U.S. patent number RE40,319 [Application Number 11/197,729] was granted by the patent office on 2008-05-20 for liquid dispenser for dispensing foam.
This patent grant is currently assigned to Hygiene-Technik Inc.. Invention is credited to Ali Mirbach, Heiner Ophardt.
United States Patent |
RE40,319 |
Ophardt , et al. |
May 20, 2008 |
Liquid dispenser for dispensing foam
Abstract
A pump assembly provides for direct replacement of volumes of
liquid from a reservoir with equal volumes of air preferably at
substantially atmospheric pressure, the same pressure or with
pressure equalization to be at least equal to atmospheric pressure.
A slide arrangement preferably positively displaces liquid from the
reservoir and air into the reservoir. The pump draws air from the
atmosphere into a chamber from which the air either is available
for passage to replace liquid from the reservoir or is pressurized
to assist dispensing liquid, preferably, admixing with the liquid
to provide foaming. Gravity separation of air and liquid to be
dispensed is used to replace liquid with air in the reservoir and
to selectively place air and liquid into communication with
passageways for ejection.
Inventors: |
Ophardt; Heiner (Vineland,
CA), Mirbach; Ali (Issum, DE) |
Assignee: |
Hygiene-Technik Inc.
(Beamsville, Ontario, CA)
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Family
ID: |
4168656 |
Appl.
No.: |
11/197,729 |
Filed: |
August 5, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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09965821 |
Jun 25, 2002 |
6409050 |
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Reissue of: |
10118340 |
Apr 9, 2002 |
06601736 |
Aug 5, 2003 |
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Foreign Application Priority Data
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Mar 20, 2001 [CA] |
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2341659 |
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Current U.S.
Class: |
222/181.1;
222/321.8 |
Current CPC
Class: |
B01F
5/0682 (20130101); B05B 11/307 (20130101); B01F
5/0693 (20130101); A47K 5/14 (20130101); G01F
11/16 (20130101); B05B 7/0025 (20130101); B05B
11/3001 (20130101); B01F 3/04446 (20130101); B05B
11/3087 (20130101); B05B 11/3098 (20130101) |
Current International
Class: |
B67D
5/06 (20060101) |
Field of
Search: |
;222/181.1,321.8,321.9,325,340 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Ngo; Lien M.
Attorney, Agent or Firm: Riches, McKenzie & Herbert
LLP
Parent Case Text
RELATED APPLICATIONS
This application is a continuation-in-part of U.S. patent
application Ser. No. 09/965,821, filed Oct. 1, 2001 and issued as
U.S. Pat. No. 6,409,050 on Jun. 25, 2002.
Claims
We claim:
1. A pump for dispensing liquid from a reservoir comprising: a
piston chamber-forming member having an inner chamber and an outer
chamber each having a chamber wall, an inner end and an outer end;
the cross sectional area of the inner chamber being less than the
cross sectional area of the outer chamber, the inner chamber and
outer chamber being coaxial with the outer end of the inner chamber
opening into the outer chamber; an inner end of the inner chamber
in fluid communication with the reservoir; a piston-forming element
received in the piston chamber-forming member axially slidable
inwardly and outwardly therein between an outward extended position
and an inward retracted position; the piston-forming element having
an axially extending hollow stem having a central passageway having
an outlet proximate an outer end; an inner disk on the stem
extending radially outwardly from the stem adapted to engage to the
chamber wall of the inner chamber; an intermediate disk on the stem
extending radially outwardly from the stem adapted to engage the
chamber wall of the inner chamber, the intermediate disk spaced
axially outwardly from the inner disk relative the inner end of the
stem; an outer disk on the stem spaced axially outwardly from the
intermediate disk and extending radially outwardly from the stem
into engagement with the chamber wall of the outer chamber to
prevent fluid flow outwardly therebetween; a first inlet located on
the stem between the outer disk and the intermediate disk in
communication with the passageway; in the retracted position, the
intermediate disk is received in the inner chamber to prevent fluid
flow from the outer end of the inner chamber outwardly therepast
and the inner disk does not prevent fluid flow between the
reservoir and the inner chamber therepast via the inner end of the
inner chamber; in the extended position, the inner disk is received
in the inner chamber to prevent fluid flow from the inner end of
the inner chamber inwardly therepast and the intermediate disk does
not prevent fluid flow between the inner chamber and the outer
chamber via the outer end of the inner chamber.
2. A pump as claimed in claim 1 wherein: on axial movement of the
piston-forming element from the retracted position to the extended
position: (a) the intermediate disk moving from a blocking position
in which it closes the outer end of the inner chamber from fluid
flow therepast to an open position in which it does not close the
outer end of the inner chamber to free fluid flow therepast
inwardly or outwardly, and (b) the inner disk moving from an open
position in which it does not close the inner end of the inner
chamber to free fluid flow therethrough inwardly or outwardly to a
blocking position in which it closes the inner end of the inner
chamber from fluid flow therepast.
3. A pump as claimed in claim 2 wherein when the inner disk is in
its blocking position, the outer disk is in the open position and
when the inner disk is in its open position, the outer disk is in
its blocking position.
4. A pump as claimed in claim 2 wherein on axial movement of the
piston-forming element from the retracted position to the extended
position air is drawn into the outer chamber from the outlet.
5. A pump as claimed in claim 1 including a porous member in the
passageway between the first inlet and the outlet for generating
turbulence in fluid passing therethrough to generate foam when air
and liquid pass therethrough simultaneously.
6. A pump as claimed in claim 4 including a porous member in the
passageway between the first inlet and the outlet for generating
turbulence in fluid passing therethrough to generate foam when air
and liquid pass therethrough simultaneously.
7. A pump as claimed in claim 1 in which each of the piston
chamber-forming member and piston-forming element is of generally
circular cross-section disposed coaxially about a central axis
along which the piston-forming element and piston chamber-forming
member are slidable relative each other.
8. The pump as claimed in claim 1 in which the inner chamber is
disposed above the outer chamber with the inner end of the inner
chamber above the outer end of the inner chamber and the inner end
of the outer chamber above the outer end of the outer chamber.
9. A pump as claimed in claim 8 including a second inlet located on
the stem between the outer disk and the intermediate disk in
communication with the passageway, the second inlet spaced on the
stem spaced axially from the first inlet inwardly toward the inner
disk.
10. A pump assembly as claimed in claim 9 including a one-way valve
providing for fluid flow through the second inlet to the passageway
but preventing fluid flow from the passageway through the second
inlet.
11. A pump as claimed in claim 10 wherein the one-way valve
prevents fluid flow through the second inlet to the passageway
under a pressure differential across the one-way valve less than a
selected pressure differential.
12. A pump as claimed in claim 5 in which the inner chamber is
disposed above the outer chamber with the inner end of the inner
chamber above the outer end of the inner chamber and the inner end
of the outer chamber above the outer end of the outer chamber.
13. A pump as claimed in claim 12 including a second inlet located
on the stem between the outer disk and the intermediate disk in
communication with the passageway, the second inlet spaced on the
stem spaced axially from the first inlet inwardly toward the inner
disk.
14. A pump assembly as claimed in claim 10 including a one-way
valve disposed providing for fluid flow through the second inlet to
the passageway but preventing fluid flow from the passageway
through the second inlet.
15. A pump as claimed in claim 8 wherein an outer compartment is
defined by the piston-forming element between the outer disk and
the intermediate disk with an annular opening open radially
outwardly therebetween, an inner compartment is defined by the
piston-forming element between the intermediate disk and the inner
disk with an annular opening open radially outwardly therebetween,
wherein in the retracted position, the inner compartment is in
communication with the reservoir via the annular opening of the
inner compartment to permit air in the inner compartment to float
upwardly under gravity into the reservoir from the inner
compartment and be replaced by liquid in the reservoir flowing
downwardly into the inner compartment.
16. A pump as claimed in claim 15 wherein in the extended position,
the outer compartment and inner compartment are both in
communication with the outer chamber via their annular openings to
permit air in the outer compartment to float upwardly under gravity
into the inner compartment and be replaced by liquid in the inner
compartment flowing downwardly into the outer compartment.
17. A pump as claimed in claim 16 including a porous member in the
passageway between the first inlet and the outlet for generating
turbulence in fluid passing therethrough to generate foam when air
and liquid pass therethrough simultaneously; including a second
inlet located on the stem between the outer disk and the
intermediate disk in communication with the passageway, the second
inlet spaced on the stem spaced axially from the first inlet
inwardly toward the inner disk; wherein in a refraction stroke
while expelling fluid from the outer compartment, the outer
compartment contains a volume of liquid with air above a level of
the liquid and the level of the liquid in the outer compartment
drops to become below the second inlet before the level of the
liquid drops to a level of the first inlet.
18. A pump as claimed in claim 1 wherein the piston chamber-forming
member having a cylindrical air pump chamber disposed inwardly of
the inner chamber coaxial therewith, the air pump chamber having a
diameter, a chamber wall, a closed inner end and an open outer end,
the stem of the piston-forming element extending axially into the
air pump chamber via the outer end of the air pump chamber, an air
pump disk on the stem extending radially outwardly from the stem,
the air pump disc received in the air pump chamber in all positions
the piston-forming element assumes in sliding between the extended
position and the retracted position with the air pump disc engaging
the chamber wall of the air pump chamber to prevent fluid flow
therepast inwardly and outwardly; an inner end of the central
passageway opening into the air pump chamber inwardly of the air
pump disc; the air pump chamber and air pump disc form a variable
volume closed compartment open only via the inner end of the
central passageway, with sliding of the piston-forming element the
relative movement of the air pump disc changing the volume of the
closed compartment to draw fluid into the closed compartment from
the central passageway on sliding of the piston-forming
.[.inwardly.]. .Iadd.outwardly .Iaddend.and to force fluid out of
the closed compartment via the central passageway on sliding of the
piston-forming element .[.outwardly.]. .Iadd.inwardly.Iaddend..
19. A pump as claimed in claim 18 wherein: on axial movement of the
piston-forming element from the retracted position to the extended
position: (a) the intermediate disk moving from a blocking position
in which it closes the outer end of the inner chamber from fluid
flow therepast to an open position in which it does not close the
outer end of the inner chamber to free fluid flow therepast
inwardly or outwardly, and (b) the inner disk moving from an open
position in which it does not close the inner end of the inner
chamber to free fluid flow therethrough inwardly or outwardly to a
blocking position in which it closes the inner end of the inner
chamber from fluid flow therepast.
20. A pump as claimed in claim 19 wherein when the inner disk is in
its blocking position, the outer disk is in the open position and
when the inner disk is in its open position, the outer disk is in
its blocking position.
21. A pump as claimed in claim 20 wherein on axial movement of the
piston-forming element from the retracted position to the extended
position air is drawn into the outer chamber from the outlet.
22. A pump as claimed in claim 18 including a porous member in the
passageway between the first inlet and the outlet for generating
turbulence in fluid passing therethrough to generate foam when air
and liquid pass therethrough simultaneously.
23. A pump as claimed in claim 21 including a porous member in the
passageway between the first inlet and the outlet for generating
turbulence in fluid passing therethrough to generate foam when air
and liquid pass therethrough simultaneously.
24. A pump as claimed in claim 18 in which each of the piston
chamber-forming member and piston-forming element is of generally
circular cross-section disposed coaxially about a central axis
along which the piston-forming element and piston chamber-forming
member are slidable relative each other.
25. A pump as claimed in claim 18 in which the inner chamber is
disposed above the outer chamber with the inner end of the inner
chamber above the outer end of the inner chamber and the inner end
of the outer chamber above the outer end of the outer chamber, and
with the air pump chamber disposed above the inner chamber.
26. A pump as claimed in claim 25 including a second inlet located
on the stem between the outer disk and the intermediate disk in
communication with the passageway, the second inlet spaced on the
stem spaced axially from the first inlet inwardly toward the inner
disk.
27. A pump assembly as claimed in claim 26 including a one-way
valve providing for fluid flow through the second inlet to the
passageway but preventing fluid flow from the passageway through
the second inlet.
28. A pump as claimed in claim 27 wherein the one-way valve
prevents fluid flow through the second inlet to the passageway
under a pressure differential across the one-way valve less than a
selected pressure differential.
29. A pump as claimed in claim 22 in which the inner chamber is
disposed above the outer chamber with the inner end of the inner
chamber above the outer end of the inner chamber and the inner end
of the outer chamber above the outer end of the outer chamber.
30. A pump as claimed in claim 29 including a second inlet located
on the stem between the outer disk and the intermediate disk in
communication with the passageway, the second inlet spaced on the
stem spaced axially from the first inlet inwardly toward the inner
disk.
31. A pump assembly as claimed in claim 26 including a one-way
valve providing for fluid flow through the second inlet to the
passageway but preventing fluid flow from the passageway through
the second inlet.
32. A pump as claimed in claim 25 wherein an outer compartment is
defined by the piston-forming element between the outer disk and
the intermediate disk with an annular opening open radially
outwardly therebetween, an inner compartment is defined by the
piston-forming element between the intermediate disk and the inner
disk with an annular opening open radially outwardly therebetween,
wherein in the refracted position, the inner compartment is in
communication with the reservoir via the annular opening of the
inner compartment to permit air in the inner compartment to float
upwardly under gravity into the reservoir from the inner
compartment and be replaced by liquid in the reservoir flowing
downwardly into the inner compartment.
33. A pump as claimed in claim 32 wherein in the extended position,
the outer compartment and inner compartment are both in
communication with the outer chamber via their annular openings to
permit air in the outer compartment to float upwardly under gravity
into the inner compartment and be replaced by liquid in the inner
compartment flowing downwardly into the outer compartment.
34. A pump as claimed in claim 33 including a porous member in the
passageway between the first inlet and the outlet for generating
turbulence in fluid passing therethrough to generate foam when air
and liquid pass therethrough simultaneously; including a second
inlet located on the stem between the outer disk and the
intermediate disk in communication with the passageway, the second
inlet spaced on the stem spaced axially from the first inlet
inwardly toward the inner disk; wherein in a retraction stroke
while expelling fluid from the outer compartment, the outer
compartment contains a volume of liquid with air above a level of
the liquid and the level of the liquid in the outer compartment
drops to become below the second inlet before the level of the
liquid drops to a level of the first inlet.
35. A pump as claimed in claim 1 including an air pump mechanism
comprising an air pump chamber and air pump disc slidable therein,
one of the air pump chamber and air pump disc carried on the
piston-chamber forming member and the other carried on the
piston-forming element, the air pump chamber and air pump disc
interacting to form a variable volume compartment open to the
central passageway to draw air into the closed compartment on
movement of the piston-forming element .[.inwardly.].
.Iadd.outwardly .Iaddend.and to force air out of the outlet on
movement of the piston-forming element .[.outwardly.].
.Iadd.inwardly.Iaddend..
Description
SCOPE OF THE INVENTION
This invention relates to liquid dispensers and, more particularly,
liquid dispensers to dispensing liquid as a foam.
BACKGROUND OF THE INVENTION
Liquid dispensers for dispensing soaps and other similar fluids in
liquid form are known. For various reasons in some applications, it
is preferable to dispense soaps and other similar fluids in the
form of a foam. Generally, in the form of a foam, less soap liquid
is required to be used as contrasted with the soap in the liquid
form. As well, soap as foam is less likely to run off a user's
hands or other surfaces to be cleaned.
Known liquid dispensers for dispensing foams include the dispenser
taught by U.S. Pat. No. 5,445,288 to Banks, issued Jul. 29, 1995. A
disadvantage which the present inventor has appreciated with
dispensers such as those taught by Banks is that when used with a
non-collapsible or rigid sealed container of soap liquid, a vacuum
comes to be developed in the container which renders the dispenser
inoperative.
Known liquid dispensers for dispensing liquids without foaming of
the liquids are also known. The present inventor has also
appreciated that many such dispensers also suffer the disadvantage
that they are not suitable for use with non-collapsible or rigid
sealed containers since the pumps develop a vacuum in the
container. Non-collapsible or rigid sealed containers have the
disadvantage of requiring various one-way valve mechanisms to
permit air to enter the containers under vacuum to equalize the
pressure in the containers with atmospheric pressure. Such one-way
valves typically suffer the disadvantage that they maintain at
least some vacuum pressure differential in the container and with
many viscous soaps, the presence of even a slight vacuum can
negatively affect dispensing.
The present inventor has also appreciated that known soap
dispensers suffer the disadvantage that they do not permit for
positive replacement of air for liquid dispensed from a liquid
reservoir and/or do not permit a positive pressure to develop in a
container.
SUMMARY OF THE INVENTION
To at least partially overcome these disadvantages of previously
known devices, the present invention provides a pump for dispensing
fluid which provides for a positive replacement of liquid dispensed
from a container, preferably with atmospheric air. The present
invention also provides a pump for dispensing liquid in the form of
a foam preferably without creating a vacuum in a non-collapsible or
rigid sealed container.
An object of the present invention is to provide an improved pump
for dispensing a liquid.
Another object is to provide an improved pump for dispensing a
liquid in the form of a foam.
Another object is to provide a pump for dispensing liquid from a
non-collapsible or rigid sealed container without creating a vacuum
in the container.
Another object is to provide a pump which provides for positive
replacement of liquid dispensed from a container by atmospheric
air.
Accordingly, in one aspect, the present invention provides a pump
for dispensing liquid from a reservoir comprising: a piston
chamber-forming member having an inner cylindrical chamber and an
outer cylindrical chamber each having a diameter, a chamber wall,
an inner end and an outer end; the diameter of the inner chamber
being less than the diameter of the outer chamber, the inner
chamber and outer chamber being coaxial with the outer end of the
inner chamber opening into the outer chamber; an inner end of the
inner chamber in fluid communication with the reservoir; a
piston-forming element received in the piston chamber-forming
member axially slidable inwardly and outwardly therein between an
outward extended position and an inward retracted position; the
piston-forming element having an axially extending hollow stem
having a central passageway closed at an inner end and having an
outlet proximate an outer end; an inner disk on the stem extending
radially outwardly from the stem adapted to engage to the chamber
wall of the inner chamber; an intermediate disk on the stem
extending radially outwardly from the stem adapted to engage the
chamber wall of the inner chamber, the intermediate disk spaced
axially outwardly from the inner disk relative the inner end of the
stem; an outer disk on the stem spaced axially outwardly from the
intermediate disk and extending radially outwardly from the stem
into engagement with the chamber wall of the outer chamber to
prevent fluid flow outwardly therebetween; an inlet located on the
stem between the outer disk and the intermediate disk in
communication with the passageway; in the retracted position, the
intermediate disk is received in the inner chamber to prevent fluid
flow from the outer end of the inner chamber outwardly therepast
and the inner disk does not prevent fluid flow between the
reservoir and the inner chamber therepast via the inner end of the
inner chamber; in the extended position, the inner disk is received
in the inner chamber to prevent fluid flow from the inner end of
the inner chamber inwardly therepast and the intermediate disk does
not prevent fluid flow between the inner chamber and the outer
chamber via the outer end of the inner chamber.
Preferably, the pump includes a porous member in the passageway
between the inlet and the outlet for generating turbulence in fluid
passing therethrough to generate foam when air and liquid pass
therethrough simultaneously.
In preferred embodiments, the pump assembly provides for direct
replacement of volumes of liquid from a reservoir with equal
volumes of air preferably at substantially atmospheric pressure,
the same pressure or with pressure equalization to be at least
equal to atmospheric pressure. A slide arrangement preferably
positively displaces liquid from the reservoir and air into the
reservoir. The pump draws air from the atmosphere into a chamber
from which the air either is available for passage to replace
liquid from the reservoir or is pressurized to assist dispensing
liquid, preferably, admixing with the liquid to provide foaming.
Gravity separation of air and liquid to be dispensed is used to
replace liquid with air in the reservoir and to selectively place
air and liquid into communication with passageways for
ejection.
BRIEF DESCRIPTION OF THE DRAWINGS
Further aspects and advantages of the present invention will become
apparent from the following description taken together with the
accompanying drawings in which:
FIG. 1 is a partially cut-away side view of a first preferred
embodiment of a liquid dispenser with a reservoir and pump assembly
in accordance with the present invention;
FIG. 2 is a partially exploded perspective view of the pump
assembly shown in FIG. 1;
FIG. 3 is a cross-sectional side view of an assembled pump assembly
of FIG. 2 showing the piston in a fully extended position;
FIG. 4 is the same side view as in FIG. 3;
FIG. 5 is a cross-sectional side view similar to FIG. 3 but with
the piston in an intermediate position in a retraction stroke;
FIG. 6 is a cross-sectional side view similar to FIG. 3 but with
the piston in a fully retracted position;
FIG. 7 is a cross-sectional side view substantially identical to
FIG. 5 with the piston in an intermediate position, however, in a
extension stroke;
FIG. 8 is a cross-sectional side view substantially identical to
that shown in FIG. 3, however, at the end of an extension
stroke;
FIG. 9 is a cross-sectional side view of a pump assembly in
accordance with a second embodiment of the present invention;
FIGS. 10 and 11 are cross-sectional side views of the body and
piston, respectively, of the pump assembly of FIG. 9;
FIG. 12 is a cross-sectional side view of the pump of FIG. 8 in a
fully extended position;
FIG. 13 is a cross-sectional side view of the pump assembly of FIG.
8 in an intermediate position;
FIG. 14 is a cross-sectional side view of the pump assembly of FIG.
8 in a fully retracted position;
FIG. 15 is a cross-sectional side view of a piston for a pump
assembly in accordance with a third embodiment of the present
invention;
FIG. 16 is a cross-sectional side view of a piston for a pump
assembly in accordance with a fourth embodiment of the present
invention;
FIG. 17 is a cross-sectional side view of a pump assembly in
accordance with a fourth embodiment of the present invention.
DETAILED DESCRIPTION OF THE DRAWINGS
Reference is made first to FIGS. 2 and 3 which show a pump assembly
generally indicated 10. Pump assembly 10 is best shown in FIG. 2 as
comprising two principal elements, a piston chamber-forming body 12
and a piston 14.
Referring to FIG. 3, body 12 has an inner cylindrical chamber 18
and an outer cylindrical chamber 20 both coaxially disposed about
an axis 22. The inner chamber 18 has an inlet opening 24 and an
outlet opening 26. The inner chamber has a cylindrical chamber side
wall 28. The outlet opening 26 opens into an inlet end of the outer
chamber 20 from an opening in a shoulder 32 forming the inner end
of the outer chamber 20. The outer chamber has an outlet opening 34
and a cylindrical chamber side wall 36.
Piston 14 is axially slidably received in the body 12. The piston
14 has an elongate stem 38 upon which four disks are provided at
axially spaced locations. An inner sealing disk 40 is provided at
an innermost end spaced axially from an intermediate sealing disk
42 which, in turn, is spaced axially from an outer sealing disk 44.
The inner sealing disk 40 and intermediate sealing disk 42 are
adapted to be axially slidable within the inner chamber 18. Each of
the inner sealing disk 40 and intermediate sealing disk 42 extend
radially outwardly from the stem 38 so as to be adapted to sealably
engage the side wall 28 of the inner chamber 18.
The outer sealing disk 44 is adapted to be axially slidable within
the outer cylindrical chamber 20. The outer sealing disk 44 extends
radially outwardly from the stem 38 to sealably engage the side
wall 36 of the outer chamber 20.
The piston 14 essentially forms, as defined between the inner
sealing disk 40 and the intermediate sealing disk 42, an annular
inner compartment 64 which opens radially outwardly as an annular
opening between the disks 42 and 44. Similarly, the piston 14
effectively forms between the intermediate sealing disk 42 and the
outer sealing disk 44 an annular outer compartment 66 which opens
radially outwardly as an annular opening between the disks 42 and
44.
An outermost portion of the stem 38 is hollow with a central
passageway 46 extending from an outlet 48 at the outermost end 50
of the stem 38 centrally through the stem 38 to a closed inner end
52. Radially extending inlets 53 and 54 extend radially through the
stem into the passageway 46, with the inlets 53 and 54 being
provided on the stem in between the outer sealing disk 44 and the
intermediate sealing disk 42. A foam inducing screen 56 is provided
in the passageway 46 intermediate between the inlets 53 and 54 and
the outlet 48. The screen 56 may be fabricated of plastic, wire or
cloth material. It may comprise a porous ceramic measure. The
screen 56 provides small apertures through which an air and liquid
mixture may be passed to aid foam production as by production of
turbulent flow through small pores or apertures of the screen
thereof in a known manner.
The piston 14 also carries an engagement flange or disk 62 on the
stem outward from the outer sealing disk 44. Engagement disk 62 is
provided for engagement by an activating device in order to move
the piston 14 in and out of the body 12.
Reference is now made to FIG. 1 which shows a liquid soap dispenser
generally indicated 70 utilizing the pump assembly 10 of FIGS. 2
and 3 secured in the neck 58 of a sealed, non-compressible, rigid
reservoir 60 containing liquid hand soap 68 to be dispensed.
Dispenser 70 has a housing generally indicated 78 to receive and
support the pump assembly 10 and the reservoir 60. Housing 78 is
shown with a back plate 80 for mounting the housing, for example,
to a building wall 82. A bottom support plate 84 extends forwardly
from the back plate to support and receive the reservoir 60 and
pump assembly 10. As shown, bottom support plate 84 has a circular
opening 86 therethrough. The reservoir 60 sits supported on
shoulder 79 of the support plate 84 with the neck 58 of the
reservoir 60 extending through opening 86 and secured in the
opening as by a friction fit, clamping and the like. A cover member
85 is hinged to an upper forward extension 87 of the back plate 80
so as to permit replacement of reservoir 60 and its pump assembly
10.
Support plate 84 carries at a forward portion thereof an actuating
lever 88 journalled for pivoting about a horizontal axis at 90. An
upper end of the lever 88 carries a hook 94 to engage engagement
disk 62 and couple lever 88 to piston 14, such that movement of the
lower handle end 96 of lever 88 from the dashed line position to
the solid line position, in the direction indicated by arrow 98
slides piston 14 inwardly in a retraction pumping stroke as
indicated by arrow 100. On release of the lower handle end 96,
spring 102 biases the upper portion of lever 88 downwardly so that
the lever draws piston 14 outwardly to a fully withdrawn position
as seen in dashed lines in FIG. 1. Lever 88 and its inner hook 94
are adapted to permit manual coupling and uncoupling of the hook 94
as is necessary to remove and replace reservoir 60 and pump
assembly 10.
In use of the dispenser 70, once exhausted, the empty reservoir 60
together with the attached pump 10 are removed and a new reservoir
60 and attached pump 10 may be inserted into the housing.
Preferably, the removed reservoir 60 with its attached pump 10 are
both made entirely out of recyclable plastic material which can
easily be recycled without the need for disassembly prior to
cutting and shredding.
FIG. 3 shows as dotted line 43 a preferred level of liquid in the
outer chamber 20 ready for expulsion in a retraction stroke. Liquid
level line 43 is above inlet 54 but below inlet 53 so that air
above line 43 is in communications with inlet 53 and liquid is in
communication with inlet 54.
Reference is now made to FIGS. 4 to 8 which show a cycle of
operation in which the piston 14 is moved in a retraction stroke
from the extended position of FIG. 4 to the intermediate position
of FIG. 5 and then to the fully retracted position of FIG. 6.
Subsequently, piston 14 is moved in an extension stroke from the
fully retracted position of FIG. 6, to the intermediate position of
FIG. 7 and, subsequently, to the fully extended position of FIG. 8.
It is to be appreciated that FIGS. 5 and 7 both show the piston 14
in the intermediate position and FIGS. 4 and 8 both show the piston
in the fully extended position. For convenience in each of FIGS. 4
to 8, the engagement disk 62 is not shown.
In the fully extended position as seen in FIG. 4, the inner sealing
disk 40 closes the inner chamber 18 preventing flow inward and
outward through the inner chamber 18. The intermediate sealing disk
42 is disposed in the outer chamber 20. With the intermediate
sealing disk 42 in the larger diameter outer chamber 20, the inner
compartment 64 and outer compartment 66 are in communication with
each other.
As seen in FIG. 4 and in every position which the piston 14 can
assume in each of FIGS. 4 to 8, the outer sealing disk 44 engages
the side wall 36 of the outer chamber 20 and prevents liquid flow
inwardly or outwardly therepast. As well, at all times, the outlet
48 of the central passageway 46 is in communication with the outer
compartment 66 via the passageway 46 and inlets 53 and 54.
In the fully extended position shown in FIG. 4 with the inner
chamber 18 vertically above the outer chamber 20, to the extent
there is any liquid in the inner compartment 64, that liquid will,
under gravity, flow from inner compartment 64 downwardly into outer
compartment 66 to be replaced by air in the outer compartment 66
rising upwardly into the inner compartment 64.
In moving from the fully extended position of FIG. 4 to the
intermediate position of FIG. 5, since the outer chamber 20 has a
larger diameter than the inner chamber 18, air and liquid in both
the inner compartment 64 and outer compartment 66 are compressed
and forced to exit the outer compartment 66 via inlets 53 and 54
into the central passageway 46, down the central passageway 46
through the wire screen 56 and, hence, down the central passageway
46 to exit the outlet 48. The nature of the inlets 53 and 54 are to
be chosen to enhance appropriate mixing of air and liquid in the
passageway 46 prior to engaging the screen 56. For example, as
shown, inlet 54 is larger than inlet 53. Larger inlet 54 is
provided closer to the outer sealing disk 44. Smaller inlet 53 is
provided at a height above the larger inlet 54 closer to the
intermediate sealing disk 42. Since liquid will flow under gravity
to lie on outer disc 44, larger inlet 54 is more likely to have
liquid forced therethrough, whereas smaller inlet 53 is more likely
to have air forced therethrough than larger inlet 54.
FIG. 5 shows an intermediate position in the retraction stroke
being illustrated as a point when each of the inner sealing disk 40
and the intermediate sealing disk 42 seal the inner chamber 18 with
both preventing fluid flow therethrough. In the preferred
illustrated embodiment, substantially simultaneously with the
intermediate sealing disk 42 commencing to close the inner chamber
18, the inner sealing disk 40 becomes moved inwardly from the inner
chamber 18 to open the inner compartment 64 to the reservoir
60.
In moving from the position of FIG. 4 to the position of FIG. 5,
air within the inner compartment 64 moves upwardly into the inner
chamber 18. In moving from the position of FIG. 4 to the position
of FIG. 5, it is to be appreciated that the inner chamber 18 is
continuously sealed against flow therethrough by the inner sealing
disk 40. In moving from the intermediate position of FIG. 5 to the
fully retracted position of FIG. 6, it is to be appreciated that
the intermediate sealing disk 42 continuously forms a seal with the
inner chamber 18 preventing fluid flow therethrough. Once the
intermediate sealing disk 42 engages in the inner chamber 18 as
seen in FIG. 5, then the inner compartment 64 is no longer in
communication with the outer compartment 66. As well, once the
inner sealing disk 40 is located inwardly from the inner chamber 18
so that it no longer seals the inner chamber 18, then the inner
compartment 64 is in communication with the interior of the
reservoir 60.
Air which is within the inner compartment 64 in the intermediate
position shown in FIG. 5, on inward movement of the piston 14 in
the retraction stroke toward the position of FIG. 6, comes to be in
communication with the interior of the reservoir 60 and such air
will, under gravity, float upwardly in the fluid 68 in the
reservoir 60 and be displaced by liquid 68 from the reservoir 60
which will flow into the inner compartment 64. Thus, once the
piston 14 moves inwardly from the intermediate position shown in
FIG. 5 with the inner sealing disk 40 no longer closing the inlet
opening 26 of the inner chamber 18, then air in the inner
compartment 64 rises upwardly into the reservoir and fluid 68 from
the reservoir 60 fills the inner compartment 64.
On the piston reaching the intermediate position shown in FIG. 5,
the intermediate sealing disk 42 forms a seal with the inner
chamber 18 and the outer compartment 66 is thereby isolated from
the inner compartment 64. Air and liquid in the inner compartment
66 is, on continued movement of the piston 14 from the position of
FIG. 5 to the fully retracted position of FIG. 6, continued to be
compressed with air and liquid to be displaced out the inlets 53
and 54.
As seen in FIG. 6 in the fully retracted position, the outer
sealing disk 44 may engage the shoulder 32 forming the inlet end of
the outer chamber 20.
An extension cycle is now discussed referring to the movement of
the piston from the position of FIG. 6 to the position of FIG.
8.
In the position of FIG. 6, only a small residual amount of liquid
will remain within the outer compartment 66. On moving of the
piston 14 from the position of FIG. 6 to the position of FIG. 7,
liquid which fills the inner compartment 64 is moved downwardly
into the inner chamber 18 and becomes captured between the inner
sealing disk 40 and intermediate sealing disk 42 within the inner
chamber 18 once the inner sealing disc 40 enters the inner chamber
18. Meanwhile, since the diameter of the inner chamber 18 is less
than the diameter of the outer chamber 20, a partial vacuum is
created within the outer compartment 66 which draws air inwardly
via the outlet 48, through the screen 56 and passageway 46 and the
inlets 53 and 54 into the outer compartment 66.
From the intermediate position shown in FIG. 7, on movement of the
piston 14 outwardly towards the fully extended position of FIG. 8,
the inner sealing disk 40 seals the inner chamber 18 against flow
therethrough and the intermediate sealing disk 42 moves inwardly
beyond the inner chamber 18 so as to provide communication between
the inner compartment 64 and the outer compartment 66. Once
communication is established between the inner compartment 64 and
the outer compartment 66, liquid in the inner compartment 64 flows
under gravity down into the outer compartment 66 and air in the
outer compartment 66 flows upwardly into the inner compartment 64.
With the further downward movement of the piston 14 to the fully
extended position of FIG. 8, air continues to be drawn into the
combined inner compartment 64 and outer compartment 66 via the
outlet 48, passageway 46 and inlets 53 and 54 such that on reaching
the fully extended position, as seen in FIG. 8, liquid in the outer
compartment 66 will form a layer upon the outer sealing disk 44.
FIG. 8 is identical to FIG. 4 and the pump cycle may be
repeated.
It is to be appreciated that the relative volume of the inner
compartment 64 and outer compartment 66 may be chosen so as to have
a desired proportion of liquid and air in the combined inner
compartment 64 and outer compartment 66 in the fully extended
position and, preferably, with volume of liquid such that a level
of liquid in the compartment 66 below the inlet 53 but above the
inlet 54.
The fact that in the first embodiment air is drawn upwardly through
the outlet 48 can be of assistance in reducing dripping of foam and
liquid and, as well, can be of assistance in ensuring a mixture of
liquid and foam in the passageway 46 above the screen 56 in a
subsequent retraction stroke when liquid and air are to be
dispensed.
The relative amounts of air and liquid in the compartments 64 and
66 in the fully extended position as well as the manner and nature
of the inlets 53 and 54 can be significant as, for example, to
determine the extent to which air may be compressed in the outer
chamber 20 which can have an effect on the velocity of air flowing
through the screen 56 and, hence, the extent to which foaming may
be accomplished.
The preferred embodiment illustrated in FIGS. 2 to 8 shows the
inner sealing disk 40 and intermediate sealing disk 42 in the
intermediate position both sealing the inner chamber 18. It is to
be appreciated that under one preferred arrangement, preferably, at
least one of the inner sealing disk 40 and intermediate sealing
disk 42 seals the inner chamber 18 at all times. It is to be
appreciated, however, that it is possible to have the inner sealing
disk 40 and intermediate sealing disk 42 spaced axially a distance
such that there is a time during movement between the fully
extended position and the fully retracted position in which neither
of the inner sealing disk 40 and intermediate sealing disk 42 seal
the inner chamber 18 and this can be advantageous, for example, to
permit increased quantities of air to move upwardly into the
reservoir while additional quantities of liquid move downwardly out
of the reservoir.
Having the condition arise that neither the inner sealing disk 40
nor the intermediate sealing disk 42 seal the inner chamber 18 for
at least a small portion of the stroke can be advantageous to
permit equalization of the pressures in the reservoir and in the
outer compartment 66 as may be useful, for example, to assist in
ensuring that a vacuum does not arise in the interior of the
reservoir and/or to reduce the likelihood of preventing an unduly
large positive pressure from being developed within the
reservoir.
The pump could alternatively be structured so as to provide with
each stroke a small amount of air under pressure into the interior
of the reservoir, which positive pressure, provided it is not
dangerous to the integrity of the container, can assist in urging
liquid to exit the reservoir into the inner chamber 18 when the
inner sealing disc 40 is not sealing entry into the inner chamber
18.
The length of the stroke of the piston as, for example, from the
intermediate position to the fully extended position can be varied
so as to control the amount of air which is drawn into the outer
chamber 20. The length of the stroke by which the piston 14 is
moved from the intermediate position to the fully retracted
position can be varied to control the extent to which liquid and
air may be expelled in any stroke.
Reference is now made to FIGS. 9 to 14 which illustrate a second
embodiment of a pump assembly in accordance with the present
invention. Throughout the drawings, the same reference numerals are
used to refer to like elements.
FIG. 9 also shows a pump assembly 10 having a piston
chamber-forming body 12 and a piston 14. The piston chamber-forming
body 12 is threadably secured to the neck 58 of a rigid sealed
bottle 60. Body 12 is provided with an axially extending generally
cylindrical rim 102 provided outwardly from the outer chamber 20
and carrying inwardly directed threads 104 adapted to engage
complementary threads 106 carried on the neck 58 of the bottle
60.
FIG. 9 also shows a removable cover 107 which fits in a snap-fit
engagement onto body 12 forming an airtight annular seal thereabout
to protect the pump assembly 10 from contamination prior to use as,
for example, during shipment. As best seen in FIG. 10, the body 12
is formed with a cylindrical outer tubular portion 108 connected at
an inner end via a radially extending flange portion 110 to a
cylindrical inner tubular portion 112. The inner tubular portion
112 extends axially radially inside the outer tubular portion
108.
The outer chamber 20 is formed radially inwardly of the outer
tubular portion 108 having a side wall 36 thereabout and open at
its outlet opening 34. As shown, the side wall 36 tapers outwardly
at chamfers 35 proximate the outlet opening 34 to facilitate entry
of the piston 14.
An inner chamber 18 is formed radially inwardly of the inner
tubular portion 112. The inner tubular portion 112 defines an
outlet opening 26 of the inner chamber 18 and a side wall 28
thereof. The inner chamber 18 has its side wall 28 taper outwardly
as a chamfer 25 proximate the outlet opening 26 to facilitate entry
of the piston into the inner chamber 18. The side wall 28 has a
portion 27 of constant diameter between chamfer 25 and an axially
inwardly spaced chamfer 29. The side wall 28 of the inner chamber
18 has a portion 31 of increased diameter relative to the constant
diameter portion 27 spaced axially inwardly from the constant
diameter portion 27 by chamfer 29. The increased diameter portion
31 permits fluid flow inwardly and outwardly in the inner chamber
18 past the inner disk 40 of the piston 14 when the piston 14 is in
the fully withdrawn position as seen in FIGS. 9 and 14.
The inner tubular portion 112, outer tubular portion 108, inner
chamber 18 and outer chamber 20 are each coaxial about axis 22.
The inner tubular portion 112 extends axially inwardly from flange
portion 110 as a series of circumferentially spaced arms 114, only
one of which is shown cross-sectioned on the left-hand side of
FIGS. 9, 10 and 12 to 14 to support an annular ring 116 disposed
coaxially about the central axis 22. The ring 116 serves as a guide
to assist in guiding a cylindrical inward guiding portion 118 of a
stem 38 of the piston 14 in coaxial sliding within the body 12.
Spaces 119 are provided between the arms 114 as shown on the
right-hand side of FIGS. 9, 10 and 12 to 14 to provide free
communication for fluid between the reservoir and the interior of
the inner tubular portion 112, radially through the tubular portion
112.
As best seen in FIG. 11, the piston 14 is formed from six elements,
namely, an outer casing 120, an inner core 122, a center plug 124,
a spacer ring 126 and two screens 56 and 57.
The outer casing 120 is of enlarged diameter at its axially inner
end where the outer disk 44 is provided. The outer disk 44 is shown
as including a locating flange 128 to locatably engage the
cylindrical side wall 36 of the outer chamber 20 and a resilient
flexible circular sealing disk 130 which sealably engages the side
wall 36 and prevents flow of fluids axially outwardly
therepast.
The outer casing 120 is shown with the outer disk 44 carried as a
radially outwardly extending flange on a cylindrical large tube
portion 132 which extends axially outwardly to a radially inwardly
extending shoulder 134 supporting a small tube portion 136
extending axially outwardly from the shoulder 134 to the outlet 48.
Outer screen 57 is located on the shoulder 134. Outer screen 57 is
held on the shoulder 134 by the annular spacer ring 126 spaced
outward of an inner screen 56. The inner core 122 sandwiches the
outer screen 57 onto the ring 126. The inner core 122 also carries
the plug 124 coaxially extending inwardly into the inner core 122
inwardly of the outer screen 57.
The inner core 122 carries the inner disk 40 and the intermediate
disk 42. Each of the inner disk 40 and intermediate disk 42
comprise circular resilient flexible disks each of which extends
radially outwardly and away from the outlet 48. Each of the inner
flexible 40 and intermediate flexible disk 42, when engaged with
the constant diameter portion 27 of the inner chamber 18, prevent
fluid flow axially outwardly therepast through the inner chamber
18, however, are adapted to have their resilient outer edges
deflect radially inwardly to permit fluid flow, under pressure
differentials above a predetermined pressure, axially inwardly past
the disks.
As seen in FIGS. 9 and 12, when the inner disk 40 is located in the
inner chamber 18 inwardly from the constant diameter portion 27 in
the increased diameter portion 31, then the inner disk 40 does not
prevent flow of fluid between the inner chamber 18 and the
reservoir 60.
The inner core 122 has a hollow bore 140 closed at an axial inner
end at 142 and open at an axial outer end. The plug 124 is
coaxially received within the bore 140 at the axial outer end. The
plug 124 has an elongate body 143 which extends inwardly into the
bore 140. The plug 124 has a radially extending base 144 at its
outer end with a plurality of circumferentially spaced opening 146
therethrough. The body 143 of the plug 124 carries an integral
central sealing disk 148 which extends radially outwardly from the
body 143 to engage the side wall of the bore 140. The central
sealing disk 148 has a deformable edge portion which engages the
side wall of the bore 140 to prevent fluid flow axially inwardly
therepast in the bore, however, permits fluid flow outwardly
therepast under pressures above a predetermined pressure necessary
to deflect the central sealing disk 148 out from engagement with
the side wall of the bore.
The inner core 122 includes a cylindrical lower portion 123 which
has a plurality of flutes at circumferentially spaced locations
thereabout which effectively form with the outer casing 120
peripheral passageways 152 which extend axially. Passageways 152
are open to the outer compartment 66 between disks 42 and 44 at
openings 150 at the inner ends of the passageways. At the outer
ends, the passageways 152 join radial inlets 54 in the lower
portion 123 which provide communication into the central bore
140.
Radially extending inlet 53 extends into the bore 140 from the
outer compartment 66 between the intermediate disk 42 and the outer
disk 44.
The piston 14 provides a common flow path which is provided for
flow of fluids in the bore 140 immediately inwardly above the base
144 of the plug 124, through the openings 146 in the base 144 of
the plug 124, through the inner screen 57, through a hollow central
opening 127 in the spacer ring 126, through the outer screen 56
and, hence, through the smaller tube portion 136 to the outlet 48.
However, the piston 14 provides two different pathways for flow of
fluid from the outer compartment 66 to the openings 146 in the base
144 of the plug 124.
A first pathway permits flow via openings 152, peripheral
passageways 150 and inlets 54 into the bore 140. The first pathway
permits fluid flow both inwardly and outwardly and is particularly
adapted to receive any liquid which under gravity flows down to the
lower and axially outermost portion of the outer compartment 66
where the openings 150 to the peripheral passageways 150 are
provided.
A second pathway provides flow via the inlet 53 into the bore 140
and past the central sealing disk 148 to the openings 146 in the
base 144 of the plug 124. It is to be appreciated that this second
pathway is only open to fluid flow outwardly from the outer
compartment 66 since the central sealing disk 148 prevents fluid
flow inwardly therepast. Preferably, as shown, the inlets 53 are
disposed at an axial inner location in the outer compartment 66 so
as to be more likely to have the inlet 53 receive air which will
rise to the upper and axial inner end of the upper compartment 64
underneath the intermediate disk 42 and be found above a level of
liquid in the lower outer compartment 66.
Operation of the second embodiment of FIGS. 9 to 14 is similar to
that with the first embodiment of FIGS. 1 to 8.
In a fully extended position as seen in FIG. 12, the inner sealing
disk 40 seals the inner chamber 18 against fluid flow outwardly
therefrom. In an intermediate position as shown in FIG. 13, both
the inner disk 40 and the intermediate disk 42 seal the inner
chamber 18 against fluid flow outwardly therethrough. In the fully
retracted position as shown in FIG. 14, the intermediate disk 42
seals the inner chamber 18 from fluid flow outwardly from the
reservoir.
In the fully extended position as seen in FIG. 12, the intermediate
disk 42 is withdrawn inwardly past the inner tubular portion 112 to
a position in which it does prevent flow of fluid between the inner
compartment 64 and the outer compartment 66 and the two
compartments are in communication.
In the fully retracted position as shown in FIG. 14, the inner disk
40 does not prevent flow of fluid therepast and, hence, the
reservoir 60 is in communication with the inner compartment 64.
In a retraction stroke, on moving from the position of FIG. 12 to
the position of FIG. 13, air and/or liquid is compressed and
thereby forced to pass outwardly from the outer compartment 66 via
either the first pathway through peripheral passageways 152 and
inlet 54 or via the second pathway through the inlet 53 and past
the central sealing disk 148 in bore 140. The central sealing disk
148 provides resistance to fluid flow axially outwardly therepast.
This is advantageous in a situation where liquid fills the
lowermost portion of the outer compartment 66 such that liquid is
being urged via the first pathway through the peripheral
passageways 152 and inlet 54 and air fills the upper portion of the
outer chamber 66 such that air is being forced via the second
pathway through the inlet 53 and bore 140 onto the central sealing
disk 148. The central sealing disk 148 is preferably chosen so as
to require a predetermined air pressure differential before air may
be permitted to flow outwardly therepast.
The resistance of liquid flowing from the peripheral passageways
152, inlet 54, openings 146 in the plug 124 and through the screens
56 and 57 requires a pressure on the liquid sufficiently to force
the liquid therethrough. The central sealing disk 148 is preferably
selected so that air pressurized to a pressure at least equal to
that required to overcome the resistance to liquid flow will be
required for air flow past the central sealing disk 148. Providing
the air to be pressurized to pass by the central sealing disk 148
is of assistance in providing for turbulent air flow through the
screens 56 and 57 which, when liquid has also been passed through
the screens, provides for preferred foaming as liquid and air are
passed effectively simultaneously through the screens.
In an extension stroke on moving from the position of FIG. 13 to
the position of FIG. 14, air is drawn into the outer compartment
66. One pathway for the air to be drawn in is via the outlet 48,
through the screens 56 and 57 and, hence, via the inlet 54 and
peripheral passageways 152 into the outer compartment 66. Air
cannot be drawn inwardly through the bore 140 and inlet 53 since
the bore 120 is blocked against flow inwardly therepast by the
central sealing disk 148.
As shown in FIG. 12, the outer disk 44 includes a resilient sealing
disk 130 which is formed as a thin resilient disk having an
elastically deformable edge portion near the side wall 36 of the
outer chamber 20. This edge portion of the sealing disk 130 is
deflectable radially inwardly so as to permit, under a sufficiently
high vacuum differential, air to flow axially inwardly therepast.
Preferably, the piston 14 may be configured such that substantially
all air to be drawn inwardly is drawn inwardly via the peripheral
passageways 146 and the first pathway, however, a device could be
arranged such that the restriction to flow through the first
pathway, and/or the screens 57 and 56 is such that some proportion
or substantially all the air is drawn past the sealing disk 130.
The locating flange 128 on the outer disk 44 is preferably provided
to permit fluid flow therepast but could be configured to prevent
fluid flow inwardly and/or outwardly.
In a withdrawal stroke, to the extent that a vacuum may come to be
developed in the inner compartment 64 and/or in the reservoir 60,
this vacuum can be relieved by reason of fluid flow inwardly past
each of the inner disk 40 and intermediate disk 42. It is to be
appreciated, however, that the development of a continuous vacuum
within the reservoir 60 in preferred operation of the pump assembly
10 should be avoided, however, a temporary vacuum can assist in
drawing air upwardly from the inner compartment 64.
Reference is made to FIG. 15 which shows a piston 14 for a pump
assembly in accordance with a third embodiment of the present
invention. The piston 14 of FIG. 15 is identical to the piston 14
of FIG. 11 with the exception that the inlet 53 of FIG. 11 has been
eliminated and the center plug 124 of FIG. 11 has been replaced
with a modified center plug 156.
Center plug 156 of FIG. 15 comprises a hollow tubular member 158
with a widened base 144. The tubular member 158 has a bore 160
extending centrally therethrough from an open inner opening 162 to
an open outer opening 164.
The tubular member 158 is disposed coaxially in bore 140 so as to
provide an annular passageway 166 annularly about the tubular
member 158.
The embodiment of FIG. 15 provides a single pathway for fluid flow
between the outer compartment 66 and the outlet 48 via passageways
152, inlet 154, annular passageway 166, bore 160, screen 56,
opening 127, screen 57 and bore 140.
This pathway can be selected to have a relative length and relative
cross-section which resists flow of fluid inwardly and outwardly
therethrough and, particularly, can assist in preventing liquid
from dripping out the outlet 48 as when the pump assembly is left
inactive as, for example, in positions similar to that of FIGS. 13
or 14.
The relative vertical height of the inner opening 162 to the
tubular member 158 relative the outer compartment 66 can determine
the level of liquid which will be maintained in the outer
compartment 66 if the liquid is free to drip under gravity out of
the outlet 48.
The relative volume of fluid which would be required to fill the
compartment 66, passageway 152, inlets 54 and passageway 166 to a
height of the inner opening 162 may advantageously be selected
towards assisting in gauging the volume of fluid to be held in the
outer compartment 66. The embodiment of FIG. 15 can be used without
screens 56 and 57 when foaming is not desired.
Reference is made to FIG. 16 which shows a fourth embodiment of a
piston 14 in accordance with the present invention and which is
identical to the piston in FIG. 15 with the exception that the two
screens 56 and 57 and the ring 126 have been eliminated, the center
plug 156 is of increased length and the bore 140 has been extended
further inwardly. FIG. 16 illustrates a piston 14 for use to
dispense liquid without foaming. The inner opening 162 of the
tubular member 158 is inward of the inner disk 40 to assist in
preventing liquid in the outer compartment 66 from flowing due to
gravity out the outlet 48. It is to be appreciated that the
relative location of the inner opening 162 can be selected to be at
any relative height from that of inlet 54 to a height inward of the
inner disk 40
To assist, or provide at least some foaming, an inlet similar to
inlet 53 in FIG. 9 could be provided from the outer compartment 66
to the annular passageway 166, preferably outwardly of, that is,
below the inner opening 162. By providing such inlet 53 to be small
in size so as to restrict air flow therethrough until air in outer
compartment 66 may be sufficiently pressurized, then pressurized
air will be injected under pressure into liquid passing through the
annular passageway 166. Other embodiments are possible in which a
one-way valve mechanism prevents flow back from the annular
passageway 166 through such an inlet 53 as is, for example,
accomplished with the central sealing disk 148 of the embodiment of
FIG. 9.
Reference is made to FIG. 17 which illustrates a fifth embodiment
of a pump assembly 10 in accordance with the present invention in a
fully retracted position.
The body 12 in FIG. 17 is similar to that in FIGS. 9 to 14 but
carries on its flange portion 110 an inward axially extending
generally cylindrical support tube 170 adapted to support an air
chamber-forming member 172. Member 172 has a cylindrical side wall
174 and is closed at its inner end by end wall 176. Openings such
as 178 are provided aligned through both the wall 174 and the
support tube 170 to provide communication from the interior of the
reservoir into the interior of the support tube and hence into the
inner chamber 18 as indicated by arrow 179.
The piston 14 in FIG. 17 is similar to that of FIGS. 9 to 14 but
carries at its inner end an air pump disk 180 fixedly supported by
a hollow neck tube 182 being fixedly secured within a hollow
support tube 118 of the inner core 122. The neck tube 182 is open
at both ends.
The air pump disk 180 includes a locating flange 184 to locatably
engage the cylindrical side wall 174 and a resilient flexible
circular sealing disc 186 which sealably engages the side wall 174
and prevents flow of fluids axially outwardly therepast. An air
chamber 186 is defined between the air chamber-forming member 172
and the air pump disk 180 which will increase and decrease in
volume as the piston 14 is moved axially in the body 12 between the
extended and retracted positions. The air chamber 186 is in
communication with the bore 140 via the neck tube 182.
In reciprocal sliding of the piston 14 from the retracted position
shown in FIG. 17 towards an extended position, fluid, notably air
from the outlet 48 but also possibly liquid and/or foam in the bore
140, is drawn upwardly into the air chamber 186 at the same time as
liquid, foam and/or air is drawn into the lower compartment 66. In
sliding of the piston 14 from the extended position to the
retracted position, air and/or other foam or fluid in the air
chamber 186 is pressurized and forced outwardly through the bore
140 through the screen 56. The air pump disk 180 provides for
inhalation and expulsion of fluids, notably air, in addition to the
quantities of fluid inhaled and expulsed by the remainder of the
pump assembly and, thus, the air pump disk 180 increases the volume
of air which is available to be forced through the screens 56 and
57 to produce foam. The configuration shown has the air pump
comprising the air chamber-forming member 172 and the air pump disk
180 inward from the remainder of the pump assembly 10 and of a
diameter not exceeding that of the outer tubular portion 108. This
is an advantageous configuration to provide additional air pumping
capacity with the same piston stroke in a device which can be
inserted into the mouth of a reservoir.
FIG. 17 shows in addition to the two screens 56 and 57 to produce
foam, a three dimensional basket-like screen 188 having generally
frustoconical walls with small openings therethrough as in the
manner of known filter members.
In FIG. 17, only one passageway 152 and inlet 54 is shown to
provide communication from the outer compartment 66 to the bore
140.
It is to be appreciated that the nature of the liquid to be
dispensed including its viscosity and flow characteristics will be
important in order for a person skilled in the art to make suitable
selection of the relative sizes and dimensions and resistance to
flow provided by the various passageways, inlets, outlets and
screens and/or past the various disks including the central sealing
disk 148. As well, the quantity of liquid desired to be dispensed
in each stroke will have a bearing on the relative proportion and
sizing of the components including particularly the inner
compartment 64, outer compartment 66 and the axial length of a
stroke of the piston.
In the preferred embodiments, the engagement disk 62 is provided on
the piston 14 for engagement to move the piston inwardly and
outwardly. It is to be appreciated that various other mechanisms
can be provided for engagement and movement of the piston relative
the body 12.
The preferred embodiments show dispensers for passing liquid and
air through screens 56 and 57 to dispense the liquid as a foam. The
screens 56 and 57 can be eliminated in which case the dispensers
illustrated could serve to dispense liquid without foaming yet to
deliver quantities of air to the reservoir and, in the context of a
reservoir which is a sealed rigid container, prevent the build up
of a vacuum in the container.
The preferred embodiments of the invention show passages for
dispensing of the air and/or liquid as being provided internally
within a piston. Such an arrangement is believed preferred from the
point of view of ease of construction of the pump assembly 10.
However, it is to be appreciated that passageways for dispensing
the liquid and/or foam may be provided, at least partially, as part
of the body 12 or removably mounted to the body 12.
In accordance with the preferred embodiment illustrated, the
relative buoyancy of air within the liquid and, hence, the
separation of air and liquid due to gravity are utilized as, for
example, to permit air in the compartment 64 to flow upwardly into
the reservoir 60 and liquid in the reservoir 60 to flow downwardly
into the inner compartment 64 as, for example, when the inner
compartment 64 is open to the reservoir. It is to be appreciated,
therefore, that the pump assembly in accordance with the presence
invention should typically be disposed with what has been referred
to as the inner end of the pump assembly at a height above the
height of the outer outlet end.
While this invention has been described with reference to preferred
embodiments, the invention is not so limited. Many modifications
and variations will now occur to persons skilled in the art. For a
definition of the invention, reference is made to the appended
claims.
* * * * *