US3489097A - Flexible tube pump - Google Patents

Description

Jan. 13, 1970 w. GEMEINHARDT FLEXIBLE TUBE PUMP Filed May 8. 1968 3 Sheets-Sheet l F/Gll/ Jan- 13 1970 w. GEMEINHARDT 3,489,097

FLEXIBLE TUBE PUMP ATTORNEYJc Jan. 13, 1970 w. GEMEINHARDT 3,489,097

FLEXIBLE TUBE PUMP Filed May e. 196e 3 Sheets-Sheet 3 INVENTOR W/l A4/V GENE//V/M United States Patent O 3,489,097 FLEXIBLE TUBE PUMP William Gemeinhardt, 143-45 Ash Ave., laughing, N Y. 1135s Filed May s, 196s, ser. No. 727,517 Int. Cl. F04b 43/08 U.S. Cl. 103-148 13 Claims ABSTRACT OF THE DISCLOSURE A pump having a llexible, tubular chamber and valve portions and a device for selectively compressing the chamber and valve portions including two valve actuating members mounted to a single, oscillatable rocker plate actuated by an eccentric which also actuates the plunger acting to compress the pump chamber, the synchronization of the valve actuating members and plunger being such as to provide a ilow of fluid through the flexible, tubular member.

BACKGROUND OF THE INVENTION Flexible tube pumps, that is, those employing some type of flexible member for both the chamber and valves of the pump, where various mechanisms act on the flexible member to provide the pumping action, are known to the art. Many of these are extremely complex in sructure employing standard cams or cranks and levers for movement of all operating parts of the device. They are relatively expensive, or are relatively limited as to the ability to vary the operation of the mechanism to provide dierent eiects. Additionally, these devices generally require extensive lubrication and maintenance and are difficult to protect from dirt and corrosion. Further,

with many of the prior art pumps there are problems with both creeping of the tubular member and with backliow of the fluid, during pumping. With respect to this creeping problem, it has often been solved by forming only the portion of the tube actually acted upon by the mechanism, of a llexible material and joining the flexible material, at its extreme ends, to a relatively solid pipe material. In this situation, much of the advantage of the flexible tube pump is lost.

In accordance with the present invention, a device has been developed which can easily be attached to a straight line liexible member, to convert a portion of that member into a pump, without cutting or bending of the flexible, tubular member. This device can be used to dispense or extract measured quantities of liquids or gases, including the dispensing or extracting of very small quantities, such as a fraction of a drop.

Further, the art has required, and according to the present invention, there is provided a liexible tube pump wherein the pressure and the capacity can be easily changed during operation. Still further, according to the present invention a flexible tube pump can be provided where, without cutting or mounting of the flexible tube on tube holders, there is little or no tendency for the tube to creep and tube life is significantly enhanced due to the particular construction. In addition, backflow within the pump is significantly minimized, or eliminated. This flexible tube pump requires a minimum of maintenance as it employs a minimum number of parts and those parts subjected to sliding friction can be made selflubricating.

SUMMARY OF THE INVENTION In accordance with the present invention, a device has been developed which can be placed at any point along a straight run of iiexible, tubular material to cause that portion of the flexible, tubular material to act as a pump.

3,489,097 Patented Jan. 13, 1970 ICC The device is extremely simple in operation and has a minimum of moving parts.

As with the prior art devices for similar purposes, it comprises one member to act upon the flexible, tubular member in the manner of an inlet valve, a second member to act upon the flexible, tubular member as an outlet valve, and a plunger to provide the pumping action within the flexible, tubular member. However, in the device of the present invention, both valve actuating members are attached to a single rocker plate. Only a single spring is provided for this rocker plate and adjustment of that spring is effective to vary the pressure of the pump.

One of the valve actuating members is always so positioned as to close the corresponding valve portion. When either valve actuating member rises to open the corresponding valve so as to permit a flow of fluid, the open ing is limited, by the device, to about 20% of the diameter of the tube.

The rocker plate is oscillatable about an attached pin which is slidable in an elongate slot. The rocker plate is moved by an eccentric which acts upon an upper surface of the rocker plate to provide the oscillating action and the combination of the resilience of the ilexible, tubular member and the spring acting on the rocker plate, act to cause the pin to which the plate is attached to move within the elongate slot. This combination also acts as a safety valve to prevent overpressuring of the flexible, tubular member. A device can also be formed, wherein two upper surfaces are formed on the rocker plate, diametrically opposed with respect to the eccentric, so that this eccentric acts to move the rocker plate in each oscillation direction.

Also in operative relation with the eccentric is a rod, joined to the plunger actuating the pump portion of the flexible, tubular member, This rod is also spring loaded so as to return it to its uppermost position, and cause it to move with the eccentric. In other embodiments, this rod can be broken away and a portion replaced by a high compression spring. Thus, if the plunger comes in contact with solid material within the tubular member, the high compression spring will compress to prevent the plunger from attempting to close, through completely solid connections, on the solid material. Such a solid closure could damage or destroy the plunger, the tubular member, and the base plate upon which the tubular member rests.

When pumping at faster rates or when it is desired to deliver shorter spurts of the liquid, the eccentric can be directly coupled to a standard cam so formed as to depress the plunger more quickly and allow it to open more quickly. This allows the pumping portion of the flexible, tubular member to remain open longer for filling during each cycle.

The angle at which the eccentric contacts the upper surface of the rocker plate can also be varied to obtain certain advantages. Thus, the rocker plate can be inclined to keep the inlet valve of the device in a more open position.

This, too, is more advantageous when the pump is ernployed for viscous materials or for slurries. Further, other adjustments of this same adjusting member can change the phase relationships of the inlet and outlet valves and the plunger. As is understood in the art, the normal relationship causes the inlet valve to open while the plunger is moving upwardly, the inlet valve to then close while the plunger is in an upright position, the outlet valve to open, and the plunger tothen depress in order to pump the lluid through the llexible, tubular member. Thereupon, the outlet valve again closes and the inlet valve opens to start a new cycle.

Below the two valve actuating members and the plunger a solidly mounted base plate is located. The ends of this base plate are cut out to a size to match the diameter of the exible, tubular member and are indented to a degree that the innermost portion of the slot is in vertical alignment with the respective valve actuating member. Thus, in operation, the ilexible, tubular member is depressed, to a degree, below the horizontal level of the base plate. This positioning aids in preventing the iiexible, tubular member from creeping perpendicular to its axis during operation of the device. As a further aid in preventing creeping of the flexible, tubular member along its axis, the elongate slot in which the rocker plate pin slides can be angled toward the inlet of the pump. Thus, any tendency of the tubular member to move toward the outlet direction is counteracted by the motion of the rocker plate, and thus the valve actuating members, in the direction of the inlet.

The volume pumped through the iiexible, tubular member employing the device of the present invention can be easily varied, during operation, by a single adjustment affecting the amplitude of the plunger motion. Thus, maximum volume is delivered by allowing the plunger to move through its full amplitude. By a simple adjustment, the plunger can be prevented from moving to its full upward position, thus cutting down the amplitude and, effectively, diminishing the volume of the chamber portion of the exible, tubular member. By this simple adjustment, accurate control can be maintained over the volume which the pump delivers, including accurate measurement to as small a volume as drops, or fractions of drops, per pumping cycle.

Thus, it is an object of the present invention to provide an inexpensive, compact pumping device, employing a exible, tubular member, which is simple in construction rand operation, and needs little maintenance, but is capable of dependable performance and easy variation of operation.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings:

FIG. 1 is an elevational view of one embodiment of the present invention;

FIG. 2 is a view, along the line 2 2 of FIG. l;

FIG. 3 is a sectional View along the line 3 3 of FIG. 1 showing the construction of one embodiment of the plunger rod ofthe device;

FIG. 4 is a sectional view along the line y4 4 of FIG. 1 showing the construction of the pressure regulating portion of the device;

FIG. 5 is a view along the line 5 5 showing the elongate slot in which the rocker plate pin is slidable;

FIG. 6 is an elevational partial sectional view of the device, along the line 6 6 of FIG. 3 showing the rocker plate and plunger in lill position;

FIG. 7 is a view of the base plate of the device, showing the positioning of the flexible, tubular member, taken along the line 7 7 of FIG. 1;

FIG. 8 is an elevational view of a second embodiment of the device showing a modified rocker plate and eccentric assembly with an added cam;

FIG. 9 is a View taken along the line 9 9v of FIG. 8;

FIG. 10 is a sectional view along the line 10-10 of FIG. 8 showing the construction of the eccentric with the added cam and of a second embodiment of the plunger rod; and

FIG. l1 is a fragmentary view of a modified rocker plate and bearing ring showing a means for adjusting the relationship between these parts.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, FIG. l shows a plan view of the overall device 1 having a rocker plate 2 with attached valve actuating members 3 and 4 which act on flexible, tubular member 5. To this rocker plate is attached pin 6 which is slidable in elongate slot 7. This elongate slot is formed in a plate 8 held by tabs 9 and 10 to the support bracket 11 of the structure. Tabs 9 and 10 are held against the support plate 11 by threaded members 12 and 13. The plate 8 is movable as shown in phantom 8 in order to vary the angle of the elongate slot 7 which is normally in a generally vertical position. This, as previously described, is an aid in preventing creeping of the flexible, tubular member 5. The elongate slot 7 and plate 8 are so formed that the elongate slot is always in juxtaposition with the opening 14, shown in hidden lines, in the support member 11.

Stud 15 is slidable in opening 65 formed in support member 47. As shown in FIG. 4, this stud 15 bears against Valve actuating member 4 to transmit the pressure of spring 16 to rocker plate 2. It should be understood that this is -merely one convenient method of applying spring pressure to rocker plate 2 and that, for example, a bearing member could be attached to the rocker plate solely for receiving this spring pressure, and thus transmitting the pressure to both valve actuating members.

The support member 47 can be formed of a self-lubricating material to provide for easier movement of parts, such as stud 15, and to avoid the necessity of providing constant lubrication. For example, it can be formed of carbon-graphite, nylon, graphite filled synthetic resins, etc.

Adjustable member 17 bears against spring 16 to control the pressure transmitted by the spring. The adjustable member comprises a threaded portion 1S, threadably received in support member 47, and a rod member 19 connected to adjusting knob 20. As this member 17 is moved downward, through action of the screw threaded portion, the pressure transmitted by spring 16 is increased and the pressure at the outlet of the pump is correspondingly increased.

Downward movement of the flexible, tubular member 5 is limited by placement of base plate 30 which is mounted to support member 11 by screw members 31 and 32, below the plane of the valve actuating members 3 and 4. Adjustment of the height of this base plate is accomplished by adjusting members 33, 34, 35, and 36 which determine the height of the base plate and its relative distance from the valve actuating members, and also control the inclination of the base plate.

Cutout portions 37 and 38 are formed at the ends of the base plate 30. The width of each cutout portion 37 and 38 is the same as the diameter of the largest flexible,-

tubular member 5 preferably accommodated by the device. The length of the cutout portions is such as to place the ends of the cutout portions 39, 39 in juxtaposition to the respective valve actuating members 3 and 4. Thus, the flexible, tubular member, in its normal position, has a portion lying below the horizontal plane of the base plate. As the valve actuating members are lowered they compress the iexible, tubular member against the surfaces 39, which aids in preventing creeping of the flexible, tubular member during operation of the device.

As the clearance between valve actuating members 3 and 4 and base plate 30 is relatively smaller than the diameter of exible, tubular member 5, there is often some difliculty in inserting the iiexible, tubular member into its proper position. As an aid in inserting this member, a lever arrangement 70 is provided, as best seen in FIG. 5. The lever has a shorter end 71 against which pin 6 of rocker plate 2, in its lowermost position, rests. The lever assembly is pivoted about pin 72 and is actuated by an elongate handle 73, shown broken away. Depression of the elongate handle 73 causes the shorter end 71 of the lever to cause pin 6 to move upwardly in elongate slot 7. This causes rocker plate 2 to move upward, away from the base plate, and thus moves valve actuating members 3 and 4 away from the base plate, to allow for easier insertion of flexible, tubular member 5.

The actual pumping of fluid is accomplished through the action of plunger 40, which lies generally in the plane of the valve actuating members, on that portion of the tlexible, tubular member lying between the valve actuators 3 and 4. Motion is transmitted to this plunger by rod 41 joined to plunger 40 by threaded member 42. This rod member 41, and thus the attached plunger 40, are maintained in a normally upper position, through the action of spring member 43.

Upward movement of the plunger is limited by rod member 44 which is threadedly adjustable by means of screw threaded portion 45, which acts in corresponding thread members formed in face plate 46. A portion of the rod `passes through an opening 48 in support member 47. This rod member can be moved by an adjusting knob 49 mounted to the top of the screw threaded portion 45. Adjustment of this rod member 44 with the corresponding limitation in upward movement of the plunger 40 determines the volume of tiuid which enters the central chamber portion of the flexible, tubular member 5, and thus controls the capacity of the pump. Maximum capacity is attained when this rod member is in its uppermost position, allowing for full travel of rod 41 and plunger 40. As the adjusting knob 49 is turned so as to move rod 44 downwardly, through action of the threaded portion 45, the upward movement of the plunger is restricted, preventing it from allowing full expansion of the central portion of flexible, tubular member 5, and thus restricting the quantity of fluid which can be taken into the chamber portion of the tubular member. Further, with the limitation on upward motion, the downward stroke of rod 41 is foreshortened, thus reducing the quantity of fluid dispensed on each stroke of the rod 41. Thus, by

restricting motion of the plunger rod 41 to the proper degree, extremely small, accurately measured quantities of fluid can be dispensed from the fiexible, tubular member, including quantities of drops, and fractions of a drop, on each stroke.

Motion of both the valve actuating members 3 and 4 and plunger rod 41 is caused by rotation of eccentric 50, through action of bearing ring 51 on surface 52 of rocker plate 2 and on the top of plunger rod 41 which actuates plunger 40. Eccentric 50 is journalled within the bearing ring 51 through ball bearings 53, or other equivalent bear ing means. These bearing means are lubricated and sealed so as to preclude the access of dirt and moisture and prevent the need for continuous lubrication.

As the eccentric rotates, in a clockwise direction as viewed in the drawings, it first forces the rocker plate 2 to the left, as more particularly shown in FIG. 6. This allows inlet valve actuating member 4 to rise up, while outlet valve actuating member 3 remains in its lowermost position to seal flexible, tubular member 5, also as more particularly shown in FIG. 6, and thus allows tiuid to enter the flexible, tubular member 5. As the rotation of eccentric 50 continues, the inlet valve actuating member 4 begin to descend, thus compressing the tube in the vicinity of the inlet valve actuating member to close that valve, and the outlet valve actuating member 3 then rises opening the outlet valve about of the tube diameter. As the outlet valve actuating member 3 continues to rise due to continued motion of eccentric 50, the spring action of the flexible, tubular member 5, and the motion of pin 6 within elongate slot 7, the plunger 40 is depressed by the downward movement of plunger rod 41, carried out through action of eccentric 50 through bearing ring 51. The purpose of the bearings between eccentric 50 and bearing ring 51 is to allow for continued free movement of the eccentric, notwithstanding any frictional binding of the bearing ring against either the top of plunger rod 41 or surface 52 of rocker plate 2.

Face plate structural member 46, which is bent to form a face plate covering the operating components is bonded to structural member 47 through screw member 60, which is also attached to the motor casing.

Modified forms of various components of the device are illustrated in FIGS. 8, 9, l0` and 11. In FIG. 8 there are shown, with the same structure as in FIG. l, the structural member 11 and base plate 30 mounted by screws 31 and 32, along with adjusting nuts 33, 34, 35, and 36. Also, in the same form as in FIG. 1 are the structural member 47 and valve actuator adjusting member 17 with screw threaded portion 18, rod 19 and adjusting knob' 20. The rod member 44 for limiting the travel of the plunger including screw threaded portion 45 and adjusting knob 49 are also as shown in the first embodiment.

The variation in FIGS. 8 through 11 involve, generally, rocker plate 102, eccentric and cam assembly 149, plunger rod 141, and a means for adjusting the contact between a rocker plate 202 and bearing ring 51. j

Particularly when pumping especially viscous fluids, or slurries, a great deal of work must be expended by the device in moving the fluid through the flexible, tubular member. Further, more pressure is required on the flexible, tubular member by the valve actuating member in order to assure proper closure. Under these circumstances, complete reliance cannot always be placed upon the single surface of the rocker plate and the spring acting on the rocker plate. However, more positive action can be imparted to the rocker plate, and hence to the valve actuating members, merely by a second leg as on the rocker plate 102, with this second leg in contact with the eccentric 150. This is illustrated in FIG. 8 where the rocker plate 102 has a first leg with a surface 152, as in the first embodiment, but additionally, has a second leg 154, shown in phantom, with a bearing surface 155. The construction of the eccentric journalled in the bearing ring 151 through a bearing surface, such as ball bearings 153, is essentially the same as shown in the first embodiment. Here, however, the bearing ring acts first against surface 152 to force the rocker plate toward the left, as with the first embodiment, but then, in continuing its clockwise rotation, positively acts against surface 155 to force the rocker plate toward the right, as viewed in FIG. 8, and thus positively acts on the inlet Valve actuating member 104 to compress the tubular member and thus close the inlet valve. The construction of the inlet valve actuating member 104 and outlet valve actuating member 103 are the same as in the first embodiment. Similarly, the modified rocker plate 102 is mounted to pin 106, which similarly rides in an elongate slot (not shown).

When the device operates at higher speeds, often the chamber portion of the flexible, tubular member 5 cannot be completely filled in the time allotted by rotation of the eccentric within the bearing ring. This can be provided for by maintaining plunger rod 141 in its upper position during a longer portion of the cycle. This is accomplished by rigidly attaching to the face of the eccentric 150 a cam 156. This cam 156 acts directly on plunger rod 141, rather than the bearing ring 151 making contact with this plunger rod 141. The cam 156 has only one high spot 157 which acts to depress the plunger rod 141. Thus, this single high spot 157 is the only portion of the cam surface which provides for depression of the plunger 140 and plunger rod 141, so that a rapid depression is achieved, rather than the relatively gradual depression achieved were the surface of bearing ring 151 employed to depress the plunger 141. This type of configuration is also employed to produce a more pulsating fiow than obtained with the construction of the first embodiment.

The modified plunger rod construction is more clearly shown in FIG. 10. Here, it can be seen that the modified plunger rod 141 is formed with an upper section 160, which is acted upon by the surface of the cam 156, or, in the first embodiment, by the surface of bearing ring 51. This upper portion 160 slides within opening 161 provided in structural member 47. Upper portion 160 is provided with shoulder 162 and opening 161 is provided with shoulder 163 for support of spring member 164 which is also within opening 161. This spring member 164 causes return of plunger rod 141 and plunger 140 to their uppermost position as allowed by the positioning of bearing ring 51 or cam 156. Plunger 140 is attached to screw member 165 having head 166. This screw member lies within center opening 167 in upper portion 160. Downward motion of the screw member 165 and plunger 140 is limited by shoulder 168 on upper portion 160 which retains screw head 166. Within opening 167, above screw head 166, is high compression spring member 169. This spring member 169 is retained in position by and the compression can be adjusted by screw threaded member 170. Member 171 is a lock nut to retain plunger 140 in its position on screw member 167.

This type of construction for the plunger rod 141 is particularly advantageous when the pump is employed for the pumping of slurries. By definition, such slurries contain undissolved solid material. In some cases, the dimensions of these solid materials are substantial and, employing the plunger rod 41 of the first embodiment, there is danger of damaging one or more of the eccentrics 50, bearing ring 51, plunger rod 41, plunger 40, base plate 30, or, particularly, the exib'le, tubular member 5 when the plunger and plunger rod are depressed to pump fluid from the central, chamber portion of the flexible, tubular member. Only a solid connection is possible and, if the dimensions of the solid particles are greater than the clearance normally provided, then damage can result. With the modified construction of plunger rod 141, the possibility of such damage is ameliorated. The spring force of spring member 169 is sufiicient to normally provide an essentially solid connection between the eccentric surface or cam surface and plunger 140. However, if a piece of solid material of relatively large dimensions is contained within the central portion of iiexible, tubular member 5, then the spring 166 will compress and thus, effectively, shorten the stroke of plunger rod 141, thereby increasing the clearance between the plunger 140 and the base plate 30. Similar problems are not presented by the valve actuating members 103 and 14, due to the mounting of rocker plate 2 or 102 on pin `6 or 106, moving in an elongate slot such as 7. The extra dimension of the solid particle will merely cause the rocker plate to ride up, through action of the pin within the elongate slot.

To provide for accurate pumping of small quantities, such as drops or fractions of drops, backflow Within the flexible, tubular, member must be avoided. Backiiow is caused by opening of the outlet valve, before the start of pumping action by the plunger.

The cutouts provided in the base plate 30, the inner edges of which are in alignment with the valve actuating members, aid in minimizing backflow within the pump. The avoiding of backflow is necessary to provide for accurate pumping of minute quantities, such as drops or fractions of drops. With the cutout construction, the tube, as previously shown and described, falls partially through the cutouts. When the valve actuating member rises, the flexible, tubular member also moves up, to some degree, within this cutout and this avoids the sudden release of pressure common in most flexible tube pumps. However, backflow can be essentially eliminated by changing the phase relationship bet-Ween the outlet valve actuating member and the plunger. This can be accomplished by means of the structure shown in FIG. 11.

A rotatable post 180, having threadably mounted therein screw member 181 is provided on a modied rocker plate 202 to allow for changing of the relationship of rocker plate 202 with respect to bearing ring `51. The screw member is provided with lock nut 182. When the rotatable post is so located that screw member 181 is in a generally horizontal alignment, the screw member 181 can be advanced through the rotatable post 180 so as to displace surface 252 slightly from the surface of bearing ring 51. Thus, the actual contact between the rocker plate 202 and the bearing ring 51 is through the end of screw member 181. By varying the angle of rotatable post 180, and the advancement of screw member 181, the rocker plate 202 can be so angled that inlet valve actuating member 4 is raised further from the base plate, while placing outlet valve member 3 closer to the base plate. This adjustment also allows for correction of inaccuracies in the formation of rocker plate 202 or valve actuating members 3 and 4. Further, inaccuracies in base plate 30 can also be corrected by this adjustment, though, of course, the base plate 30 can be adjusted, itself, through screw members 31 and 32 and nuts 33, 34, 35 and 36. Such an arrangement is also advantageous for the pumping of viscous iiuids, Where a wider opening in the inlet valve is desirable to allow for filling of the central, chamber portion of flexible, tubular member 5 during the pumping cycle.

Employing a device as previously described with a flexible rubber tube having an internal diameter of about one-half inch, the pump device can deliver about 230 cc.s per minute with a 1/250 horsepower motor, at 70 revolutions per minute. Obviously, other tubing diameters, motors, and revolution rates can be employed.

Because of the construction of the device of the present invention, including the mounting of the rocker plate pin in an elongate slot, the entire operating mechanism of the device which comes in contact with the flexible, tubular member will move up or down, in response to differing tube wall thicknesses. Thus, the device of the present invention is far more adaptable than those of the prior art.

The portion of the flexible, tubular member lying beneath the valve actuating members are, in normal operation, never allowed to expand to more than about 20% of their full diameter. Thus, there is significantly less flexing of the tubular member employing the device of the present invention, which limits Wear on the tube.

In some applications, it may be desirable to allow for a controlled amount of creep of the flexible, tubular member. For example, this controlled creep would aid in avoiding wear on the flexible, tubular member, as the valve actuating members and plunger would strike different portions of the flexible, tubular member. The ability to angle the elongate slot in which the rocker plate pin rides provides the capability of controlling this creep. Thus, if desired, this elongate slot can be angled in a forward direction about 15 which would provide for about one-quarter inch of creep for each hours operation of the pump.

Thus, an improved device for acting upon a flexible, tubular member to provide a pumping action has been shown and described. These devices are superior to those of the prior art, both in operation and in ease and economy of construction.

What is claimed is:

1. A pump having for the chamber and valve members a flexible, tubular member, said member acted upon by a device comprising:

(a) a rocker plate having mounted thereon an inlet valve actuating member and an outlet valve actuating member;

(l) said rocker plate mounted on a pin slidable in a generally vertically disposed elongate slot,

(b) a plunger, disposed above the central portion of the flexible, tubular member which acts as the pump chamber,

(l) a rod for actuating said plunger;

(c) an eccentric acting upon said rocker plate for movement of the inlet valve actuating member and outlet valve actuating member, and on the plunger rod for actuation of the plunger;

(d) a base plate mounted below the plane of the inlet valve actuating member, outlet valve actuating member, and plunger, for supporting the flexible, tubular member.

2. The device of claim 1 wherein the eccentric is iournalled, through a bearing surface, into a bearing ring which makes contact with an upper surface of the rocker plate and with the plunger rod.

3. The device of claim 2 wherein the rocker plate is provided with two surfaces for direct contact with the bearing ring.

4. The device of claim 2 wherein adjustable means are provided, adjacent the contact surface of the rocker plate, to vary the relationship between the valve actuating member and the plunger.

5. The device of claim 2 wherein said plunger rod is formed in two sections, a lirst section contacted by said bearing ring and a second section connected to the plunger, the two sections being joined by a spring member.

`6. The device of claim 1 wherein said elongate slot is rotatable to vary the motion of the rocker plate.

7. The device of claim 1 wherein the base plate is provided With cutout portions to allow for depression of a portion of the exible, tubular member into a plane beneath that of the vbase plate, the edges of said cutout portions lying below the respective inlet valve actuating member and outlet valve actuating member.

8. The device of claim 1 wherein said eccentric is journalled within a lbearing ring and a cam member is attached to the face of said eccentric, the bearing ring acting upon an upper surface of the rocker plate and the cam acting upon the plunger rod.

9. The device of claim 1 wherein the rocker plate can be moved manually upward through motion of the pin within the elongate slot, through action of a lever, to allow for easier insertion of the flexible, tubular member.

10. The device of claim 1 wherein adjustable means are provided to vary the capacity of the pump, said means being adjustable during operation of the device to limit upward motion of the plunger.

11. The device of claim 1 wherein adjustable means are provided to vary the pressure of the pump output, said means comprising a spring member, the compression of which is adjustable during operation of the device, acting against the rocker plate.

12. A pump employing, as the chamber and valve members, a flexible, tubular member, and a device for acting upon said flexible, tubular member comprising:

(a) a rocker plate having mounted thereon an inlet valve actuating member and an outlet valve actuating member,

(1) said rocker plate mounted upon a pin located in an elongate slot,

(2) said elongate slot being rotatable;

(b) a plunger for contact with the chamber portion of said flexible, tubular member,

(1) a rod attached to said plunger for actuating said plunger,

(2) said rod being formed in two sections, a first upper section, and a second lower section attached to said plunger, said sections `being joined by a spring member;

(c) an eccentric journalled within a bearing ring,

(1) the surface of said bearing ring contacting an upper surface of said rocker plate and the upper section of said plunger rod;

(d) a base plate mounted below the plane of the inlet valve actuating member, outlet valve actuating member, and plunger,

(l) said base plate having cutout portions, the edges of said cutout portions lying directly below the respective inlet valve actuating member and outlet valve actuating member.

13. The device of claim 10 wherein means are provided to limit the travel of the plunger to control the volume output of the pump.

References Cited UNITED STATES PATENTS 1,988,624 1/1935 Kipp 103-148 2,393,838 l/1946 Tarbox 10S-148 2,412,397 12/1946 Harper 103-148 2,922,379 1/1960 Schultz 103-l48 3,359,910 12/1967 Latham 103-149 3,437,050 4/1969 Hrdina 103,-148

DONLEY I. STOCKING, Primary Examiner WLLBUR I. GOODLIN, Assistant Examiner U.S. Cl. X.R. 103-149

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