U.S. patent number RE33,235 [Application Number 07/258,878] was granted by the patent office on 1990-06-19 for liquid dispensing pump.
Invention is credited to Douglas F. Corsette.
United States Patent |
RE33,235 |
Corsette |
June 19, 1990 |
Liquid dispensing pump
Abstract
A liquid dispensing pump in the form of a trigger sprayer
includes a thimble-shaped valving element containing inlet and
outlet valves, and located within a cylindrical portion of the pump
body. In one embodiment, a pressure accumulation chamber is defined
between the pump body and the valving element, and a pump piston
operates within the valving element and defines therewith a pump
chamber in open communication with the accumulation chamber via
spaced, flexible and extendable straps which interconnect the inlet
and outlet valves for permitting a portion of the valving element
to move axially into a discharge valve opening position. Vent
valving is effected by either the pump piston or the valving
element during inward reciprocation movement of the piston. In
another embodiment, the sprayer is converted into a throttle pump
by the provision of a pump piston which operates within the
cylindrical portion of the pump body.
Inventors: |
Corsette; Douglas F. (Los
Angeles, CA) |
Family
ID: |
26946928 |
Appl.
No.: |
07/258,878 |
Filed: |
October 17, 1988 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
587070 |
Mar 7, 1984 |
04618077 |
Oct 21, 1986 |
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Current U.S.
Class: |
222/383.1;
222/340; 239/333 |
Current CPC
Class: |
B05B
11/3011 (20130101); B05B 11/304 (20130101); B05B
11/3064 (20130101); B05B 11/3067 (20130101); B05B
11/3069 (20130101); B05B 11/3074 (20130101); B05B
11/3022 (20130101) |
Current International
Class: |
B05B
11/00 (20060101); B67D 005/40 () |
Field of
Search: |
;222/383,384,340,380,321,335 ;239/333,322 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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0020840 |
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Jan 1981 |
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EP |
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55-02516 |
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Nov 1980 |
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JP |
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8004831 |
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Nov 1980 |
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NL |
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Primary Examiner: Rolla; Joseph J.
Assistant Examiner: Noland; Kenneth
Attorney, Agent or Firm: Watson, Cole, Grindle &
Watson
Claims
What is claimed is:
1. In a liquid dispensing pump which includes: a pump body defining
a pressure accumulation chamber having an inlet port at one axial
end thereof for communication with a source of flowable product to
be dispensed, and an outlet port opening radially from said
chamber; a unitary element including an inlet check valve
controlling said inlet port, further including an outlet valve
disposed for axial movement in said chamber from a closed position
adjacent said one axial end in which it blocks communication
between said ports to an open position remote from said one axial
end in which it establishes communication between said ports, and
still further including a pump cylinder defining a pump lying
coaxially with said accumulation chamber and in open communication
therewith; a pump piston reciprocable in said cylinder
independently of the movement of said outlet valve; resilient means
normally urging said outlet valve toward its closed position; and
means for manually reciprocating said piston; the improvement
wherein:
said unitary element comprises a thimble-shaped element having an
inner end containing said valves;
said inner end of said element including a wall connected to said
pump cylinder and defining an inner end of said pump chamber, said
wall containing said inlet valve and a plurality of straps lying
between said valves and defined by openings establishing the open
communication between said chambers, said straps being flexible and
extendably-shaped to facilitate relative axial shifting of said
valves during a pumping operation;
said head of said piston and the wall which opposes said head are
complementarily contoured to facilitate effective priming as any
air within said pump chamber is evacuated during pumping.
2. The liquid dispensing pump according to claim 1, wherein said
resilient means comprises a coil spring encircling said piston and
compressed axially between said piston and said unitary
element.
3. The liquid dispensing pump according to claim 1, wherein said
pump body includes mutually perpendicular inlet and outlet passages
respectively terminating in said inlet and outlet ports, the axis
of said unitary element and said piston extending at an angle
between said passages.
4. The liquid dispensing pump according to claim 1, wherein said
pump body includes mutually perpendicular inlet and outlet passages
respectively terminating in said inlet and outlet ports, the axis
of said unitary element and said piston extending laterally of said
inlet passage.
5. The liquid dispensing pump according to claim 1, wherein said
means for manually reciprocating said piston comprises a finger
operated trigger element mounted on said pump body in engagement
with said piston.
6. The liquid dispensing pump according to claim 1, wherein said
pump body has a cylindrical wall including a vent opening to
establish communication between a container to which the pump is
applied and the atmosphere, said piston having a vent seal in
engagement with said cylindrical wall for closing said vent opening
upon outward reciprocation of said piston, and means at said
cylindrical wall for disengaging said vent seal therefrom for
opening said vent opening, upon an inward reciprocation of said
piston within said cylinder.
7. The liquid dispensing pump according to claim 1, wherein said
pump body has a cylindrical wall having a vent passage to establish
communication between a container to which the pump is applied and
the atmosphere, said unitary element having a peripheral wall
surrounding said pump cylinder and including a vent valve for
closing said vent passage in the closed position of said outlet
valve, and for opening said vent passage in the open position of
said outlet valve.
8. The liquid dispensing pump according to claim 1, wherein said
pressure accumulation chamber is defined by said inner end of said
element and said axial end, said pump body including an annular
ring at said axial end, and said unitary element having an annular
groove defining said outlet valve in the form of an annular valve
flange, said unitary element being in sealing engagement with said
pump body outwardly of said outlet port, and said valve flange
engaging only said ring in the closed position of said outlet
flange so as to define a quick acting outlet valve.
9. The liquid dispensing pump according to claim 1, wherein said
pressure accumulation chamber is defined by said inner end of said
element and said axial end, said pump body including an annular
ring at said axial end, and said unitary element having an annular
groove defining said outlet valve in the form of an annular valve
flange, said pump body having a cylindrical wall containing said
outlet port, said valve flange having a terminal end engaging said
cylindrical wall inwardly of said outlet port in the closed
position of said outlet valve so as to define a slow acting outlet
valve.
10. A liquid dispensing pump, comprising a pump body having a pump
cylinder defining a pump chamber, said cylinder having an end wall
containing a coaxial inlet port for communication with a source of
flowable product to be dispensed, and said cylinder having a side
wall containing an outlet port opening radially from said chamber,
a pump piston reciprocable in said cylinder, a thimble-shaped
valving element located in said cylinder and having an end wall
defining an inlet check valve controlling said inlet port, said end
wall having openings surrounding said inlet check valve through
which product is admitted into said chamber from said inlet port,
said valving element further having an annular resiliently flexible
lip seal defining an outlet check valve, said lip seal being in
engagement with said side wall of said pump cylinder in an outlet
closing position and being flexible radially inwardly away from
said side wall in an outlet opening position in response to an
increase in pressure within said pump chamber, resilient means
extending between said piston and said valving element, means for
manually reciprocating said piston against the force of said
resilient means, said pump body having acylindrical wall containing
a vent opening, said piston having an annular vent seal in
engagement with said cylindrical wall for closing said vent
opening, and means at said cylindrical wall for disengaging said
vent seal from said cylindrical wall to thereby establish in a
pumping position a vent passage for venting the container through
said vent opening.
11. The pump according to claim 10, wherein said resilient means
comprises a coil spring encircling said piston and compressed
axially between said piston and said valving element.
12. The pump according to claim 10, wherein said pump body includes
mutually perpendicular inlet and outlet passages respectively
terminating in said inlet and outlet ports, the axis of said
valving element and said piston extending at an angle between said
passages.
13. The pump according to claim 10, wherein said pump body includes
mutually perpendicular inlet and outlet passages respectively
terminating in said inlet and outlet ports, the axis of said
valving element and said piston extending laterally of said inlet
passage.
14. The liquid dispensing pump according to claim 11, wherein said
means for manually reciprocating said piston comprises a finger
operated trigger element mounted on said pump body in engagement
with said piston.
15. The pump according to claim 10, wherein said means at said
cylindrical wall comprises an axial rib.
16. A liquid dispensing pump, comprising a pump body, a separate
closure cap engaged with said pump body for mounting said pump body
on a container of flowable product to be dispensed, said pump body
including outwardly opening cylinder means having a bore of
predetermined diameter and a counterbore of relative greater
diameter, said cylinder means being disposed at an angle to the
central axis of said closure cap, a pump piston reciprocable in
said cylinder means, said piston having piston seal means in
sliding sealing engagement with the wall of said bore and defining
together therewith a variable volume pump chamber, said pump body
having inlet and outlet means for delivering product into and out
of said pump chamber, means for manually reciprocating said piston,
said cylinder means including a vent port establishing
communication between the interior of said counterbore and the
interior of the container, said piston having an annular seal means
in sliding sealing engagement with the wall of said counterbore for
sealing off said vent port from the atmosphere in a non-pumping
position, and means at said wall of said counterbore for
disengaging said annular seal means from said wall of said
counterbore to thereby establish in a pumping position a vent
passage for venting the container through said vent port, said
annular seal means being located outwardly of said disengaging
means in said non-pumping position.
17. The pump according to claim 16, wherein said seal means
comprises an annular, flexible, resilient lip seal, and said
disengaging means comprises an axial rib for flexing said lip seal
radially inwardly of said counterbore for establishing said vent
passage.
18. The pump according to claim 16, wherein said cylinder means
includes a thimble-shaped element defining said bore, said pump
body defining a pressure accumulation chamber with said element in
open communication with said pump chamber, said element having an
inner end containing inlet and outlet check valves for controlling
said inlet and outlet means.
19. The pump according to claim 18, wherein said inner end of said
element includes a wall defining a plurality of straps lying
between said valves and defined by openings establishing the open
communication between said chambers, said straps being flexible and
extendably-shaped to facilitate relative axial shifting of said
valves in said pumping position.
20. A liquid dispensing pump, comprising a pump body, a separate
closure cap engaged with said pump body for mounting said pump body
on a container of flowable product to be dispensed, said pump body
including outwardly opening cylinder means having a bore of
predetermined diameter and a counterbore of relative greater
diameter, said cylinder means being disposed at an angle to the
central axis of said closure cap, a pump piston reciprocable in
said cylinder means, said piston being in sliding sealing
engagement with the wall of said bore and defining together
therewith a variable volume pump chamber, said pump body having
inlet and outlet means for delivering product into and out of said
pump chamber, means for manually reciprocating said piston, said
piston having an annular lip seal in sliding sealing engagement
with the wall of said counterbore for defining an annular chamber
therewith, said cylinder means including a sump drain port
establishing communication between said annular chamber and the
interior of the container, said port being inwardly spaced from
said lip seal in non-pumping and pumping positions of said piston,
whereby any leakage of product from said pump chamber around said
piston is purged from said annular chamber into the container
through said sump drain port, any leakage of product is prevented
from the container through said port and outwardly of said cylinder
means, and any abrasion of said piston or said lip seal by the wall
of said port, during pumping or assembly of the piston, is
avoided.
21. The pump according to claim 20, wherein said cylinder means
includes a thimble-shaped element defining said bore, said pump
body defining a pressure accumulation chamber with said element in
open communication with said pump chamber, said element having an
inner end containing inlet and outlet check valves for controlling
said inlet and outlet means.
22. The pump according to claim 21, wherein said inner end of said
element includes a wall defining a plurality of straps lying
between said valves and defined by openings establishing the open
communication between said chambers, said straps being flexible and
extendably-shaped to facilitate relative axial shifting of said
valves in said pumping position.
23. A liquid dispensing pump, comprising a pump body, a separate
closure cap engaged with said pump body for mounting said pump body
on a container of flowable product to be dispensed, outwardly
opening cylinder means in said pump body, said cylinder means being
disposed at an angle to the central axis of said closure cap, a
pump piston reciprocable in said cylinder means and defining
together therewith a variable volume pump chamber, said pump body
having inlet and outlet means for delivering product into and out
of said pump chamber, means for manually reciprocating said piston,
said cylinder means including a cylindrical wall, a container vent
port located in said wall at a position lying outwardly of said
pump chamber, a vent chamber located between said piston and said
wall in communication with said port, annular seal means on said
piston spaced outwardly of said vent port in both pumping and
non-pumping positions of said piston for sealingly engaging said
wall at the end of outward reciprocation of said piston for sealing
said vent chamber closed to the atmosphere, and means at said wall
for opening said vent chamber to the atmosphere during inward
reciprocation of said piston, said means at said wall being located
between said vent port and said seal means when in engagement with
said wall.
24. The pump according to claim 23, wherein said seal means
comprises an annular, flexible, resilient lip seal, and said means
at said wall comprising an axial rib for deforming said lip seal
radially inwardly of said wall for opening said vent chamber.
25. A liquid dispensing pump, comprising a pump body, a separate
closure cap engaged with said pump body for mounting said pump body
on a container of flowable product to be dispensed, outwardly
opening cylinder means in said pump body, said cylinder means being
disposed at an angle to the central axis of said closure cap, a
pump piston reciprocable in said cylinder means and defining
together therewith a variable volume pump chamber, said pump body
having inlet and outlet means for delivering product into and out
of said pump chamber, means for manually reciprocating said piston,
said cylinder means including a cylindrical wall, a sump drain port
located in said wall at a position lying outwardly of said pump
chamber, said piston having an annular lip seal defining an annular
chamber with said wall and being spaced outwardly of said port in
both pumping and non-pumping positions of said piston, said annular
chamber being in communication with said port, said lip seal
sealingly engaging said wall at the end of outward reciprocation of
said piston for sealing said chamber closed to the atmosphere,
whereby any leakage of product from said pump chamber around said
piston is purged from said annular chamber into the container
through said port, any leakage of product is prevented from the
container through said port and outwardly of said cyinder means,
and any abrasion of said piston or said lip seal by the wall of
said port, during pumping or assembly of said piston, is
avoided.
26. The pump according to claim 25, wherein means are provided at
said cylindrical wall for opening said annular chamber to the
atmosphere during inward reciprocation of said piston, said means
at said wall being located between said port and said lip when in
engagement with said cylindrical wall.
27. The pump according to claim 25, wherein said means at said wall
comprises an axial rib for deforming said lip seal radially
inwardly of said cylindrical wall for opening said annular chamber.
.Iadd.
28. A manually actuated dispensing pump comprising a pump body for
mounting with a closure cap at the upper end of a container for
fluent product, the pump body comprising a pump cylinder open at
its outer end to atmosphere and within which is provided at its
inner end region, a pump chamber for a manually reciprocable
piston, the cylinder having in its lower region a vent port
positioned outwardly of the chamber and in permanent open
communication with the interior of the container, wherein the pump
further comprises a valving element which is axially reciprocable
within the pump cylinder in response to the balance between pump
pressure and an opposing spring force and in which said piston is
received to define the pump chamber, the valving element and
cylinder defining between them a pressure accumulation chamber in
open communication with the pump chamber, the valving element
engaging the inner surface of the cylinder and having a flange
engaging the outer end of the cylinder in an at-rest position of
the piston, and the cylinder having adjacent its outer end, in its
inner surface, a vent passage, and the valving element having in
its outer surface vent means, outward axial movement of the valving
element during pumping action to disengage the flange from the pump
cylinder and to permit the free flow of air between atmosphere and
the interior of the container through the vent passage, the vent
means and the vent port. .Iaddend. .Iadd.29. A pump according to
claim 1, wherein said vent passage comprises a groove. .Iaddend.
.Iadd.30. A pump according to claim 1 or 2, wherein said vent means
comprises an annulus. .Iaddend.
Description
BACKGROUND OF THE INVENTION
This invention relates generally to a liquid dispensing pump in the
form of a trigger operated sprayer, and relates to my earlier U.S.
Pat. No. 4,046,292.
The pump disclosed by such patent is of the pressure-accumulating
type including a unitary member having an inlet check valve, an
outlet check valve acting in response to an increase in pressure
within an accumulation chamber, and a pump cylinder carried by the
outlet valve. The inlet port is located coaxially of the pump body,
and the outlet port opens radially from the accumulation chamber. A
pump piston reciprocates within the pump cylinder and defines
therewith a pump chamber in open communication with the
accumulation chamber. Thus, upon an increase in pressure within the
accumulation chamber, a dripless product discharge is attained by
an automatic low pressure cut off at the end of each piston stroke.
Also, a container vent valve is carried by the outlet valve for
controlling a vent passage located in the pump body.
SUMMARY OF THE INVENTION
As an alternative construction over the aforementioned patent, the
pump according to the invention includes a thimble-shaped element
which includes inlet and outlet check valves and defines a pump
cylinder in which a piston operates, the thimble-shaped element
being of a simple construction which is simple to manufacture and
assemble, and which renders the pump easy to operate while at the
same time effects a dripless product discharge.
A container vent is located in the pump body and may be controlled
by a flexible lip seal on the piston when it engages means provided
on the pump body for opening a vent passage in the inward movement
of the piston. Otherwise, the container vent may be controlled by a
flange provided on the piston which uncovers the vent in the inward
movement the piston. Alternatively, the container vent may be
controlled by the thimble-shaped element itself, a portion of which
moves axially during an open position of the outlet into a vent
opening position.
Also, the pump body according to the invention includes inlet and
outlet passages respectively terminating in inlet and outlet ports
respectively located at one axial end of a cylindrical pressure
accumulation chamber and opening radially outwardly from such
chamber, the axis of the thimble shaped member extending at an
angle between such passages, or extending parallel to the outlet
passage.
The piston operating within the pump cylinder defines therewith a
pump chamber in open communication with the pressure accumulation
chamber via openings defining flexible extendable-shaped straps
located in an end wall of the thimble-shaped element, such end wall
preferably being of conical configuration when the axis of the
element extends at an angle to the inlet and outlet passages, and
being flat when the axis of the element extends parallel to the
outlet passage.
In another embodiment according to the invention, the pressure
accumulation chamber is omitted, and the pump chamber is defined
between the piston and a cylindrical portion of the pump body. The
outlet valve is defined by an annular flexible lip seal on the
cup-shaped member which flexes away from such cylindrical pump body
portion in response to an increase in pressure within the pump
chamber. And, the container vent may be controlled by an annular
flange on the piston which either uncovers the vent or establishes
a container vent passage with the pump body upon inward movement of
the piston.
In addition, the invention makes provision for quick opening and
slow opening outlet valves.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical sectional view of a dispensing pump according
to one embodiment of the invention;
FIGS. 1A and 1B are sectional views similar to FIG. 1 showing
details of quick opening and slow opening discharge valves,
respectively;
FIG. 2 is a perspective view of the thimble-shaped member according
to FIG. 1;
FIGS. 3, 4 and 5 are sectional views similar to FIG. 1 of other
embodiments according to the invention, with portions only of the
pump being shown; and
FIG. 6 is a vertical sectional view of yet another dispensing pump
according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
Turning now to the drawings wherein like reference characters refer
to like and corresponding parts throughout the several views, a
liquid dispensing in the form of a trigger operated sprayer is,
according to one embodiment of the invention, generally designated
10 in FIG. 1 which includes a pump body 11 defining an inlet
passage 12 and an outlet passage 13. A conventional dip tube 14 is
received within the inlet passage and extends into a container (not
shown) of product to be dispensing in a manner well known in the
art. A container cap 15, having internal threads or other container
securement means, engages an annular lip 16 of a circular section
of the pump body for mounting the sprayer onto the neck of the
container, and if desired a seal ring 17 may be disposed between
the lower end of pump body and the upper end of the container
neck.
The pump body further includes a cylinder 18 having a conical end
wall 19 containing an inlet port 21 in which the inlet passage
terminates. The cylinder axis lies between and extends at an angle
to inlet and outlet passages 12 and 13. And, the outlet passage
extends from an outlet port 22, located in wall 18, through a
nozzle plug 20 fitted within the pump body, and terminates in a
discharge orifice located in a nozzle cap 23 in engagement with the
plug. Also, the pump body is provided with an integral shroud 24,
which may otherwise be made separately and assembled in place and
having a contoured wall 25 shaped to fit against the hand when the
trigger sprayer is grasped by the operator.
A unitary, thimble-shaped valving element 26, shown in more detail
in FIG. 2, is disposed within cylinder 18 and has at one end
thereof a conical wall 27 substantially corresponding in shape to
end wall 19. Wall 27 includes a plurality of flexible and
extendably-shaped straps 28 which extend from adjacent the tip to
the base and are defined by openings 29 which may be of maze-like
configuration. Thus, the tip of wall 27 is capable of axially
shifting relative to the remainder of elements 26, and vice-versa.
And, rather than openings 29 of the configuration shown, S-shaped,
or the like, openings may be provided to facilitate such relative
axial shifting movements, without departing from the invention.
The tip of conical wall 27 defines an inlet check valve 31 for
controlling inlet port 21, and straps 28 are neutral from a
pressure standpoint, a pressure accumulation chamber 32, shown in
detail view 1A, is defined between the inner end of element 26 and
the confronting surfaces of the pump body. Thus, the inlet port is
located at one axial end of this chamber and the outlet port opens
radially from such chamber.
A ring 33 extends from wall 19 toward element 26, and an annular
flange 34 on element 26 adjacent wall 27 defines a discharge valve
which seats against ring 33 in a discharge closing position, the
flange defining an annular groove 35 with the body of element 26 so
as to effectively form an extension of accumulation chamber 32.
An annular flexible lip seal 36 on element 26 is located adjacent
the free end thereof, although may lie further inwardly toward
flange 34 if desired, for slideably engaging the inner surface of
cylinder 18 in a fluid tight manner.
A pump piston in the form of a thimble or cup-shaped element 37
extends into element 26 and has a flexible, circular skirt 38
adapted for sliding along the inner surface of the valving element
in fluid tight engagement therewith. The piston thus defines a
variable volume pump chamber 39 with element 26, and the pump
chamber is in open communication with accumulation chamber 32 via
openings 29. As shown, the piston head is complementarily contoured
to the opposing conical wall 27 to permit the piston to bottom out
within pump chambers 39 during pumping. Thus, any air within the
pump chamber is effectively evacuated during priming. Moreover, an
annular, flexible skirt or lip seal 41 on piston element 37
surrounds the open end thereof and is slideable along the inner
surface of cylinder 18 in a fluid tight manner to define an annular
chamber therewith, as shown. Thus, cylinder 18 and element 26
define cylinder means having a counterbore engaged by lip seal 41
of the piston and a bore engaged by skirt 38 thereof. A return
spring 42 encircles piston element 37 and extends between flange 41
and the outer rim of element 26 for normally urging the outlet
valve toward its closing position. Cooperating snap beads on skirt
41 and the inner surface of cylinder 18 may be provided for
retaining the piston within the pump body.
Sprayer 10 further includes a trigger actuator in the form of a
lever 43 having a trunnion 44 to facilitate mounting the lever for
pivotal movement about the axis thereof on the pump body. The lever
has a pair of spaced actuator flanges 45 (only one being shown in
FIG. 1) spaced apart at outer ends 46 thereof a sufficient distance
for bearing against outer circular rim 47 of the piston element.
Alternatively, a rod-like member may extend between the trigger
actuator and the end wall of the piston, the rod-like member may be
integral with either the piston or the trigger member, or it may be
separate from both.
A container vent 48 is located in the wall of cylinder 18, and at
least one axially disposed rib 49 is provided on the inner surface
of cylinder 18 for flexing skirt 41 radially inwardly when in
contact therewith during a piston inward position so as to define a
passage from atmosphere to the inside of the container through vent
48 through which the dispensed product is replaced with air during
the dispensing operation.
As shown, vent 48 is inwardly spaced from lip seal 41 in both
non-pumping and pumping positions of the piston. And, in the FIG. 1
arrangement, vent 48 inherently functions as a sump drain port
which establishes communication with the aforementioned annular
chamber and the interior of the container. Thus, with such
arrangement, any leakage of product from pump chamber 39 around
piston skirt 38 is purged from the annular chamber into the
container through port 48, any leakage of product from the
container through port 48 and outwardly of cylinder 18 is
prevented, and any abrasion of piston skirt 38 or lip seal 41,
during pumping or during assembly of piston element 37, is
avoided.
In operation, after the pump chamber is primed with product to be
dispensed, the piston is inwardly reciprocated upon manual
actuation of the trigger lever against the force of spring 42 and
the enclosed fluid to thereby increase the pressure within the pump
chamber which maintains inlet valve 31 closed during the
compressing stroke. As the compression force increases, there will
manifestly be a progressively increasing fluid pressure within
accumulation chamber 32 until such pressure creates a force on the
outer end surfaces of valving member 26 which extend from the pump
chamber diameter outwardly to flange 34 sufficient to overcome the
opposing force of the spring. This will result in movement of
flange 34 in an axial direction away from ring 33 to thereby open
the discharge passage whereby the contents of chamber 39 will be
discharged under pressure through discharge passage 13. Such
discharge will continue as long as the pressure within the pump
chamber is sufficient to overcome the force of the return spring.
However, when the pressure within the accumulation chamber is
reduced, either by reduced actuating force on the piston or through
approach of the piston to the end of its pressure stroke, so as to
produce insufficient force to overcome the return spring, the
spring will act to return the outlet valve immediately to its
closed position, thereby affording an abrupt sharp cutoff of the
discharge to minimize dripping of product from the discharge
nozzle.
Since the discharge valve makes tangential contact (FIG. 1A) with
ring 33, and the outer surface of the discharge valve is radially
inwardly spaced from the wall cylinder 18, a quick acting discharge
is effected as soon as this tangential contact is broken.
On the other hand, a modification is shown in FIG. 1B wherein
discharge valve 34 is out of contact with ring 33 in the discharge
closing position and is instead in fluid tight engagement with the
wall of cylinder 18 for covering the outlet as shown. Thus, the
free end of the discharge valve slides along the wall of cylinder
18 at a larger diameter than flange 33 until the outlet port is
uncovered during the opening of the discharge, so as to effect a
slow opening discharge. The aforedescribed quick opening and slow
opening discharging is likewise included in my dispensing pump
disclosed in my U.S. Pat. No. 4,402,432.
On the succeeding outward stroke of the piston under actuation of
the return spring, after the closing of the discharge as
aforedescribed, the discharge valve will remain seated to prevent
back flow of liquid through the outlet onto the accumulation
chamber, while the resulting reduced pressure within chambers 32
and 39 will open inlet valve 31 against the cushion of strips 28,
thereby enabling a charge of flowable product from the container to
be drawn upwardly through the dip tube and the inlet port into the
intercommunicating accumulation pump chambers.
Discharge valve 34 will remain closed throughout the entire outward
stroke of the piston and, at or near the end of such stroke, the
inlet valve will be reseated over the inlet port, under the elastic
memory action of straps 28 tending to retain the conicity of wall
27, in preparation for the next ensuing compression stroke of the
piston.
Reciprocation of the pump piston continues for as long as is
necessary to dispense the desired amount of product from the
container to which the sprayer is applied, following which the
discharge valve will be automatically seated and sealed by the
action of its return spring, while the inlet valve is urged
immediately to its seated position and retained in such position
over the inlet port, by the action of straps 28.
Throughout the pumping and dispensing action as aforedescribed,
vent valve 41 will automatically be opened simultaneously with
inward displacement of the piston flange to rib 49, with the result
that each time a charge of flowable product is delivered through
the outlet port to the atmosphere, a vent passage is in open
communication with the atmosphere through the clearance space
between the vent valve and the inner wall of cylinder 18 as
produced by rib 49. Thus, automatic air may be drawn into the
container through vent 48 as necessary to replenish dispensed
product.
Another embodiment of the liquid dispensing pump or trigger sprayer
of the invention is generally indicated 10A in FIG. 3 and is
constructed in essentially the same manner as pump 10 except for
the venting feature. Here, an annular vent seal 41 forming a vent
valve is located sufficiently inwardly from rim 47 of the piston so
as to cover vent opening 48 at the end of the piston suction
stroke. As in FIG. 1, snap beads are provided on the piston and the
inner wall of cylinder 18 for retaining the piston within the
cylinder, except that in FIG. 3 a vent passage 51 is defined
outwardly of the vent valve between skirt 52 on which the vent
valve is located and the inner surface of cylinder 18. Thus, when
the vent valve uncovers vent opening 48 in the discharge opening
position, atmospheric air is drawn into the container through the
open vent passage and the uncovered vent opening.
In FIG. 4, a liquid dispensing pump generally designated 10B is
similarly constructed as the aforedescribed embodiments except for
the .[.valving.]. .Iadd.venting .Iaddend.feature. In addition,
valving element 26 has an inner concentric sleeve 53 defining an
annular space with the cylindrical wall of the valving element for
the reception of the return spring and having an inner cylindrical
wall along which piston skirt 38 slidingly and sealingly engages.
And, valving element 26 is extended for engagement by means of its
annular flange 54 with the outer end of cylinder 18 in the
discharge closing position. This is a fluid tight engagement since
valving element 26 functions as a vent valve, in addition to an
intake and discharge valve, in this embodiment. And, skirt 41 of
the piston slides along the inner surface of the valving element in
a fluid tight manner during the pumping operation.
To facilitate venting, element 26 has a smaller outer diameter
relative to the inner diameter of cylinder 18 between the vent
valve and discharge valve 34 so as to define an annulus 55. And, at
least one axially extending groove 56 is provided in the wall of
cylinder 18 between this annulus and flange 54. Thus, in the
discharge opening position, valve 34 shifts outwardly as in the
other embodiments described above as does the outer annular wall of
the valving element to thereby cause flange 54 to shift outwardly
to define an open vent passage from the atmosphere to the container
via open groove 56, annular 55 and the container vent which is now
uncovered.
A still further embodiment of the invention is shown in FIG. 5 as a
liquid dispensing pump 10C which is essentially the same as FIG. 1
except that the piston and valving member axes are parallel to the
discharge passage rather than extending at an angle between the
inlet and discharge passages as before. And, end wall 19c of the
pump body, end wall 27c of valving element 26c, and the piston head
of piston 37c are all flat and substantially parallel to one
another, as shown, so as to lie perpendicular to the concentric
axes of the cylinder, and the valving and piston elements.
Otherwise, the operation of the pump is essentially the same as
that described in detail with reference to FIG. 1. While only a
section of this dispensing pump 10C is shown, it should be noted
that a portion of shroud 24 is sealed against the upper end of the
passage which terminates in outlet port 22 so as to avoid
leakage.
Still another embodiment of the trigger sprayer according to the
invention is generally designated 10D in FIG. 6 which is similar to
sprayer 10A of FIG. 3 regarding the venting feature. However,
unlike the foregoing embodiments, trigger sprayer 10D has a piston
37d with no skirt or lip seal 38 whereupon the volume of pump
chamber 39 is enlarged as product additionally fills the annular
space between cylinder 18 and the piston. And, although valving
element 26 is the same as that of the sprayer 10A valve unit, only
the inlet valve portion 31 thereof functions the same as in FIG. 3.
Otherwise, valving element 26 of FIG. 6 has no accumulator function
or effect. Flange 34 of the valving element seals against ring 33
under the force of spring 42 but cannot be dislodged from this
sealing position contrary to the aforedescribed sprayers. Since the
piston operates within cylinder 18 which functions as a pump
cylinder, rather than within the valving element which functions as
a pump cylinder in the foregoing embodiments, lip seal 36 of the
valving element functions as a discharge valve in the FIG. 6
embodiment in response to an increase in hydraulic pressure within
the pump chamber during the compression stroke so as to flex
radially inwardly away from the inner wall of cylinder 18 for
opening the discharge, while remaining closed at all other times.
Thus, by simply removing piston skirt 38, sprayer 10A of the
pressure accumulating type is converted into a sprayer 10D of the
throttling type in which lip seal 36 functions as a circular bunsen
valve in the discharge path which opens from hydraulic pressure
within the pumping bore during the piston compression stroke, and
remains closed during the piston suction stroke. All other parts of
the sprayer are thus interchangeable with the parts of sprayer 10A,
although sprayer 10D has approximately double the spraying capacity
compared to the other sprayers described above. And, trigger lever
43 is preferably longer to provide a high strength for effecting an
increased leverage and stroke.
Although the venting feature of sprayer 10D is shown similar to
that of sprayer 10A, the venting feature of the FIG. 1 sprayer
could be adopted without departing from the invention. And, if
desired, the cylinder, valving element and piston of FIG. 6 could
lie parallel to the discharge passage as in FIG. 5.
Each of the trigger sprayer embodiments of the invention has
shipping seals for the vent passage as well as for the inlet and
discharge ports which are automatically self-closing when the pump
is at rest and between dispensing strokes. And, each of the
sprayers is adapted for fabrication from a minimum number of parts
using a minimum number of assembly operations. As noted above,
shroud 24 may be integrally fabricated with the remainder of the
pump body. Also, a nozzle plug 20 can be simply inserted in place
together with the trigger lever, and nozzle cap 23 is snapped or
threaded into place. Dip tube 14 is conventional, and the piston,
valving element and return spring are capable of being assembled as
a sub-assembly and inserted within the bore of cylinder 18. And,
the cylinder connecting portion of the pump body and the internally
threaded closure cap may be permanently attached together as in the
manner disclosed in my prior U.S. Pat. No. 4,361,256.
The quick opening and slow opening discharge valves described with
reference to FIG. 1 apply equally as well to the FIGS. 3, 4 and 5
embodiments. And, straps 28, which interconnect the inlet valve at
the tip of wall 27 of the valving member and the base of this wall,
shown in detail in FIG. 2, are similarly arranged in the valving
elements of the FIGS. 3, 4 and 6 embodiments, as well as in the
FIG. 5 embodiment except that wall 27c is flat rather than conical
therein. A central portion of this wall 27c nevertheless functions
as an inlet valve. And, straps 28 are neutral from a pressure
standpoint and flange 34, together with annular groove 35, define
an accumulation chamber of appreciably larger diameter than the
pump chamber such that, as the compression force of the piston
continues, there will be a progressively increasing fluid pressure
within the accumulation chamber until such pressure creates an
outward force in an axial direction causing the side wall of the
valving element to shift outwardly relative to inlet valve 31 which
remains seated during the influence of increased pressure within
the pump chamber and against the inlet valve. The straps permit
wall 27 or 27c to flex and to resume its initial position during
the discharge valve opening and closing operations. Although a
plurality of such straps are illustrated, it should be pointed out
that as few as two straps may be provided without departing from
the invention. Moreover, the straps may be shaped other than shown,
so long as they are extendable between tip and base of wall 27 to
facilitate relative axial shifting during the pumping operation as
in the manner aforedescribed.
And, by simply providing a piston member without a piston skirt 38,
a sprayer of the pressure accumulating type can be easily converted
into a sprayer of the throttle type having an increased pump
capacity.
Obviously, many other modifications and variations of the present
invention are made possible in the light of the above teachings. It
is therefore to be understood that within the scope of the appended
claims the invention may be practiced otherwise than as
specifically described.
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