structure of Fig. 63.

Fig. 66 shows the structures machined or fabricated into the metal portion of Fig. 63.

Fig. 67 illustrates an isometric view of an exemplary metal portion for the nozzle component of Fig. 61.

Fig. 68 is a top view of the nozzle of Fig. 67.

Fig. 69A is a cross section view of the nozzle of Fig. 67.

Fig. 69B shows the nozzle structure of Fig. 69A at a 90 degree cross section from that shown in Fig. 69A.

Fig. 70 shows a bottom view of the nozzle structures of Fig. 67.

Nozzle

A sprayer in accordance with the present invention is capable of delivering a high performance spray pattern for an extended period of time from a light, compact, hand held, self contained, battery operated unit. The unit has advantages for spraying high viscosity and low volatility fluids, such as cooking oil and has advantages in a commercial high duty cycle environment. The unit is capable of self priming operation and includes a non-spill vent to prevent collapse of an attached container. The unit is adaptable for numerous different container attachments by exchanging a single part.

The sprayer achieves advantages in battery life and ease of use through a combination of an efficient sprayer coupled with a high capacity battery. The sprayer comprises ergonomic handle/spray head combination. The handle is configured for maximum battery compartment volume consistent with ease of use and handling in order to provide the largest battery practical to maximize spray time with a single charge. The handle is sized to be comfortable to hold and operate. Thus the size of the handle is limited and the size of the contained battery is limited. In one exemplary sprayer, the diameter of the grip is 1.75 in (4.4cm), preferably between 1.5 in (3.8 cm) and 2 in (5 cm). The battery is fitted into the handle to occupy the maximum space fraction feasible allowing for manufacturability and economy. The battery 2004 is incorporated into the battery module 1822 to make the battery quickly and easily replaceable. In one embodiment, battery 2004 may be a battery assembly comprising three rechargeable lithium cells, each 3.7 volts and 880 mAH. Each cell may be 6 mm x 30 mm x 48 mm, making the three cells 18 mm x 30 mm x 48 mm. The battery assembly 2004 may also include charge balancing and protection components as well as a connector. The sprayer avoids the use of a battery appendage to increase battery capacity, as is often done in the power tool industry. A battery appendage would add weight to the sprayer and interfere with the operation of the sprayer. A battery assembly is uniquely configured for one handed replacement without removing the bottle. The battery assembly may be removed from the unit by gripping two tabs accessible within finger recesses in the sprayer unit. The two tabs may be gripped with a single hand motion. The grip can remove the battery, hold the battery and transfer the battery to a charger in a single motion. A charged battery may be then gripped by the corresponding tabs, or otherwise, and slipped into the sprayer unit in a single motion. The battery is contained within the center of the grip/handle portion of the sprayer such that the battery is near the vertical center line and contributes to a centered center of gravity to minimize any tipping tendency that would result from an off center, out of balance position.

The sprayer has features providing advantages for high viscosity fluids. In particular, the nozzle end of the sprayer is adapted to minimize drip tendency by providing a wide angle nozzle exit to prevent interference with the spray pattern. Further, the lower side of the nozzle end is provided with a drip shield that is ahead of the finger grip and trigger area to direct any drip flow to form drops and drip without conducting the fluid to the hand grip, trigger and electrical switch area. One characteristic of high viscosity fluids, is a typical low volatility. Thus, any small flow left over from the spray does not evaporate as is typical with water based cleaners or paints. This flow may accumulate over multiple operations of the sprayer. The drip shield provides a low point for accumulation of this flow, where it may be easily wiped away or may drop, typically on a table or stand, rather than flow into the trigger area. As a further feature, the trigger is provided with a low point capable of accumulating fluid and preventing flow deeper into the sprayer, i.e., into the electrical switch compartment.

As a further feature, one embodiment of the sprayer may utilize an integrated motor, pump, nozzle assembly providing a high speed pulsating flow to a swirl chamber nozzle to efficiently provide a circular filled spray pattern when spraying viscous oil. A wobble plate pump drive yields a compact cylindrical form factor with a centered center of gravity, permitting compact, convenient, attractive packaging for the device. Figs. 1-17 illustrate various sprayer pump and nozzle concepts usable in the present invention. Figs, 18-25 illustrate an exemplary sprayer system with further features and advantages for spraying fluids.

The present invention relates to an efficient integrated sprayer pump and nozzle assembly having numerous benefits serving numerous applications. The sprayer may be used with a wide range of liquids, including water, alcohol, numerous cleaners and cleaner solutions. In one application, the sprayer is well suited for spraying heavy oils, such as paints or other oils, in particular, for applying non-stick cooking oil in a food preparation facility. A problem with conventional sprayers of light weight fluids, when attempting to spray oils is that the nozzles fail to deliver a spray, but deliver an irregular stream instead. In addition, far more power is typically required to push the heavy oil through the nozzles. Conventional nozzle design typically ignores the viscosity property in the theoretical analysis. This works fine for water and other fluids with a kinematic viscosity near 1 centiStoke, but breaks down when the viscosity is more like 40 to 80 centiStokes like cooking oil. Alternatively, conventional sprayers may use high power to develop high pressures or mix with gas or air, as is done for typical paint sprayers. The result is a heavy sprayer requiring a plug in chord or a compressed air line for operation. Paint sprayers also typically deliver a fine mist that may be undesirable in food preparation, producing oil contamination distant from the work station and possibly producing a fire hazard. When discussing cooking oils, kinematic and dynamic viscosity may be closely related and close in numeric value. Dynamic viscosity in centipoises (cP) may be determined by:

Dynamic Viscosity (cP) = Kinematic Viscosity (cSt) * Density (g/mL).

Since the density (specific gravity) of typical cooking oil is about 0.92, a kinematic viscosity value of 80 cSt yields a dynamic viscosity value of 74 cP.

The present invention achieves numerous advantages that cooperate to yield a sprayer having a desirable spray pattern using heavy oil while requiring a low operational power. The sprayer achieves a small size, light in weight, thus enabling a battery operated, light weight, hand held, power sprayer for cooking oil. The sprayer delivers a desirable well contained spray cone with a filled circular pattern and a droplet size that avoids undesirable mists.

The sprayer' s achievements may be attributed to the cooperation of one or more features described herein, including:

A swirl chamber nozzle having unconventional design and dimensions.

An efficient pump having a unique diagonal axis spinner plate/wobble plate drive to convert motor rotational drive to piston reciprocating motion.

The spinner plate drive detail allows area contact on friction surfaces to avoid point contact or line contact to minimize wear and promote long life.

The spinner plate/wobble plate drive allows orientation of pistons parallel to the motor axis yielding a compact linear form cooperating to yield a compact linear sprayer form factor.

The spinner plate/wobble plate configuration eliminates gear trains and provides compact unit for small size and light weight.

The functional partitioning of the integrated piston/cylinder/nozzle assembly permits ease of component manufacture and ease of assembly.

Dual piston pulse flow reduces/eliminates stationary flow time at the nozzle, mitigating drip/drool issues.

The sine function pulse flow delivered to the nozzle promotes a filled circular pattern.

The flow pulses are close coupled to the nozzle to avoid smoothing of the pulses.

Each piston is separately coupled to the swirl chamber from opposite sides to promote a more uniform spray pattern.

High speed rotation produces a high pulse rate, which further breaks up the flow and promotes a wider filled circular spray pattern.

High speed rotation produces a sufficiently high pulse rate that the flow is effectively continuous in operation.

The sprayer may be packaged into a cordless, hand held unit, which may be attached to a sprayer bottle for convenient hand-held operation.

The sprayer unit may include a battery and trigger for operating the sprayer.

The sprayer unit may include a drip guard to redirect drip flow away from the trigger and hand grip, while allowing quick access to a grip/handle portion of the sprayer for operation of the sprayer.

The sprayer battery may be located within a grip section and may be easily removable and replaceable. The sprayer battery module may include grip/latch tabs that allow releasing the battery from the sprayer, removing the battery, and placing the battery in a charger using a single continuous grip and move operation without releasing the grip until completed.

These and further advantages and further features will be appreciated in light of the following detailed description with reference to the drawings.

Fig. 1 A- Fig ID illustrate an exemplary liquid delivery system 100 in accordance with the present invention. Fig. 1A is a side view. Fig. IB is a cross section through Fig. 1A in the plane of Fig. 1A. Fig. 1C is an isometric view of the system of Fig. 1A. Referring to Figs 1A- 1C, particularly Fig. IB, the system comprises a motor 108 integrated with a pump section 101 containing a spray nozzle 104. The motor 108 drives a diagonal wobble plate 110. The wobble plate 110 drives two pistons through direct sliding contact with a diagonal surface 111 of the wobble plate 110, i.e., without an intervening non-rotating plate. The piston contact surfaces are beveled for maximum surface contact and minimum wear against the wobble plate. In this disclosure, a wobble plate drive refers generally to a reciprocating drive developed from a rotating diagonal plate referred to as a wobble plate, sometimes referred to as a swash plate.

Referring to Fig. 1 A, Fig. 1 A shows a pump assembly 100. The pump assembly comprises a motor 108 mounted to a pump housing 102 of a pump section 101. The pump housing 102 has two input ports 106a and 106b. The two input ports separately feed each of the two pistons. Alternatively, a single input port may feed both pistons. The outputs of the two pistons are combined at a single swirl spray nozzle 104.

Fig. IB is a cross section of Fig. 1A showing additional detail. The motor shaft 112 drives a wobble plate

110. The wobble plate is a cylindrical section attached to the motor shaft 112 and rotating within a bore of the pump housing 102. The wobble plate has a diagonal face providing sinusoidal drive to two pistons. Alternatively, one or more pistons may be used. The wobble plate is shown with an O-ring seal to prevent migration of the pumped fluid to the motor.

Fig. 1C is an isometric view of the pump assembly of Fig. 1A.

Fig. ID is a magnified view of a portion of the cross section view of Fig. IB. Fig. ID shows more clearly the pump and nozzle structure. The view shows the pump housing 102 and nozzle plate 126. The nozzle plate 126 forms the structures for the piston valve recesses flow passages from the pistons to the swirl chamber, the swirl chamber 124 itself, and the nozzle port 123 and nozzle cone 104. The pump housing 102 forms the piston cylinder and guide. The cylinder bore is not completely through, but bottoms in the pump housing leaving a wall for forming the outlet valve. The outlet valve seat is formed in the pump housing wall at the end of the cylinder.

An inlet port is provided in the cylinder side wall. In one embodiment the inlet port is at the top of the piston stroke. The inlet port may be covered and closed by the piston through the bottom of the stroke. This may permit the elimination of the inlet valve in one embodiment of the invention. Fig. ID, however, shows an inlet valve between the inlet connection and the cylinder inlet port. Fig. ID shows the pistons 114a, 114b spring loaded against the wobble plate 110.

In operation, the motor 108 rotates the wobble plate 110, which produces sinusoidal drive to the pistons 114a, 114b. Beginning at the top of a piston stroke, the piston 114b pushes downward, pressurizing the fluid. The pressurized fluid then forces open the outlet valve 122a, 122b and closes the inlet valve 118a, 118b. The fluid passes through the outlet valve recess and flow passage to the outer circumference of the swirl chamber 124, where the fluid is injected off center, producing a vortex action in the fluid as the fluid travels to the center nozzle outlet opening 123. Upon exit from the nozzle, the centrifugal component of fluid motion produces a conical spray pattern. The angle of the nozzle cone 104 is typically a wider angle than the spray pattern angle to avoid interference with the spray pattern.

As the piston returns from bottom to top, the outlet valve 122a, 122b closes, and a low pressure is produced in the cylinder chamber 120. As the piston uncovers the inlet port, the low pressure is transmitted to the inlet fluid, opening the inlet valve 118a, 118b and allowing fluid to enter the cylinder chamber 120.

By having a short direct rigid connection from the pistons to the swirl chamber, the pressure and flow fluctuations produced by the piston are coupled to the swirl chamber. This acts to vary the spray pattern width during the stroke and fill in the center of the pattern. With a constant flow, a hollow circular cross section pattern is produced. For some applications, the solid, filled in circular cross section produced by the pulsation may be preferred. By using two pistons 180 degrees out of phase in the configuration shown, each piston produces a separate independent pulse to the swirl chamber. Alternatively, by using four pistons 90 degrees out of phase (not shown), a more constant flow resulting from overlapping pulses would be presented to the swirl chamber.

One advantage of the invention is in the simplicity of the device. Only two housing parts are required, the pump housing 102 and the nozzle plate 126. Many of the chambers, passages, valve seats and components may be formed in these parts. The housing is a two part housing with a single separation plane 128. The two parts may be joined with a gasket or o-rings to prevent leakage. The housing chambers and features may be cast or machined into the housing parts. The arrangement allows for the forming of all of the features of the part by the mold being pulled apart with few or no sliders coming in from the side or other mechanized mold parts. The arrangement also requires little or no secondary machining operations.

Fig. 2A is a side view of a second exemplary embodiment of the invention. Fig. 2A shows a motor 108, pump housing 202, inlet port 206, nozzle 104 and mounting screw recess 204.

Fig. 2B is a cross section view of the embodiment of Fig. 2A. The pump of Fig. 2B comprises two structural components, the pump housing 202 and a cylinder insert 210. The pump housing 202 forms a single continuous outer shell of the pump assembly, thus minimizing the chances for external leaks.

Fig. 2C is a magnified view of a portion of the cross section of Fig. 2B. Fig. 2C shows the motor shaft 112 and wobble plate 110. The wobble plate 110 is coupled to two pistons 208 operating in cylinder recesses formed in the piston insert 210. The piston insert includes piston cylinders. The cylinders are not drilled through, but have a bottom wall in which the outlet valve seat is formed. The pump housing 202 includes the swirl chamber 212, nozzle 214, cone 104, valve recesses 209, and feed channels leading from the valve recesses 219 to the swirl chamber 212. (The feed channels are not visible in this cross section- see Fig. 3B 304.)

The nozzle of Fig. 2C illustrates alternative features relative to the nozzle of Fig. ID. A tapered bottom of the swirl chamber is shown and a non-zero length for the nozzle throat 214 is shown. Note also the ball valve 216 used in Fig. 2C. The spring loaded ball may represent a lower cost alternative.

Fig. 2C also shows the elimination of the input valve by placing the input port 203 at the top of the piston stroke. In operation, the piston 208 first travels from top to bottom. As the piston passes the input port 203, the piston covers and closes the input port 203. Further travel toward the bottom forces the fluid out through the outlet valve 216. Upon retracing from bottom to top, the outlet valve 216 closes and the piston 208 creates a vacuum in the cylinder chamber 213. When the piston 208 reaches and uncovers the input port 203, fluid is allowed to enter, drawn in by the vacuum in the cylinder 213. Fig. 2C also illustrates a piston variation allowing lower friction and wear against the wobble plate. The piston comprises a non-rotating outer shell 208 and a rotating inner cap pin 206. The inner cap pin 206 is in operative contact with the wobble plate 110. The outer shell 208 may be a low friction material, for example but not limited to TEFLON^®, acetyl (DELRIN^®), nylon, also metallic materials, for example steel, stainless steel, NITRONIC-60^®. The inner cap pin 206 may be metallic. The top surface of the cap pin may have a conical shape or slightly convex curved conical shape to maximize the contact area between the wobble plate and the cap pin. The cap pin and outer shell are generally cylindrical in shape coaxially aligned with the cylinder. The outer shell acts as a piston within the pump cylinder. The cap pin is allowed to rotate as a cylindrical bearing within the outer shell. The outer shell may be allowed to rotate within the piston cylinder bore, but may preferably be rotationally restrained by contact with the return springs 220.

Fig. 3A, Fig. 3B, and Fig. 3C are outline drawings showing the features of the exemplary nozzle structure. Fig. 3A is a side view of an exemplary nozzle. Fig. 3A shows a side view of a swirl chamber 124, injection channel 304, nozzle 123, nozzle throat 214, nozzle flare 310.

Fig. 3B shows a top view of the nozzle of Fig. 3B further including valve recesses. Fig. 3B shows the swirl chamber 124, injection channels 304, valve outlet port 123 and valve recesses 211. The valve recesses 211 house the valve springs 218 and ball 216 (Fig. 2C). Fluid flows from the pistons into the valve recess 211, then from the valve recess through the injection channel 304 to the swirl chamber 124. The injection channel 304 preferably injects the flow into the top of the swirl chamber 124 directed tangentially to the swirl chamber circumference. The flow forms a vortex flow in the swirl chamber 124 and exits through the nozzle 123.

Fig. 3C shows typical exemplary dimensions for the nozzle of Fig. 3 A. The nozzle of Fig. 3 A has particular advantages for spraying high viscosity fluids, for example, cooking oil. Referring to Fig. 3C, Fig. 3C shows the swirl chamber diameter 320, swirl chamber height 322, feed channel height 330, feed channel width 332, outlet port (nozzle) diameter 334, nozzle throat length 324, flare angle 326 and flare length 336.

Fig. 3C shows a flat rather than tapered or conical bottom surface 311 for the swirl chamber. A typical low viscosity swirl chamber may utilize a conical (not shown) bottom leading to the nozzle 123. For high viscosity fluids, a flat bottom surface may be preferred, and the ratio of swirl chamber height to diameter should preferably be about 0.5. For viscous fluids, a short swirl chamber, with a height to diameter of less than 0.3 loses too much swirl to viscous losses, as does a narrow swirl chamber with a height to diameter ration of greater than 0.7. Thus, the preferred range of height to diameter is 0.3 to 0.7, more preferably 0.4 to 0.6 and more preferably 0.45 to 0.55. A typical exemplary swirl chamber dimension may be 0.050 in height and 0.100 in diameter. The outlet port 123 may be .020 in diameter.

In one variation, the ratio of the diameter of the swirl chamber 320 to the diameter of the nozzle 334 may be from 0.15 to 0.25, preferably 0.2.

The throat 214 may not exist, i.e., may have a zero length. For high viscosity fluids the transition from swirl chamber to nozzle cone may preferably be a sharp angle transition as shown in Fig. 3A. Any length of the throat contributes to viscous damping of the fluid rotation; however, practical construction considerations may require a short length 324. Length 324 of the throat 214 should preferably be small in relation to the width of the nozzle/throat 334, for example, equal or less than 0.25 times the width 334.

An exemplary throat length 324 may be .027 in, although for high viscosity fluids the throat length may be preferably zero. An exemplary conical angle may be +- 60 degrees. In addition, the swirl chamber preferably includes no chamfers at the joining of the bottom and top walls with the cylinder or in the formation of the injection channels 304.

The nozzle dimensions and flow rate can be varied to produce a variety of spray patterns and droplet sizes. In one exemplary embodiment, the system may deliver a spray pattern 4 inches (100 mm) wide at 12 inches (30 cm). In another embodiment the spray pattern may be 12 inches (30 cm) wide at 14 inches (35 cm) distance.

Table 1 shows exemplary nozzle dimensions (inches) associated with Fig. 3C.

Table 1

Dimension 320 is the diameter of the swirl chamber 124.

Dimension 334 is the diameter of the nozzle opening 123 from the swirl chamber 124.

Dimension 322 is the height of the swirl chamber 124.

Dimension 324 is the length of the nozzle throat 214. In one variation the length may be zero, or effectively zero, less than one tenth the diameter of the nozzle 334. Preferably, the cone may form a knife edge with the bottom of the swirl chamber.

Dimensions 322 and 330 are the height and width of the fluid transfer channel 304 from the valve wells 211 to the swirl chamber 124.

Dimension 326 is the angle of the nozzle cone. The angle is typically larger than the spray pattern cone angle to avoid interference with the spray pattern. In one variation, the nozzle cone may be optional, i.e., the angle may be 180 degrees full width.

Dimension 336 is the length of the nozzle cone. The length is typically governed by any thickness necessary to provide supporting structure to the pump or pump structures, for example the outlet valve wells 211 (also referred to as valve recesses 211.)

Fig. 4A-Fig. 4H illustrate various spray pattern effects. Fig. 4A shows a hollow cone spray pattern as may be produced by a swirl nozzle fed by a steady flow from a single injection channel. Fig. 4 A shows a sprayer 100 with nozzle. Boundary lines 402 depict the spray pattern as the sprayer sprays a fluid onto a surface 404. Fig. 4B illustrates a dual cone spray pattern as produced by the dual feed point alternating drive swirl nozzle. When the sprayer 100 is driven by a single offset feed channel, the swirl is slightly asymmetrical and produces an offset cone spray pattern with the center of the cone slightly offset from the centerline of the sprayer. With two feed channels driving from opposite sides as shown in Fig. 3B, and when each feed channel is driven alternately with non simultaneous, non overlapping pulses, each feed channel generates an oppositely offset cone pattern, viz., the right pattern 406 and left pattern 408 shown in Fig. 4B. Fig. 4C shows a top view of the single spray pattern of Fig 4A. The circle indicates the locus of greatest spray density. A circular spray pattern refers to a pattern with an equal density contour containing 90% of the spray with at least a two to one major diameter to minor diameter ratio, preferably at least a 1.5 to one major diameter to minor diameter ratio. Fig. 4D shows a top view of the dual spray pattern of Fig. 4B showing the overlapping circular patterns for the left 412 and right 414 spray patterns.

Fig. 4E depicts a spray density plot 416 through the center of the pattern of Fig. 4C showing the high spray density at the circular pattern and low density in the "hollow" center of the pattern. The "hollow" center is particularly characteristic of a constant flow through the nozzle, in contrast to the pulsating flow of the present invention. Fig. 4F depicts a spray density plot 418 through the center of the pattern of Fig. 4B. The pattern has a more even distribution than that of Fig. 4E. The two spray patterns tend to fill the center better with less peak concentration on the circle.

Fig. 4G depicts the spray distribution 420 for a varying pulse flow in accordance with the sine wave pulsed flow of the present invention. The pulsed flow tends to fill the center better than the constant flow of Fig. 4E. A filled circular pattern preferably has a density minimum between the peaks of no less than 50% of the peak value, more preferably no less than 75% of the peak. Fig. 4H depicts the pulsed flow effect 422 on the distribution of the dual swirl nozzle of Fig. 4B and 3B.

Fig. 41 - Fig. 4L depict a three piston embodiment. The nozzle is configured like Fig. 4B, but modified to have three pistons with three feed channels at 120 degree intervals around the swirl chamber. Each piston produces a respective spray pattern 424, 426, 528, 430, 432, 434. The composite spray pattern is more evenly distributed than Fig. 4C 436, 438 and is more circular than that of Fig. 4D. See Fig 4J.

Applications

In one application of the invention, the sprayer may be configured to deliver oils in a food preparation operation, in particular, non- stick oils. For delivery of such oils a larger droplet size than typically used for cleaner application or spray painting may be desirable. A larger droplet size may allow better control of the direction of the spray and may minimize mists that may drift in the air and coat undesired surfaces as well as reduce the air purity for the food workers. The use of a swirl chamber nozzle to produce larger droplet sizes allows the use of lower pressures, permitting a smaller motor and battery. Thus the configuration of he present invention may enable a small hand held battery operated sprayer suitable for use in a kitchen or other food-processing environment. The unit may be small and light enough to replace a typical aerosol can or hand pump sprayer. A powered pump sprayer based on high pressure spray techniques would likely utilize much more power and require a larger motor and battery or a plug-in design.

In a further advantage of the invention, the pump may be driven by a fixed field voltage driven electric motor, i.e., not series wound, for example, a permanent magnet or shunt wound motor. Thus, the RPM is held constant rather than the torque, resulting in a constant flow rate (cubic centimeters per minute) rater than constant pressure to the nozzle. This maintains performance over temperature in spite of variations in viscosity of the fluid.

For an exemplary application of spraying vegetable oil, the oil may have a kinematic viscosity of about 15 to 250 centiStokes, typically 40 centiStokes at 25 C room temperature. Water is about 1 centiStoke. Sprayer Tests

Two exemplary sprayers were tested for comparison of spray pattern and battery life. The sprayers were designed in accordance with a vegetable oil spray application of the present invention. One sprayer was fitted with a 22 oz (624 ml) bottle and the other one was fitted with a 36 oz (1020 ml) bottle. In addition, an aerosol can and two trigger sprayers were tested for comparison.

The spray patterns were observed at a distance of 8 inches (20 cm). The spray pattern results were as follows:

The sprayers were tested for adequacy of battery performance for use in a commercial kitchen setting. The nickel metal hydride (NiMH) sprayer batteries were fully charged to 10.8 V. The sprayers were each alternately sprayed for 8 seconds to mimic the time to spray a sheet pan. The process was continued for one hour. Both sprayers performed fully for the one hour test. The 22 oz sprayer battery discharged to 9.5 V and the 36 oz sprayer battery discharged to 9.3 v, indicating substantial charge remaining in both sprayers. Thus, it appears that both sprayers would likely operate on a single battery charge for a full typical 8 hour work shift in a kitchen setting. An alternate variation may utilize lithium ion batteries or other battery types.

Another exemplary sprayer operates at 12000 RPM on a voltage of 11. IV at 0.5 A using an 800 mAH battery. Thus, the sprayer can run for 1.6 hours at 100% duty cycle and 8 hours at 20% duty cycle, which may be typical for some kitchen operations.

Embodiments

Fig. 5 illustrates a side cross section view of an exemplary sprayer having an intermediate plate

(alternatively referred to as a spinner plate) between the wobble plate and the pistons. The intermediate plate 502 is rotationally mounted on the wobble plate 110 at a diagonal angle and allowed to rotate freely relative to the wobble plate. The intermediate plate has a planar surface 504 perpendicular to the axis of rotation of the intermediate plate. The planar surface 504 is for contacting the pistons and driving the pistons. Friction with the top of the pistons 114b, will reduce rotation relative to the pistons and minimize wear on the top of the pistons 114b. Fig. 6 illustrates a 90 degree rotated side view of the sprayer of Fig. 5. A portion of a bearing mount for the intermediate plate 502 is shown. The sprayer of Fig. 6 shows a two piece 602, 604 construction for the cylinder insert. The top section 602 includes the piston cylinder side wall and a fluid inlet port. The inlet valve seat is formed in the top insert. The bottom insert 604 forms the cylinder head surface. The arrangement allows the inlet port to be at the bottom of the cylinder through the side wall of the cylinder. Fig. 7 illustrates a side cross sectional view of an exemplary sprayer wherein the pistons have a top cap 702 for contact interface with the intermediate plate 502. The piston top cap 702 has a flat surface for contact with the intermediate plate 502 to minimize contact pressure and resulting wear. The underside of the piston cap 702 has a spherical contact with the piston 704. The top cap 702 can thus rotate freely relative to the piston 704.

Fig. 8 illustrates a 90 degree rotated side cross sectional view of the sprayer of Fig. 7. The piston cap 702 can be seen to have a flat contact with the intermediate plate and a spherical contact with the piston. The two piece piston insert allows for fluid inlet at the bottom side wall of the cylinder.

Fig. 9 illustrates a side cross sectional view of the sprayer of Fig. 7 showing assembly screws 902.

Fig. 10 illustrates an alternative embodiment of Fig. 9. Fig. 11 illustrates a side cross sectional view of the sprayer of Fig. 7 showing the rotational mounting of the intermediate plate 502. The intermediate plate 502 has a shaft 1102 disposed in a bore in the wobble plate 110 for free rotation of the intermediate plate 502 relative to the wobble plate 110. The shaft 1102 is fixed to the intermediate plate 502 and perpendicular to the face of the intermediate plate 502. Fig. 12 illustrates a side cross sectional view of the sprayer of Fig. 7 showing an alternative ball bearing mounting 1202 of the intermediate plate 502 to the wobble plate 110.

Fig. 13 illustrates a side cross sectional view of an exemplary sprayer in accordance with the present invention. Fig. 13 shows a sprayer comprising a motor 108 and integrated pump and nozzle section 1302. The integrated pump and nozzle section is shown in greater detail in Fig. 14.

In one variation, the sprayer of Fig. 13 may comprise a highly efficient sprayer for spraying heavy oil generally, more particularly, for example, for applying non-stick cooking oil to a cooking surface. The oil may have a kinematic viscosity of typically 40 centistokes and may range from 15 to 250 centistokes. Typical prior art sprayers for paint produce a fine mist and utilize very high pressures, requiring considerable power. The present sprayer avoids the fine mist and efficiently delivers dropletized spray in a filled circular pattern. The high efficiency of the sprayer enables a unique hand held battery operated unit that can operate for a full work shift in an active kitchen on a single battery charge. Less efficient sprayers may likely require a plug-in or reduced operating time on a charge.

In one variation, the sprayer may be characterized as:

Motor 14000 rpm, 12 Volts, 0.55 Amps

Battery 12 V, 800 mAH

Pumping rate 1.2 ml/second

Fluid kinematic viscosity 40 centiStokes

8 hour total pumping capacity 7 liters

Duty cycle of use during 8 hour shift 20%

Overall length (without motor) 3 cm Overall width (without motor) 3 cm

Total weight without motor 20 grams

Motor added length 3 cm

Motor added weight 30 grams

Fig. 14 shows the integrated pump and nozzle section of the sprayer of Fig. 13.

Referring to Fig. 13 and Fig. 14, the wobble plate 110 is coupled to the motor shaft 102. The wobble plate member 110 comprises a wobble hub for attaching to the motor and a wobble plate having a diagonal face or diagonal axis bearing for holding and driving the spinner plate. The wobble hub assembly may be fabricated from a single piece of material. The wobble hub assembly is a multifunctional part for coupling to the motor and for holding and driving the diagonal spinner plate and allowing the spinner plate to free rotate. The assembly may be modified in accordance with Fig. 12 to mount the spinner plate using a ball bearing or separate bearing. It may be appreciated that when using a separate bearing, the diagonal planar face shown for the wobble hub component 110 may not be needed, only the bearing axis features need be provided.

The motor shaft drives the wobble plate to rotate around a motor axis 1424. An exemplary setscrew 1308 is shown securing the wobble plate 110 to the motor shaft 102. The wobble plate 110 is a cylinder with a diagonal face opposite the motor end and a bore 1416 perpendicular to the diagonal face for receiving a shaft 1418 of an intermediate plate member 502 (alternatively referred to as a spinner plate 502). The bore axis may preferably intersect the motor axis, i.e., may be coplanar with the motor axis. The intermediate plate member 502 freely rotates around the axis 1426 of the bore, allowing low friction rotation of the intermediate plate. In the embodiment shown in Fig. 14, a proximal side (close to the motor) of the intermediate plate 502 is in contact with the diagonal face of the wobble plate 110. A distal side is in contact with the piston assemblies and drives the piston assemblies.

The motor drive axis 1424 and the spinner plate rotation axis 1426 should intersect at the plane of the distal surface of the spinner plate 502 in contact with the piston caps 502. The invention, however, tolerates deviations in any direction, vertical, horizontal or out of plane (as shown in the drawing) due to the free rotation of the spinner plate. The spinner plate 502 and wobble hub 110 together should be rotationally mass balanced with respect to the drive axis 1424 to minimize vibration.

The piston assemblies each comprise a piston 704 and a piston cap 706. Each piston 704 has a spherical head end proximal to the motor 108. The piston cap 702 has a matching spherical recess for receiving the piston spherical head. The piston cap 702 has a substantially flat side proximal to the motor for contacting the intermediate plate 502. The sides of the piston cap 702 are sufficiently deep to maintain the cap disposed on the top of the piston 704 during operation. As shown, the sides of the cap 702 encompass more than 180 degrees of the piston spherical head and "snap" into place during assembly. The piston cap 702 may freely rotate axially and laterally on the piston head, allowing low friction rotation.

Each piston has a shoulder 1422 for spring loading by preload springs 220. Each piston is spring loaded against a cylinder assembly (1402, 1404, and 1406), thus maintaining spring loaded contact through a stack comprising the pistons 704 through the piston caps 702 and intermediate plate 502 to the wobble plate 110.

Multiple factors may be considered when setting the spring preload. The spring preload should be minimized to minimize friction in the wobble plate drive members; however the preload should be sufficient to prevent unloading the stack at the maximum rotation rate, i.e., the spring force should be greater than the mass of the cap and piston multiplied by the maximum axial acceleration of the cap and piston. f > (m_p + m_c ) ¾r tan(#)

where,

/ is the minimum required force for the spring;

m_p is the mass of the piston;

m_c is the mass of the cap;

<¾, is the maximum rotation rate of the motor drive;

r is the contact radius of the piston cap on the intermediate plate; and

Θ is the angle of the intermediate plate.

Alternatively, or in addition, the spring rate may be set such that the spring - mass resonance of the spring acting with the mass of the piston with cap is between two harmonics of the rotation rate, for example 1.5, 2.5, or 3.5 times the rotation rate. Thus, for 2.5 times the rotation rate:

F■

2π m p + m c

F =2.5{^≡-) , (2·5¾ )²

m_p + m_c where,

F is the resonant frequency of the spring - mass system;

k is the spring constant;

m_p is the mass of the piston;

m_c is the mass of the cap; and

CQn is the maximum rotation rate of the motor drive, (radians). One may also consider pump priming and may set the piston preload to overcome a vacuum in the cylinders. Thus the force may be:

where,

/ is the spring force required;

k is the spring constant;

x is the maximum displacement;

P_a is the atmospheric pressure (14.7 psi); and d is the diameter of the piston.

Lateral forces on the pistons resulting from drive from the intermediate plate are resisted by the side walls of the cylinders. The pistons are sealed with an o-ring 1412 recessed into the cylinder block assembly. The o-ring channel is formed by the first and second cylinder block sections at the interface between the first and second cylinder block sections. Dividing the cylinder block at the interface between section 1 and section 2 as shown allows easy assembly of the o-ring and allows easy machine fabrication of injection mold tooling for the o-ring. The o-ring is preferably configured in a slot in the cylinder block rather than the piston to prevent weakening the piston by an o-ring slot in the piston.

The cylinder block assembly comprises three sections configured for injection molding utilizing two part simple molds. The top section 1402 (proximal to the motor) includes a recess for the piston spring seating surface. An o-ring 1414 is provided to prevent leakage of pumping fluid into the wobble plate chamber. The middle section 1404 includes the piston o-ring 1412 to prevent leakage through the piston bore back into the wobble plate chamber. The third section 1406 includes the cylinder head section of the cylinder including inlet and outlet ports in the cylinder head. The third section also includes the outlet valve seats formed directly in an outlet channel 1410 leading from the outlet ports in the cylinder head recess. The three sections 1402, 1414, 1406 form an assembly fastened together by two bolts (Fig. 15 ref 1504) through the top and middle sections, threaded into the nozzle section 1304. The cylinder block assembly fits into a nozzle section 1304 and cooperates with the nozzle section to form the outlet valve chambers 211, swirl chamber 124, and nozzle feed channels 304 (Fig 3B).

The nozzle section 1304 cooperates with the distal section 1406 of the cylinder head assembly to form the output valve structures 211 and the swirl chamberl24. The nozzle section has recessed wells configured to hold the valve plunger 1408 and spring. The wells include a wide top section and a narrow bottom section. The bottom section locates the valve spring and valve plunger. The wider top section allows for flow through the well and out through a transfer slot 304 to the swirl chamber 124. The wells, transfer slots, and swirl chamber may be formed by injection molding requiring a simple two part mold. The mold tooling may be fabricated with simple machining operations, since there are no complex shapes, only straight line holes and slots. The open side of each is closed by the cylinder head distal section, which provides for flow into the valve chamber from the cylinder outlet port. The cylinder head assembly provides a simple flat face covering the top of the transfer slot and swirl chamber, also requiring no complex mold tooling structure. The outlet port 1410 lines up with the valve plunger 1408 forming a valve seat at the interface. The tapered valve plunger 1408 provides self alignment with the outlet port valve seat.

Fig. 15 and Fig. 16 illustrate cross sections of the exemplary pump of Fig. 13 from planes perpendicular to the plane of Fig. 13.

Referring to Fig. 15, Fig. 15 is a cross section through the center of the pump. Fig. 15 shows the inlet port and manifold and the mounting screws.

Fig. 16 is a cross section parallel to the plane of Fig. 15, but offset from center, passing through the inlet and outlet valves of one of the pistons. Referring to Fig. 16, Fig. 16 shows the arrangement of elements in relation to the cylinder block illustrating the utilization of simple moldable components. The inlet fitting is threaded into the nozzle block, which is face to face coupled to the center section of the cylinder block assembly. The center section includes a manifold chamber leading to the two cylinder inlet valves and inlet ports. The manifold is ported to the side of the center section and opens through a round passage to the bottom of the center section. The passage terminates in a valve seat for the inlet valve. The valve seat opens into an inlet passage leading to the inlet port. The inlet passage is formed as a trough in the distal section covered by the flat side of the center section. The center section and distal section are separated at a planar face. The inlet valve is disposed within a valve recess in the in the inlet passage of the distal section. The valve recess may extend through the distal section. A spring loaded valve is disposed within the valve recess and extending through the inlet passage to the valve seat of the center section. The inlet passage leads to the inlet port at the bottom of the cylinder. The outlet valve is coupled to the bottom of the distal section. The outlet port is at the bottom of the cylinder and leads to the outlet passage, which couples through the distal section to the bottom of the distal section. The end of the outlet passage forms a valve seat for the outlet valve. The outlet valve is disposed within an outlet valve recess or well in the nozzle section. The outlet valve and nozzle are described in greater detail with reference to Fig. 13 above.

Fig. 17 is an exploded view of the sprayer of Fig. 13 - Fig. 16. Fig. 17 shows with greater clarity the individual components of the sprayer of Fig. 13 and Fig. 14.

Compression Ratio

The configuration of Fig. 13 allows for variation and tolerances in the dimensions of the various components and allows for wear in the pistons, caps and intermediate plate components. The spring return of the pistons will always keep the stack of components in contact and producing a full piston stroke for a full volume pump per cycle. As the stack wears, the pistons may move slightly up allowing the minimum cylinder volume to increase and thus decreasing the compression ratio. However, for incompressible fluids, such as oil, the compression ratio is substantially immaterial. Thus, the pump performance is constant for a wide range of wear. It remains desirable, however, to maintain a good compression ratio for self priming of the pump at startup. A good compression ratio will allow a suction vacuum to be developed to draw fluid from a container when pumping air or other compressible fluids out of the lines. A compression ratio of two to one or better should allow priming from nearby or attached containers. High speed pulsation

In one application of the sprayer, the sprayer is used to spray non-stick vegetable oil. The vegetable oil is preferably sprayed in small droplets, but not so small that they become airborne and drift beyond the application surface. To assist in breaking up the stream into a spray and generating a desired circular filled pattern, the sprayer may be operated at a high rotation rate, for example 7000 revolutions per minute. This results in 14000 pulses per minute (233 pulses per second) from the two piston sprayer. The high rotation rate and resulting high pulse rate itself may be responsible in part for the breakup of the stream into droplets. This may be due to additional radial stress on the spray cone due to rapid modulation of the spray velocity and cone size by the varying flow rate. Thus a modestly performing nozzle may be improved by feeding the nozzle with a pulsed flow at a high pulse rate.

The pulsed flow simultaneously modulates the flow from the swirl chamber in two ways. First, the higher flow creates more centrifugal force to overcome surface tension and distribute the spray in a wider cone. Second, the higher flow produces a higher forward velocity in the instantaneous spray cone. Thus, the combined effect is to generate a modulated spray with a radial velocity shear across the flow pattern that tends to break up the initial flow into droplets. Thus, the modulated flow simultaneously fills the interior of the conical pattern defined by the fastest flow and breaks up the flow into droplets. For example, an average flow of 1 ml/sec through a 0.25 square mm nozzle is initially 400 cm/sec velocity through the nozzle. Peak velocity would be double, or 800 cm/sec. The 80 cm/sec flow might produce a 10 cm wide instantaneous conical pattern at 40 cm distance. The 40 cm/sec flow might produce a 6 cm wide instantaneous conical pattern. At 200 pulses per second, the 800 cm/sec flow travels 4 cm in one pulse cycle; whereas the 400 cm/sec flow travels 2 cm - a difference of 2 cm. During this time, the difference in radial travel is 0.2 cm - one tenth as much. Thus, the modulation induced shear greatly exceeds the spreading effect of the cone by itself. The two effects would appear to be equal at a pulse rate of one tenth as much or 20 pulses per second, which would result from 600 rpm motor speed. The effect would be more pronounced at five times that speed or 3000 rpm.

In the case where the flow rate is high and the spray cone angle changes little with the velocity modulation, the spray velocity difference causes turbulence in the spray cone as the high velocity fluid overtakes the slow fluid and as the high velocity separates from the slow velocity. High and low velocity flows may interact in the same pulse or between subsequent pulses. This turbulence contributes to the breakup of the flow into droplets. Thus, the pulse rate should be high enough so that the fast flow catches up with the slow flow and mixes before reaching the spray target. In the above example, the fast flow would just catch the slow flow in 40 cm at ten pulses per second (300 RPM with two cylinders). To give time to mix and develop the pattern, the rate should preferably be somewhat higher, for example at least five times higher 3000 pulses per minute (1500 RPM,) or at least ten times higher 6000 pulses per minute (3000 RPM,) which agrees with observations.

In one variation adapted for applying cooking oil, the motor rotation rate may be above 2000 revolutions per minute, preferably from 3000 to 30,000 revolutions per minute, more preferably from 4000 to 20,000 revolutions per minute.

At a very high pulse rate, the pistons should be closely coupled through rigid lines and passages to the swirl chamber. Long lines or flexible lines may allow smoothing of the pulse flow and reduction of the benefits.

A second reason for a high pulse rate relates to producing a substantially continuous spray for depositing a uniform layer when sweeping across a target surface.

When applying oil or other high viscosity fluids to a surface, the operator typically directs the sprayer at the surface from a distance, for example, 20 cm to 40 cm, and scans (or sweeps) the spray pattern across the surface to coat the surface. Thus, the spray pattern should be essentially continuous and constant during the application. Pulses that are too slow would produce a discontinuous coating. The pulse rate should be sufficient to produce a uniform pattern while being scanned across a target surface. Thus, the pulsations should occur several times across the scanning of the width of the spray pattern. For example, if the sprayer sprays a two inch (5 cm) wide pattern and the operator scans the target at 10 inches (25 cm) per second, a pulse rate of five pulses per second would just fill the centerline of the scan. A preferred pulse rate would be twice that or ten pulses per second. More preferable would be ten times or fifty pulses per second. Thus, the 233 pulses per second of the exemplary embodiment would be suitable for even higher scanning rates.

In the sprayer of Fig. 13 and Fig. 14, the wobble plate/intermediate plate drive produces an approximate offset sine function flow rate. Alternatively the function may be described as a sine squared function. The practical geometry and real world implementation may cause some deviation from an ideal sine function. Each piston operates 180 degrees out of phase with respect to the other piston. Thus the resulting flow rate follows an offset sine function with two pulses for each turn of the motor. Thus, the flow rate varies over the sine function cycle of each piston from zero to a maximum value and then back to zero. Each piston performs an input cycle when the other piston is performing an output pulse cycle. Alternatively, a cam system may be used to alter the pump pulse shape. The wobble plate would be replaced with a drive cam. In one variation, the pump delivers at least two different non-zero flow rates.

Nozzle Dimensions

The sprayer of Fig. 13 may be used with various nozzle dimensions. Table 1, nozzle 4 is preferable for delivering 50 ml/min, nozzle 5 is preferable for delivering 75 ml/min, and nozzle 6 is preferable for delivering 100 ml/min vegetable oil.

Alternating plastics

In one variation, the pump parts may be made of plastic. One desirable combination uses nylon sliding against acetyl as a low friction pair. Thus, the wobble plate may be nylon, the intermediate plate may be acetyl, the piston caps may be nylon, and the pistons may be acetyl. The cylinder assembly may be nylon to continue the alternating pattern or may be acetyl for greater strength. An alternate pattern would begin with acetyl and alternate with nylon. Other plastic combinations may be used. Low friction treatments or additives to the plastics may be used. In one variation, at least one friction interface comprises a low friction pair of materials, for example low friction plastics, for example nylon and acetyl.

Asymmetrical drive

In one embodiment, the pump may comprise a swirl chamber and may pulse the swirl chamber with differing alternating pulses. The differing pulses may produce two different instantaneous spray patterns resulting in a desired composite spray pattern. For example the swirl chamber may be pulsed with a strong pulse alternating with a weaker pulse (less pressure and/or less flow rate). The stronger pulse may produce a wider spray pattern.

The weaker pulse may produce a more narrow spray pattern. The more narrow spray pattern may serve to fill in the wider pattern, producing a more even, filled in pattern.

In one alternative, the differing pulses may be produced by differing piston diameters for the two pistons.

In another alternative, the differing pulses may be produced by differing center offset for the two pistons relative to the wobble plate drive, or a cam drive with differing cams for the different pistons.

Alternatively, the swirl chamber may be fed by two feed channels having differing geometry - a first channel at the edge, a second channel slightly more centered. The edge channel may produce more swirl with a wider pattern and the more centered feed channel may produce a more narrow pattern.

Tolerance Stack Up

A further advantage of the configuration of the present invention is that the part tolerance requirements are mitigated. For example, assuming a typical tolerance of +/- 0.003 in per part. Considering the preload on the spring of the outlet valve 1602, Fig. 16. If the valve were placed higher in the stack, multiple layers would contribute to the spring preload error. Given that the preload of the 0.125 in length spring is .002 in., a +/- 0.009 in, worse case tolerance would be intolerable. However, the present configuration ensures that the only tolerance on the recess is the height of the piston insert. +/- 0.003 in. Alternatives

In one alternative the pump section may be used as a pump for other purposes by replacing the nozzle with an outlet fitting. In a further alternative, the nozzle may be distant from the pump section by replacing the nozzle with an outlet fitting and running a length of tubing to the nozzle. However, in this configuration, one may note that a long length of flexible tubing may act as an accumulator and smooth the pulsations of the pump. This may result in a hollow core circular spray pattern if a swirl chamber nozzle is used. In one variation, an accumulator may be placed between the output of the pump and the nozzle to smooth the variations in pressure and provide amore hollow cone circular spray pattern, when using a swirl chamber nozzle. Power Trigger Sprayer

Fig. 18 illustrates a perspective view of an exemplary sprayer head assembly in accordance with the present invention. Referring to Fig. 18, the sprayer head assembly 1800 comprises a left side shell 1802 and a right side shell 1816. Fig. 18 shows the nozzle 1804 of the integrated sprayer pump and nozzle. An expansion pattern 1806 surrounds the nozzle 1804 to transition from the nozzle to the shell. A drip shield 1808 may be part of the shell and extends downward from the nozzle 1804 and extends laterally on both sides of the nozzle 1804. A low point 1809 of the drip shield is directly below the nozzle 1804 and overhangs outside of an area to be occupied by a finger positioned for operating the sprayer. The drip shield should be disposed above at least part of the trigger and, horizontally, preferably at least 2 cm from the trigger 1810, more preferably at least 2.5 cm from the trigger. The drip shield should avoid the space directly in front of the center of the trigger, allowing quick access to grip the sprayer and activate the trigger.

A handle portion 1826 of the sprayer houses the trigger 1810 and battery holder 1822. A grip pattern 1812 is formed into the handle portion. The handle portion includes a lower recess 1818 for accessing the lower battery grip/latch 1814. An upper recess 1820 is provided in an upper portion 1824 for accessing an upper battery grip/latch 1815.

Fig. 19 is a left side elevational view of the exemplary sprayer head assembly of Fig. 18. The shell of Fig.

19 comprises an upper portion 1824, and a lower portion 1826. The lower portion 1826 comprises a transitional portion 1904. A transitional boundary 1908 at or above the bottom of the trigger and before mid trigger demarks a change in the contour of the shell. Below the boundary 1908, the vertical shell contour is essentially straight, except for features such as the grip 1812 or the battery holder 1822. Above the boundary, the vertical contour is curved from the grip portion to the spray head. See Figs. 18-19. The straight portion simplifies tooling and production, reducing complex curves to a defined portion, the transitional portion.

In Fig. 19, the profile of the drip shield 1808 is shown. It can be observed that the lower edge 1910 has an upward slope from the lowest point 1809 at the front of the sprayer to a point 1911 of joining the upper portion 1824. The slope 1910 is at an upward angle of between five and forty five degrees, preferably between fifteen and thirty degrees, preferably about 20 degrees, measured when the bottom surface 1906 of the sprayer is level, as would typically be the case when the sprayer is mounted on a bottle and the bottle on a level surface.

Fig. 20 is a front cross section view of the exemplary sprayer head assembly as indicated in Fig. 19. Fig.

20 shows again the right 1802 and left 1816 shell structure. The integrated pump, motor, nozzle 2002 is shown mounted in the upper section 1902. The battery 2004 is shown laterally centered in the grip section. The battery holder mechanism may be seen in this view. The battery holder is held in place by two grip/latch tabs 1814, 1815 accessible from two recesses 1820, 1818 in the shell 1816. The grip/latch tabs are spring loaded 2010 and move vertically to release the catch from engagement with the shell when pressed by finger pressure. The grip/latch tabs slidably move in a channel in the battery module cover 2011 in response to the finger grip force. The tabs stop at a position allowing release of the battery, at which position, the same grip may remove the battery and place the battery in a charger (not shown) in one continuous motion. Another, charged, battery may then be placed in the sprayer. The grip/latch tabs are beveled to allow insertion and automatic latching without needing the tabs to be depressed to insert the battery.

Fig. 20 also shows the threaded bottle interface cap 2006. The cap includes threads for matching a desired fluid source bottle and a friction fit recess for receiving a fluid pickup tube. The fluid pickup tube may have a screen to limit the size of solid particles allowed in the flow and may have a weight to follow the lowest point in the bottle to pick up the last bit of fluid. Alternatively, the pickup tube may be fixed and located in a most typical location for the last bit of fluid. The fluid pickup tube is coupled from the interface cap to the pump inlet port (not shown).

Fig. 21A is a front elevational view of the exemplary sprayer head assembly of Fig. 18. Fig. 21 shows the nozzle transition structure 1806 that provides a transition from the nozzle to the shell. The transition structure provides support for the nozzle/pump assembly and should not interfere with the spray pattern. The transition structure may also be formed to have aesthetic appeal.

Fig, 21 A also shows an exemplary grip pattern 1812. The grip pattern provides roughness or indentations to engage the grip of a hand. When the sprayer is used with oil or other fluids, a completely smooth plastic surface may be difficult to grasp. A grip pattern on part or all of the handle portion may be used to improve handling characteristics. Alternatively, or in addition, part or all of the handle may be coated or covered with a special grip enhancing material.

Fig. 21B is a cross section view as indicated in Fig. 21 A. Fig. 21B shows the cross section of the battery 2004 contained within the cross section of the shell 1802 and 1816. The cross section of the battery 2004 achieves a cross section area greater than 50% of the cross section area of the interior of the shell 1802 and 1816. The lithium battery has a rectangular form factor. The rectangular form factor is geometrically a good match for maximizing battery cross section and allowing straight lateral movement for installation and removal of the battery module. Fig. 22 is a left side cross section view of the exemplary sprayer head assembly as indicated in Fig. 21.

Fig. 22 shows the pump, nozzle assembly, the battery 2004, switch 2204, battery connection board. Fig. 22 also shows the pump inlet tubing. The pump inlet tubing is run from the underside of the pump and angles toward the top of the battery compartment. The drip shield is modified with a downward sloping portion 2210 to allow the tubing to run above the drip shield on the way to the battery compartment. The drip shield has a first upward sloping portion 2208 from the lowest point to a higher point, then slopes downward 2210 parallel to the inlet tubing. The first upward sloping portion 2208 is sufficient to prevent drips from running backward toward the trigger.

Fig. 22 also shows the switch 2204 and battery connector board 2202. The switch is a single pole switch that switches battery power to the motor when depressed, (wiring not shown). The battery connector is positioned opposite the spray side of the sprayer to minimize the likelihood of contamination. Fig. 23 is a left side view of the exemplary sprayer of Fig. 18 with the left shell and battery pack removed. Fig. 23 shows the battery compartment and path for the fluid tubing. The battery connector board 2202 and connector 2203 are shown. Fig. 24 is a detail drawing of a portion of the cross section of Fig. 22A showing an exemplary vent check valve embedded in a bottle interface cap. The bottle should preferably be sealed to prevent flow of fluid out of the bottle for any orientation of the bottle. For example, if the bottle is tipped over and the fact is not observed for some time, most of the fluid may leak out creating a mess and possibly a fire hazard. Referring to Fig. 24, the vent check valve comprises a valve ball 2406 preloaded with a valve spring 2408 against a valve seat formed in a plug 2404. The plug 2404 is vented to the interior 2402 of the sprayer. As a vacuum forms in the interior of the bottle 2412, the vacuum is conducted through the valve 2410 and draws the valve ball 2406 down, opening the valve and allowing air to fill the bottle. The check valve prevents flow of fluid (oil) out of the bottle if the bottle is tipped over, while allowing air into the bottle as the fluid is used. Without a vent, the pump may collapse the bottle. Fig. 25 is an exploded view of the exemplary sprayer head assembly of Fig. 18. Fig. 18 shows the right shell 1802, the left shell 1816, the integrated nozzle/pump assembly 2002, the trigger 1810, the switch 2204 and the battery module 1822. The battery module 1822 comprises the latch tabs 1814, 1815, the battery holder cover 2011, latch spring 2010, and battery itself 2004. Fig. 26 is a right side elevational view of the exemplary sprayer head with a spray bottle 2702. The spray bottle may preferably screw onto the sprayer head 1800; however, other attachments may be used, such as quick connect. Various bottle sizes may be used.

Fig. 27 is a front elevational view of the exemplary sprayer head with the spray bottle of Fig. 26.

Fig. 28 is a right side elevational view of the exemplary sprayer head with a pickup tube installed. The fluid pick up tube 2902 may be a straight tube as shown. Alternatively the tube may be bent and directed to a low point in the bottle. Alternatively, the tube may be flexible and may have a weight to gravitate to the lowest point of the bottle. The pickup tube may be open as shown or may have a filter screen installed.

Fig. 29 is a schematic diagram of an exemplary control circuit for the sprayer of Fig. 18. Referring to Fig. 29, the trigger 1810 controls the switch 2204 to turn on or off the battery 2004 power supplied to the motor 2002 of the sprayer pump. Alternatively, the controller may be a variable speed controller. Fig. 30 shows the operational capability for two usage profiles. The sprayer used for the test of Fig. 30 sprayed 100 ml/min oil with a 10 cm full width pattern at 30 cm distance using oil with a viscosity of about 50 centipoise.

The first profile 3002 is for a 30% duty cycle, 3 second trigger pulse (7 second "off interval between trigger "on" pulses), resulting in 4.5 hours of use and 78 minutes of "on" time (total pulse time). The second profile is for a 10 % duty cycle, 3 second trigger pulse (27 seconds "off time between trigger pulses), resulting in 13.7 hours of intermittent use and 82.5 minutes of total "on" time. Note a slightly longer total "on" time for the lower duty cycle.

Wobble Drive

Fig. 31 A and Fig. 3 IB are two different isometric views illustrating an exemplary integrated sprayer pump, nozzle, motor in accordance with one embodiment of the present invention. Referring to Fig. 31 A, A motor 3102 is coupled to a wobble drive section 3104 that is coupled to a piston/nozzle section 3106. A nozzle 3110 and fluid input coupling 3108 are shown.

Fig. 32A and Fig. 32B are a side and front view, respectively of the sprayer of Fig. 31 A. Fig 32A and Fig. 32B show locations of cross section views in subsequent figures.

Fig. 33 is a cross section view of the exemplary sprayer as shown in Fig. 32A. The cross section passes through the center of the motor shaft and is in a plane cutting through two pistons. Referring to Fig. 33, the motor shaft 3206 is coupled to the drive plate 3204 to rotate the drive plate around the motor axis. In one embodiment the motor shaft 3206 may not be attached to the drive hub 3204, the drive hub 3204 may be free to move axially on the motor shaft 3206, being constrained laterally by the motor shaft 3206. The motor shaft 3206 may have a D shape or alternatively may have a spline shape or other shape for coupling to the drive plate hub 3204. The drive plate 3204 may be constrained laterally by the motor shaft. Alternatively or in addition, the drive plate may be constrained by a drive hub bore 3203. The drive plate vertical position may be constrained by the drive hub waist band surface 3205 in contact with a complementary surface in the drive housing 3104. Bearings or anti-friction materials may be used to reduce friction. The drive hub has a diagonal surface 3207 for driving the wobble carrier 3202. The wobble carrier 3202 transfers the diagonal rotational drive of the diagonal drive plate 3204 to a reciprocating motion to drive the pistons 3212 by tilting or nutating within a spherical bearing 3211 in response to the diagonal drive. The wobble carrier 3202 carries two piston end cap shoes (alternatively referred to as reciprocating drive shoes) 3208 that couple the nutation motion to the pistons 3212. The piston shoes 3208 permit two axis lateral rotation (tilting) of the wobble carrier 3202 while constraining vertical linear motion to thereby drive the pistons vertically and allow tilting of the wobble carrier 3202. The piston shoes 3208 may also move axially in a bore (see Fig. 40A 4004) of the wobble carrier 3208 to accommodate piston lateral motion constraint. In one embodiment, the center of a sphere defining the spherical bearing 3211 may be on the center line (4008 Fig. 40) of the cylindrical bore 4004 of the wobble carrier 3202. The bore 4004 and piston 3212 shown are cylindrical; however, other shapes may alternatively be used.

The wobble carrier 3202 has a generally flat side for contacting the drive plate 3204. The opposite side of the wobble carrier is substantially spherical in operational envelope for operating constrained by a spherical cavity 3211 in the piston assembly. The wobble carrier assembly includes two split shoes 3208 within the lateral bore in the wobble carrier. Each split shoe couples to a dual bearing T shape end coupling on each piston. The shoes 3208 can move rotationally within the wobble carrier 3202 and can move linearly along the bore axis as needed. The piston end cap (shoe) bearings allow tilting of the shoes along the bearing axis to maintain contact of the wobble carrier 3202 assembly to the diagonal wobble drive 3204. The piston T axis allows tilt in an orthogonal axis to the wobble carrier bore axis. Thus the two tilt axes allow for the wobble carrier to follow the changing tilt of the drive plate as the drive plate rotates around the drive axis. The pistons couple directly to two cylinders having valve structures 3214 to accomplish pumping. As shown, the pumped fluid may then be delivered to a spray nozzle 3110. Alternatively, the pump may deliver fluid, i.e., liquid or pressurized gas flow in an alternative pumping application. Alternatively, the valve structures 3214 may be configured as a motor, operating the mechanism as a motor instead of a pump - receiving high pressure fluid and producing a rotation output.

Fig. 34 is a cross section view as indicated for Fig. 33 in Fig. 32B, however the diagonal drive 3204 is rotated 90 degrees showing the pistons 3212 at half travel. Note that the wobble carrier 3202 is level in this cross section view, although tilted in an orthogonal cross section (not shown). Note also the piston shoes 3208 are level in this cross section view.

Fig. 35 is a cross section view of the exemplary sprayer as shown in Fig. 32B. The cross section passes through the center of one of the pistons 3212. It can be appreciated that the motor shaft is not shown due to the location of the section plane. The wobble carrier 3202 can be seen disposed between the diagonal drive surface 3207 of the diagonal drive plate 3204 and the spherical recess 3211 in the top section 3120 of the cylinder section 3106. The spherical recess 3211 provides a two axis spherical bearing allowing rotation of the wobble carrier 3202 in response to the rotation of the diagonal drive 3204.

The wobble carrier couples to the pistons through two half shoes that fit on the ends of the piston T section. The half shoes fit within a cylindrical bore in the wobble carrier and are free to move axially within the bore. The shoes are free to rotate around the axis of the cylindrical bore. The pistons have a T section. The lateral ends of the T section are cylindrical shafts that fit within the shoes forming a shaft and bearing. The T section bearings allow tilt of the shoes and wobble carrier orthogonal to the cylindrical bore axis, thus permitting two axis tilting of the wobble carrier.

As the wobble drive rotates, the wobble carrier tilts, driving the pistons in and out of the piston cylinder in response to the tilting of the wobble carrier

Fig. 36 shows a center cross section parallel to the cross section as indicated in Fig 32B.. Fig. 36 more clearly shows the motor shaft and assembly screws.

Fig. 37 is a cross section as indicated for Fig. 35 in Fig. 32B, but with the diagonal drive rotated 90 degrees. The piston shown is at the top of the travel range.

Fig. 38 is a cross section as indicated in Fig. 32B parallel to the cross section of Fig. 37, but showing the opposite piston. The piston shown is at the bottom of the travel range.

Fig. 39 is the same cross section as Fig. 36, but with the diagonal drive rotated 90 degrees. Fig. 40A and Fig. 40B show two isometric views of the wobble carrier. Referring to Fig. 40A, the wobble carrier 3202 has a flat side 4002 for contact with the diagonal drive plate 3204 for receiving drive from the rotating diagonal drive plate 3204. The wobble carrier 3202 has a spherical surface 4006 opposite the flat surface 4002 for operational contact and support in the spherical recess 3211 of the top cylinder section 3210. The wobble carrier 3202 also has a cylindrical bore 4004 having a bore axis 4008 preferably parallel to the flat surface 4002. The cylindrical bore 4004 carries the piston drive features, i.e., the piston shoes 3208a,3208b and piston T end shafts 4402 (Fig. 44).

Fig. 41 A and Fig. 41B show an isometric view of a left and right piston shoe bearing. The left and right half-shoes 3208a and 3208b fit over the ends of the piston T end shaft structure (4404 Fig. 44) to operate with each shaft 4402 of the T structure. (Half shoes 3208a and 3208b are each halves of the shoe 3208.) Each half shoe 3208a or 3208b has a recess 4104 for allowing the shoe to pivot on the end of the T structure 4404. Each shoe has a partial cylindrical surface 41 6 for operating within the cylindrical bore 4004 of the wobble carrier 3202. The two half shoes may be first assembled over respective ends of the T end 4404 of the piston structure so that the flat sides 4102 are face to face. The resulting assembly may be inserted into the wobble carrier 3202. When two piston assemblies are assembled with the wobble carrier 3202, the pistons 3212 are inserted into the cylinders (see 4204 Fig. 42A) and the spherical surface 4006 of the wobble carrier 3202 seats into the spherical recess 4202 Fig. 42A of the top cylinder section 3210. The pieces fit together like the pieces of a puzzle, one piece holding another in place without the use of attachment screws, lock rings, spring clips or other attachments typically used to assemble motor parts.

Fig. 41C and Fig. 41D illustrate a different isometric view of the piston shoe bearings of Fig. 41 A and Fig.

41B.

Fig. 42A and Fig. 42B illustrate an exemplary cylinder top section. Fig. 42A shows the spherical recess 4202 for receiving the spherical end 4006 of the wobble carrier 3202. Also shown are piston drive holes 4204 and mounting screw holes 4206. Additional holes 4208 are provided for lightening the structure.

Fig. 43A and Fig. 43B show an exemplary diagonal drive plate. The diagonal drive plate 3204 comprises a motor coupling structure 4302, which may be a D shape or a spline shape, square shape, or other shape allowing rotational drive coupling. In one embodiment, a set screw or other fastener may not be necessary. In other embodiments a set screw or other fastener may be used. Ribs 1304 are shown for lightening the structure. The outer surface of the ribs 4304 fit a cylindrical bore 3203 in the housing and the step surface 3205 is a thrust bearing operating with a corresponding surface on the housing. Fig. 43B shows the diagonal drive surface 3207 for contacting and driving the wobble carrier 3202.

Fig. 44 shows an exemplary piston assembly. The piston assembly 3212 may be fabricated as a single part, but contains several functional areas. A piston portion 4408 at the bottom serves to pump the fluid and fit in a cylinder in the manner of a piston pump. A center section 4406 (alternatively referred to as a connecting rod) serves to connect the piston section to a drive coupling section 4404. The drive coupling section may be a T section 4404 as shown or other structure. The T section 4404 at the top serves to couple the piston to the shoes in the wobble carrier. Each side of the T is a cylindrical shaft 4402 for operating within the cylindrical bearing recess 4104 in each shoe 3208. Alternatively, the T section may be a ball end or other rotational coupling to work with a corresponding complementary coupling in the shoe structure. Fig. 45 illustrates a second exemplary embodiment in accordance with the present invention. Fig. 45 illustrates the use of a ball end bearing on the piston coupling to the shoes. Fig. 45 also illustrates the use of ball bearings or low friction pads on sliding surfaces.

Referring to Fig. 45, a motor is coupled to the diagonal drive plate 4502 using a coupling structure 4502. An option for a set screw is shown. A bearing 4506 may be used between the top housing 4530 and the hub of the diagonal drive plate 4504. The diagonal drive plate may also operate with a thrust bearing 4528. The diagonal drive plate 4504 is coupled to the wobble carrier 4508 using a bearing 4526. The bearing 4526 is optional and, if used, may be a ball bearing or an anti-friction pad. The bearing 4526 may be in the diagonal drive plate 4504 as shown or may be in the wobble carrier 4508. The wobble carrier carries piston cap shoes (also referred to as piston shoes, reciprocating drive shoes, or shoes) 4510 that drive coupling rods 4512 that may include the pistons as shown. The wobble carrier operates in a spherical recess in the cylinder top section 4516. Valve structures 4518 are shown leading to the output port 4520. A bottom section 4522 houses the cylinder and valve components. A mid housing section 4524 is provided for ease in assembly.

Fig. 46 illustrates the system of Fig. 45 with the diagonal drive plate rotated.

Fig. 47 illustrates the system of Fig. 45 at a center section.

Fig. 48 shows the system of Fig. 45 at a section through one piston with the piston at maximum upward position.

Fig. 49 shows the system of Fig. 48 with the diagonal drive rotated to show the piston at maximum downward travel.

Fig. 50 shows the wobble carrier of the system of Fig. 45. The wobble carrier 4508 has a flat surface 5002 and a spherical surface 5006. The wobble carrier may have a cylindrical bore 5004 with an axis 5008. The bore

5004 may alternatively be referred to as a slot, track, or channel. The bore axis is preferably parallel to a plane of the flat surface 5002. The bore, as shown has a cylindrical shape (circular cross section) with an opening 5010 in one side to allow for the piston connecting rod. The opening extends through the spherical surface to allow for the connecting rod during operation and extends to the side of the wobble carrier at the end of the bore to allow for insertion of a subassembly comprising the reciprocating drive shoe components with the rod end coupling and connecting rod, during assembly of the device.

As shown, the opening 5010 extends along the full length of the bore in the wobble carrier (see for example Fig. 45); however, depending on the wobble angle and the space for the connecting rod, the opening 5010 may be filled at the center bottom of the wobble carrier. Including material at the bottom center, between the two connecting rods, to connect the two sides of the wobble carrier 4508 may improve the strength of the part. Alternatively, (not shown) the bore 5004 may have a rectangular cross section or other shape to work with a shoe having a corresponding shape for sliding in the bore.

The wobble motion of the wobble carrier has two orthogonal components of tilt rotation that need to be accommodated. The cylindrical shoe operating in a cylindrical bore may accommodate one axis of rotation, i.e., rotation about the bore axis 5008. The other tilt axis, perpendicular to the bore axis 5008 may be accommodated by the spherical piston rod end bearing or the T bearing, with a corresponding shoe socket to fit the piston end bearing. In an alternative variation, if the spherical piston end bearing is used, the bore may have a rectangular or other cross section because the piston shoe does not need to accommodate the tilt around the bore axis 5008. The tilt in both directions may be accommodated by the piston spherical end.

In one variation, the center of a sphere defining the spherical surface 5006 may be located on the axis 5008. This location may be preferred, but is not critical. The location may preferably be at or below the flat surface of the wobble carrier, and more preferably within the radius of the bore from the centerline of the bore. For center of sphere locations higher or lower than on the centerline of the bore, the reciprocating action may function, but the lateral motion of the piston shoes in the bore may be increased, thereby increasing friction losses.

The radius of the sphere as shown is sufficient to include the full length of the drive shoe at the full extent of travel in the bore; however, other radius values may be selected. Preferably the radius is sufficient that the spherical bearing operates below the drive shoe, i.e., the bore is between the flat surface and the operative surface of the spherical bearing. The radius of the sphere may be sufficient that a part of the spherical surface is altered to allow passing of the connecting rod through the spherical surface defining the spherical bearing, and possibly through the spherical bearing seat as well (see Fig 52).

Fig. 51 shows the piston shoes for the wobble carrier of Fig. 45. The piston half shoes 4510a and 4510b together form a piston shoe 4510. The half shoes have a cylindrical surface 5102 and a flat surface 5104. The half shoes have a recess 5106 for receiving the connecting rod end 5402 and an opening 5108 for the connecting rod 5406. The piston shoe may also be referred to as a reciprocating drive shoe 4510.

The piston shoe of Fig. 51 is partitioned into two parts as an exemplary partitioning that allows assembly of the piston spherical end into the shoe during assembly and capturing the spherical rod end when assembled into the wobble carrier. Alternatively (not shown), the partition plane may be horizontal rather than vertical as shown. The resulting top portion would include a hemispherical bearing. The bottom portion would include the annular spherical bearing with an aperture for the piston connecting rod portion. For further alternative partitioning, see, for example, the end-cap partitioning of the piston shoe in Figs 55-60.

The piston shoe is partitioned into two or more components, preferably into only two components. The two or more components collectively include a top bearing portion proximal to the wobble hub for coupling axial compression motion to the pistons (extension motion of the reciprocating motion), also a bottom bearing portion for retracting the pistons and an aperture for passing therethrough a piston connecting rod portion.

When assembled, the piston shoe captures the piston end coupling to transfer bi-directional axial motion to the pistons while allowing bi-axial tilting motion of the wobble carrier around axes orthogonal to the piston axis.

As shown the two or more components of the reciprocating drive shoe are held in place for operation by the walls of the wobble carrier bore and the coupling rod end coupling. The walls of the wobble carrier bore prevent the separation of the components and the coupling rod end coupling prevents relative sliding of the reciprocating drive shoe components. Thus the components of the reciprocating drive shoe may be held in place without fasteners, welding, or glue.

Fig. 52 shows the top cylinder section for the system of Fig. 45. The top section 4516 comprises the spherical recess 5202 for receiving the wobble carrier 4508. Piston cylinder holes 5204 are shown and mounting screw holes 5206 are shown.

The spherical recess forms a spherical bearing seat 5208 for the spherical surface of the wobble carrier. The spherical recess 5202 may have sufficient lateral width or extent to ensure capturing the wobble carrier between the diagonal drive plate and the top section for all rotation angles of the diagonal drive plate. Thus the spherical recess 5202 may contain at least an angular section of the sphere equal to the diagonal angle of the diagonal drive plate, and preferably greater. For example, if the diagonal drive plate 4504 has a diagonal angle of 20 degrees, then the spherical recess 5202 may extend from the center at least 20 degrees. To positively capture the wobble carrier, an additional amount, for example, three degrees to fifteen degrees may be added to ensure the wobble carrier 4508 cannot 'pop' out of the bearing 5208 under pumping stresses and part tolerances. The angular section of the sphere defining the recess 5202 may also be specified as the depth at the center or the radius or diameter of the circle at the maximum lateral extent of the recess 5202.

The piston cylinder holes 5204 are shown which hold the connecting rods 5406 leading to the pistons 5408 (see Fig 54). The side walls of the piston cylinder hole 5204 provide lateral restraint for the connecting rod 5406 to prevent the wobble carrier 4508 from rotating around the drive axis 4503 as a result of friction between the wobble carrier 1508 and diagonal drive plate 4504. The piston cylinder holes 5204, as illustrated, pass through the spherical surface 5208 of the spherical recess 5204, thus permitting a greater radius and a greater lateral extent of the spherical bearing seat 5208 than would otherwise by available. The side walls of the cylinder holes 5204 provide lateral restraint for the pistons 5408 and connecting rods 5406 (assembly 4512). The lateral restraint is communicated through the connecting rods 5406 to the wobble carrier 4508, preventing rotation of the wobble carrier 4508 around the input drive axis 4503.

Fig. 53 shows the diagonal drive plate 4504 of the system of Fig. 45. The diagonal drive plate 4504 comprises a drive structure 4502 a drive hub 5304, a thrust bearing surface 5306. The diagonal drive surface 5308 is hidden from view, but is evident in the profile. The angle of the diagonal drive surface 5308 from the drive axis may be, for example 20 degrees. Other angles may be used, for example from slightly more than zero degrees to forty five degrees.

Fig. 54 shows the piston of the system of Fig. 45. The piston assembly 4512 may be fabricated as a single part, but contains several functional areas. A piston portion 5408 at the bottom serves to pump the fluid and fit in a cylinder in the manner of a piston pump. A center section 5406 (alternatively referred to as a connecting rod) serves to connect the piston section to a drive coupling section 5404. The drive coupling section may be a ball end 5402 as shown or other structure, for example the T structure 4402 of Fig 44.

Fig. 55 is a cross section view of an alternative exemplary embodiment related to the exemplary embodiment of Fig. 45. Referring to Fig. 55, Fig. 55 shows an alternative piston end coupling shoe structure for coupling from the piston to the wobble carrier. The end coupling shoe structure comprises a cylindrical section (alternatively referred to as a shuttle) that holds a spherical end of the piston rod 4512. The cylindrical section 5504 comprises a cap plug 5502 fitting within the cylindrical section and providing a spherical mating surface 5506 for the top end of the piston spherical end. The cap plug 5502 fits within a cylindrical recess in the cylindrical section through the side of the cylinder forming the cylindrical section. The cap plug 5502 has a cylindrical profile for the top surface - opposite the piston spherical top. The cylindrical profile matches the curvature of the cylindrical section and fits within the cylindrical bore (Fig. 50, 5004) of the wobble carrier 4508. When installed in the wobble carrier bore 5004, the cylindrical section 5504 and cap plug 5502 are held in place by the constraint of the wobble carrier bore. The cap plug should preferably be close fitting within the cylindrical section bore, but need not be press fit, glued, or welded as the close fitting wobble carrier bore provides sufficient constraint to maintain operational configuration.

The cylindrical section can be seen to form a stepped through hole having three regions. The top region is a cylindrical hole 5506 for receiving the top cap 5502 and should preferably be close fitting to the top cap. Other shapes may be used, for example square, but cylindrical is advantageous for simple construction. The cylindrical hole at the top region should be large enough to insert the piston spherical end cap during assembly. The second section of the through hole forms an annular spherical bearing seat 5508 for the bottom annular part of the spherical piston end, next to the piston shaft. The third part of the through hole forms a connection aperture (hole) 5510 allowing the piston shaft to couple the spherical piston end to the piston portion within the cylinder. The connection aperture 5510 may preferably have a conical profile matching the wobble limits of the piston shaft portion. Alternatively a cylindrical hole may be provided.

The configuration of Fig. 55 may operate without a piston preload return spring. The wobble drive provides both push and pull action on the piston. As the motor turns the wobble hub 4504, the wobble carrier 4508 is tilted biaxially, i.e., left - right and front - back. The wobble carrier is constrained from rotating around the drive axis by the two pistons and rigid connecting shafts 4512 that constrain lateral motion relative to the pistons. Thus, the wobble carrier is constrained to nutate in place in response to the rotating wobble hub 4504. The nutating includes a rocking component in the plane of the two cylinders, i.e., the section plane of Fig. 55. The nutating motion transfers vertical motion to the pistons. During a downward push from the wobble hub 4504 (extension motion of the reciprocating drive), the force is transferred from the wobble hub 4504 to the cap plug 5502 and then to the spherical end 5404, and to the connecting rod 5408 to actuate the piston. The connecting rod 2408 lateral restraint enforces linear motion in the piston and piston spherical end, and prevents rotation of the wobble carrier

4508 around the drive axis 4503. The lateral restraint is provided by the cylinder walls 4515 in the spherical bearing component 4516. The linear motion constraint requires that the two piston ends and shuttles 5504 operate a varying distance apart related to 1/cos a, where a is the tilt angle of the wobble drive diagonal surface in a plane containing the two piston axes (the plane of Fig. 55), where a perpendicular angle to the drive axis 4503 is reference zero degrees. This varying distance is accommodated by the wobble carrier bore and coupling shuttles 5504 that are free to slide axially in the wobble carrier bore.

During an upward pull (retraction motion of the reciprocating drive), the wobble hub 4504 drives the wobble carrier 4508 to pull the piston upward in the cylinder. This motion is coupled from the wobble carrier through the coupling shuttle 5504, which contacts the bottom of the spherical end of the piston rod through an annular spherical bearing seat section 5508 of the coupling shuttle. The piston rod extends through a coupling aperture 5510 in the side of the shuttle 5504. The coupling aperture 5510 typically needs to be slightly larger than the piston shaft diameter to accommodate the nutating motion. Accordingly, the aperture 5510 may be tapered or conical to match the nutation.

Additional variations may be noted in the partitioning. A top cylinder piece is provided that includes the spherical bearing seat for the wobble carrier, the cylinder and input ports and valve seat for the input. A single piece outer case and output valve seat is shown with a cavity for the top cylinder piece. A combined output valve carrier and nozzle structure is shown at the bottom of the sheet.

Fig. 56 shows a section view of the exemplary pump of Fig. 55 at a section rotated 90 degrees.

Fig. 57 shows a section view of the exemplary pump of Fig. 55 with the input wobble hub rotated 90 degrees.

Fig. 58 shows a section view the exemplary pump of Fig. 57 at a section rotated 90 degrees.

Fig. 59A and Fig. 59B show a top front right, and bottom back left view the exemplary coupling shuttle of Fig. 55. Referring to Fig. 59A, and Fig. 59B the exemplary shuttle 5504 as shown has a cylindrical surface 5902. Lateral to the cylindrical surface 5902 is a through hole having a cylindrical bore portion 5506, an annular spherical bearing seat portion 5508 and a coupling aperture 5510.

Fig. 60A and Fig. 60B show a top, front, right view and bottom, back, left view of the exemplary cap plug of Fig. 55. The cap plug 5502 has a cylindrical profile top surface 6002 for matching, fitting to, and sliding in the bore of the wobble carrier. The outer surface 6004 is sized to fit into the wobble shuttle. The diameter should be sufficient to pass the piston spherical head during assembly. A cylinder shape 6004 is shown. Other shapes may be used. Keys or notches (not shown) may optionally be provided to prevent rotation of the cap plug within the shuttle; however the curved top surface may be sufficient to maintain alignment. A bottom surface 6006 matches the top of the spherical end of the piston and forms a spherical bearing seat for the spherical end of the piston. Dotted contour lines in Fig. 60B indicate the spherical concave surface 6006.

In further variations, the cap plug 5502 may be larger in diameter or rectangular or may extend to the end of the shuttle. In a further alternative, the cap plug may be adapted to the bottom of the shuttle rather than the top as shown. When configure for the bottom, the cap plug would include the annular spherical bearing and piston rod aperture.

Overmold Alternative

Fig. 61 illustrates an exemplary overmold alternative having a dual divergence nozzle cone. Fig. 61 represents an alternative to the nozzle end 1304 of Fig. 15 -Fig 17. See Fig. 15 - Fig. 17 for additional features of the complete sprayer pump. Referring to Fig. 61, the nozzle structure 6102 may be a metal part over molded with plastic body 6104 to produce the final combination part 6100. Nozzle structures, may require precision that is difficult to achieve in plastic. In particular, the knife edge nozzle opening 123 may be difficult to mold in plastic. Thus, a compound part comprising a metal portion 6102 for the nozzle structure and plastic for the body 6104 may be advantageous. Fig. 61 shows the metal nozzle structure portion 6102 comprises the nozzle orifice 123 and expansion cone 310. The plastic body 6104 includes the input port 6108 and mounting features 6106.

Fig. 62 is a cross section of the exemplary structure of Fig. 61. The nozzle structure can be seen to form the swirl chamber 124, and swirl chamber feed structures as well as the nozzle orifice 123 and expansion cone 310. (see Fig. 3A and Fig. 3B) Recess 6202 is threaded to receive assembly screw 1504 (see Fig. 15) The body structure 6104 houses the components of the pump as previously described with reference to Figs 13-17 and includes the input port 6108. Input port 6108 may be threaded to receive the fitting 1508 shown in Fig. 15.

Fig. 63 is a cross section view of the nozzle structure portion of the assembly of Fig. 61. Fig. 63 shows the nozzle orifice opening into a 90 degree expansion cone section that feeds a 120 degree expansion cone section. The dual divergence profile of the expansion cone provides greater strength at the orifice and minimal drip performance. Fig. 63 also shows the valve wells 211, the swirl chamber 124 and the feed channels 304 from the valve wells to the swirl chamber. Exemplary dimensions are shown. Dimensions may vary. See Table 1.

Fig. 64 shows the metal component 6102 of Fig. 63 at a 90 degree cross section, showing the threaded assembly bolt recesses 6202. Also indicated are the expansion cone 310, swirl chamber 124. Exemplary dimensions are shown. Dimensions may vary. See Table 1.

Fig. 65 shows a detail view of the nozzle structure of Fig. 63. Note that the "knife edge" characterization of the nozzle edge need not be a zero radius, but may be a finite structure 6502 for ease of manufacturing. The structure 6502 may be, for example, a straight section of 0.002 inch length.

Fig. 66 shows the structures machined or fabricated into the metal portion of Fig. 63. Shown are the nozzle orifice 123, swirl chamber 124, feed channels 304, valve wells 211, threaded assembly recesses 6202.

Low Viscosity Nozzle

Low viscosity fluids typically perform poorly when used with a high viscosity nozzle.

Fig. 67 illustrates an isometric view of an exemplary metal portion for the nozzle component of Fig. 61, but adapted for low viscosity fluids. The nozzle structure component 6704 forms a nozzle orifice 23 without an expansion cone.

Fig. 68 is a top view of the nozzle of Fig. 67. The dashed line features show the nozzle structures below. Included are the valve wells 211, the swirl chamber 124 and the assembly structures 6202.

Fig. 69A is a cross section view of the nozzle of Fig. 67. Note that the swirl chamber is narrower and longer than shown in Fig. 63. The swirl chamber 124 extends nearly the full height of the part 6704. The swirl chamber 124 is terminated at the top (i.e., the output end) in a conical transition to the nozzle orifice 123. The nozzle orifice 123 has a substantial length, i.e., the structure is substantially longer than the "knife edge" as shown in Fig. 65 for high viscosity fluids. The extra length dampens the swirl and contributes to a more compact pattern. Exemplary dimensions are shown. Dimensions may vary. Various exemplary lengths may be as follows: an exemplary length 6902 of the orifice 123 may be 0.015 inch, swirl chamber diameter may be 0.065 inch, swirl chamber 124 length 6902 may be 0.150 inch, and the length portion 6908 that is tapered may be 0.025.

Fig. 69B shows the nozzle structure of Fig. 69A at a 90 degree cross section from that shown in Fig. 69A. Fig. 69B section view is aligned to show the mounting screw threaded recesses 6202.

Fig. 70 shows a bottom view of the nozzle structures of Fig. 67. Note that the swirl chamber is narrower than the swirl chamber of Fig. 66.

Conclusion

Relative terms such as "bottom" and "top" with respect to features shown in the drawings typically refer to the orientation of drawing features relative to the page and are for convenience of explanation only. The device itself may be operated in any orientation relative to gravity. In this disclosure, typical exemplary ranges may be provided. It is intended that ranges given include any sub-range within the provided range.

While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.

Claims

Claims

What is claimed is: 1. A power trigger sprayer comprising:

a shell for housing components for said sprayer; said shell adapted for coupling to a fluid source container; a pulsating pump capable of producing a varying flow rate at a pulse repetition rate, said pulse repetition rate sufficient to maintain multiple pulses of said fluid simultaneously in flight to develop a predetermined spray pattern at a predetermined distance from said sprayer;

a swirl chamber nozzle coupled to said pulsating pump;

a tube coupled to said pulsating pump for picking up fluid from said fluid source container;

a power source contained, at least in part, within said shell; and

a trigger for controlling power to said pulsating pump from said power source.

2. The power trigger sprayer of claim 1, wherein said power trigger sprayer is capable of spraying 1 liter of fluid having a viscosity of at least 20 centiStokes on a single charge from said power source.

3. The power trigger sprayer of claim 1, wherein said shell comprises a drip shield for preventing drip flow from the nozzle from contaminating the trigger.

4. The power trigger sprayer of claim 1, wherein said drip shield is disposed below said nozzle and beyond at least 2 cm forward of said trigger.

5. The power trigger sprayer of claim 1, wherein said shell includes a grip section for holding said power trigger sprayer for hand held operation, and said power source is contained, at least in part, within said grip section.

6. The power trigger sprayer of claim 1, wherein said pulse repetition rate is sufficient for a portion of the flow from a following pulse to overtake a portion of the flow from a preceding pulse before reaching a distance of 30 centimeters.

7. The power trigger sprayer of claim 1, wherein said power source comprises a module, said module comprises a first grip tab configured for gripping and holding said power source by an operator using a single hand to grip and hold the power source.

8. The power trigger sprayer of claim 7, wherein said first grip tab operates to release, at least in part, said power source from said sprayer.

9. The power trigger sprayer of claim 8, further comprising a second grip tab, wherein said first grip tab and said second grip tab operate to release said power source from said sprayer.

10. The power trigger sprayer of claim 9, wherein said power source occupies a grip section.

11. The power trigger sprayer of claim 10, wherein said power source spans from above said grip section to a point below said trigger.

12. The power trigger sprayer of claim 11, wherein said power source is laterally centered in said grip section.

13. The power trigger sprayer of claim 1, wherein said varying flow rate is from zero to a maximum flow rate.

14. The power trigger sprayer of claim 13, wherein said varying flow rate is characterized by a sine function.

15. The power trigger sprayer of claim 14, wherein said pulse repetition rate is at least 3000 pulses per minute.

16. The power trigger sprayer of claim 1, wherein said fluid is a fluid with a kinematic viscosity greater than 30 centiStokes.

17. The power trigger sprayer of claim 1, wherein droplets of said composite pattern have

sufficient size such that 90% have a settling rate in air greater than 30 centimeters per second.

18. The power trigger sprayer of claim 1, wherein the swirl chamber is a cylindrical chamber having a height to diameter ratio from 0.4 to 0.6.

19. The power trigger sprayer of claim 18, wherein the swirl chamber exit port has a neck less than ¼ port diameter.

20. The power trigger sprayer of claim 19, wherein the nozzle recess has an initial cone angle at the nozzle of greater than 45 degrees half angle.

21. A method for spraying viscous fluid comprising:

providing an integrated swirl chamber nozzle, pump, and motor assembly;

forming a sprayer head by housing the integrated nozzle -pump in a cordless hand held case with a power source and trigger switch;

adapting the sprayer head for attaching a fluid reservoir and receiving said viscous fluid from said fluid reservoir;

pulsing a fluid flow to the nozzle at a high pulse rate in response to said trigger switch, said high pulse rate sufficient to maintain multiple fluid pulses simultaneously in flight over a predetermined distance to develop a predetermined spray pattern at said predetermined distance; and

configuring the sprayer head with a drip shield below the nozzle configured for directing drip flow away from the trigger switch to a low point forward of the trigger switch and above at least part of the trigger switch.

22. The method of claim 21, further comprising the step: providing a battery within a grip section of said housing, said battery occupying a cross section having an area at least 50% of the area of the cross section of the grip section.

23. The method in accordance with claim 21, wherein the drip shield is at least 2 cm forward of said trigger switch.

24. The method in accordance with claim 21, wherein said predetermined pattern is developed at said predetermined distance of at least 30 centimeters.

25. The method in accordance with claim 21, further including steps:

1) gripping said battery module by gripping at least one release tab;

2) removing said battery module from said sprayer while holding said at least one release tab;

3) placing said battery module in a charger;

wherein steps 1), 2), and 3) are performed without releasing the grip on the battery module.