GB2211251A - Trigger-actuated elastomeric pump - Google Patents

Abstract

A trigger-actuated elastomeric pump employs slanting resilient partitions 34, 35 for one-way valving. The pump has a stop 28 formed in its interior at a location adjacent the downstream side of the inlet partition 34 and adapted to prevent the inlet partition from inverting during the pumping action, which would subsequently render the pump inoperative. Through the use of the stop, the pump can handle greater pressures without concurrent increase in likelihood of failure. <IMAGE>

Description

TRIGGER-ACTUATED ELASTOMERIC PUMP TECHNICAL FIELD This invention relates to an elastomeric pump and, more particularly, to a trigger-actuated elastomeric pump adapted to be mounted on the side of a blow-molded bottle.

BACKGROUND ART Humphrey U.S. Patents 3,575,949 and 3,648,902, issued respectively on April 20, 1971 and March 14, 1972, relate to a method and product involving an elastomeric pump which is incorporated into the side of a blow-molded bottle while it is formed. The elastomeric pump is actuated by the user's finger and utilizes slanting resilient partitions to provide one-way valving.

Humphrey U.S. Patent 3,486,663, issued December 30, 1969, concerns an elastomeric pump and check valve employing slanting resilient partitions for one-way valving in a pump adapted to be mounted on a container and operated by thumb or finger pressure to spray fluids.

Humphrey U.S. Patent 3,561,648, issued February 9, 1971, is directed to an elastomeric pump which incorporates a poppet-valve construction for establishing pressure thresholds determining fluid flow and slanting resilient partitions for one-way valving. The pump is operated by pressing the upstanding top wall to deform it.

Cooprider et al., U.S. Patent 3,995,774, issued December 7, 1976, teaches the structure of a dispensing pump of the deformable diaphragm type, wherein a trigger is employed to deform the domed portion of the diaphragm to reduce the volume of the pump chamber to force the liquid contents through a discharge nozzle. Flap valves are used to control unidirectional flow.

In elastomeric pumps using slanting resilient partitions, the angle, thickness and shape of the partitions can be varied to solve manufacturing problems, ameliorate pump sizing problems and, more importantly, to provide the desired performance characteristics of the pump. These characteristics can also be affected by the pressures applied by the user and the rapidity with which such pressures are applied. Thus, even though the partitions are properly designed to result in the pump operating in a desired manner, this does not necessarily mean that will happen because the operator can adversely impact on it. For example, it has been found that the use of trigger actuators in elastomeric pumps employing slanting resilient partitions can be troublesome and under some circumstances can cause the pump to perform at lower than design capacity or, in many cases, become inoperative.

DISCLOSURE OF THE INVENTION It is an object of this invention to obviate the above-described problem.

It is another object of the present invention to provide greater freedom in design of elastomeric pumps using slanting resilient partitions.

It is a further object of the present invention to provide a trigger-actuated elastomeric pump which uses slanting resilient partitions and which is not subject to loss of design capacity or inoperability due to inherent rapid rise of pressure therein effecting inversion of the inlet partition.

In accordance with one aspect of the present invention there is provided an elastomeric pump comprising a base member having an outer surface, an elastomeric member having a recessed portion with a peripheral rim seated on the surface and therewith defining a closed chamber, and spaced inlet and outlet passageways communicating with said chamber. A partition in the recessed portion has an edge resting resiliently across and against outer surface between the passageways to separate an inlet compartment from the rest of the chamber. The partition is attached through its periphery, except its edge, to the elastomeric member and defines an acute angle with the outer surface within the inlet compartment.A trigger is positioned outwardly of the elastomeric member in its unstressed condition and has an actuator thereon adapted to contact the elastomeric member to depress it to reduce the chamber volume when the trigger is moved inwardly. A stop projects outwardly from the outer surface and is located between the partition and the inlet passageway adjacent its edge when said elastomeric member is in its unstressed condition.

The stop is adapted to block inversion of the partition.

BRIEF DESCRIPTION OF THE DRAWINGS While the specification concludes with claims particularly pointing out and distinctly claiming the present invention, it is believed that the same will be better understood from the following description taken in conjunction with the accompanying drawings in which:: Figure 1 is a side elevational view of a bottle having an elastomeric pump of the present invention incorporated into one side; Figure 2 is an enlarged exploded perspective view of the various parts comprising the elastomeric pump illustrated in Figure 1; Figure 3 is an enlarged plan view of the inner side of the pump body illustrated in Figure 2; Figure 4 is a vertical sectional view of the pump body of Figure 3, taken along line 4-4; Figure 5 is an enlarged, fragmentary vertical cross-sectional view of the assembled pump and bottle of Figure 1, taken along the longitudinal central axis of the pump, and Figure 6 is an enlarged fragmentary vertical sectional view of the assembled bottle and pump, taken along its longitudinal central axis and showing the condition of the pump during the discharge phase of the pumping cycle.

DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings in detail, wherein like numerals indicate the same elements throughout the views, Figure 1 illustrates a bottle 10 having a pump 12 of the present invention incorporated into its sidewall. A closure 14 is applied to the neck at the top of bottle 10. The basic pump arrangement, operating principles and features and the manner in which the pump is incorporated into the bottle are fully described in the aforesaid Humphrey U.S. Patents 3,486,663, 3,561,648, 3,575,949 and 3,648,902, the disclosures of each of which are hereby incorporated herein by reference. The pump of this invention is an improvement to the referenced Humphrey pumps.

As shown in Figure 1, the subject invention is an elastomeric pump 12 which is actuated by a trigger 58. The pump itself is comprised of four parts which are shown in Figure 2, i.e. pump housing or base member 20, elastomeric pump body 30, pump frame 50 and nozzle 70. These preferably are designed to be assembled in a tight fitting telescoped relationship and the parts sealed in a manner which prevents leakage of the product being pumped.

The pump housing 20 has a depending, channel-defining dip tube 21, the outer side 21a of which is conformed to match the profile of the bottle into which it is to be incorporated. Preferably, it is injection molded and made of the same thermoplastic material as that of the bottle 10, such as various types of polyethylene,polypropylene or polyvinyl chloride. The inner side of the dip tube 21 is formed into an open, U-shaped channel which ultimately provides a tubular passageway 21b (see Figure 5) in the dip tube 21 following blow molding of the bottle 10, as described in the referenced '949 patent.

The U-shaped channel has a lower end which is sized so as to cause the bottle material to thin down and perforate in that area, due to the blow molding pressure, thereby automatically providing communication between the lower interior of the bottle 10 and the passageway 21b in dip tube 21. Such techniques are well known to those skilled in the art of blow molding.

The upper portion of the pump housing 20 (Figure 2) is a base member or plate 22, the outer surface 23 of which is generally planar. A peripheral wall 24 encloses outer surface 23 and integrally connects with dip tube 21. The passageway 21b (Figure 5), formed in dip tube 21 extends along the inner surface 23a for a short distance, where it terminates. An inlet passageway 25 extends through the plate 22 and interconnects with passageway 21b near its terminal end. A vent passageway 26 extends through the upper portion of plate 22 and, as will be noted in Figure 6, is axially aligned with cylindrical wall 26a projecting from inner surface 23a of plate 22. (Although vent 26 and cylindrical wall 26a are not aligned along the longitudinal central axis of the pump, they are sectioned as if they are, i.e. the section line in that area is offset to their mutual center line.) As was the case in establishing communication through the bottle wall to the dip tube passageway 21b, the wall 26a is sized to induce automatic perforation at passageway 26b through the bottle 10 wall as it is blow molded.Reinforcements 27 comprising two lines of spaced ribs shown in Figure 2 are designed to fit closely into the interior sidewalls of elastomeric pump body 30 to insure that its elastomeric partitions (hereinafter described) cannot be subjected to compressive forces which could cause the partitions to buckle inwardly and therefore leak. The gaps between the reinforcements 27 merely prevent interference in the positioning and functioning of transversely extending parts of the overlying pump body 30. A stop 28 projects outwardly from outer surface 23, serving a purpose which will be described fully hereinafter.

The elastomeric pump body 30 can be constructed of polymeric substances having suitable chemical and physical properties, such as Neoprene, flexible PVC or, preferably, thermoplastic rubbers, such as block co-polymer rubbers, as exemplified by Kraton G8230, a product of Shell Chemical Company of Houston, Texas, and which is described by the manufacturer as a styrene-ethylene/butylene-styrene block co-polymer. The elastomeric pump body 30 can be injection molded into the desired configuration. The hardness of such substances are preferably in the range of Shore "A" scale values of about 40 to about 80. As shown most clearly in Figures 3 and 4, the pump body has an upstanding hollow flexible bubble 31 which encloses a recessed portion 31a.A peripheral rim 32 has continuous pressure seal ribs 33 formed on its inner surface and a groove 32a formed in its outer surface. Various resilient partitions extend transversely across the pump body 30, intermediate the pressure seal ribs 33, each having a slightly arcuate (i.e. convex) distal edge and other edges which are attached to corresponding parts of the pump body 30.

The inlet partition or valve 34 is generally planar and is formed at an angle of about 550 to about 750, preferably, about 700, with the plane of the inner surface of the peripheral rim 32. The inlet partition 34, should be thin and flaccid enough to permit pump operation at high capacity and efficiency yet of sufficient strength and stiffness to prevent failure. For example, it can have a thickness in the range of from about 0.5 to about 0.85 mm (0.020 to about 0.035 inches) preferably .7 mm (.028 inches), when the elastomeric pump body 30 is made of Kraton 8230, the interior transverse dimension of the pump body 30 is about 2.381 mm (.375 inches) and the product being handled has a viscosity similar to that of water. For larger pumps, proportionately larger dimensions can be used.

The location of inlet partition 34 is adjacent the side of bubble 31 nearest the inlet passageway 25 of the pump housing 20 when the pump 12 is assembled. As will be noted from Figure 5, the inlet partition is adjacent the stop 28 following such assembly. On the opposite side of the bubble 31 is outlet partition or valve 35 which is generally planar and parallel to inlet partition 34. An arcuately configured poppet partition or valve 36 extends across the central area of a thinned circular shaped wall section 36a. It is oriented perpendicularly with respect to the inner surface of the peripheral rim 32 and is designed to establish a pressure threshold for operation, as described in the referenced Humphrey '648 patent, which is high enough to ensure the desired spray quality.

Sealing partition 37 is generally frustoconically shaped, is about twice the thickness of the inlet and outlet partitions 34, 35, and slants in a direction opposite thereto. Vent partition or seal 38 is generally planar, skewed to one side and inclined at about a 700 angle with the inner surface of the peripheral rim 32. A vent passageway 39 extends through the pump body 30 between the vent partition 38 and the adjacent wall of the peripheral rim 32.

In injection molding the elastomeric pump body 30, it has been found necessary to vent trapped air at the center of the distal edges of the partitions to prevent the formation of notches therein due to incomplete filling of the mold in that location. One way in which this can be done is to construct the mold core in two pieces, assembled at the center line of the pump body 30, and provide a narrow escape route therebetween at each partition, thereby permitting venting of the air but blocking flow of the elastomer.

Nozzle chamber housing 40 is located between poppet valve 36 and sealing partition 37, projecting outwardly, but having an openbottomed, frustoconically shaped reentrant collar 40a formed therein.

The pump frame 50 is shown most clearlyin Figures 2 and 6. It is preferably injection molded and made of materials similar to that used in pump housing 20. It has a peripheral, outwardly extending flange 51 with a continuous sealing bead 52 formed on its inner surface alongside an inwardly projecting flange 53 formed perpendicular to such inner surface and sized to telescope into groove 32a in the flange 32 of pump body 30. A nozzle stem 54, which is tubular and has a wall 54a across its outer end, extends through and is supported by the outer wall of the rectangular, generally parallelepipedally configured enclosure 55, with an inner portion or stub 56 cantilevered from the inner surface of enclosure 55. The wall 54a has a product exit hole 54b eccentrically located therein.

A nozzle snap ring 60 is formed concentrically with the nozzle stem 54 on the outer surface of enclosure 55.

An aperture 57 is formed through pump frame 50, sized and located so as to permit bubble 31 to telescope thereinto for assembly. The proximal end of trigger 58 is integrally formed with and hinged to (or otherwise cantilevered from) pump frame 50 intermediate enclosure 55 and aperture 57. An integrally molded plunger or actuator 59 projects from the inner side of trigger 58 in a location in alignment with bubble 31 in assembled condition. The actuator 59 can comprise one or two or more parallel, spaced walls or projections shaped to make good contact with the outer surface of bubble 31 when the trigger is pulled. Above the enclosure 55, a vent passageway 61 passes through the frame 50.

Where the pump frame 50 material flexural property is such as to make it undesirable for hinged attachment of the trigger 58, the trigger 58 can be radiused, as shown, to distribute flexural stresses over a length of the trigger to avoid cracking in use. The trigger 58 can be designed to permit actuation by a multiplicity of fingers, preferably two, of the user in order to obtain higher pressures for a better and finer spray.

Nozzle 70 is in the form of a hollow truncated pyramid with spray orifice 71 centrally located on its outermost wall 70a. A socket 72 projects inwardly from the inner face of wall 70a, enclosing the orifice 71 and being adapted to receive the outer end of nozzle stem 54 therein. A shallow land 70b raised on the inner face of wall 70a eccentrically of spray orifice 71 within socket 72 is arranged to press against and seal product exit hole 54b when the nozzle stem 54 is within socket 72 and the nozzle is properly positioned with the land aligned with the exit hole 54b. Beads 73 are formed on the interior edges at the inner (larger) end of the nozzle 70 and these are designed to facilitate the snap engagement of nozzle 70 onto nozzle snap ring 60.The nozzle 70 is therefore adapted to be selectively rotated on stem 54 into a position with the exit hole 54b either blocked or open, as desired. Indicia (not shown) on the nozzle 70 can be used to indicate the proper orientation thereof for either option.

The pump 12 is assembled-by inserting pump body 30 within the inner side of pump frame 50, with the bubble 31 extending through aperture 57, the nozzle chamber housing 40 within enclosure 55 and stub 56 of nozzle stem 54 telescoped within reentrant collar 40a. As mentioned previously, the inwardly projecting flange 53 is received in groove 32a in the flange 32 of pump body 30.

Next, the pump body 30/pump frame 50 assembly is pressed onto the pump housing 20, with the peripheral rim 32 of the pump body 30 received within peripheral wall 24. The manner in which the various parts fit together is shown most clearly in Figures 5 and 6. At this point, the outer edge 24a of peripheral wall 24 of the pump housing 20 is adjacent the continuous sealing bead 52 and the inner surface of flange 51 of the pump frame 50 and these adjacent parts are joined by ultrasonic welding in a manner well known to those of ordinary skill in the art.

The assembled and welded pump 12 is then incorporated into a blow molded bottle in the manner described in the referenced Humphrey '949 patent, resulting in the spray bottle assembly depicted in Figure 1 when it is filled and the closure 14 applied. The spray bottle pump can be said to comprise several functional areas. Inlet partition 34 defines an inlet compartment or chamber 34a, shown in Figure 5 and 6, which communicates with the bottle 10 interior through inlet passageway 25 and passageway 21b formed in dip tube 21.

Outlet partition 35 separates an outlet compartment 35a (Figure 6) from pump compartment 31a', which is the interior volume of the pump between partitions 34 and 35. Poppet partition 36 lies intermediate the outlet compartment 35a and spray compartment 36b, thereby establishing the pressure threshold for spraying of product through spray compartment 36b, the interior of nozzle stem 54 and product exit 54b. Thus, the chamber comprising inlet compartment 34a, outlet compartment 35a, pump compartment 31a' and spray compartment 36b, i.e. the interior volume for entire elastomeric pump body 30 when it is pressed into sealing engagement with outer surface 23 of pump housing, is divided into various compartments adapted to perform the pumping/spraying function desired.

The pumping/spraying function is illustrated in Figure 6, wherein it will be noted that the trigger 58 has been moved inwardly, causing the actuator to press against flexible bubble 31, deforming it inwardly to reduce the volume of the pump compartment 31a' and increasing the pressure of the contents thereof. The pressure increase forces the inlet partition 34 downwardly to a position in which the distal edge of the inlet partition 34 seals against the surface 23 of the pump housing 20 and the upstream side 24b moves into contact with stop 28.

The design of the partition 34 is such as to facilitate the supply of product from the bottle to the pump compartment 31a', as will be understood from subsequent description and from the aforesaid referenced Humphrey patents, and consequently is desirably as thin and flaccid as possible consistent with good pump performance. If the partition 34, however, is too thin and flaccid, the high pump pressures which can be induced by the leveraged trigger would, in the absence of stop 28, cause the partition 34 adjacent its convex edge to invert so as to slant in the reverse direction within inlet chamber 34a (i.e. would form an obtuse angle with surface 23). In doing so, the center of the convex edge of partition 34, moves beyond the projected centerline of partition 34 (i.e. an imaginary line on the surface 23 along which the edge would fall if it had been straight instead of convex).This inverted condition would prevent subsequent product pumping action since it would seal the pump from the product supply during the intake phase of the pumping cycle.

Inversion can be prevented by strengthening the partition 34, but this would have the propensity to restrict inflow of product, thus limiting pump and spray capacity and, possibly, necessitating the use of springs to assist in pump compartment 31a' expansion in the intake phase. This kind of redesign is expensive and can be obviated, as is accomplished by use of the present invention, through the use of the stop 28. This physical obstruction to inversion beyond the projected centerline described hereinabove permits the use of efficiently designed partitions 34 in trigger-equipped pumps without the downside risk of pump malfunction.

As the pressure in the pump compartment 31a' increases, outlet partition 35 is deflected downstream, lifting its distal edge from surface 23 to form an outlet passageway and forcing product into outlet compartment 35a. The pressure in compartment 35a, in turn, increases until it reaches the level at which poppet valve 36 is forced upwardly, forcing product into spray compartment 36b and, thereafter, into the passageway through nozzle stem 54, through product exit 54b and, subsequently, out nozzle orifice 71.

When the trigger 58 is released, the resilience of bubble 31 moves the trigger 58 outwardly as it seeks to reestablish its initial unstressed volume and concurrently causes the pressure in pump compartment 31a' to decrease. As this occurs, poppet valve 36 reseats and outlet partition 35 seals against surface 23. When the pressure in the pump compartment 31a' is reduced below that in the inlet compartment 34a, the inlet partition 34 deflects upstream, permitting inflow of product until the pressures on each side of the partition 34 are approximately equal. The bottle interior is vented by ambient air moving through vent passageways 61, 39 and 26, flowing under vent partition 38 in the process. Thus, the bottle interior is maintained at approximately atmospheric pressure.

The operation described above assumes that air in the pump initially has been displaced by product during the initial pumping operation. Any trapped air in the pump would be compressible and its presence would interfere with the efficient dispensing of product.

Having shown and described the preferred embodiment of the present invention, further adaptions of the trigger-actuated elastomeric pump described herein can be accomplished by appropriate modifications by one of ordinary skill in the art without departing from the scope of the present invention. Accordingly, the scope of the present invention should be considered in terms of the following claims, and is understood not to be limited to the details of structure and operation shown and described in the specification and drawings.

Claims (5)

We claim:

1. An elastomeric pump comprising a base member having an outer surface, an elastomeric member having a recessed portion with a peripheral rim seated on said surface and therewith defining a chamber, spaced inlet and outlet passageways communicating with said chamber, a partition in said recessed portion having an edge resting resiliently across and against said surface between the passageways to separate an inlet compartment from an adjacent portion of the chamber constituting a pump compartment, said partition being attached throughout its periphery except said edge to the elastomeric member and defining an acute angle with the said surface within the inlet compartment, a trigger positioned outwardly of said elastomeric member and having an actuator thereon adapted to contact the elastomeric member to depress it to reduce the pump compartment volume when the trigger is moved inwardly and a stop projecting outwardly from said surface and located between said partition and said inlet passageway adjacent said edge when said elastomeric member is in its unstressed condition, said stop being adapted to block inversion of said partition.

2. The elastomeric pump of Claim 1 in which said elastomeric member is located intermediate the base member and a pump frame made of thermoplastic material, the proximal end of said trigger being integrally attached to said pump frame.

3. The elastomeric pump of Claims 1 or 2 in which said elastomeric member is made of a thermoplastic rubber.

4. The elastomeric pump of Claim 3 in which the acute angle between the partition and the surface in the inlet compartment lies in the range of from about 550 to about 750 and wherein the partition has a thickness of about .5 to about .85 mm.

5. The elastomeric pump of Claims 1 or 2 in which the edge of said partition is convex and wherein the stop is positioned to prevent the center of the edge of the partition from moving beyond its projected centerline on the said surface to form an obtuse angle therewith in said inlet compartment.