US3549050A - Pressurized dispenser having a valve extension - Google Patents

Description

United States Patent [72] Inventors John K. Bruce;

Theodore R. Bruce, Burbank, Calif.

[2l 1 Appl. No. 866,121 [22] Filed Oct. 8, 1969 i Continuationinpart of application Ser. No.

548,963, May l0, 1966, now Patent No. 3,393,842.

[45] Patented Dec. 22, 1970 [73] Assignee Sterigard Company Burbank, Calif.

a limited partnership of California [54] PRESSURIZED DISPENSER HAVING A VALVE EXTENSION 4 Claims, 10 Drawing Figs.

[52] U.S. Cl. 222/95, Z22/402.22, 222/464 [5l] Int. Cl B650 35/28 [50] Field of Search 222/95, 386.5, 402.21, 402.22, 402.23, 464, 547, 564

[56] References Cited ,UNITED STATES PATENTS 3,181,735 5/1965 Miskel et al. 222/95 Primary Examiner-Robert B. Reeves Assistant Examiner-Frederick R. Handren Attorney-Christie, Parker & Hale ABSTRACT: A valve extension is associated with the dispensing valve of a pressurized dispenser to prevent blockage of the valves orce by a flexible, elastic bag which separates the dispensers product from its propellant. In one form, the valve extension is carried by the stem of the dispensing valve and has a plurality of circumferentially disposed slots outside the valves seat which allow the bag to collapse upon the body of the extension adjacent the slots without affecting product flow through the valve. In another form, the extension is a generally cylindrical tube having a plurality of spaced-apart openings through its wall along its longitudinal extent.

PRESSURIZED DISPENSER HAVING A VALVE EXTENSION CROSS REFERENCE TO RELATED APPLICATIONS This is a continuation-in-part application of U.S. application Ser. No. 548,963, filed on May 10, 1966 =(now U.S. Pat. No. 3,393,842).

BACKGROUND OF THE INVENTION The present invention relates to pressurized dispensers in general and, in particular, to a means for preventing dispensing valve blockage by a flexible, product-carrying bag.

Products are often marketed in self-dispensing containers commonly referred to as Aerosol" containers or bombs. These containers are rigid cylindrical cans filled with a mixture of the product to be dispensed and a propellant. The container is provided with a finger-actuated valve which, when operated, dispenses a mixture of the product and the propellant. The pressure of the propellant provides the dispensing force.

Such dispensers are only useful where propellant is readily miscible with the product. The propellant and product are always combined which results in a change of product characteristics and performance. ln the dispensing of most items it is difficult to combine the product and propellant and retain required product characteristics. ln food products the required texture and flavor cannot be produced. Catsup, for example, becomes a pink foam. Moreover, vmany products are not suitable for pressurized dispensing because of chemical interaction between the product and the; propellant or the product and its metal container.

To overcome the problems inherent with a propellant and a product in the same chamber, several concepts have been proposed to separate the product and the propellant. One such concept envisions a piston between a product and propellant chamber. The chamber volume occupied by the piston is considerable, often reaching 50 percent of the total container volume. In addition to the cost of providing a piston and the waste space, the container must be of an expensive extruded type to present a smooth and continuous wall for the piston. This is necessary to provide relatively free piston movement and a sealing surface to reduce excessive product seepage into the propellant. Because of the required fit between the piston and wall, any dents inthe container wall render the dispensing device inoperative. Moreover, a highpressure propellant is necessary with this type of container because of piston friction. High-pressure propellants increase the hazard of explosion and the amount of propellant required. In addition, only highly viscous products may be used with this -type dispenser because the product is required to seal the product chamber from the propellant chamber.

Pressurized dispenser concepts also include diaphragm and sack-type dispensers. These concepts have not been accepted because of substantial problems in manufacture, difficulties in operation and excessive cost.

U.S. application Ser. No. 548,963, filed on May l0, 1966 describes a pressurized container withf'a flexible inner follower. The dispenser described in this application overcomes the problems associated with the types` of dispensers just described by separating the product from its propellant while maximizing product volumes and dispenser reliability at a minimum in manufacturing cost. The inner follower or bag is of a flexible, elastic material, for example, polyethylene. The bag has an arched bottom portion for maximizing the amount of contained product while admitting to propellant charging. The arched configuration of the bag also produces excellent bag collapse as product is dispensed by resisting islanding or pocketing of product out of communication with the dispensing valve. The bag is attached in the dispenser in the seam connecting the dispensers dome-shaped cover with its cylindrical body. The unique attachment assures dispenser reliability while minimizing problems of manufacture. As the bag collapses it tends to follow the interior geometry of the cover and thus collapses inwardly toward the dispensing valve. This mode of collapse can block the discharge passages of of the dispensing valve. To avoid this problem, a valve extension was disclosed. y

SUMMARY OF THE INVENTION The present invention overcomes the problem of dispensing valve blockage with a unique valve extension which prevents the flexible plastic bag used in the dispenser of the invention from stopping product flow through the valve.

The dispenser of the present invention includes an elastic, flexible, product-carrying bag which is affixed within the dispenser in the seam connecting the dispensers body with its cover. The interior of the bag defines a product chamber which is in product communication -with a dispensing valve located within the cover. The exterior of the bag defines a propellant chamber whose boundaries include the bottom of the bag and the bottom of the container. A valve extension is provided which extends downwardly from the dispensing valve into the product chamber. The valve extension has blockage prevention means for preventing the bag from blocking product flow through the valve when the valve is actuated. These means include at least one passage in communication with the longitudinal exterior of the valve extension along its length.

ln one form the dispensing valve is mounted in the cover through a resilient sealing member which has an annular sealing portion or seat at its lower end. The stem of the dispensing valve has at least one port through its lower end for c0mmuncating the stems product passage with the product chamber. Normally, these ports are prevented from communicating with the interior of the product chamber by the valve extension which seats on the sealing portion of the resilient member outside the ports. The extension has a plurality of longitudinal slots outside the seat. The body of the valve extension adjacent the slots prevents the bag from collapsing into the ports when product is being discharged. The valve extension may have a generally cylindrical portion with the circumferential slots disposed in this portion. A segmented frustoconical section having spaces between each segment depends from the cylindrical portion. The spaces are disposed to register with the slots of the cylindrical portion.

When the valve is actuated and after a sufficient amount of product is dispensed from the dispenser, the bag will begin to collapse against the valve extension. The slots and spaces between the segments of the frustoconical section allow bag collapse against the valve extension without plugging or blocking the dispensing valve because they provide product communication between the valve and the interior of the bag An alternate form of the valve extension includes a tube which extends downwardly from thedispensing valve. The tube is open at its bottom and has a plurality of spaced apart radial openings through its wall. The bottom and radial openings communicate the interior of the tube with the interior of the bag. ln one form, the tubes radial openings are defined by spaced apart, circumferential bands connected together by longitudinal ribs. In another form, the tube openings are in the form of holes.

The particular valve extension which is most suitable for a given dispenser and product is dependent upon the interrelation of such factors as the diameter-length ratio of the dispenser, the viscosity of the product and propellant pressure.

With high viscosity products such as cheese, for example, smaller openings or slots are required to prevent bag failure which might occur by the bag spanning large openings and experiencing relatively greater stresses. This is because with viscous products the propellant pressure is greater than with thin products, and as a consequence the force on the bag along the perimeter of an opening will be relatively large. To compensate for the higher force, the perimeter of the openings should be reduced to reduce the area acted on by the bag failure is reduced because propellant pressure is lower.

Accordingly, a large diameter opening at the bottom of the valve extension may be -used to allow the bag to stuff" into the extensions interior to maximize the amount of product discharged and reduce the overall length of the extension. Stuffing may be augmented by having the radial openings relatively small to produce preferential collapsing of the bag towards the extensions bottom.

With a given product, the collapsing mode of the bag will, in general, be the same regardless of the dispensers diameter-tolength ratio s'o long as the extensions length is proportional to the length of the dispenser. However, if the length of the ext'ension is the same in a tall, thin dispenser as in a short, squat one, the collapsing modes of the two bags will be different. In 'this case, tlie bag in the tall and thin dispenser will tend to island product below the lower terminus of the extension and stuff into an opening in the bottom of the extensionprematurely.. To compensate for these effects, the total radial open area in the valve extension, in general, should bejlarger with tall and thin dispensers.

vThe pressurized.r dispenser of the present invention effects maximum product'discharge from a given size dispenser. The flexible bag affords extremely high product volume and product flexibility. The valve extension prevents blockage of the dispenserfs valve by the bag as product is dispensed. Thus, 'the valve extension maximizes the amount of product which can be discharged by preventing product isolation from the dispensing valve. By avoiding product isolation, more product may be dispensed from a given size container. Moreover, the extension increases the variety of products which may be used in pressurized-dispensers. Highly viscous products such as cheese, for example, are as compatible to dispensation by the dispenser of this invention as is vinegar.

These and other features, aspects and advantages of the present invention will become more apparent from the following description, appended claims and drawings.

BRIEF 'DESCRIPTION OF THE FIGURES FIG. I is an exploded view, partly in half section, of one form of the dispenser of the present invention;

FIG. IA is a fragmentary view showing the seam between the cover and the body of the dispenser shown in FIG. l;

FIG. 2 is a viewalong line 2-2 2 of FIG. I showing the end view of one form of the valve extension of the present invention;

FIG. 3 is a view, partly in half section, of another embodiment of the present invention;

FIG. 4 is a side view showing still another embodiment of the valve extension of the present invention; and

FIGS. 5 through 9 depict schematically the operation of the 1 valve extension shown in FIG. 3

DESCRIPTION OF THE PREFERRED EMBODIMENTS IG. l illustrates a dispenser l0 which includes a rigid body 1-22which has an annular opening 24 at its top. This opening is defined by an annular bead 26. Cover 22 has an annular, channel-shaped flange 28 for the cover's mounting on body portion l2.l 'Valve assembly 20 includes a valve cup 30 which has an annular flange 32. Flange 32 is crimped over bead 26 when dis`penser 10 is assembled. A stem 34 is carried by valve cup 3(l through a resilient sealing and mounting member 36. A

.valve extension 38 depends downwardly from stem 34. Stem 34 has an annular flange 40 inslight compressive engagement with the top edge of resilientmember 36. Valve extension 38 hasan annular sealing surface 42 at its top which is also in compressive engagement with resilient member 36. The seal effected between surface 42 and resilient member 36 prevents product flow through the valve until it is actuated. When the valve is actuated by the application of horizontal finger pressure, the seal is broken. A passage 44 in valve stem 34 serves to communicate the interior of dispenser 10 with its exterior. A plurality of circumferentially disposed ports 46 extend through the wall of stern 34 to communicate passage 44 with an annular chamber 48. Chamber 4 8 is defined by the space between resilient member 36 and stem 34.

- Valve extension 38 includes a plurality of circumferentially disposedslots 50 which open intosealing surface 42. These slots open into the surface outside the annular seal between surface 42 and the bottom edge of resilient member 36. Slots 50 are disposed in a generally cylindrical portion 52 of valve extension 38. A segmented invented frustoconical section S4 depends below cylindrical portion 52. The segments are defined by crossed slits 56. These slits are in register with slots 50 of cylindrical portion 52. The flat, lower end of the valve extension has a small area to avoid a long edge against which the bag might otherwise bear and tear. The lower end of the valve extension is indicated by reference numeral 58.

Body 12 is hollow and cylindrical and has radially extending mounting flanges 60 and 62 at either end. The body may be formed of commercially available rigid tubing.

Bag 18 is stretched over flange 60 and down the exterior side .wall of body 12 to effect'tensioned contact along this outer surface. The bag has an arched portion 64 at'its closed,v

lower end.

Flexible bag 18 is normally fabricated from commercially available rolled tubing which comes in a flattened configura. tion. This tubing is inexpensive and is readily prepared for use in the dispensing container of the present invention. It has the further advantage that no side seam is required which might affect the seal formed-between cover 22 and body 12. The dimension of the perimeter of the flexible bag is selected such that it is approximately thesame as the inner perimeter of body portion I2. When inserted and affixed in Spenser l0, flexible bag 18 takes a generally cylindrical configuration down to arched portion 64 to conform to the interior configuration of body I2.

The tubing is heat sealed at one end either before or after it is cut from its roll. The heat seal is in a line and is partially responsible for the arched configuration. The end opposite the sealed endis left open. It is the open end which is expanded and slipped over the mouth at the top end of body portion 12 and then relaxed. As seen in FIG. l, the exterior portion of the bag adheres to the exterior of the body in skinlike elastic contact. The bag also completely encompasses flange 60.

Bag 18 may be fabricated from extruded polyethylene tubing having a relatively thin wall thickness, for example, 0.002 inch. A bag formed of polyethylene or similar plastic materials has the advantage that it undergoes very little expansionduring its filling. This enhances the measure accuracy for the product placed in the dispenser.

The physical characteristics of the bag are important. The n material should have good memory characteristics for itsv contraction into intimate contact with the outer wall of the body portion and the encompassed flange. This avoids bunching which affects the seal in the seam formed in the assembled dispenser. The material must have a relatively high hardness to avoid squeezing or thinning during seaming and;

As previously indicated, the open end of bag 18 is affixed in the dispenser by a seam formed between flange 28 and flange 60. The open end of the bag thus takes v.a circular configuration. The bag, however, is initially formed of flat stock. The heat-sealed bottom end prevents this end from assuming a cylindrical configuration. By virtue of the fact that the perimeter of bag 18 is only slightly smaller than the interior circumference of body 12, the bag is constrained against flaring outwardly of the interior diameter of the body. The constraining influence of the can together with the line seal at the bags closed ends produces arched configuration 64.

After bag 18 has been'inserted in body portion 12 with a portion in tensioned contact along the exterior sidewall of the body, top portion 14 and bottom portion 16 may be mounted onto the body. Mounting is effected by seaming flange 28 of cover 22 and flange 60 of body portion 12 together. The resulting seam is shown in FIG 1A and is indicated by reference numeral 63. Seam 63 locks bagl 18 in place. Seam 63 is a double seam wherein flange 28 is bent back upon itself with a portion of flange 60 being bent downwardly at the same time. The covers flange tucks inside the downward portion of flange 60 against the stretched portion of the bag on the outside of body l2. The bag is sandwiched within the seam as shown in FIG 1A. The stretching of the bag over the mouth of the body andtightly down its external side avoids gathering or doubling while forming seam 63. Any separation or tearing of bag material during seaming is normally localized because of the large seamed area, thereby avoiding the loss of the seal. Moreover, the tensioned contact of the bag over the top and down the external sidewall of the body portion l2 prevents the bag from being pushed back into the interior of body portion 12 when cover 22 is inserted onto the body for the seaming operation. Y

Bottom portion 16 includes a self-sealing valve 67 disposed on its upper surface along the longitudinal axis of the dispenser. This valve admits a propellant gassing or pressurizing needle into the space between the upper surface of bottom portion 16 and arched portion 64 of bag 18. When the gassing needle is withdrawn, valve 67 seals itself and thus the propellant charged into the dispenser.

Flange 62 of body l2 and the flange of bottom portion 16 are also seamed together preferably with the double seam just described. Valve assembly is mounted to cover 22 by crimping lip or flange 32 to beaded portion 26 after product has been charged into the interior of the dispenser and bag. Propellant is then charged into the chamber defined between top of bottom portion 16 and arched portion 64 of bag 18. As previously mentioned, propellant charging is effected through sealing valve 67 by a standard gassing needle.

The product is dispensed from dispenser l0 by applying horizontal pressure to stem 34 of valve assembly 20. This creates a space between sealing surface 42 and resilient member 36 and provides a path for the product within bag 18 to enter passage 44. The propellant causes the bag to collapse as its product is discharged. Bag 18 will collapse towards the longitudinal axis of the dispenser. However, bag 18 is attached to the container at the seam effected by flanges 28 and 60 of cover 22 and body portion 12. This causes the bag, as it collapses, to tend to follow the outline of the interior of cover 22. Pressure from the propellant causes the collapsing bag to squeeze its contained product towards valve extension 38. Because the bag is of filmlike consistency, little resistance is offered to the pressure exerted by the propellant. It therefore collapses substantially completely leaving little or no product within dispenser l0. Valve extension 38 provides a body against which bag -18 collapses. Slots 50, together with slits 56 in segmented portion 54, prevent the lbag from blocking product passage through ports 46. As the bag collapses against the valve extension, slots 50 and slits 56 maintain ports 46 open to the interior of bag 18.

FIG. 3 depicts an alternate embodiment of the pressurized dispenser of the present invention. A pressurized dispenser 70 includes a cylindrical body portion 72 onto which is seamed a dome-shaped cover 74. The bottom of body 72 is closed by a bottom cap 75. As in the previously described embodiment the container has a flexible, elastic bag shown by reference numeral 76 in schematic depictions 5 through 9. The bag is of the same construction and is affixed in the same manner as described with reference to FIG. 1. Cover 74 and bottom 75 are also affixed to body 72 in the manner previously described.

A valve assembly 78 is carried on cover 74. This assembly includes a valve cup 80 and a valve element 82. Valve cup 80 has a flange 84 which is crimped over an annular lip 86 of cover 74. The valve cup has an inwardly extending, annular flange 88 which bounds a product opening 90. Valve element 82 is carried by the upper surface of flange 88 and bridges across opening 90. The valve includes a frustoconical, indented portion 92 which cooperates with an annular rubber seal 94 to prevent product passage. Seal 94 is held by valve cup 80. Valve element 82 is self-biased such that frustoconical portion 92 normally seats in annular seal 94.

A dispensing cover 96 is mounted over flange or lip 84 of valve cup 80. This cover is of plastic material and thus is easily deformed. An actuator 98 depends concentrically downward from a top portion 100 of the cover. An actuator arm 102 extends above top portion 100 as does product discharge nozzle 104. The nozzle has a product passage 106 in open fluid communication with an interior chamber 108 in dispensing cover 96. Depression of arm 102 forces actuator 98 against the upper flat surface of frustoconical portion 92 of valve 82. This unseats the valve allowing product passage into chamber 108 and out passage 106 of nozzle 104. t

A valve extension 110 is carried by valve cup 80 through a pair of outwardly extending ears 112 which overlay the upper surface of flange 88. The extension depends downwardly from its connection with the valve cup into the interior of dispenser 70. The extension, which may be formed of a plastic material, has a head 114 for the attachment of ears 112. This head has an annular product passage 116. A plurality of spaced-apart circumferential bands 118 are disposed below head 114. These bands are connected together by diametrically opposed and longitudinally extending ribs 120 and 122. Product is then capable of passing interiorly of bands 118 through the large open area between them into the hollow interior of the valve extension.

FIG. 4 shows an alternate fonn of the tubularlike valve extension depicted in FIG. 3. This valve extension is in the form of a cylinder carried by a valve cup 132 in a manner identical to that of valve extension 110 and valve cup 80. A plurality of longitudinally spaced apart holes 134 extend through the walls of extension 130 for product communication with its hollow interior. The end lof extension 130 is open to augment product flow into its interior and provide an opening through which the plastic bag can be stuffed.

FIGS. 5 through 9 depict the operation of the dispenser illustrated in FIG. 3 in its discharging or horizontal orientation. Product discharge through valve assembly 78 has been previously described.

In FIG. 5, the dispenser is fully charged. lt is also in its normal horizontal attitude employed for discharge of product. Bag 76 is then fully filled and bounds the majority of the volume within the dispenser.

FIG. 6 illustrates the bag as it would appear with about three-quarters of the product remaining in it. Because of the weight of the product the bag takes an asymmetrical shape. It is beginning to collapse inwardly towards valve extension.110. lt is also beginning to collapse towards the interior surface of cover 74.

In FIG. 7, about one-half of the product has been discharged. The gravity influence is still apparent. The ears of the arched bottom of the bag have closed appreciably. In addition, the bag embraces relatively more ofthe interior of cover 74 and, as a consequence, the bottom yof the bag is close to the bottom of extension 110.

In FIG. 8, only about 25 percent of the product remains within bag 76. The bag is essentially completely collapsed against the interior surface of cover 74. The upper portion of the bag contacts extension 110.

ln FIG. 9, the bag is completely empty. The only product remaining in the dispenser is within extension 110. The collapsing of the bag is therefore complete. The bag has collapsed about extension 110 and against the interior surface of cover 74. Becauseof the circumferential open area provided in extension 110, the product has been freely admitted into the extensions interior and out of the dispenser through nozzle 104.

The present invention has been described with reference to certain preferred embodiments. It should be understood by those skilled in the art, however, that the spirit and scope of the appended claims should not necessarily be limited by the foregoing description.

We claim:

l. An improvement in combination with a pressurized dispenser for dispensing a fluid product of the type having a flexible, elastic bag affixed within the dispenser in a seam connecting the dispensers body and cover, the bag defining a product chamber in product communication with a dispensing valve located in the cover and a propellant chamber between the closed bottom of the bag and the bottom of the dispenser, the dispensing valve having a stem with a longitudinal product passage and at least one port through the lower end of the stem for communicating the stems passage with the product chamber, the stem being mounted in a resilient member which has an annular sealing portion. at its lower end, the improvement comprising:

a longitudinally extending valve extension carried by the stem and depending downwardly from the dispensing valve into the product chamber between the dispensing valve and the bag, the valve extension including a generally cylindrical portion with an annular sealing surface normally in compressive contact with the sealing portion of the resilient member to prevent product from entering the longitudinal passage, a plurality of longitudinal slots through the cylindrical portion at intervals around its circumference, the slots being outside the diameter of the sealing portion of the resilient member, and an inverted frustoconical section depending downwardly from the cylindrical portion, the frustoconical section' being divided into spaced-apart segments with the spaces between segments in register with the slots of the cylindrical portion; and y whereby, product communication with the stem's product passage is effected upon actuation of the'stem to break the seal between the sealing portion and the sealing surface, the body of the valve extension adjacent the slots preventing the bag from blocking the ports upon such actuation.

2. An improvement in a pressurized dispenser for dispensing a fluid product of the type having a flexible, elastic bag affixed within the dispenser in a seam connecting the dispensers body and cover, the bag defining a product chamber in product communication with a dispensing valve located in a cover, and a propellant chamber between the bottom of the bag and the bottom of the dispenser, the improvement comprising:

a valve extension depending longitudinally downward from the dispensing valve into the product chamber, the valve extension comprising a longitudinally hollow tube having a plurality of openings through the tube's wall along its longitudinal length to communicate the tube's hollow interior with the product chamber, a pair of diametrically opposed ears at the top of the extension, each ear being defined by an upstanding longitudinal portion and an engaging portion extending radially from the longitudinal portion to define therewith an exterior shoulder; and

annular flange means proximate the dispensing valve, the valve extension being carried by the flange means by the shoulders of the ears oyerl ing the flange means. 3. The improvement claime in claim 2 wherein: the valve extensions openings are defined by spaced-apart circumferential bands connected together by longitudinal ribs, and the hollow interior of the valve extension opens to the product chamber at the bottom of the valve extension.

4. The improvement claimed in claim 3 wherein the valve extension has a head between the circumferential bands and the ears, the upstanding longitudinal portions of the ears being attached to and extending upwardly from the head, and the head having a longitudinal passage forming a part of the hollow interior.

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