DE69411919T2 - COMPRESSIBLE PUMP CHAMBER WITH A SPECIFIC FOLDABLE PATTERN - Google Patents

Abstract

A liquid dispensing pump (20) for use with consumer product packages is provided with a shipping seal. The housing of the pump device includes an upper housing (24) and a lower housing (26) which are movable relative to each other between open and closed shipping seal positions. The liquid dispensing pump (20) includes a collapsible pump chamber (40), e.g. a bellows. Integral with the bellows (40) is at least one functional element of the shipping seal. The housing includes cooperating actuation elements which prevent actuation of the pump device when the shipping seal is closed. The housing may also include a tamper evident device which prevents actuation of the pump device prior to removal of the tamper evident tab; and may prevent movement of the housing from the closed shipping seal position to the open shipping seal position prior to removal thereof. The bellows (40) may also include an integral valve including a valve member, a valve seat and a valve opening which are all integral components of a wall of the collapsible pump chamber (40), the valve seat facing one side of the wall and the valve member being formed at an angle away from the other side of the wall so that upon pushing the valve member through the valve opening the valve member is biased against the valve seat.

Description

BACKGROUND OF THE INVENTION 1. Field of invention

The present invention relates to hand-squeezable pump chambers for use with liquid dispensing pump devices for consumer products.

The known liquid dispensing pump devices for use with consumer product containers are numerous and varied. Such dispensing pumps can be used to dispense liquids, for example, as a foam, spray or liquid stream (e.g., as in moisturizing lotions). Typically, such liquid dispensing pump devices utilize a piston and a cylinder pump chamber. Such pump chambers require that a liquid-tight movable seal be provided between the piston and the cylinder. There are generally disadvantages associated with this requirement for a liquid-tight seal. For example, a relatively large amount of friction is generated when the piston moves against the cylinder, since these parts must fit tightly together to form the seal. Additionally, or alternatively, the parts themselves must be manufactured within close tolerances so that the parts fit together precisely to form the seal. In addition, the wear caused by friction can attack the seal over time, reducing the performance of the pump. Furthermore, these piston and cylinder dispensing devices have been designed without significant effort to reduce the number of parts and overall cost.

Partly in response to the disadvantages of piston and cylinder pumps, various liquid dispenser pumping devices have been developed which use pumping chambers with collapsible walls. For example, balloon-type pumping chambers have been used. More widely used have been flexible elastic bellows as collapsible pumping chambers in liquid dispenser pumping devices. Such bellows pumps allow the pumping chamber to expand and contract in volume without the disadvantages associated with the movable seals used in piston and cylinder pumps. pens are necessary. Furthermore, the bellows can replace the piston, cylinder and springs, thereby reducing the molding and assembly costs. US-A-4 336 895, which represents the prior art to which the preambles of claims 1 and 4 refer, relates to a pump assembly which is actuated by a finger. However, these known liquid dispenser pumping devices do not offer all of the advantages of the invention described here.

Summary of the invention

According to one aspect of the present invention, there is provided a collapsible pumping chamber for use in a manually operated liquid dispenser pumping device as defined by claim 1. The collapsible pumping chamber includes a folded annular side wall defining an interior volume region of the pumping chamber. Furthermore, the folded annular side wall has a structure adapted to be folded in a predetermined pattern upon actuation of the pumping device. The predetermined folding pattern results in an initial relatively small volume change of the interior volume region for a predetermined stroke length, followed by an increased volume change of the interior volume region for a predetermined stroke length.

According to a further aspect of the present invention there is provided a manually operated liquid dispensing device as defined by claim 4.

Short description of the drawings

While the specification concludes with claims particularly describing and specifically claiming the present invention, it is believed that the present invention will be better understood from the following description taken in conjunction with the following accompanying drawings:

Fig. 1 is an expanded top perspective view of a specific preferred embodiment of a hand-assembled human-operable pumping chamber for use in a liquid dispenser pumping device according to the present invention;

Fig. 2 is an expanded bottom perspective view of the hand-collapsible pump chamber and the fluid dispenser pump of Fig. 1;

Fig. 3 is a cross-sectional view taken along the centerline of the assembled liquid dispenser pump assembly of Figs. 1 and 2 (with the pusher locking tab intact and the transport seal closed);

Fig. 4 is a cross-section similar to Fig. 3 with the pusher locking tab removed and the transport seal open;

Fig. 5 is, similar to Fig. 3, a cross-section of the pump of Fig. 1 in operation during the downstroke while the collapsible pumping chamber is being collapsed;

Fig. 6 is, similar to Fig. 3, a cross-section of the pump of Fig. 1 in operation during the downstroke as the collapsible pumping chamber expands;

Fig. 7 is, similar to Fig. 3, a cross-section through another collapsible pumping chamber not forming part of the present invention and capable of pumping relatively large volumes in another liquid dispenser pumping device representing the prior art;

Fig. 8 is, similar to Fig. 3, a cross-section of the collapsible pumping chamber of Fig. 7 in the liquid dispenser pumping device of Fig. 1.

Detailed description of the invention

In the specific preferred embodiment shown in Fig. 1, the present invention includes a manually collapsible pumping chamber 40 for use in a liquid dispensing pumping device, generally indicated at 20. This dispensing pumping device 20 is particularly useful in conjunction with a liquid product reservoir 22 (partially seen in Fig. 3). The illustrated liquid dispensing pump 20 generally comprises an upper housing 24, a lower housing 26, an outlet valve member 30, an inlet valve member 34, a dip tube 38 and a collapsible pumping chamber 40.

The term "collapsible pumping chamber" as used herein refers to a pumping chamber formed at least in part by a flexible wall which moves in response to a manually applied compressive force in such a manner as to reduce the volume within the pumping chamber without sliding friction between the parts forming the pumping chamber. Such collapsible pumping chambers may comprise balloon-like membranes and bladders made from elastomeric materials such as thermoplastic elastomers, elastomeric thermosets (including rubber) or the like. For example, the collapsible pumping chamber may comprise, in a manner not shown, a metal or plastic coil spring surrounding (or being enveloped by) a resilient material to form an enclosed pumping chamber. However, the preferred collapsible pumping chamber shown is a bellows 40, i.e., a substantially cylindrical, hollow structure with accordion-like walls. For example, bellows are preferred because they can be made elastic so that they behave like a spring, eliminating the need for a spring. Furthermore, the collapsible pumping chamber can be designed to fold in accordance with a predetermined pattern. In addition, the manually collapsible pumping chamber includes additional integral components. The term "integral" as used herein is defined as molded or otherwise formed into a single, unitary part.

As can be seen in Fig. 3, the upper housing 24 is fitted onto the lower housing 26 and is held together by the interaction between an annular by a collar 25 and an annular rib 27. The lower housing 26 includes screw threads 28 which act to seal the pumping device 20 to the container 22. Alternatively, the lower housing may include a bayonet-type mounting structure (not shown) such as that described in U.S. Patent 4,781,311 issued to Dunning et al. on November 1, 1988 or U.S. Patent 3,910,444 issued to Foster on October 7, 1975.

The lower housing 26 also includes an inlet channel 42 with an internal conical inlet valve seat 35 which cooperates with the inlet valve member 34 to form the inlet valve 34 and 35. The lower housing 26 also includes three equally spaced retaining tabs 36 which hold the inlet valve member 34 during operation of the pumping device 20, as will be explained later. Alternatively, a ball valve (not shown) may be used. The lower housing 26 also includes a vent opening 37, three equally spaced release pins 44, an engagement pin 45 and three equally spaced anti-rotation pins 46. A dip tube 38 is fitted onto the inlet channel 42 of the lower housing 26 and extends downwards into the container. 22 extends.

The upper housing 24 includes an outlet channel 48 which opens into a dispensing opening 50. An inner cylindrical wall 52 is disposed within the upper housing 24 at an angle to and connected to the outlet channel 48. As seen in Figure 2, the upper housing 24 also includes a collar 25 having three equally spaced actuation channels 54, three stops 56, three pairs of tactile pins 58, a projection 60 and a removable trigger locking tab 62. The term "trigger locking tab" as used herein defines a lock that ensures that the pump has been previously actuated; this does not necessarily mean that the product has not already been tampered with (since the entire pumping device can be unscrewed and replaced). A pressure safety feature in this sense is important because it prevents a sample from being taken from the product on the store shelf. In addition, the housing 24, 26 may include a known pressure safety feature (not shown) to indicate that the pumping device 20 has been removed from the container 22.

There passes through the housing 24, 26 a fluid passage defined by various parts, namely the dip tube 38, the inlet passage 42 of the lower housing 26, the outlet passage 48 of the upper housing 24 and the collapsible pump chamber 40. The fluid passage provides fluid communication from the distal end of the dip tube 38 within the reservoir 22 downstream to the dispensing opening. The term "downstream" as used herein is defined as the direction from the reservoir 22 to the dispensing opening 50 and "upstream" is defined as the direction from the dispensing opening 50 to the reservoir 22. Similarly, the term "inlet end" as used herein means the upstream facing end; and the term "outlet end" means the downstream facing end.

A portion of this fluid passage is defined by the collapsible pumping chamber 40. The collapsible pumping chamber 40 has a structure that is flexible in such a way that it can be manually compressed; in this way, the volume within the collapsible pumping chamber 40 is reduced. Although a spring (not visible) may be used to assist the collapsible pumping chamber 40 in returning to its original shape, the collapsible pumping chamber 40 is preferably sufficiently resilient so that it returns to its original shape when the manually applied compressive force is released.

The collapsible pumping chamber is a bellows 40 having a structure that ensures that the bellows 40 collapses according to a predetermined pattern. In general, the bellows 40 preferably has several properties. For example, the bellows 40 should allow easy actuation of the pumping device. In general, this means that it has a spring force of about 3 to 5 pounds. The bellows 40 should therefore have good resilience with minimal hysteresis and creep. Furthermore, the bellows 40 should preferably have good radial stiffness (ring strength) to ensure that the bellows 40 does not radially deform under normal operating conditions. Finally, the bellows 40 should preferably have good volumetric efficiency; i.e., the change in internal volume divided by the total expanded internal volume.

Some geometric features that can be used to give the bellows 40 the appropriate properties relate to the diameter of the bellows 40. The larger the diameter, the smaller the spring force and the smaller the radial stiffness. Although a smaller spring force is generally desirable, a smaller radial stiffness can be a problem; e.g., the bellows 40 can bulge in a pre-compression pressure sprayer. By increasing the wall thickness of the folds, the radial stiffness will increase, but the spring force will be increased, resulting in a decreased volumetric efficiency of the bellows. Decreasing the fold angle will generally decrease the spring force but decrease the volumetric efficiency. The fold angle is the sum of two angles; the angle above a line perpendicular to the axis and through the origin of the fold, and the angle below that line. Preferably, the fold angle above the vertical line is about 30º and the fold angle below the vertical line is about 45º (which makes removal of the bellows from the core pin easier). Increasing the number of folds will decrease the spring force and reduce the volumetric efficiency.

Although this statement is not to be taken as binding, it appears that the more important properties for spring force are the wall thickness and the upper and lower fold angles, while the most important property for resilience is the choice of material. Consequently, one way to provide the bellows with regions that will fold first (such as the smaller diameter regions of the illustrated bellows 40) is to use thinner walls and more acute fold angles in those regions. As can be seen in Fig. 3, the side wall of the illustrated bellows 40 actually gets gradually thinner from bottom to top. Similarly, the fold angles become increasingly acute. The bellows 40 will therefore begin to fold at its upper end and deliver a relatively small volume; thus providing good control for small doses. As the actuation of the pumping device 20 is continued, assuming a constant actuation speed, the flow rate will gradually increase.

In addition, the choice of material can be helpful in providing the bellows 40 with the desired properties. In general, the material rial preferably has a modulus of elasticity of less than 10,000 psi. For lotion pumps, a modulus of elasticity of less than 3,000 psi is preferred. The material should be able to retain its mechanical properties, be dimensionally stable and resistant to stress cracking. These properties should be maintained over time in air and in the presence of the liquid product. For pressure sprayers, which generally spray acidic or alkaline cleaning products that contain a significant amount of water, the material should therefore not be pH sensitive and should not be subject to hydrolysis. For example, such materials include polyolefins such as polypropylene, low density polyethylene, very low density polyethylene or ethylene vinyl acetate. Other materials to be used include thermosets (e.g. rubber) and thermoplastic elastomers. For pressure sprayers, ethylene vinyl acetate with a high molecular weight and a vinyl acetate content between 10 and 20% is usually preferred. For other pumps (e.g. lotion pumps), pH and hydrolysis are not important. Instead, a low spring force with a high elasticity is more important. In such cases, ethylene vinyl acetate with a small modulus or polyethylene with a very low density are preferred.

The inlet end of the manually compressible pump chamber 40 is placed on the essentially cylindrical inner wall of the lower housing 26. During installation, three equally spaced notches 47 on the inlet end of the bellows 40 engage the three anti-rotation pins 46 of the lower housing 26. The collapsible pump chamber 40 has a molded, annularly expanded flange 64 in the area of its inlet end. This flange 64 seals against the inner surface of the lower housing 26, so that a vent valve 26, 64 is formed. The vent valve 26, 54 thus comprises the flange 64, which acts as a valve member, and the housing 26, which forms the valve seat.

Similarly, the outlet end of the collapsible pumping chamber 40 is clip-mounted to the inner cylindrical wall 52 of the upper housing 24. The outlet end of the collapsible pumping chamber 40 includes an elongated channel 66 with an integral outlet valve seat 32 which cooperates with the outlet valve member 30 to form the outlet valve 30,32. The elongated channel 66 also includes an integral outlet opening 68.

The inlet valve member 34, 35 and an outlet valve member 30, 32 are arranged within the fluid channel. These valves may be of a type known in the art, including duckbill valves, ball or ring valves or the like. Preferably, the outlet valve member 30 is a light ball or ring valve member providing for back suction, as will be explained later.

As can be seen in Fig. 3, the liquid dispenser pump 20 is in the closed position. In this position, the outlet opening 68 of the bellows 40 is displaced relative to the outlet channel 48 so that a liquid-tight transport seal is formed. The transport seal comprises several functional elements, e.g. the outlet opening 68 and the cylindrical wall 52 which can be moved relative to the latter so that the outlet opening 68 is sealed. In this way, the liquid channel formed by the dip tube 38, the inlet channel 42 of the lower housing 26, the bellows 40 and the outlet channel 48 of the upper housing 24 is tightly closed so that a transport seal is formed.

In addition, the trigger pins 44 are offset from the actuation channels 54 so that actuation of the pumping device 20 is prevented when the transport seal is closed. Without this feature, an increase in pressure within the collapsible pressure chamber 40 could be caused by an attempt to actuate the pumping device 20 when the transport seal is closed, which could damage the collapsible pumping chamber 40. In the closed position, one side of the upper end of each trigger pin 44 is located at one end of a respective stop 56. The other side of the respective trigger pin 44 abuts one of the sensing pins 58. Furthermore, the pusher locking tab 62 extends substantially horizontally from the upper housing 24 over the upper end of the lower housing 26. The pusher locking tab 62 shown includes a slot 63 which cooperates with the locking pin 45 so that rotation of the upper housing 24 relative to the lower housing 26 is prevented. In this way, the transport seal cannot be opened without removing the pusher locking tab 62. Furthermore, the pump device 20 cannot be operated without removing the pusher locking tab 62.

As seen in Figure 4, the liquid dispenser pump 20 is in the open position. The upper housing can be rotated relative to the lower housing 26 from the closed position to the open position once the pusher locking tab 62 has been removed. The pusher locking tab 62 is removed by simply rotating it upward. This rotation causes the projection 60 to contact the pusher locking tab 62, thus exerting a force that pushes the tab 62 away from the upper housing 24. This force causes the tab 62 to be torn away from the upper housing 24 along the thinned connection between the tab 62 and the upper housing 24. In this way, continued rotation of the tab 62 will cause the trigger locking tab 62 to break off if the tab 62 is rotated to a point where the locking slot 63 and locking pin 45 are disengaged from each other due to this force. As a result, the shipping seal cannot be opened until the trigger locking tab 62 is broken off. Needless to say, this prevents sampling of the liquid product from the store shelf by actuating the pumping device 20 without leaving traces of such sampling.

As the upper housing 24 is rotated, each trigger pin 44 moves from a position against a stop 56 to a position 90º away against the adjacent stop 56. During rotation, each trigger pin 44 moves against the sensing pins 58 which produce a tactile and/or audible signal indicating that the transport seal of the dispenser pump assembly 20 is being moved first to the closed position and second to the open position. The sensing pins 58 also assist in maintaining the pump assembly 20 in the open or closed position by cooperating with the trigger pins 44.

As shown in Fig. 4, the trigger pins 44 are aligned with the actuating channels 54 in the open position. Furthermore, the molded dispensing opening 68 is aligned with the outlet channel 48, thereby opening the fluid channel. When the upper housing 24 is rotated relative to the lower housing 26, the upper housing 24 is also rotated relative to the bellows 40. The bellows 40 remains in the open position due in part to the interaction between the notches 70 at the inlet end of the bellows 40 and the rotation-locking ribs 46 of the lower housing 26 is stationary relative to the lower housing 26. In contrast, the extended channel 66 of the bellows 40 rotates within the cylindrical wall 52 of the upper housing 24 until the outlet opening 58 is aligned with the outlet channel 48.

Once the pumping device is in the open position as shown in Fig. 5, it is ready for manual operation. Manual operation of the pumping device 20 is achieved by axial up and down movement of the upper housing 24 relative to the lower housing 26. As this up and down movement is performed, the actuating pins 44 slide within the actuating channels 54. During the downward movement of this up and down movement, the inlet valve member 34 is sealed against the inlet valve seat 35. This causes an increase in pressure within the collapsible pumping chamber 40, which causes the outlet valve member 30 to act to move away from the outlet valve seat 32, thereby opening the outlet valve 30, 32. As a result, the fluid within the reducing volume of the collapsible pumping chamber 40 is discharged through the molded outlet opening 68 and the outlet channel 48. As the fluid is discharged, it causes an upward force on the outlet valve member 30 which moves the outlet valve member 30 toward the remote end of the molded, elongated channel 66.

As can be seen in Fig. 5, the bellows 40 will begin to collapse at its upper end with the thinner wall and sharper folding angles. This region of the bellows 40 (i.e. its upper end) will have a progressively larger diameter towards its lower end. As a result, the initial collapse will result in a relatively small and gradually increasing volume of liquid being dispensed initially for a given stroke length. Therefore, if a small amount is required, this bellows will provide good control during the initial actuation. Should a larger amount be required, continued actuation of the bellows will result in a larger volume of product being dispensed for a given stroke length, thereby increasing the flow rate.

When the pressure applied by hand is released, the bellows 40 begins to expand due to its elasticity. Optionally, a spring (not visible) may be added to replace or supplement the elasticity of the bellows 40. This expansion creates a negative pressure (i.e., below atmospheric pressure) within the collapsible pumping chamber 40. As a result, atmospheric pressure forces the fluid in the outlet channel 48 back into the bellows 40 (at least for relatively viscous fluids) until the outlet valve member 30 reseals the outlet valve seat 32, thereby closing the outlet valve 30,32. Of course, the longer the integral extended channel 66, the more time the valve member 30 needs to seal and the more fluid is sucked back into the bellows 40. Such sucking back is desirable because it helps to keep the outlet channel clear between operations.

Once the outlet valve 30,32 is closed, as shown in Fig. 6, the negative pressure within the bellows 40 that is created as the bellows 40 continues to expand causes the inlet valve member 34 to move away from the inlet valve seat 35, thereby opening the inlet valve 34,35. The inlet valve member 34 is prevented from moving too far away from the inlet valve seat 35 by the three retaining tabs 36. In this way, liquid is drawn from the container 22 through the dip tube 38 and through the inlet valve 34,35 into the bellows 40. At the same time, air can enter the container 22, replacing the volume of liquid exiting the container 22 by flowing along the piston sleeve of the vent valve member 64, which is designed as an annular flange, and the vent valve seat 26 through the vent opening 37 into the container 22.

Referring to Fig. 7, there is provided an embodiment of a bulk dispensing pump assembly according to the present invention, designated overall at 120. This pump assembly 120 is substantially identical to the previously seen pump assembly 20. However, the lower housing 126 extends into the container 122 to allow for a bellows 140 of increased length. The pusher locking tab 162 is mounted on the lower housing 126 rather than on the upper housing 124. Although the pusher locking tab 162 does not prevent rotation of the pump assembly 120 between the open and closed transport seal positions, it does prevent actuation of the pump assembly 120 in the open transport seal position by engaging the nozzle surrounding the outlet channel 148. The operation of this pump assembly 120 is substantially identical to that previously discussed with respect to the preceding pumping device 20.

The diameter of the bellows 140 is constant. However, the bellows 140 has a thin wall portion at its upper end and a relatively thick wall portion at its lower end. In addition, the folding angles at the upper end are more acute than the folding angles in the thicker wall portion. As a result, the upper end of this bellows 140 will fold first, and then the lower end of this bellows 140 will fold. Since the diameter does not change substantially, the volume of liquid delivered for a given stroke length is substantially constant during compression. However, as can be seen in Fig. 8, this bellows is also suitable for use with the pumping device of Fig. 1.

Although specific embodiments of the present invention have been illustrated and described, variations may be made within the scope of the appended claims. For example, the liquid may be dispensed by a simple liquid stream (as in a lotion pump) where the nozzle is an open channel, or as a foam where air is mixed with the liquid (e.g., by using a venturi nozzle) on or near a foam forming device (e.g., a disk or stationary mixer). Accordingly, the present invention encompasses all embodiments within the scope of the appended claims.

Claims (4)

1. A collapsible pumping chamber (40) for use in a manually operated liquid dispenser pumping device (20), having an annular folded side wall defining an internal volume region of the pumping chamber and having a structure designed to fold in a predetermined pattern upon actuation of the pumping device, characterized in that the predetermined folding pattern results in an initially relatively small volume change of the internal volume region for a predetermined stroke length, followed by an increased volume change of the internal volume region for a predetermined stroke length. 2. A collapsible pumping chamber (40) according to claim 1, characterized in that the folded annular side wall has a thickness and that changes in the thickness of the folded annular side wall form a region of the structure which causes the side wall to collapse in the predetermined pattern when the pumping device is actuated. 3. A collapsible pumping chamber (40) according to one of claims 1 or 2, characterized in that the side wall has a fold angle and changes in the fold angle of the folded annular side wall form a region of the structure which causes collapsing of the side wall in the predetermined pattern when the pumping device is actuated. 4. Manually operated dispenser pump device (20) for pumping a liquid from a storage container and for dispensing the liquid through an outlet opening, with (a) a housing (26) for sealingly mounting the dispenser pumping device on the reservoir, the housing including a portion of a fluid channel (38, 42, 48, 40) allowing fluid to flow from the reservoir downstream to the outlet opening; (b) an inlet valve (34, 35) arranged within the liquid channel, which inlet valve is closed to block the liquid flow during phases with positive pressure downstream and is open during phases with negative pressure downstream; (c) an outlet valve (30, 32) arranged within the liquid channel, which outlet valve is open to allow a liquid flow to pass through during phases of positive pressure upstream and is closed during phases of negative pressure upstream; and (d) a collapsible pumping chamber defining a portion of the fluid passage downstream of the inlet valve and upstream of the outlet valve, the collapsible pumping chamber having a collapsible side wall defining a region of the pumping chamber and having a structure adapted to fold in a predetermined pattern upon actuation of the pumping device, characterized in that the side wall defines an internal volume region of the pumping chamber and has a structure adapted to fold in a predetermined pattern upon actuation of the pumping device, the predetermined folding pattern resulting in an initially relatively small volume change of the internal volume region for a predetermined stroke length, followed by an increased volume change of the internal volume region per predetermined stroke length.