Collapsible pump chamber having predetermined collapsing pattern

A collapsible pump chamber, e.g., a bellows, for use with a liquid dispensing pump device is provided. The collapsible pump chamber includes a collapsing side wall which defines an internal volumetric portion of the pump chamber. The collapsing side wall has a structure which collapses in a predetermined pattern as the pump device is actuated. For example, the predetermined pattern of collapse could result in an initially relatively small volumetric change in internal volume per given stroke length followed by an increased volumetric change in internal volume per given stroke length. Thus, the pump device would initially provide very good control over the amount of product is dispensed; giving precise control during a partial actuation. However, the same pump device would also be capable of delivering a large volume of product during a complete actuation.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to manually compressible pump chambers for 
use with consumer product liquid dispensing pump devices. 
2. Description of the Prior Art 
Known liquid dispensing pump devices for use with consumer product 
containers are many and varied. Such dispensing pumps may be utilized to 
deliver liquids as a foam, a spray, or a liquid stream (e.g., as with 
moisturizing lotions), for example. Most commonly, such liquid dispensing 
pump devices utilize a piston and cylinder pump chamber. Such pump 
chambers require that a liquid tight moving seal be maintained between the 
piston and the cylinder. Disadvantages are commonly associated with this 
liquid tight seal requirement. For example, a relatively large amount of 
friction is generated as the piston moves against the cylinder, since 
these parts must fit tightly to form the seal. Additionally or 
alternatively, the parts themselves must be manufactured within tight 
tolerances such that the parts fit correctly to form the seal. Moreover, 
the wear caused by the friction can deteriorate this seal over time, 
reducing the efficiency of the pump. Furthermore, these piston and 
cylinder dispensing devices have generally been designed without 
significant effort to reduce the number of parts and overall cost. 
Partially in response to some of the disadvantages of piston and 
cylinder-type pumps, several liquid dispensing pump devices have been 
developed which utilize pump chambers with collapsible walls. For example, 
balloon type pump chambers have been utilized. More commonly, flexible, 
resilient bellows have been utilized as collapsible pump chambers in 
liquid dispensing pump devices. Such bellows-type pumps permit the pump 
chamber to expand and contract in volume without the disadvantages 
associated with the moving seal required in piston and cylinder pumps. 
Furthermore, the bellows can replace the piston, the cylinder and the 
spring; thereby reducing molding and assembly costs. These prior liquid 
dispensing pump devices, however, do not offer all of the advantages of 
the invention described herein. 
SUMMARY OF THE INVENTION 
In accordance with one aspect of the present invention a collapsible pump 
chamber for use in a manually actuated liquid dispensing pump device is 
provided. The collapsible pump chamber includes a pleated annular side 
wall defining an internal volumetric portion of the pump chamber. 
Moreover, the pleated annular side wall has a structure adapted to 
collapse in a predetermined pattern as the pump device is actuated. 
Preferably, the predetermined pattern of collapse results in an initially 
relatively small volumetric change in the internal volumetric portion per 
given stroke length followed by an increased volumetric change in the 
internal volumetric portion per given stroke length. 
In accordance with another aspect of the present invention a manually 
operated liquid dispensing device is provided. The dispensing device 
includes a housing for sealingly mounting the dispensing device to a 
supply container. The housing includes a portion of a liquid passage 
providing fluid communication from the supply container downstream to the 
discharge orifice. An inlet valve is located within the liquid passage. 
The inlet valve is closed to prevent liquid flow therethrough during 
periods of positive downstream pressure and is open during periods of 
negative downstream pressure. An outlet valve is located within the liquid 
passage, the outlet valve is open to permit liquid flow therethrough 
during periods of positive upstream pressure and is closed during periods 
of negative upstream pressure. A collapsible pump chamber defines a 
portion of the liquid passage downstream of the inlet valve and upstream 
of the outlet valve. The collapsible pump chamber has a collapsing side 
wall defining a portion of the pump chamber. The collapsing side wall has 
a structure adapted to collapse in a predetermined pattern as the pump 
device is actuated.

DETAILED DESCRIPTION OF THE INVENTION 
In a particularly preferred embodiment shown in FIG. 1, the present 
invention provides a manually compressible pump chamber 40 for use in a 
liquid dispensing pump device, indicated generally as 20. This dispensing 
pump device 20 is particularly useful in conjunction with a liquid product 
supply container 22 (seen partially in FIG. 3). The illustrated liquid 
dispensing pump 20 basically includes an upper housing 24, a lower housing 
26, an outlet valve member 30, and inlet vent member 34, a diptube 38, and 
a collapsible pump chamber 40. 
As used herein, the phrase "collapsible pump chamber" is defined as a pump 
chamber delineated--at least partially--by a flexible wall which moves in 
response to a manual compressive force in such a way that the volume 
within the pump chamber is reduced without sliding friction between any 
components delineating the pump chamber. Such collapsible pump chambers 
may include balloon-like diaphragms and bladders made from elastomeric 
materials such as thermoplastic elastomers, elastomeric thermosets 
(including rubber), or the like. For example (not seen), the collapsible 
pump chamber may include a helical metal or plastic spring surrounding (or 
covered by) an elastic material; creating an enclosed pump chamber. 
However, the illustrated and preferred collapsible pump chamber is a 
bellows 40; i.e., a generally cylindrical, hollow structure with 
accordion-type walls. Bellows are preferred, for example, because they can 
be made resilient to act like a spring; eliminating the need for a spring. 
Furthermore, the collapsible pump chamber is designed in such a manner 
that it collapses according to a predetermined pattern. Also the manually 
collapsible pump chamber preferably includes additional integral 
components. As used herein, the term "integral" is defined as molded, or 
otherwise formed, as a single unitary part. 
Referring to FIG. 3, the upper housing 24 is telescoped onto the lower 
housing 26 and retained by cooperation between an annular collar 25 and an 
annular rib 27. The lower housing 26 includes screw threads 28 which 
operate to sealingly attach the pump device 20 to the container 22. 
Alternatively, the lower housing 26 may utilize a bayonet-type attachment 
structure (not seen) such as that described, for example, in U.S. Pat. No. 
4,781,311 issued to Dunning et al. on Nov. 1, 1988; or U.S. Pat. No. 
3,910,444 issued to Foster on Oct. 7, 1975. 
Additionally, the lower housing 26 includes an inlet passage 42 with an 
inner conical inlet valve seat 35 which cooperates with the inlet valve 
member 34 to form the inlet valve 34 and 35. Furthermore, the lower 
housing 26 includes three equally spaced retaining tabs 36 which retain 
the inlet valve member 34 during operation of the pump device 20, as 
discussed hereinafter. Alternatively, a ball valve (not seen) could be 
utilized. The lower housing 26 also includes a vent opening 37, three 
equally spaced actuation lugs 44, a cooperating lug 45, and three equally 
spaced anti-rotation lugs 46. Friction fit onto the inlet passage 42 of 
the lower housing 26 is a diptube 38 which extends down into the container 
22. 
The upper housing 24 includes an outlet passage 48; terminating in a 
dispensing opening 50. An inner cylindrical wall 52 is located within the 
upper housing 24 at an angle to, and connected with the outlet passage 48. 
Additionally, (as seen in FIG. 2) the upper housing 24 includes a collar 
25 with three equally spaced actuation channels 54, three stops 56, three 
pairs of tactile lugs 58, a projection 60, and a removable tamper evident 
tab 62. As used herein, the phrase "tamper evident" is defined as 
providing evidence that the pump has been previously actuated; not 
necessarily that the product has not been tampered with (since the entire 
pump device may be unscrewed and replaced). Tamper evidence, in this sense 
is important because it discourages sampling of the product on the store 
shelf. Moreover, the housing 24 and 26 could include any tamper evident 
feature (not seen) known in the art to indicate that there has been 
removal of the pump device 20 from the container 22. 
Passing through the housing 24 and 26 is a liquid passage which is 
delineated by several parts, including the diptube 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 liquid passage provides fluid 
communication from the distal end of the dip tube 38 within the supply 
container 22 in a downstream direction to the discharge orifice. As used 
herein, the term "downstream" is defined as in the direction from the 
supply container 22 to the discharge orifice 50; and "upstream" is defined 
as in the direction from the discharge orifice 50 to the supply container 
22. Similarly, as used herein, the phrase "inlet end" means the upstream 
end; and the phrase "outlet end" means the downstream end. 
A portion of this liquid passage is defined by the collapsible pump chamber 
40. The collapsible pump chamber 40 has a structure which is flexible such 
that it can be manually compressed; thereby reducing the volume within the 
collapsible pump chamber 40. Although a spring (not seen) may be utilized 
to help return the collapsible pump chamber 40 to its original shape, the 
collapsible pump chamber 40 is preferably sufficiently resilient that it 
returns to its initial shape when the manual compression force is 
released. 
The collapsible pump chamber is a bellows 40 with a structure which ensures 
the bellows 40 collapses along a predetermined pattern. In general, the 
bellows 40 preferably has several qualities. For example, the bellows 40 
should make the pump device easy to actuate. Generally this means having a 
spring force from about three pounds to about five pounds. The bellows 40 
should also have good resiliency with minimal hysterisis and creep. 
Furthermore, the bellows 40 preferably has good stiffness in the radial 
direction (hoop strength) to ensure the bellows 40 is not radially 
deformed under normal operating conditions. Lastly, the bellows 40 
preferably has a good volumetric efficiency; i.e., change in internal 
volume divided by the total expanded internal volume. 
Some geometric features which can be utilized to endow the bellows 40 with 
the appropriate qualities include the diameter of the bellows 40. The 
larger the diameter the lower the spring force and the lower the radial 
stiffness. Although lower spring force is generally desirable, lower 
radial stiffness can be a problem; e.g., the bellows 40 might blow out in 
a precompression trigger sprayers. Increasing the wall thickness of the 
pleats will increase radial stiffiness but it increases the spring force 
and results in decreased volumetric efficiency of the bellows. Reducing 
the pleat angle generally decreases the spring force but decreases the 
volumetric efficiency. The pleat angle is the aggregate of two angles; the 
angle above a line normal to the axis and passing through the origin of a 
pleat and the angle below that line. Preferably, the pleat angle above the 
normal line is about 30.degree. and the pleat angle below the normal line 
is about 45.degree. (making removal of the bellows from the core pin 
easier). Increasing the number of pleats will lower the spring force and 
lower the volumetric efficiency. 
Although not wishing to be bound, it is believed that the major components 
of the spring force are the wall thickness and the upper and lower pleat 
angles while the major component of resiliency is material selection. 
Consequently, one way to endow the bellows with portions which will 
collapse first (such as the smaller diameter portions of the illustrated 
bellows 40) is to utilize thinner walls and more acute pleat angles in 
these areas. In fact, as seen in FIG. 3, the side wall of the illustrated 
bellows 40 gets gradually thinner from bottom to top. Similarly, the pleat 
angles get progressively more acute. Thus, this bellows 40 will begin by 
collapsing on its upper end and dispensing a relatively low volume; giving 
good control for small doses. As actuation of the pump device 20 
continues, and assuming a constant speed of actuation, the flow rate will 
gradually increase. 
Material selection can also help endow the bellows 40 with the appropriate 
qualities. In general the material preferably has a Young's modulus below 
10,000 psi. For lotion pumps the a Young's modulus below 3,000 psi is 
preferred. The material should enable retention of mechanical properties, 
be dimensionally stable and be resistant to stress cracking. These 
properties should be present over time in air and in the presence of the 
liquid product. Thus, for trigger sprayers which generally spray acidic or 
alkaline cleaning products comprised of significant quantities of water 
the material should not be pH sensitive and should not undergo hydrolysis. 
Exemplary such materials include polyolefins such as polypropylene, low 
density polyethylene, very low density polyethylene, ethylene vinyl 
acetate. Other materials which may be utilized include thermosets (e.g., 
rubber), and thermoplastic elastomers. Most preferred for trigger sprayers 
is a high molecular weight ethylene vinyl acetate with a vinyl acetate 
content between about 10 and 20 percent. For other pumps (e.g., lotion 
pumps) pH and hydrolysis may not be an issue. Instead a low spring force 
with a high resiliency may be more important. In such cases a low modulus 
ethylene vinyl acetate or a very low density polyethylene are preferred. 
The inlet end of the manually compressible pump chamber 40 is attached by 
friction fit to the generally cylindrical inner wall of the lower housing 
26. When attached, three equally spaced notches 70 on the inlet end of the 
bellows 40 cooperate with the three anti-rotation lugs 46 on the lower 
housing 26. The collapsible pump chamber 40 includes an integral annularly 
extending flange 64 near its inlet end. This flange 64 seals against the 
interior surface of the lower housing 26; to form a vent valve 26 and 64. 
Thus, the vent valve 26 and 64 includes the flange 64 which operates as a 
valve member and the housing 26 which provides the valve seat. 
Similarly, the outlet end of the collapsible pump chamber 40 is attached by 
friction fit to the inner cylindrical wall 52 of the upper housing 24. The 
outlet end of the collapsible pump chamber 40 includes an elongate channel 
66 which has an integral outlet valve seat 32 which cooperates with the 
outlet valve member 30 to form the outlet valve 30 and 32. The elongate 
channel 66 also includes an integral outlet opening 68. 
The inlet valve member 34 and 35 and an outlet valve member 30 and 32 are 
located within the liquid passage. These valves may be of any type known 
in the art, including duckbill, ball, poppet or the like. Preferably the 
outlet valve member 30 is a lightweight ball or poppet valve member which 
provides suckback, as discussed hereinafter. 
As seen in FIG. 3, the liquid dispensing pump 20 is in the closed position. 
In this position the outlet opening 68 of the bellows 40 is misaligned 
with the outlet passage 48; providing a fluid tight shipping seal. The 
shipping seal includes several functional elements; e.g., the outlet 
opening 68 and the cylindrical wall 52 which can be moved relative thereto 
to seal the outlet opening 68. Therefore, the liquid passage which flows 
through the diptube 38, inlet passage 42 of the lower housing 26, the 
bellows 40, and the outlet passage 48 of the upper housing 24 is sealed 
closed; thereby providing a shipping seal. 
Additionally, the actuation lugs 44 are misaligned with the actuation 
channels 54 which prevents actuation of the pump device 20 when the 
shipping seal is closed. Without this feature, a increase in the pressure 
within the collapsible pump chamber 40 which might damage the collapsible 
pump chamber 40 could be caused by attempted actuation of the pump device 
20 while the shipping seal is closed. In the closed position, one side of 
the upper end of each actuation lug 44 is located against one end of each 
stop 56. The other side of each actuation lug 44 is located against one of 
the tactile lugs 58. 
Furthermore, the tamper evident tab 62 extends generally horizontally from 
the upper housing 24 over the top end of the lower housing 26. The 
illustrated tamper evident tab 62 includes a slot 63 which cooperates with 
a locking lug 45 to prevent rotation of the upper housing 24 relative to 
the lower housing 26. Thus, the shipping seal cannot be opened without 
removal of the tamper evident tab 62. Furthermore, the pump device 20 
cannot be actuated without removing the tamper evident tab 62. 
As seen in FIG. 4, the liquid dispensing pump 20 is in the open position. 
The upper housing 24 may be rotated relative to the lower housing 26 from 
the closed position to the open position once the tamper evident tab 62 
has been removed. The tamper evident tab 62 is removed by simply rotating 
it upwardly. This rotation causes the projection 60 to interfere with the 
tamper evident tab 62; creating a force which pushes the tab 62 away from 
the upper housing 24. This force causes the tab 62 to tear away from the 
upper housing 24 along the thinned line connecting the tab 62 to the upper 
housing 24. Thus, continued rotation of the tab 62 causes the tamper 
evident tab 62 to break off of if the tab 62 is rotated to a point where 
the locking slot 63 and the locking lug 45 release, due to this force. 
Consequently, the shipping seal cannot be opened until the tamper evident 
tab 62 is broken off. Needless to say this prevents on shelf sampling of 
the liquid product through actuation of the pump device 20 without leaving 
evidence of such sampling. 
As the upper housing 24 is rotated, each actuation lug 44 moves from a 
position against one stop 56 to a position 90.degree. away against the 
adjacent stop 56. During rotation, each actuation lug 44 moves against the 
tactile lugs 58 which provide a tactile and/or audible signal that the 
shipping seal of the dispensing pump device 20 is being moved -first, from 
the closed position and - second, into the open position. The tactile lugs 
58 also help maintain the pump device 20 in the open or closed position 
through interaction with the actuation lugs 44. 
Referring to FIG. 4, in the open position the actuation lugs 44 align with 
the actuation channels 54. Furthermore, the integral dispensing opening 68 
aligns with the outlet passage 48; thereby opening the liquid passage. As 
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 stationary relative to the lower housing 26 due in part to the 
cooperation between notches 70 on the inlet end of the bellows 40 and the 
anti-rotation lugs 46 of the lower housing 26. In contrast, the elongate 
channel 66 of the bellows 40 rotates within the inner cylindrical wall 52 
of the upper housing 24 until the outlet opening 68 aligns with the outlet 
passage 48. 
Referring to FIG. 5, once the pump device is in the open position it is 
ready for manual actuation. Manual actuation of the pump device 20 is 
accomplished by axially reciprocating the upper housing 24 relative to the 
lower housing 26. As this reciprocating action is accomplished the 
actuation lugs 44 slide within the actuation channels 54. During the 
downstroke of this reciprocating action, the inlet valve member 34 is 
sealed against the inlet valve seat 35. This causes pressure to increase 
within the collapsible pump chamber 40 which causes the outlet valve 
member 30 to move away from the outlet valve seat 32; thereby opening the 
outlet valve 30 and 32. Consequently, the liquid within the decreasing 
volume of the collapsible pump chamber 40 is dispensed through the 
integral outlet opening 68 and the outlet passage 48. As the liquid is 
dispensed it provides an upward force on the outlet valve member 30 which 
can move the outlet valve member 30 to the distal end of the integral 
elongate channel 66. 
As seen in FIG. 5, this bellows 40 will begin by collapsing at the upper 
end with the thinner wall and the more acute pleat angles. This portion of 
the bellows 40 (i.e., its upper end) gets progressively larger in diameter 
toward the bottom thereof. Consequently, the initial collapse will result 
in a relatively small volume of liquid being dispensed per given stroke 
length initially and gradually increasing. Thus, if a small dose is 
required, this bellows provides good control during initial actuation. 
Should a larger dose be required, the continued actuation of the bellows 
will result in a higher volume of product being dispensed per given stroke 
length; thereby increasing the flow rate. 
Upon release of the manually compressive force, the bellows 40 begins to 
expand, due to its resiliency. A spring (not seen) may alternatively be 
added to replace or supplement the resiliency of the bellows 40. This 
expansion creates a negative pressure (i.e., below atmospheric) within the 
collapsible pump chamber 40. Consequently, atmospheric pressure pushes 
liquid in the outlet passage 48 back into the bellows 40 (at least 
relatively viscous liquids) until the outlet valve member 30 again seals 
against the outlet valve seat 32; thereby closing the outlet valve 30 and 
32. Of course, the longer the integral elongated channel 66, the more time 
it takes for the valve member 30 to seat, and the more liquid is sucked 
back into the bellows 40. Such suck back is desirable since it helps keep 
the dispensing passage clear between operations. 
Referring to FIG. 6, once the outlet valve 30 and 32 closes the negative 
pressure within the bellows 40 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 and 35. The inlet valve member 
34 is retained from moving too far from the inlet valve seat 35 by the 
three retaining lugs 36. Thus, liquid from within the container 22 is 
pulled into the bellows 40 via the diptube 38 and past the inlet valve 34 
and 35. Simultaneously, air is able to enter the container 22 to replace 
the volume of liquid exiting the container 22 by passing around the cup 
seal of the annular flange vent valve member 64 and the vent valve seat 26 
and into the container 22 through the vent opening 37. 
Referring to FIG. 7, a large dose embodiment of a dispensing pump device of 
the present invention, indicated generally as 120, is provided. This pump 
device 120 is substantially identical to the previous pump device 20. The 
lower housing 126, however, extends into the container 122 to permit a 
bellows 140 of increased length. The tamper evident tab 162 is attached to 
the lower housing 126 instead of the upper housing 124. Although the 
tamper evident tab 162 does not prevent rotating the pump device 120 
between open and closed shipping seal positions, it prevents actuation of 
the pump device 120 through interference with the nozzle surrounding the 
outlet passage 148 when in the open shipping seal position. Operation of 
this pump device 120 is substantially identical to that discussed above 
with respect to the previous pump device 20. 
The diameter of the bellows 140 is constant. However, the bellows 140 
includes a thin wall section at its upper end and a relatively thick wall 
section at its lower end. In addition, the pleat angles at the upper end 
are more acute than the pleat angles of the thick wall section. 
Consequently, the upper end of this bellows 140 will collapse first, and 
then the lower end of this bellows 140 will collapse. Since the diameter 
is essentially unchanged the volume of liquid dispensed per given stroke 
length will be essentially constant throughout the collapse. However, as 
seen in FIG. 8, this bellows is also suitable for use with the pump device 
of FIG. 1. 
Although particular embodiments of the present invention have been 
illustrated and described, modifications may be made without departing 
from the teachings of the present invention. For example, the liquid may 
be discharged in a simple liquid stream (as in with a lotion pump) wherein 
the nozzle is an open channel; or as a foam wherein air is mixed with the 
liquid (e.g., through use of a venturi) at or near a foam forming device 
(e.g., a screen or static mixer). Accordingly, the present invention 
comprises all embodiments within the scope of the appended claims.