Note: Descriptions are shown in the official language in which they were submitted.
2 i 653 l 5
Vf ) 95/00253 PCT/US94I04254
1
COLLAPSIBLE PUMP CHAMBER
HAVIrIG PREDETERMINED COLLAPSING PATTERN
BACKGROUND OF THE IN~IENTION
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 fiiction 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 foam the seal. Moreover,
the
wear caused by the friction can deteriorate this seal over time, reducing the
e~ciency of the pump. Furthermore, these piston and cylinder dispensing
devices
have generally been designed without significant effort to reduce the number
of
parts aad 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
3 5 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.
WO 95/00253 .~ ~ ~ PCT/US94/04254
2'16 ~ ~ 2 ,;.
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 deuce 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 presswe. 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.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims particularly pointing out and
distinctively claiming the present invention, it is believed the present
invention will
be better understood from the following description in conjunction with the
accompanying drawings in which:
Figure 1 is an expanded perspective view from above of a particularly
preferred embodiment of a manually collapsible pump chamber for use in a
liquid
dispensing pump of the present invention;
3 5 Figure 2 is an expanded perspective view from below of the manually
collapsible pump chamber and liquid dispensing pump of Figure 1;
i
~_d 95/00253 2 i 6 5 31 ~ pCT/L1S94/04254
3
Figure 3 is a cross-sectional view taken along the center line of the
assembled liquid dispensing pump device of Figures 1 and 2 (with the tamper
evident tab intact and shipping seal closed);
Figure 4 is a cross sectional view, similar to Figure 3 with the tamper
evident tab removed and the shipping seal open;
Figure 5 is a cross sectional view, similar to Figure 3, of the pump of
Figure 1 in operation, during the downstroke as the collapsible pump chamber
collapses;
Figure 6 is a cross sectional view, similar to Figure 3, of the pump of
Figure 1 in operation, during the upstroke as the collapsible pump chamber
expands;
Figure 7 is a cross-sectional view, similar to Figure 3, of another preferred
collapsible pump chamber of the present invention capable of pumping
relatively
large volumes in another liquid dispensing pump device;
Figure 8 is a cross-sectional view, similar to Figure 3, of the collapsible .
pump chamber of Figure 7 in the liquid dispensing pump device of Figure 1.
DETAILED DESCRIPTION OF THE INVENTION
In a particularly preferred embodiment shown in Figure 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 Figure 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 6iction 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,
,~ , CA 02165315 2000-07-25
4
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 Figure 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 29 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. 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.
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 Figure 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 previoiusly
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
2165315
95/00253 PCT/US94/04254
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
5 "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 radiaUy 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
stiffness
but it increases the spring force and results in decreased volumetric e»ciency
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° and the pleat angle below the normal line is
about 45°
", CA 02165315 2000-07-25
6
(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 components 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 Figure 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
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 present 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 avinyl
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 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 seals against the interior
surface of the lower
housing 26; to form a vent valve 26 and 64. Thus, the vent valve 26 and 54
X165315
~_; 95/00253 PCTILJS94/04254
7
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 Figure 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
acdution lug 44 is locafed 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
3 5 tab 62. Furthermore, the pump device 20 cannot be actuated without
removing
the tamper evident tab 62.
As seen in Figure 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
CA 02165315 2000-07-25
8
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° 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 Figure 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 (see Figure 1) 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 Figure 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
CA 02165315 2000-07-25
9
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 Figure 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 Figure 6, once the outlet valve 30 and 32 closes the negative
pressure within
the bellows 40 created as the bellows 40 continuos to expand, causes the inlet
valve member 34
(see Figure 5) to move away from the inlet valve seat 35 (see Figure 5);
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 (see Figure 5). Thus, liquid from 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 provided
by the lower housing 26 (see Figure 5) and into the container 22 through the
vent opening 37.
2165315
9a
Referring to Figure 7, a large dose embodiment of a dispensing pump device of
the
present invention is provided. The pump device is substantially identical to
the previous
pump 20 (see Figure 1). Like parts in Figures 7 and 8, as compared to Figure
1, have
been identified by corresponding reference numerals in the 100 series. The
>.; .
r J
CA 02165315 2000-07-25
lower housing 126, however, extends into the container 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
between open and closed shipping seal positions, it prevents actuation of the
pump device
S through interference with the nozzle surrounding the outlet passage 148 when
in the open
shipping seal position. Operation of this pump device 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 Figure 8, this bellows is also suitable for use
with the pump
device of Figure 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.
