Note: Descriptions are shown in the official language in which they were submitted.
WO 96/11065
PCT/ITS95/12484
1
ASSEMBLY PROCESS INCLUDING SEVERING PART OF
INTEGRAL COLLAPSIBLE PUMP CHAMBER
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the process for assembling manually
operated liquid dispensing pump devices for use with consumer product
containers;
and more particularly, to such processes for assembling such devices having a
collapsible pump chambers (e.g., a bellows pump chamber) wherein multiple
functions are integrally molded into the bellows.
2. Description of the Prior Art
I5 Manually operated dispensing devices for pumping liquid from a supply
container are widely known in the art. These liquid dispensers traditionally
utilize a
piston and cylinder pump chamber. A helical metal spring is generally utilized
to
provide the force necessary to return the piston to its initial position.
Additional
parts are generally related to an inlet valve, an outlet valve end a vent
valve.
2o Furthermore, in cases where a liquid spray discharge is desired, additional
parts are
often related to a swirl chamber. One disadvantage of such piston and cylinder
dispensing devices is the great amount of sliding friction developed between
the
piston and the cylinder due to the tight telescopic fit required to maintain a
fluid
tight seal. Binding, may also occur between the piston and cylinder. Another
25 disadvantage includes the relatively large number of parts such sprayers
typically
utilize which generally increases the cost of such pumps.
Consequently, attempts to ufilize a rnanuaIly compressible flexible pump
chamber in place of the piston and cylinder have been made. For example,
bellows
have been utilized to replace the function of the piston, cylinder and return
spring.
3o Still other liquid dispensing devices have utilized a diaphragm or bladder
as the
manually compressible pump chamber. The use of such manually compressible
pump chambers is substantially free of the sliding friction and the potential
binding
' losses associated with the piston and cylinder. Some of these pump devices
have
integrally molded duckbill, flapper and/or annular sealing valves with the
pump
' 35 chamber. One disadvantage in the use of such valves is that they do not
readily
enable the further integral molding of additional functions. Thus, additional
parts
are generally required; thereby increasing the cost of the pump device.
Furthermore, the integral molding of reliable valves can be difficult.
CA 02201899 1999-03-10
2
SUMMARY OF THE INVENTION
In accordance with one aspect of the present invention there is provided
a process for assembling a manually operated dispensing device for pumping a
liquid
from a supply container and spraying the liquid through a discharge orifice,
said process
S comprising the steps of (a) integrally molding a collapsible pump chamber
having an
outlet end and a retaining means, and having a volume within which is reduced
in
response to a manual compressive force, with a functional element of another
function
at the outlet end of the collapsible pump chamber; (b) molding a nozzle with a
retaining
means for cooperating with the retaining means from the collapsible pump
chamber to
attach the nozzle and the collapsible pump chamber together; (c) pressing and
attaching
together the collapsible pump chamber and the nozzle via the retaining means;
and (d)
severing the functional element of another function from the collapsible pump
chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims particularly pointing out and
distinctively
IS 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 I is an exploded perspective view of a particularly preferred liquid
dispensing pump device of the present invention;
Figure 2 is a cross-sectional view, taken along the center line, of the
assembled liquid dispensing pump device of Figure 1;
Figure 3 is a cross-sectional view, similar to Figure 2, of the liquid
dispensing pump device in operation;
Figure 4 is an enlarged perspective view of the multiple function
collapsible pump chamber of the liquid dispensing pump device of Figure l;
Figure 5 is a cross-sectional view of the Figure 1 bellows and nozzle - each
being held by assembly tools - immediately prior to being assembled together;
Figure 6 is an enlarged fragmentary cross-sectional view similar to Figure
5 but taken as the bellows and nozzle are being assembled;
Figure 7 is an enlarged fragmentary cross-sectional view similar to Figure
6 but taken as the flexible ribs are being severed;
Figure 8 is an exploded perspective view, similar to Figure 1 of another
particularly preferred liquid dispensing pump device of the present invention;
Figure 9 is a perspective view of the fully assembled liquid dispensing
pump device of Figure 8;
2C~~~9~
WO 96/11065 PCT/US95/12484
3
Figure 10 is a cross-sectional view, similar to Figure 2, of the assembled
liquid dispensing pump device of Figure 8;
Figure 11 is a cross-sectional view, similar to Figure 3, of the liquid
dispensing pump device of Figure 8 in operation;
Figure 12 is a cross-sectional view of the Figure 8 bellows and nozzle - each
being held by assembly tools - immediately prior to being assembled together;
Figure 13 is an enlarged fragmentary cross-sectional view similar to Figure
12 but taken as the bellows an nozzle are being assembled; and
Figure 14 is an enlarged fragmentary cross-sectional view similar to Figure
l0 13 but taken as the flexible ribs are being severed.
DETAILED DESCRIPTION OF THE INVENTION
In Figure 1 there is seen, in exploded perspective view, a particularly
preferred liquid dispensing pump device of the present invention, indicated
generally
as 20. A cross-sectional view of this particularly preferred, fully assembled,
liquid
dispensing pump device 20 is seen in Figure 2; and is seen in operation in
Figure 3.
The illustrated liquid dispensing pump device 20 basically includes a trigger
22; a
vent tube 16; a dip tube 40; a housing 10 including a nozzle 70, a shroud ll,a
closure 12; a collapsible pump chamber 60 and an inlet valve member 50.
Integral
2o with the inlet valve member is a dunnage means 51.
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 compressible pump chambers may include balloon-like
diaphragms and bladders made from elastomeric materials such as thermoplastic
sa~~etnmnre n~oet~,mer:.. +1...-..,...,...a.. l:~_t__~'_~~ -tt v
v~4JLV1114~J, 1,lCLJlVIIlGlllr L(IGIILIUJGLJ ~ulclualn~ ruD~erJ, 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
3o chamber. However, the preferred collapsible pump chamber 60 is a bellows;
i.e., a
generally cylindrical, hollow structure with accordion-type walls. Bellows are
preferred, for example, because they can be made resilient to act Iike a
spring;
eliminating the need for a spring. Furthermore, the collapsible pump chamber
. includes one or more integral elements which enable to collapsible pump
chamber to
perform multiple functions. As used herein, the term "integral" is defined as
molded, or otherwise formed, as a single unitary part.
The housing 10 is used for sealingly mounting the liquid dispensing device
20 to a liquid supply container (not seen) via the closure. The illustrated
closure 12
CA 02201899 1999-03-10
4
includes screw threads 17 for attaching the housing 10 to the container (not
seen).
Alternatively, the closure 12 may utilize a bayonet-type attachment structure
(not seen)
such as that described, for example, in the following Patents and patent
applications:
U.S. Patent 4,781,311 issued to Dunning et al. on November 1, 1988; and U.S.
Patent
3,910,444 issued to Foster on October 7, 1975; PCT Application US93/00899
published
August 5, 1993 (see, e.g., Figures 11 and 12) and PCT Application GB93/02561
published June 23, 1994. Also, the closure 12 may be integral with the shroud
11. The
illustrated shroud 11 includes an integral "C"-shaped hinge 13 for attaching
the trigger
22 to the housing 10; and a plurality of tabs 14 for attaching the nozzle 70
to the
housing 10. Additionally, the illustrated housing 10 includes a vent tube 16
having a
vent valve seat 15. Alternatively, the vent tube 16 and its vent valve seat 15
and may
be integral (not seen) with either the shroud 11 or the closure 12. The
housing 10 may
be molded from one or more thermoplastic materials, such as polypropylene,
polyethylene or the like.
Passing through the housing 10 is a liquid passage which is delineated by
several parts, including the dip tube 40, the tubular pipe 24, the collapsible
pump
chamber 60, and the nozzle 70. The liquid passage provides fluid communication
from
the distal end of the dip tube 40 within the supply container (not seen) in a
downstream
direction to the discharge orifice 77 of the nozzle 70. As used herein, the
term
"downstream" is defined as in the direction from the supply container (not
seen) to the
nozzle 70; and "upstream" is defined as in the direction from the nozzle 70 to
the
supply container (not seen). Similarly, as used herein, the phrase "inlet end"
means the
upstream end and the phrase "outlet end" means the downstream end.
A portion of the liquid passage is provided by a tubular pipe 24 which is
integral with the trigger 22. The trigger 22 is utilized to manually compress
the
collapsible pump chamber 60, as described hereinafter. The trigger 22 is
attached to the
housing 10 by the hinge 13 through an integral cylinder pivot 21; allowing the
trigger
22 to rotate freely relative to the housing 10. The trigger 22 further
comprises an angled
tube pipe 24, a pump coupler 23, and inlet valve seat 26, and a vent valve
member 29,
all preferably integral with the trigger 22. The trigger 22 may be molded from
a
thermoplastic material such as polypropylene, polyethylene, or the like.
The exterior surface of the upstream end of the tubular pipe 24 is a
conically shaped vent valve member 29. Additionally, a conically shaped valve
seat 15
is provided by vent tube 16. Thus, the vent valve member 29 and the vent valve
seat
15 form a vent valve 15 and 29. The vent valve 15 and 29 is biased closed due
to
X20 ~ ~ 9~
WO 96/11065 PCT/US95/12484
the resiliency of the bellows 60 to seal the vent channel 42 between the dip
tube 40
and the vent tube 16. When the trigger 22 is manually rotated about the pivot
21,
the vent valve 15 and 29 opens; thereby providing fluid communication via the
vent
channel between the interior of the container (not seen) and the atmosphere;
. 5 permitting the internal pressure within the container (not seen) to
equalize with the
' atmosphere as liquid is dispensed from the container (not seen) through the
pump
device 20.
Additionally, the dip tube 40 which is fi-iction fit within the tubular pipe
24
provides another portion of the liquid passage. The dip tube 40 is preferably
held
to by the tubular pipe 24 at an angle with respect to the pump coupler 23.
This angle
is preferably equal to one half the maximum rotational angle through which the
trigger 22 is rotated when liquid dispensing pump device 20 is attached to the
liquid
supply container (not seen). The dip tube 40 is preferably formed of
thermoplastic
material such as polypropylene, polyethylene, or the like.
A liquid inlet valve member 50 is located within the liquid passage. The
inlet valve member 50 is connected to an outer annular wall 25 via three
equally
spaced flexible ribs 33. The outer annular wall 25 (and in turn the inlet
valve
member 50) is attached to the pump coupler 23 via retaining rib 28 and
cooperating
retaining recess 27. The inlet valve member SO of this embodiment includes a
2o conical surface at its distal end. Thus, this conical surface of the inlet
valve member
50 cooperates with the inlet valve seat 26 to seal the liquid passage under
positive
downstream pressure conditions. Alternatively, the liquid inlet valve 26 and
50 may
be of any type generally known in the art including a duckbill, ball, poppet,
or the
like.
The inlet valve member 50 of this embodiment also functions as dunnage
means 51 for reducing the compressed volume within the pump chamber. The inlet
valve ineinber ~~ extenris into the interior of tF~e bellows and terminates at
an end
wall; thereby forming an open-ended, hollow, generally cylindrical structure
which
operates as the dunnage means 51. Such a hollow structure is preferred. For
3o example, hollow structures require significantly less material in relation
to the
volume they can occupy within the collapsible pump chamber 60; and hollow
structures are susceptible to high cycle times during molding since cooling
time is
reduced. It is also preferred that the dunnage means 51 not be integral with
the
housing 10, e.g., because such hollow structures are difl7cult to mold
attached to
' 35 the housing 10 (unless , e.g., the valve seat is extended into the
interior of the
bellows). Alternative dunnage means could be attached to the outlet valve
member
75, the bellows 60, or even be free floating (as seen, e.g., in Figures 8
through 11).
Dunnage means 51 significantly reduces the interior volume of the collapsible
pump
X20 1~ 99
WO 96/11065 PCT/US95/12484
6
chamber 60 which fluid may occupy; providing a particularly large reduction
during
the collapsed state of the collapsible pump chamber 60. A more detailed
explanation of the function of the dunnage means S 1 is discussed hereinafter.
Another portion of the liquid passage is defined by the collapsible pump
chamber 60. The collapsible pump chamber 60 has a structure which is flexible
such that it can be manually compressed; thereby reducing the volume within
the
collapsible pump chamber 60. Although a spring (not seen) may be utilized to
help
return the collapsible pump chamber 60 to its original shape, the collapsible
pump
chamber 60 is preferably suffciently resilient that it returns to its initial
shape when
1o the manual compression force is released.
The illustrated collapsible pump chamber is a bellows. A preferred bellows
should have several qualities. For example, the bellows should make the pump
device easy to actuate. Generally this means having a spring force from about
three
pounds to about flue pounds. The bellows should also have good resiliency with
~5 minimal hysterisis and creep. Furthermore, the bellows preferably has good
stiffness in the radial direction (hoop strength) to ensure the bellows is not
radially
deformed under normal operating conditions. Lastly, the bellows preferably has
a
good volumetric efficiency; i.e., change in internal volume divided by the
total
expanded internal volume.
2o Some geometric features which can be utilized to endow the bellows with
the appropriate qualities include the diameter of the bellows. 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 might blow out in a precompression trigger sprayers.
Increasing
25 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
30 line. Preferably, the pleat angle above the normal line is about 30°
and the pleat
angle below the normal line is about 45° (making removal of the bellows
from the
core pin easier). Increasing the number of pleats will lower the spring force
and
lower the volumetric e~ciency.
Although not wishing to be bound, it is believed that the major components
35 of the spring force are the wall thickness and the upper and lower pleat
angles while
the major component of resiliency is material selection.
Material selection can also help endow the bellows with the appropriate
qualities. In general the material preferably has a Young's modulus below
10,000
x'20 1 ~ 99
WO 96/11065 PCT/US95/12484
7
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. 7.'hus, 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
to 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.
An exemplary bellows made of ethylene vinyl acetate or very low density
polyethylene might have a 0.6 in inner large diameter and a 0.4 inch inner
small
diameter and a wall thickness of between about 0.02 inch and 0.03 inch. The
aggregate pleat angle would be about 75°; with the upper pleat angle
30° and the
lower pleat angle 45°.
The bellows, which provides the manually compressible pump chamber 60
of this embodiment, is attached to the housing 10 via the pump coupler 23 of
the
trigger 22. The downstream, or inlet, end of the bellows 60 is attached to the
pump
coupler 23 via cooperating annular ribs 31 and 62. The cooperating ribs 31 and
62
also help provide a liquid tight seal under positive pump pressure. Thus, the
inlet
end of the bellows 60 is in liquid communication with liquid supply container
(not
shown). The inlet end of the bellows 60 is wide open to permit reliable, cost
et~ective thermoplastic molding.
Similarly, the outlet end of the bellows 60 is attached to the nozzle 70 via
3o cooperating annular ribs 72 and 65 to provide a liquid tight seal under
positive
pump pressure. The nozzle 70 is attached to the shroud 11 through a plurality
of
tabs 14 that are positively engaged with an equal number of slots 78 in the
nozzle
70. The nozzle 70 is in liquid communication with the outlet end of the
bellows 60
and forms a portion of the liquid passage; including the discharge orifice T~.
Furthermore, the nozzle 70 includes the outlet valve seat 72. The nozzle 70
may
further include a hinged door (not seen) shipping seal which can be moved to a
closed position sealing the discharge orifice 77 - or to an open position
permitting
the discharge of liquid through the discharge orifice 77. An exemplary nozzle
and
CA 02201899 1999-03-10
8
hinge door structures are disclosed in U.S. Patent 5,158,233 issued October
27, 1992
to Foster et al. The nozzle 70 may be molded from a thermoplastic material
such as
polypropylene, polyethylene, or the like.
Referring to Figures 4 and 5, the bellows 60 is preferably molded including
an integral functional element of the swirl chamber 90. The swirl chamber 90
comprises
the downstream terminal portion of the liquid passage. The illustrated swirl
chamber 90
is defined by two parts; the nozzle 70, including an end wall 76 and the
discharge
orifice 77, and the spinner 91 which is integral with the downstream end of
the bellows
60. The illustrated bellows 60 is directly in line with and adjacent to the
nozzle 70. The
spinner 91 has a generally hollow cylindrical shape with two arcuate channels
92 in the
side wall which direct the liquid traveling therethrough tangentially toward
the inner
surface of the spinner's 90 side wall, and tangential to the axis of the
discharge orifice
77. This imparts radial momentum to the liquid just prior to exiting said
discharge
orifice 77; aiding in spray formation. Alternatively, the swirl channels 92
may be
molded integral with the nozzle 70 as seen, for example, in Figures 12, 14 and
15;
discussed hereinafter. Examples of alternative springs and swirl chambers are
disclosed
in the following patents: U.S. Patent 4,273,290 issued to Quinn on June 16,
1981; and
U.S. Patent 5,234,166 issued to Foster et al. on August 10, 1993.
The bellows 60 is also preferably molded including an integral functional
element of the outlet valve. The outlet valve includes the outlet valve member
80 and
the outlet valve seat 75. As illustrated, the outlet valve member 80 is the
portion
integral with the bellows 60 through two or more integrally formed flexible
legs 66 that
radially extend like spokes between the valve member 80 and the body of the
bellows
60. The outlet valve seat 75 includes a conically shaped surface which
cooperates with
a conical surface on the outlet valve member 80. The outlet valve 75 and 80 is
located
within the liquid passage and operates to seal the passage under negative
upstream
pressure conditions. Alternative liquid outlet valves (not seen) may be of any
type
generally known in the art, including a duckbill, ball, poppet, or the like.
Preferably the outlet valve 75 and 80 or the inlet valve 26 and 50 is closed
at rest such that the pump will not lose its prime between operations. More
preferably,
it is the outlet valve 75 and 80 which is closed, since this provides many
benefits. For
example, since the outlet valve 75 and 80 is closer to the discharge orifice
77, less
product is likely to drip from the nozzle 70 when the outlet valve is closed.
Even more
preferably, the outlet valve 75 and 80 is biased closed. Most preferably, the
outlet valve
75 and 80 is significantly biased closed such that
WO 96/11065
PCT/US95/i2484
9
precompression is provided. Precompression is provided at the consumer product
flow rates typical of such pump sprayers when the outlet valve 75 and 80
remains
closed until a pressure of about 50 psi is reached inside the bellows 60.
Biasing
helps provide good spray formation and helps give the spray stream a quick
start
and stop. As discussed hereinafter, the outlet valve 75 and 80 may be biased
in
such a way that the biasing force drops as the outlet valve 75 and 80 opens.
As
illustrated the biasing force can be provided by the legs 66, a spring 82, or
both. It
has been found that under some circumstances, at least, it is preferable to
sever the
flexible legs 66 during the assembly process as discussed hereinafter - so
that the
to entire biasing force is provided by the spring 82.
The illustrated spring 82 is diamond shaped and can be formed utilizing a
side action mold. In addition, such springs 82 provide a force which acts
directly
along the axis of the spring 82. The undeformed legs of the spring 82 are at
small
angle Beta (f3) with respect to the axis of liquid passage. In this state, the
product
of the force of biasing spring 82 and the 13 force vector in line with the
passage is
near maximum. As the positive liquid pressure within the bellows 60 acts upon
surface the outlet valve member 80, the legs of the spring 82 flexibly rotate
about
the corners and angle Beta, (J3), increases, thus decreasing the f3 force
vector
multiplier. Consequently, when this spring force component is great, compared
to
2o the spring force components due to the resiliency of the legs 66 and the
resiliency of
the spring 82 leg material, the outlet valve 75 and 80 may be biased in such a
way
that the biasing force of the spring 82 drops as the valve opens. Alternative
springs
(not seen) which may be utilized to bias the outlet valve 75 and 80 include
helical
springs and wavy plate springs. In addition, some or all of the biasing force
may be
provided by the legs 66 connecting the bellows 60 to the outlet valve member
80.
Thus, the illustrated bellows 60 of the present invention includes an integral
functional component of all of the internal downstream functions (i.e., the
outlet
valve - including the biasing element, and the swirl chamber) of this liquid
dispensing pump device 20.
3o As indicated above, it has been found that under some circumstances, at
least, it is preferable to sever the flexible legs 66 during the assembly
process so that
the entire biasing force is provided by the spring 82. Variations in the
molded parts
(and/or how well the parts are fit together) including the distance from the
outlet
valve seat 75 to the point where the flexible legs 66 join the main body of
the
bellows 60, can result in variation of the biasing force due to the flexible
legs 66. In
turn, this biasing force variability results in variation of the
precompression force -
and thus, sprayer 20 performance. Consequently, utilizing only this spring 82
as the
biasing force can reduce the variability of the biasing force from sprayer to
sprayer.
WO 96/11065 ~ ~ ~ S
PCT/US95/12484
However, integrally molding the bellows 60, outlet valve member 80, biasing
spring
82 and spinner 91 offers reduced costs associated with molding and handling
separate parts during the manufacturing process. Therefore, these functions
are
. molded as a single integral part and then the functions are severed during
the
5 assembly process.
T he process of severing the flexible legs 66 during assembly of the trigger '
sprayer 20 is described with reference to Figures 5, 6 and 7. Referring to
Figure 5,
a nozzle assembly tool 75 with a recess matching the configuration of the
nozzle 70
can be utilized to hold the nozzle 70. Similarly, the bellows 60 is held via
friction fit
10 on the illustrated bellows assembly tool 63. The bellows assembly tool 63
includes
a housing 64, a insertion pin 67, and a sharp annular wall 68.
Referring to Figure 6, the entire bellows assembly tool 63 moves forward
such that the shoulder of the outer distal end of the housing 64 pushes the
bellows
60 onto the nozzle 70 such that the cooperating ribs 65 and 72 operate to
attach the
two together. The insertion pin 67 mates with the recess of the outlet valve
member 80; thereby helping alignment. The insertion pin 67 continues to push
the
outer valve member 80 past the outer valve seat 75. This step stretches the
ribs 66
somewhat. Referring to Figure 7, the sharp annular wall 68 then moves forward
until it presses against the distal end of the outlet valve seat 75 wall;
thereby
2o severing the ribs 66. The bellows assembly tool 63 is then removed; leaving
the
bellows 60 and nozzle 70 held by the nozzle assembly tool 74.
Of course, there are many alternative assembly tools and processes which
would accomplish attaching the nozzle 70 and bellows 60 together and severing
the
flexible legs 66. For example, the insertion pin 67 and the sharp annular wall
68
could be a single integral part which would travel forward together to
simultaneously push the outlet valve member 80 past the outlet valve seat 75
and
sever the flexible legs 66. Similarly, the insertion pin 67 could move forward
to
engage the recess of the outlet valve member 80, then the sharp annular wall
68
could move forward to sever the ribs 66; and then the insertion pin 67 could
3o continue forward to push the outlet valve member 80 into place.
Additionally, a
sharp edge may be provided on the distal end of the outlet valve seat 75 wall
to
provide a sharp cutting edge. Alternatively, the distal end of the outlet
valve seat
75 wall could be located remote from the severing operation. One advantage of
utilizing a sharp cutting edge on the assembly tool 63, the distal end of the
outlet
valve seat 75 wall, or both, is that the flexible legs 66 need not be
particularly thin
which can aid in molding the downstream functions integral with the bellows
60,
since during molding the plastic may need to flow to these downstream
functions
(i.e., the outlet valve member 80, the biasing spring 82, and the spinner 90)
through
X20 ~ 8 ~~
WO 96/11065 PCT/US95/12484
11
the channels which become flexible legs 66. Other alternatives processes are
discussed hereinafter with reference to Figures 12, I3 and 14.
Referring to Figure 3, operation of thisc liquid dispenser 20 involves
manually depressing the trigger 22 which causes rotation of the trigger 22
about the
pivot 21. Since the trigger 22 is attached to the bellows 60 through the pump
' coupler 23, this rotational motion of the trigger 22 results in rotational
manual
compression of the bellows 60 which moves the bellows from an expanded volume
to a compressed volume. The resultant compression creates a positive pressure
within the bellows 60. Since the inlet valve 26 and 50 is not biased closed,
this
to positive pressure forces the inlet valve 26 and 50 to close if it is not
already closed.
Thus, during this period of positive pressure downstream of the inlet valve 26
and
50, the inlet valve 26 and 50 is closed which prevents liquid inside the
bellows 60
from returning to the container (not seen).
Simultaneously, this positive pressure in the bellows 60, upstream of the
outlet valve 75 and 80 acts upon the outlet valve member 80 and when the
pressure
within the pump chamber 60 reaches a level high enough to cause flexure of
legs 66
(if attached) and spring 82, the outlet valve member 80 disengages from the
outlet
valve seat 75; opening the valve. Liquid in the bellows 60 then flows under
pressure around the annular gap created between liquid outlet valve member 80
and
outlet valve seat 75. The liquid continues to flow under pressure through spin
chamber 90; i.e., spin channels 92 of the spinner 91 and out through the
discharge
orifice 77. As the liquid passes through the spin chamber 90 it gains a radial
momentum prior to exiting the discharge orifice 77. The combination of radial
and
axial momentum causes the liquid to exit the discharge orifice 77 in a thin
conical
sheet which quickly breaks up into liquid particles. As an alternative to
biasing the
outlet valve 75 and 80 closed to generate pressure in the exiting liquid, the
spin
channels 92' (or the discharge orif ce 77, for example) may operate as flow
restrictions which result in increasing the pressure in the exiting liquid.
As seen in Figure 3, dunnage means 51 reduces the compressed volume
3o capable of being occupied by liquid in the collapsible pump chamber 60 as
compared to the collapsed volume of the collapsible pump chamber 60 without
dunnage means 51. Without the dunnage means 51 the collapsed volume of the
collapsible pump chamber 60 includes the interior cylindrical volume defined
by the
collapsed length of the bellows 60 and the diameter of the collapsed interior
folds of
- s5 the bellows 60. With the dunnage means 50, this collapsed volume is
reduced by
the cylindrical volume of the dunnage means 51.
Such a reduced collapsed volume within the collapsible pump chamber 60 is
advantageous. For example, the dunnage means 51 helps generate higher
pressures
WO 96/11065 ,~ ~ ~ PCT/US95/12484
12
within the pump chamber 60 when air is present; thereby being capable of
overcoming a precompression biasing force on the outlet valve member 80.
Additionally, the reduced volume results in fewer strokes to prime.
Preferably, the
number of strokes to initially prime the pump device 20 is at least one stroke
less
with the dunnage means 51 than without. Additionally, the.total number of
strokes
to initially prime the pump device 20 with the dunnage means 51 is preferably
less
than about 6; and more preferably, less than about 4.
The reduced volume provided by the dunnage means 51 is particularly
advantageous in collapsible pump chambers 60 whose major dimension is
to substantially horizontal; such as the illustrated trigger sprayer 20. In
such
horizontally oriented collapsible pump chambers 60 , e.g., air can become
trapped in
the collapsible pump chamber 60 near the inlet valve 26 and S0. This can cause
the
trigger sprayer 22 to air lock and not prime; particularly if the sprayer 20
is pointed
downwardly. Consequently, it is often preferable to associate the dunnage
means
51 with the inlet valve 26 and 50. With the dunnage means 51 the air is forced
from
this position near the inlet valve 26 and 50 toward the outlet valve 75 and 80
so that
it is moved out of the pump chamber 60 with much greater efficiency.
Rotation of the trigger 22 also results in the simultaneous opening of the
vent valve 15 and 29. The vent valve member 29 at the end of the tubular pipe
24 is
2o attached to the trigger 22 such that rotation of the trigger 22 moves the
vent valve
member 29 away from the vent valve seat 15. This provides a generally annular
vent channel 42 between the vent W be 16 of the housing 10 and the dip tube
40.
The vent channel 42 provides liquid communication between the interior of the
container (not seen) and the atmosphere. Thus, air is able to flow from the
atmosphere into the container (not seen) through this vent channel 42 to
replace the
volume of liquid being dispensed from the container (not seen). The vent tube
16
includes an annular rib 18 at its lower end which reduces the diameter of the
vent
channel 42 such that liquid will not readily splash out the vent channel 42
during
operation. For example, the annular rib 18 preferably has an internal diameter
3o which is about 0.005 inches larger than the outside diameter of the dip
tube 40.
Since the dip tube 40 is held by the rotating trigger 22, the diptube 40
flexes to
follow the natural arc of the trigger 22. Alternatively, the vent valve
opening may
be large enough that no flexing of the dip tube 40 is required. '
When the trigger 22 is released, the bellows 60 restores itself to its
uncompressed state, through its resiliency. Alternatively, the bellows 60 may
be
aided in restoration by a spring (not seen) operating in conjunction with the
bellows
60. Since the bellows 60 is attached to the trigger 22 through the coupler 23,
restoration of the bellows 60 rotates the trigger 22 to its original position.
As the
WO 96/11065
PCT/US95/12484
13
bellows 60 returns to its original uncompressed state, a negative pressure, or
vacuum, is created within the pump chamber 60. 'This negative pressure,
upstream
of the outlet valve 75 and 80, along with biasing spring 82 and the resiliency
of the
legs 66, causes the liquid outlet valve 75 and 80 to close. Simultaneously
this
y 5 negative pressure, downstream ofthe inlet valve 26 and 50, opens liquid
inlet valve
26 and 50; allowing liquid to enter the bellows 60 through the diptube 40. The
tabs
28 limit the amount of disengagement of liquid inlet valve member SO so that
it is
properly located for closing upon the next manual actuation of the liquid
dispensing
pump device 20.
to Refernng to Figures 7 through 11, a second alternative embodiment of a
liquid dispensing device 120 of the present invention is illustrated. This
embodiment utilizes linear, instead of rotary, motion of the bellows 160. The
nozzle 170 is generally similar to nozzle 70. However, the nozzle 170 is
slightly
smaller in overall dimension and includes a lug 178 on each of its three sides
and a
15 depending wall 173 (seen in Figure 8). Likewise, the bellows 160 is
generally
similar to the bellows 60. However, the bellows 160 includes a resilient
annularly
extending flange 161 near its inlet end which makes a cup seal against the
inside of
the housing 110.
Trigger 122 is subst4ntially modified from 'that of Figure 1. For example
2o trigger 122 includes two upper elongated arms which each include a hinge
113.
The hinges 113 cooperate with pivots 121 located on top of the shroud 111.
Thus,
the pivot point of this trigger 122 is located at the top of the housing 110.
The
trigger 122 also includes a push tab 119 which cooperates with the depending
wall
173 of the nozzle 170 to enable linear compression of the bellows 160 upon
manual
25 actuation (i.e., rotation) of the trigger 122. Alternatively (not seen),
the trigger 122
may be rigidly afl-ixed to the nozzle 170 such that the trigger 122 is
actuated
through linear motion rather than rotational motion.
Likewise the housing 110 is substantially modified. For example the
housing 110 includes channels 114 which cooperate with the three lugs 178 on
the
3o nozzle 170 to retain the nozzle 170 in place while allowing linear,
reciprocating
movement of the nozzle 170 relative to the housing 110. The housing 110 also
includes the pump coupler 123 for the bellows 160 and an internal vertical
wall 130
which provides an enclosed annular volume between it and the resilient flange
161
of the bellows 160. A vent hole 142 in the housing 110 provides fluid
35 communication between this enclosed annular volume and the interior of the
supply
container (not seen). Similar to the inlet valve 26 and 50 of the previous
embodiment, a poppet valve member 150 cooperates with a conically shaped inlet
valve seat 126. In an alternative arrangement (not seen) the housing 110 can
be
WO 96/11065 ~ ~ ~ PCT/US95/12484
14
modified to enclose a ball check valve member between the housing 110 and the
diptube 140 in place of the illustrated inlet valve 126 and 150.
Dunnage means 151 of this embodiment is a hollow, free floating, .
substantially cylindrical structure. One advantage of such a dunnage means 151
is
that it may tend to move toward any air pocket in the collapsible pump chamber
,
160; thereby forcing the air out of the collapsible pump chamber 160. The
edges of
the dunnage means 151 are rounded (e.g., like as capsule) to enable the
dunnage
means 151 to slide past the folds of the bellows 160 as the bellows 160 is
collapsed;
thereby avoiding binding the bellows 160 and interfering with the collapse of
the
to bellows 160. One preferred way to form such a dunnage means 151 is to blow
mold or injection mold the hollow cylindrical shape and pinch offthe open
ends) to
form the dunnage means 151.
As with the previous embodiment, the assembly process includes the step of
severing the resilient legs 166 from the collapsible pump chamber 160. Thus,
the
combination spinner 190, spring 182 and outlet valve member 180 becomes a
separate part and the spring 182 provides the entire biasing force for the
outlet
valve member 180. Consequently, the advantages of molding these parts as a
single
integral part which reduces molding and assembly costs are achieved along with
the
advantages of having these parts as separate structures (e.g., reduced biasing
force
2o variability).
Referring to Figures 12, 13 and 14, the process of severing the flexible legs
166 is accomplished utilizing a nozzle assembly tool 174 and a ended bellows
assembly tool 163 including a housing 164 and a insertion pin 167. As with the
previously illustrated process, the shoulder at the distal end of the housing
164
pushes the bellows 160 onto the nozzle 170 such that cooperating ribs 172 and
165
operate to attach the bellows 160 and nozzle 170 together (seen in Figure 13).
Referring to Figure 14, the insertion pin 167 of the bellows assembly tool 163
then
moves forward, engaging the recess of the outlet valve member 180. As the
insertion pin 167 continues to move forward, the legs 166 are sheared by the
3o insertion pin 167 working in conjunction with the distal end of the outlet
valve seat
175 wall. As the legs 166 are sheared, the outlet valve member 180 is pushed
past
the outlet valve seat 175. The legs 166 of this embodiment include a weakened
,
zone 169 in the form of a recess which forms a line of thinness across the
flexible
legs 166. Alternatively, the legs 166 may be sized so that they are
sufficiently thin
that severing is effected as described. Additionally, the outlet valve member
180
may be simply pushed past they outlet valve seat 175 by the insertion pin 167
until
the legs 166 simply tear which eliminates the need for a separate cutting or
shearing
WO 96/11065 ~ PCT/US95/12484
tool. It may also be desirable to cool the bellows 160 prior to insertion to
make the
bellows 160 more brittle; thereby aiding the shearing/tearing process.
To dispense liquid product from the source container (not seen), the trigger
122 is manually operated, as seen in Figure 10, such that the tab 119
cooperates
5 with depending wall 173; resulting in the nozzle 170 moving back toward the
closure 112 in a linear direction. The nozzle 170 is guided in this direction
by the
cooperation between the lugs 178 and the channels 114. As the nozzle 170 moves
back the bellows 160 is compressed which results in closing of the inlet valve
1126
and 150 and opening of the outlet valve 175 and 180 allowing liquid to be
sprayed
to through the swirl chamber 190. The liquid flows into the swirl chamber 190
through swirl channels 191 which, in combination with the side wall, causes
the
fluid to spin as it exits the discharge orifice 177. Thus, liquid product is
sprayed
from the supply container (not seen).
Upon release of the trigger 122, the resiliency of the bellows 160 acts like a
15 spring and expands, returning to its original shape. Alternatively, a
spring (not
seen) may be added to provide additional resiliency. The expansion of the
bellows
160 creates a negative pressure therein. During this period of negative
upstream
pressure, the outlet valve 175 and 180 closes. Also during this period of
negative
downstream pressure, the inlet valve 126 and 150 opens; allowing product to
flow
2o into the bellows 160 for the next dispensing operation. Simultaneously, air
may
pass through the cup seal vent valve created by the annular flange 161 of the
bellows 160 and the inner surface of the housing 110, if su~cient negative
pressure
is generated within the container (not seen). Thus, the container (not seen)
is
vented and the liquid dispensing pump device 120 is primed for the subsequent
dispensing operation.
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 major axis of the
collapsible
pump chamber may be vertical and/or 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.
