Note: Descriptions are shown in the official language in which they were submitted.
~ 32 3 6 1 8
ATOMIZ ING PUMP
TE CHNI CAL F IEL D
This invention relates to liquid dispensers
or pumps. The present invention is particularly
well-suited for use as a small, hand-held,
finger-operated pump disposed on the top of a
container of liquid for dispensing the liquid in a
desired form, such as in an atomized spray or foam,
from a nozzle communicating with the top of the
pump.
BACKGROUND OF THE INVENTION
AND
TEC~NICAL P~OBLEMS POSED BY THE PRIOR ART
Finger-operated pumps are conventionally
employed with a suitable nozzle structure as part of
a closure at the top of a liquid product container,
such as a metal can, glass bottle, or plastic
; bottle. Depending upon the nozzle structure, the
liquid may be discharged as a jet stream, a spray, an
atomized fine spray, a foam, or other suitable form.
Such pumps may be used to dispense a wide variety of
liquid products such as cleaners, hair styling
preparations, perfumes, deodorants, throat sprays,
air fresheners, lotions, and the like.
U.S. Patent No. 4,025,046 issued to Michel
i Boris discloses a number of prior art designs for
.:f finger-operated dispensing pumps. One design
~` includes a pump chamber with an internally disposed,
upwardly projecting, supply conduit having an open
upper end and having a lower end connected at the
bottom of the chamber to a suction tube extending
down into the container of liquid.
A piston is slidably disposed in the pump
chamber and includes a piston rod extending upwardly
out of the top of the pump chamber to the nozzle. A
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1323618
--2--
discharge passageway is defined in the piston and rod
to provide communication between the pump chamber and
the nozzle.
A poppet is provided with a valve member to
seal against a valve seat on the piston, and the
poppet is normally biased against the piston by a
spring 50 as to occlude flow through the discharge
passage to the nozzle. The poppet also has an outer
pressure-bearing surface exposed in the pump chamber
at all times. A generally cylindrical sleeve extends
- downwardly from the poppet and is spaced above the
supply conduit when the pump is in the inactive
position.
When the piston is displaced downwardly in
the pump chamber, as by pushing down on the top of
the nozzle, the poppet is pushed against the spring
and the poppet sleeve telescopically slides down over
the suction conduit open upper end to seal around the
suction conduit. The pressure of the liquid and
residual gas within the pump chamber then increases
as the piston is pushed down further. The increasing
pressure acting upwardly on the piston is opposed by
the finger force exerted downwardly on the piston,
and the increasing pressure acting downwardly on the
poppet pressure-bearing surface produces a force
acting through the poppet against the spring. When
this pressure increases sufficiently to overcome the
spring force, the poppet moves further downwardly in
the pump chamber, still sealing against the supply
conduit, so that the poppet valve member moves away
from the piston thereby opening the discharge passage
and permitting the pressurized liquid to escape
through the nozzle while being atomized.
In other proposed designs for dispensing
pumps, a secondary piston is continuously engaged
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3 2 3 6 1 8
--3--
with a supply conduit, and a gravity-biased check
valve is interposed between the pump chamber and the
supply conduit to accommodate a refilling of the pump
chamber. In most such designs, the check valve tends
to undesirably move away from the seat when the pump
is inverted if the pump chamber is not under
sufficient pressure. If this occurs during the
operation of the pump, the pump may malfunction or
may not function as well as when the pump is in a
generally upright orientation.
After the above-described pumps are operated
to discharge the liquid by initially pushing the
nozzle and connected piston downwardly, the finger
force is typically removed or greatly reduced so as
to permit the spring to urge the poppet back up
against the piston and to continue urging the poppet,
along with the engaged piston and nozzle, upwardly to
the fully raised position (i.e., the initial,
inactive "rest" position). As this occurs, liguid
from the container is drawn up into the pump
chamber.
The rate of refilling of the pump chamber
with liquid from the container, and the amount of
liquid that can be held in the pump chamber, depend
upon the nature of the pump chamber and the pump
features provided for accommodating the refilling
flow of liquid. In some applications, it would be
desirable to provide a relatively large amount of
; pump chamber capacity, and it would be desirable to
refill the pump chamber as quickly and as fully as
possible.
Another problem that must be overcome is the
priming of the pump, especially where the pump
chamber has a relatively large volume. Air and/or
liquid vapor that is initially present in the pump
1323618
--4--
chamber is compressed on the downward stroke of the
piston. Owing to the high compressibility of the
air, the resulting pressure is usually not great
enough to move the poppet away from the piston to
permit the discharge of the air out through the
nozzle with a concomitant reduction in chamber
pressure. Consequently, little or no liquid is drawn
into the pump chamber during the return stroke of the
piston, and the entrapped air merely expands to
occupy the increasing volume of the pump chamber.
Various mechanisms have been proposed for
venting air from the pump chamber to facilitate
priming of the pump chamber with the liquid from the
container. For example, the U.S. Patent No.
3,774,849 issued to Michel Boris discloses the use of
-~ long vent ridges on the inner wall of a lower portion
of the pump chamber. This permits the compressed air
to vent upwardly around the piston at the bottom of
the piston stroke and to then flow into the container
through an aperture in the upper part of the pump
` chamber. While this generally works well with the
particular pump structure for which it was designed,
it would be desirable to provide an improved
structure for facilitating the air venting and liquid
priming of a pump chamber, particularly a pump
chamber having an increased capacity and increased
liquid refill or priming flow rates.
It would also be beneficial if a pump having
~ the above-described improved features could be
i 30 provided with a configuration which, when the pump is
in the unactuated position, has a reduced number of
components that are in sealing engagement.
Continuous engagement of seal parts over a long
period of time can cause soft seal part material to
creep and permanently deform. This can lead to
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-` ~32361~
reduced effectiveness of the sealing function between
the engaged components.
In many applications, it is desired to
produce a very highly atomized, fine mist. A problem
with some pump designs is that the desired fine mist
will be dispensed only if the operator pushes down
the nozzle actuator with sufficient force and speed.
Otherwise, liquid droplets may dribble out of the
nozzle rather than the liquid being atomized in a
fine mist--especially at the beginning and end of the
liquid discharge. Thus, it would be desirable to
provide an improved, finger-actuated pump for
dispensing the liquid in a fine mist regardless of
how slowly or discontinuously the nozzle actuator is
pushed down by the user.
It would also be advantageous if an
improved, finger-operated pump could be provided with
a minimum number of small components that could be
relatively quickly and easily assembled so as to
facilitate fabrication of the pump.
Finally, it would be desirable to provide
such an improved pump in which the configurations of
the components could be simplified so as to
facilitate fabrication of the components, as well as
assembly of the components.
~ SUMMARY OF THE INVENTION
^/ The present invention provides an improved,
finger-operated pump. The pump includes a pump
chamber and supply conduit communicating with the
pump chamber. A movable sealing conduit is provided
for slidably and sealably engaging the supply conduit
in a telescoping relationship.
A primary piston is operably disposed in the
pump chamber and defines a discharge passage out of
the pump chamber.
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~ 1 323b 1 8
A poppet is provided with a primary valve
means for occluding the discharge passage. The
poppet also has a secondary valve means for occluding
flow through the top of the movable sealing condu;t.
A lost motion means is provided for
permitting a limited degree of relative movement
between the poppet and the sealing conduit between
first and second extremes of the relative movement.
In the preferred embodiment, the lost motion
means includes a spring means for (1) engaging the
poppet and sealing conduit at least when the poppet
and sealing conduit are at the first extreme, and (2)
biasing the poppet primary valve means against the
primary piston.
The present invention may be alternatively
characterized as including (1) a biasing means, such
; as a spring, for biasing the poppet primary valve
means against the primary piston and (2) a lost
motion means for permitting the limited degree of
relative movement between the poppet and sealing
conduit between first and second extremes of the
relative movement--the lost motion means including a
portion of the biasing means that is located to
engage the poppet and sealing conduit at the first
~ 25 extreme of relative movement.
- In the preferred embodiment, the biasing
means or spring means includes a single spring which
is operatively disposed to engage the poppet and not
the sealing conduit when the poppet and sealing
conduit are at the second extreme of the relative
movement. At the second extreme of relative
movement, a portion of the poppet and a portion of
- the sealing conduit become engaged and, when engaged,
fulfill two functions: (1) occluding flow through
the sealing conduit, and (2) defining a pa~t of the
,
1323618
7 23158-1531
lost motlon means which llmlts the relatlve movement at the second
extreme of the relatlve movement.
Wlth this lnventlon, the pump can be deslgned so that
the poppet secondary valve means can seal agalnst the top of the
sealing condult durlng the pressurlzlng stroke of the prlmary
plston when seallng condult and poppet are orlented at one of the
extremes of relatlve movement. As the prlmary plston starts to
rlse to the fully elevated rest posltlon on the return stroke, the
secondary valve means and seallng condult separate, owlng to the
lost motlon arrangement, and the seallng condult and poppet are
malntalned at the other extreme of the relatlve movement for the
remainder of the upward stroke alded by the frlctlonal reslstance
of the seallng condult wlth the supply condult. Thls permlts alr
to be vented down the suctlon tube lnto the contalner, and thls
also permlts llquld to flow out of the contalner through the
seallng condult for refllllng the pump chamber.
: .
The novel lost motlon arrangement permlts, lf deslred,
the advantageous use of a pump deslgn ln whlch the seallng condult
:,~
, ls completely dlsengaged from the supply condult when the pump ls
~, 20 ln the lnactlve, "rest" posltlon. Thls provldes an addltlonal
. ~
flow path for the llquld when refllllng the pump chamber. Thls
.:. .
also prevents the seallng parts of the supply condult and seallng
~- condult from taklng on a permanent deformatlon or set whlch would
have a deleterlous effect on the seallng functlon.
,
The use of a sprlng whlch, ln the preferred embodlment,
functlons as both (1) a blaslng means for blaslng the poppet to
'J close the dlscharge passage and (2) a part of the lost motlon
means, has the advantage of provldlng a lost motlon structure
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~ 1 32361 ~
7a 23158-1531
means, has the advantage of provldlng a lost motlon structure
whlch ls easlly fabrlcated and assembled.
In accordance wlth the present lnventlon, there ls
provlded a flnger-operated pump comprlslng: a pump chamber; a
supply condult communlcatlng wlth sald pump chamber; a movable
seallng condult for movement between a ralsed, unactuated posltlon
and a range of lowered, actuated posltlons ln whlch sald seallng
condult slldably and seallngly engages sald supply condult ln a
telescoplng relatlonshlp; a prlmary plston operably dlsposed ln
sald chamber for movement between a ralsed, unactuated rest
posltlon and a range of lowered, actuated posltlons, sald prlmary
plston deflnlng a dlscharge passage out of sald pump chamber; a
poppet havlng a prlmary valve means for occludlng flow through
sald dlscharge passage and havlng a secondary valve means for
occludlng flow through sald seallng condult, sald poppet belng
movable a llmlted amount relatlve to sald seallng condult when
'~ sald seallng condult ls engaged wlth sald supply condult; and
sprlng means for (1) blaslng sald poppet prlmary valve means
agalnst said prlmary plston to urge sald prlmary plston toward lts
sald ralsed, unactuated, rest posltlon and (2) engaglng both sald
. poppet and seallng condult after actuatlon of sald pump to return
sald seallng condult to lts sald ralsed, unactuated rest posltlon
7 and malntaln sald poppet prlmary valve means blased agalnst said
prlmary plston ln lts sald ralsed, unactuated posltion.
' In accordance wlth the present lnventlon, there ls
provlded a flnger-operated pump comprlslng: a pump chamber; a
supply condult communlcatlng wlth sald pump chamber; a movable
seallng condult for movement between a ralsed, unactuated posltlon
-
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-- 1323618
7b 231S8-1531
and a range of lowered, actuated posltlons ln whlch sald seallng
condult slidably and seallngly engages sald supply condult ln a
telescoplng relationshlp; a prlmary plston operably dlsposed ln
sald chamber f or movement between a ralsed, unactuated rest
posltlon and a range of lowered, actuated posltlons, sald prlmary
plston deflnlng a dlscharge passage out of sald pump chamber; a
poppet havlng a prlmary valve means for occludlng flow through
sald dlscharge passage and havlng a secondary valve means for
occludlng flow through sald seallng condult; blaslng means for
blaslng sald poppet prlmary valve means agalnst sald prlmary
plston to urge sald prlmary plston toward lts sald ralsed,
unactuated, rest posltlon; and means for permittlng a llmlted
degree of relatlve movement between sald poppet and seallng
condult, sald means includlng a portlon of sald blaslng means
being located to engage both sald poppet and sald seallng condult
after actuatlon of sald pump to return sald seallng condult to lts
' sald ralsed, unactuated rest posltlon and malntaln sald poppet
j prlmary valve means blased against sald prlmary plston in its said
ralsed, unactuated positlon.
In accordance wlth the present lnventlon, there ls
, provided a finger-operated pump comprlslng: a pump chamber; a
supply condult communlcatlng wlth sald pump chamber; a movable
seallng condult for slldably and sealingly engaglng sald supply
. condult ln a telescoplng relatlonshlp; a prlmary plston operably
!~ dlsposed ln sald chamber and deflnlng a dlscharge passage out of
sald pump chamber; a poppet havlng a prlmary valve means for
. occludlng flow through sald dlscharge passage and havlng a
secondary valve means for occludlng flow through sald seallng
. . .
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~-` 1 3236 1 8
7c 23158-1531
condult; and lost motlon means for permlttlng a llmlted degree of
relatlve movement between sald poppet and seallng condult between
flrst and second extremes of said relatlve movement, sald lost
motion means including sprlng means for (1) biasing sald poppet
primary valve means against said prlmary plston and (2) engaging
. said poppet and seallng condult at least when sald poppet and
seallng condult are at sald flrst extreme, sald sprlng means
lncluding only one sprlng operatlvely dlsposed to engage sald
poppet and not sald seallng condult when sald poppet and seallng
0 condult are at sald second extreme.
In accordance wlth the present lnventlon, there ls
provlded a flnger-operated pump comprising: a pump chamber; a
supply conduit communicatlng with said pump chamber; a movable
''J sealing condult for slldably and seallngly engaglng sald supply
i~ conduit ln a telescoplng relationship; a primary plston operably
~ dlsposed ln sald charnber and defining a discharge passage out of
:~. said pump chamber; a poppet having a prlmary valve means for
~;~ occludlng flow through sald dlscharge passage and havlng a
.;. secondary valve means for occluding flow through sald sealing
.. 20 conduit; biasing means for biasing sald poppet prlmary valve means
against said prlmary plston; and lost motlon means for permlttlng
a llmlted degree of relative movement between sald poppet and
seallng condult between flrst and second extremes of sald relatlve
movement, sald lost motlon means lncludlng a portlon of sald
blaslng means belng located to engage sald poppet and sald seallng
condult at sald flrst extreme of sald relatlve movement, sald
blaslng means belng operatlvely dlsposed to engage sald poppet and
not sald seallng condult when sald poppet and seallng condult are
,- at sald second extreme.
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1 3236 1~8
It has been found that the novel, improved
pump of the present invention can operate at
relatively large capacities and at relatively high
refill flow rates. When employed with an appropriate
nozzle structure, the improved pump of the present
invention operates to produce a fine mist with little
or no dribble or sputtering. With other appropriate
nozzles, suitable liquids may be dispensed as a
lotion, stream, foam or the like.
Further, since the pump of the present
invention does not have a gravity-biased check valve
or gravity-biased back flow-preventing valve,
operation of the pump in an inverted position during
a continuous pressurizing portion of the piston
stroke does not result in an undesired communication
between the pump chamber and the liquid container.
Numerous other features and advantages of
the present invention will become apparent from the
following detailed description taken in conjunction
with the accompanying drawings.
BRIEF DESCRIPTION OF T~E DRAWINGS
A preferred embodiment of the invention will
next be described, by way of example only, with
reference to the accompanying drawings, in which:
FIG. 1 is an elevational view, partly in
cross-section, of the finger-operated pump of the
present invention shown connected with a fragmentary
portion of a suction tube and shown mounted in a
closure cap on the top of a container that is
illustrated in phanto~ by dashed lines;
FIG. 2 is a cross-sectional view taken
generally along the plane 2-2 in FIG. 1 (looking up);
FIG. 3 is a cross-sectional view taken
generally along the plane 3-3 in FIG. 1 (looking up);
.
1 32361 8
FIG. 4 is a cross-sectional view taken
generally along the plane 4-4 in FIG. 1 ~looking
down)
FIG. 5 is a cross-sectional view taken
generally along the plane 5-5 in FIG. 1 (looking
down);
FIG. 6 is a cross-sectional view taken
generally along the plane 6-6 in FIG. 1 (looking up);
FIG. 7 is a cross-sectional view taken
generally along the plane 7-7 in FIG. 1 (looking up);
FIG. 8 is an enlarged view of the pump with
~-, the components in the position illustrated in FIG. l;
; and
FIGS. 9, 10, 11, llA, 12, and 13 are views
similar to FIG. 8, but show sequentially moved
` positions of the pump components to illustrate the
: sequence of the operation of the pump.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
While this invention is susceptible of
~-~ 20 embodiment in many different forms, this
specification and the accompanying drawings disclose
~sl only one specific form as an example of the use of
i the invention. The invention is not intended to be
limited to the embodiment so described, and the scope
l 25 of the invention will be pointed out in the appended
`~ claims.
For ease of description, the apparatus of
this invention is described in the normal (upright)
: operating positionr and terms such as upper, lower,
horizontal, etc., are used with reference to this
position. It will be understood, however, that the
apparatus of this invention may be manufactured,
stored, transported, and sold in an orientation other
than the position described.
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--10--
, Some of the figures illustrating the
preferred embodiment of the apparatus show structural
details and mechanical elements that will be
recognized by one skilled in the art. However, the
detailed descriptions of such elements are not
ecessary to an understanding of the invention, and
accordingly, are not herein presented.
:,
Description Of The Components
And of The Arran~ement of The Com~onents
With reference to FIG. 1, the pump of the
- present invention is designated generally by the
reference numeral 20. The pump 20 is mounted within
a conventional closure cap 22 which includes suitable
means, such as threads 24, for attaching the cap 22,
, along with the pump 20 mounted therein, to the open
~ top of a conventional container 26.
. The container 26 is loaded with a liquid
-I 20 product (not visible below the pump 20 in the
:'~ container 26 illustrated in FIG. 1). The liquid is
1 drawn up into the pump 20 through a conventional
suction tube or dip tube 30 which is connected by
~ suitable conventional means to the bottom of the pump
:~ 25 20. The suction tube 30 extends to near the bottom
of the container 26. The bottom end of the suction
~ tube 30 is thus normally submerged in the liquid when
.. the container 26 is in a generally upright
orientation as illustrated in FIG. 1.
;. 30 The cap 22 has a generally cylindrical,
hollow wall 31 defining an interior cylindrical
opening 32 above, and separated from, the threads 24
by an inwardly projecting annular flange 34. Mounted
- within the cap opening 32 is a collar 38 which has an
outer wall 40 defining an outwardly projecting
;
132361~
annular flange 42 on its lower end. The collar
flange 42 is retained by the cap flange 34 tight
against the top of the mouth of the container 26.
The collar 38 is adapted to engage and
retain the pump 20 within the cap 22. To this end,
the pump 20 includes a housing 48 with an outwardly
projecting flange 50 at its upper end. The flange 50
is engaged by a radially inwardly projecting ring 56
on the outer wall 40 of the collar 38. The collar 38
can be easily snap-fit onto the pump housing 48 to
effect this engagement.
The pump housing 48 defines an internal pump
chamber 80. In the preferred embodiment, the pump
chamber 80 is a generally cylindrical cavity with an
open top in which is received an inner cylindrical
wall 72 of the collar 38. The wall 72 is connected
to the collar outer wall 40 via an annular top wall
64. The inner wall 72 terminates with a tapered
bottom end 73 inside the pump chamber 48.
The flange 50 at the upper end of the pump
. housing 48 has a vertical notch 62 (visible in the
. left-hand side of FIG. 1~ to provide an air venting
gap between the pump housing 48 and the collar outer
wall 40 for cooperating with certain vent passages in
the collar 38. In particular, the collar annular top
wall 64 defines a circumferential groove 68 in its
underside. The groove 68 communicates with the top
- of the notch 62 (FIG. 1). At a position 180 degrees
from the notch 62, the groove 68 communicates with a
radial groove 70 defined in the underside of the
collar top wall 64 (FIGS. 2 and 8). As best
illustrated in FIG. 8, the groove 70 extends inwardly
beyond the wall of the pump housing 48.
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132361~
-12-
The collar inner cylindrical wall 72 has a
plurality of circumferentially spaced, outwardly
projecting ribs 74 (FIGS. 2 and 8). The outer
vertical surfaces of the ribs 74 engage the inner
surface of the wall of the pump housing 48 and
function to generally align the collar 38 and the
pump housing 48 in a coaxial relationship.
The entire circumference of the inner top
edge of the pump housing 48 is chamfered at 75 to
define an annular passage around the collar 38 at the
tops of the ribs 74. The ribs 74 function to define
spaces between the ribs to permit the annular region
below the ribs 74 at the bottom of the collar inner
cylindrical wall 72 to communicate with the annular
passage around the tops of the ribs 74. This
establishes an air vent path from the interior of the
pump housing 48 that continues outwardly through
radial groove 70, around circumferential groove 68,
through notch 62, past collar ring 56, and then down
between the collar outer cylindrical wall 40 and the
pump housing 48 into the interior head space of the
container 26 above the liquid. This air vent path
~ functions, in conjunction with other pump components,
-, to vent atmospheric air into the container 26 as
described in detail hereinafter.
As best illustrated in FIG. 1, primary
piston 82 is sealingly and slidably disposed for
reciprocation in the pump chamber 80. The primary
piston 82 includes an upwardly extending rod or stem
portion 86 which projects out of the pump chamber 80
- past the collar 38 and above the cap 22. The rod or
; stem 86 has an upper cylindrical portion 88 adapted
to accept an actuator and nozzle discharge head or
button 90. The illustrated discharge head 90 is of
3~ the conventional spray type having an associated
,, - .
1323~18
spray orifice 92 communicating through suitable
passages 94 with the top end of the primary piston
stem 86. The primary piston 82, including the
upwardly projecting stem 86, is hollow and defines a
discharge passage 98 establishing communication
between the nozzle passages 94 and the pump chamber
80.
The exterior of the primary piston end 86 is
tapered so that the diameter of the stem 86 decreases
with increasing height from the collar 38. An
annular clearance always exists around the stem 86
and the top of the collar 38 for permitting air to
vent down along the stem 86 toward the bottom of the
piston 82. The bottom end of the primary piston 82
defines an upwardly concave sealing surface 102 for
receiving and sealing against each side surface of
the collar inner wall bottom end 73 when the primary
piston 82 is in the fully raised, "rest" position
illustrated in FIGS. 1 and 8.
However, as best illustrated in FIGS. 9 and
13, whenever the primary piston 82 is partially or
substantially fully depressed, the piston concave
sealing surface 102 moves out of sealing engagement
with respect to the collar inner wall bottom end 73.
Clearance is established between the exterior of the
rèduced diameter upper portion of the downwardly
moving primary piston stem 86 and the collar inner
wall bottom end 73. This permits the ambient
atmosphere to flow into the container 26 to replace
the volume of the discharged contents and maintain
atmospheric air pressure within the container 26.
Specifically, with reference to FIG. 1, it can be
seen that ambient air can flow from outside the cap
22, over the cap top into the cap opening 32, and
then up under the hollow discharge head, or button
90.
~ - .
- 1323618
-14-
With reference to FIG. 13, it can be seen
that when the stem 86 is in a lowered position, the
air from under the actuator ~utton 90 flows down
along the path illustrated by the flow arrows 106
between the collar 38 ana the stem 86. As
illustrated by the flow arrows 108 in FIG. 13, the
air then flows upwardly between the collar inner
cylindrical wall 72 and the pump housing 48. As
illustrated in FIG. 13 by the flow arrow 110, the air
then flows through the radial groove 70 to the
circumferential groove 68 (see also FIG. 2). The air
flows through the circumferential groove 68 in both
directions around the circumference of the collar 38
; for about 180 degrees where it then flows through the
pump housing notch 62 as illustrated by the flow
arrow 114 in FIG. 13. The air continues flowing
downwardly between the collar 38 and pump housing 48
and then into the top of the container 26 as
- indicated by the flow arrows 116 in FIG. 13.
s 20 The pump 20 is constructed to admit liguid
into the pump chamber 80 from the supply tube 30
through a fixed supply conduit which, in the
preferred illustrated embodiment, includes a
. cylindrical tube 120 that projects upwardly inside
. 2S the pump chamber 80 and that terminates in an open
upper end 121.
A poppet 150 is axially aligned above the
fixed supply conduit or tube 120 and is adapted to
move with, as well as relative to, the primary piston
82 above the fixed supply conduit 120. In
particular, the poppet 150 has a primary valve means
for occluding flow through the primary piston
discharge passage 98. To this end, the primary
piston 82 includes an enlarged bore 154 (FIGS. 2 and
8), the upper end of which opens to the smaller
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1 32i6 ~ 3
-15-
diameter discharge passage 98 at a port defined by an
annular valve seat 158.
: The poppet 150 has an upwardly extending
primary valve member or means 162 (FIGS. 2 and 8) for
sealing against the annular valve seat 158 in the
. primary piston 82 so as to occlude upward flow of
liquid from the pump chamber 80 through the discharge
. passage 98.
The poppet 150 includes a lower portion with
10 a flange 170 (FIGS. 5 and 8) and a downwardly
projecting pin 230. As best illustrated in FIGS. 4
and 8, the flange 170 has an upper piston surface 172
, with four, outwardly radiating ribs 174 projecting
above the surface 172. The upwardly facing surface
172 functions as a piston surface for being
. pressurized by the liquid in the pump chamber 80
.~ under conditions explained in detail hereinafter.
~ The poppet flange 170 also includes a
;~j plurality of circumferentially spaced-apart guide
20 ribs or fingers 194 (FIGS. 5, 6, and 8). As best
- illustrated in FIG. 8, the exterior of each rib or
finger 194 is aaapted to slidably engage the wall of
; the pump chamber 80 and guide the axial movement of
the poppet 150.
The pin 230 projecting downwardly at the
bottom of the poppet 150 includes four,
circumferentially space-apart ribs 234 (FIGS. 5, 6,
~ and 8). The ribs 234 define circumferentially
- spaced-apart, vertical, grooves 241 (FIG. 6 only).
The bottoms of the ribs 234 are adapted to be engaged
by the upper end of a biasing means or spring means,
such as a helical coil compression spring 240 (FIG.
8).
The spring 240 is mounted within the pump
35 chamber 80, and the bottom end of the spring 240 is
', ,, `
- ~
. ~ -
-' ~32~6~
-16-
received inside the fixed supply conduit 120. The
bottom end of the spring 240 is maintained in axial
alignment by an inner conduit 246 which projects
upwardly inside the supply conduit 120 and which
defines an inlet passage 248 communicating between
the supply tube 30 and the supply conduit 120. The
upper end of the spring 240 is maintained in axial
alignment by the pin 230 extending downwardly from
the poppet 150.
The underside of the poppet flange 170
functions as a secondary valve means, and in
particular, defines a concave valve member surface
180 for sealing against the top of a movable sealing
means or sealing conduit 190 that is engageable with
the poppet 150 through a lost motion structure,
described hereinafter, which permits relative
~ movement between the poppet 150 and sealing conduit
'' 190.
To this end, the sealing conduit 190, in the
preferred form illustrated, has a generall~
cylindrical configuration that includes a generally
cylindrical, hollow, lower wall 202 and an upper
cross wall 222.
The upper cross wall 222 of the sealing
25 conduit 190 defines therein an aperture 226 (FIGS. 6
and 8) through which projects the poppet pin 230.
Liquid can flow through this aperture 226 for
refilling the pump chamber 80 during a step in the
operation of the pump as explained in detail
hereinafter. Air or other vapor can also flow in the
reverse direction through the aperture 226 during
venting of the pump chamber 80 to facilitate priming
of the pump in a manner described in detail
hereinafter in the Section entitled "Operation Of The
Pump--Venting And Priming Of The Pump Chamber. n The
, .
. : -:
-` 1323618
-17-
grooves 241 defined between the poppet ribs 234
.:. function, along with the aperture 226, as flow
channels for the filling liquid or the venting air.
It can be seen in FIG. 8 that a peripheral
~ S portion of the top of the spring 240 extends radially
; outwardly beyond the poppet pin ribs 234 by an amount
sufficient to engage the sealing conduit 190.
Specifically, in the inactive position of the pump
illustrated in FIGS. 1 and 8, the cross wall 222 of
: 10 the conduit 190 engaged by the outer periphery of the
. top of ~he spring 240. The sealing conduit 190 thus
rests under the influence of gravity by its own
weight on the outer periphery of the top of the
spring 240.
The engagement of the poppet 150 and the
sealing conduit 190 with the spring 240 may be
characterized as defining a first extreme or end of
relative axial movement in a lost motion arrangement
or means between the poppet 150 and sealing conduit
190. The second extreme or end of the relative axial
movement in the lost motion arrangement is defined as
the orientation of the poppet 150 and sealing conduit
190 wherein the sealing conduit 190 contacts the
concave valve member surface 180 of the poppet
. 25 secondary valve means (FIG. 9). The sealing conduit
upper cross wall 222 defines a peripheral contact
surface 218 for being engaged by the concave valve
member surface 180 at this second end of the relative
movement range (FIG. 9). The circumstances under
which this relative movement occurs--from the first
end of the movement range illustrated in FIG. 8 to
the second end of the movement range illustrated in
FIG. 9--is described in detail hereinafter.
The hollow cylindrical wall 202 of the
sealing conduit 190 includes outwardly projecting,
.
. ,.
'
- , ' ' '.
., . - . .
-` 1 32~6il 8
--18--
circumferentially spaced-apart guide ribs 250 for
slidably contacting the inside of the pump chamber 80
to maintain axial alignment of the sealing conduit
190 within the chamber 80 and relative to the supply
conduit 120.
The location of the ribs 234 (FIGS. 6 and 8)
and grooves 241 (FIG. 6 only) on the poppet pin 230
is a preferred construction as opposed to locating
the grooves in the inner cylindrical surface of the
. 10 surrounding aperture 226 of the poppet 190. This is
because it is desired to mold the poppet 190 from a
- thermoplastic material with a uniform configuration
that will be subject to little or no deformation as a
result of the molding process.
. 15 If the grooves 241 were instead molded in
the inner cylindrical surface of the aperture 226 in
the upper end of the sealing conduit 190, then the
upper end of the sealing conduit 190 would have thick
and thin regions radially inwardly of the sealing
surface 218 of the sealing conduit 190. When the
.,
~` plastic material cooled after being injection molded,
: the thick sections could shrink more than the thin
sections. This could pull or deform the sealing
surface 218 out of the desired precise circular
` 25 configuration, and this could lead to a defective
. seal when the sealing conduit 190 is engaged against
- the surface 180 on the underside of the poppet valve', 150.
In contrast, when the ribs 234 and grooves
241 are molded in the poppet pin 230 as in the
preferred illustrated embodiment, minor uneven
shrinkage-and any resulting minor deformation of the
poppet pin 230 is not particularly critical since
- there is a circumferential clearance around the pin
35 230 and since the pin 230 does not have to perform
,
, .
.
. .
.
,' ' "'", ` '' '"
1323618
--19--
any sealing function.
It can be seen that the spring 240 functions
as a biasing means to normally bias the poppet 150,
along with the engaged primary piston 82, to a fully
raised position when the pump is in the inactive
(i.e., unactuated) rest position. When the pump 20
is in the unactuated position, the spring 240 also
supports the sealing conduit 190, and the bottom of
the sealing conduit 190 is spaced above the open
upper end 121 of the fixed supply conduit 120.
The bottom end of the sealing conduit 190 is
adapted to slide downwardly along, and in sealing
engagement with, the fixed supply conduit 120 in a
- telescoping relationship (see FIGS. 9-13). To this
end, the bottom of the sealing conduit 190 includes
an inwardly projecting annular seal 260 for engaging
the exterior of the supply conduit 120 when the
movable sealing conduit 190 moves downwardly under
circumstances explained in detail hereinafter.
The above-described components of the pump
20 may be conveniently fabricated from thermoplastic
materials. However, the spring 240 is preferably
stainless steel. The novel design of the pump 20 is
especially suitable for accommodating fabrication of
the pump housing 48, including the fixed supply
conduit 120, from polypropylene. Other internal
components (e.g., the primary piston 82, poppet 150,
and sealing conduit 190, or portions of these other
components) may be fabricated from polyethylene to
provide a better sealing action.
The novel design of the pump 20 permits the
pump components to be easily assembled. Typically,
the internal components of the pump 20 are assembled,
and thereafter the suction tube 30 is attached to the
bottom of the pump chamber 48 by conventional
techni g~es.
': :
:
1 32 3 G l ~
-20-
With respect to assembly of the internal
components, it is to be noted that the movable
sealing conduit 190 may be readily disposed on the
poppet pin 230 of the poppet 150. The assembled
. 5 sealing conduit 190 and poppet 150 are then easily
seated within the piston 82, and the three components
are inserted together with the spring 240 into the
pump chamber 80 of the pump housing 48.
~, Alternatively, the components lend
themselves to automatic assembly. The pump housing
48 may be held in a jig or nest and then the spring
240 can be dropped into the housing pump chamber 80
inside the supply conduit 120. Next, the sealing
: conduit 190 is dropped over the spring 240. The
. 15 poppet 150 is then dropped into the pump housing 48
. with the poppet pin 230 projecting downwardly into
the spring 240. Then the primary piston 82 is
dropped on top of the poppet 150.
The collar 38 is seated on top of the pump
`~' 20 housing 48 around the primary piston stem 86, and the
.:.
cap 22 is mounted around the collar 38.
:. Attachment of the actuator head or button 90
' to the upper end of the primary piston stem 86
., completes the assembly of the pump 20 with the
related actuator and container closure components.
The entire assembly, including the pump 20, cap 22,
- button 90, and suction tube 30, may then be attached
. to the top of the container 26.
Operation Of The PumP
--Dispensing From A Primed PumP
The operation of the pump 20 will next be
described with reference to the operation sequence
,
~' ', : -. . .
'
.
/
1 ~2361 ~
-21-
steps illustrated in FIGS. 8-13. The operation
description assumes that the pump chamber 80 is
initially primed substantially full of liquid and
that the pump chamber 80 may also contain some
S residual air and/or liquid vapor. The actual priming
of the pump will be described later. For purposes of
clarity, the liquid per se is not illustrated in the
Figures.
The initial, inactive, raised position of
the pump 20 is shown in FIG. 8. The primary piston
82 is in the maximum elevated position and engages
the lower portion of the inner cylindrical wall 72 of
the collar 38. The collar 38 thus determines the
maximum height of the primary piston 82 in the pump
chamber 80.
The poppet 150 is biased upwardly by the
spring 240 to occlude the primary piston discharge
passage 98. The sealing conduit 190 is supported by
the periphery of the upper end of the spring 240.
The bottom end of the sealing conduit 190 is spaced
`~ above the top end 121 of the fixed supply conduit 120.
The pump 20 has been primed with liquid
which fills the interior of the fixed supply conduit
120 as well as a substantial portion of the remaining
volume in the pump chamber 80 below the primary
piston 82 both inside and outside of the sealing
conduit 190.
The pump 20 is actuated by applying a
downward force on the actuator head or button 90
(FIG. 1) so as to begin to move the primary piston 82
downwardly in the pump chamber 80. The poppet 150 is
also necessarily forced downwardly by the primary
piston 82 with which it is engaged. The sealing
conduit 190 continues to be supported by the spring
240 until the inw;-rdly pro~ecting annular seal 260 at
,,.. , ::,
-' 1 3236 1 ~
--22--
the bottom end of the sealing conduit 190 engages the
exterior of the top end 121 of the supply conduit 120
as illustrated in FIG. 9. At this point, there is
sufficient frictional engagement between the sealing
5 conduit 190 and the supply conduit 120 to retard
further downward movement of the sealing conduit 190
under its own weight. Until this engagement occurs,
the pump chamber 80 cannot, of course, be pressurized
since the pump chamber is in communication with the
interior of the container 26 through the supply
conduit 120.
As illustrated in FIG. 9, the sealing
conduit 190 thus remains stationary and engaged with
the fixed supply conduit 120 while the primary piston
82 and poppet lS0 continue moving downwardly to~ether
relative to the sealing conduit 190. The range of
. downward movement of the poppet 150 that is permitted
. by the lost motion arrangement between the poppet 150
and sealing conduit 190 is such that concave valve
member surface 180 of the poppet lS0 eventually seals
against the peripheral contact surface 218 at the top
of the sealing conduit 190.
Until this sealing engagement occurs at the
top of the sealing conduit 190, any tendency of the
! 25 downwardly moving primary piston 82 to pressurize the
pump chamber 80 can result in a very small amount of
the liquid and/or residual air (or vapor) being
forced from the pump chamber 80 down the fixed supply
:~ conduit 120 and back into the container 26. After
30 the sealing engagement occurs between the poppet 150
and the top of the sealing conduit l9û, communication
between the container 26 and the pump chamber 80 is
interrupted, and the pump chamber 80 becomes
increasingly pressurized with increasing downward
35 movement of the primary piston 82.
.
.
.
1 3236 1 8
-23-
It is to be noted that once the poppet 150
engages the top of the sealing conduit 190, any
~ continued downward movement of the poppet 150 will
necessarily effect downward movement of the sealing
5 conduit 190 along the fixed supply conduit 120 with
: the sealing engagement being maintained between the
poppet secondary valve means surface 180 and the
. sealing conduit peripheral contact surface 218.FIG. 10 illustrates the relationship of the
pump components at a point of maximum pressure just
before the liquid is first discharged upwardly
through the pump. The elevation of the primary
piston 82 in the chamber 80 at the point of maximum
chamber pressure depends upon the strength of the
spring 240 as well as upon the initial chamber liquid
load conditions (i.e., the amount of liquid and/or
residual air (or vapor) initially in the pump chamber
80).
~ At the point of maximum pressurization, the
:~ 20 degree of compression of the liquid and entrapped
residual air and/or vapor within the pump chamber 80
is such that the thrust acting downwardly on the
~ poppet piston surface 172 exceeds the upward thrust
; of the spring 240, with the result that the poppet
150 moves downwardly at a greater velocity than the
primary piston 82. This, in turn, causes the primary
: valve means sealing surface 162 to open the discharge
. passage 98, and to remain open as long as such
differential pressure is maintained (see FIG. 11).
. 30 During the time that the discharge passage
98 is open, the liquid product is discharged through
. the passage 98 as illustrated by the flow arrows 280
in FIG. 11. The liquid is thus forced under pressure
to the nozzle assembly where it is discharged from
35 the orifice 92 as a finely atomized spray or mist.
i~ . .. .
1323618
-24-
If the downward movement of a primary piston
82 is slowed or completely stopped at, for example,
elevation Y as illustrated in FIG. 11, then the
sealing conduit 190 will stop along the inlet conduit
120 at, for example, elevation X as illustrated in
FIG. 11. The spring 240 will subsequently force the
poppet 150 back upwardly against the primary piston
82 as illustrated in FIG. llA to occlude the
discharge passage 98 after a sufficient amount of the
pressurized fluid has been discharged. That is, the
discharge of the fluid from the pump is terminated
whenever the pressure drops below the predetermined
operating pressure (established by the spring 240
operating in conjunction with the other pump
components). Since the liquid is thus always
discharged at a predetermined pressure, proper
atomization can be ensured by employing a suitable
nozzle. The tendency of the pump to dribble from the
spray orifice 92 is very substantially reduced or
eliminated altogether.
When the poppet 150 moves upwardly toward
the primary piston 82 to occlude further discharge
from the pump (FIG. llA), the sealing conduit 190
initially remains stationary owing to its frictional
engagement with the supply conduit 120. Thus, the
poppet 150 will separate from the top of the sealing
conduit 190.
Eventually, as the poppet 150 moves upwardly
far enough to seal against the discharge passage 98,
30 the top of the spring 240 around the poppet pin 230
r will engage the sealing conduit 190 (FIG. llA). If
the primary piston 82 has been maintained at the
initially depressed elevation, say at elevation Y in
FIGS. 11 and llA, then the poppet 150 will reclose
the discharge pa3~age 93 at the s~me instant the top
'
" .
., ~ .
; ' .
-` 1323618
-25-
of the spring 240 again just engages the sealing
conduit 190 which has remained at the elevation X.
Thus, the upwardly moving poppet 150 separates from
the sealing conduit 190 within the extent permitted
5 by the spring in the lost motion arrangement. At
this point, any residual pressure in the pump chamber
: 80 could force a small amount of the liquid (and/or
entrapped air and vapor) into the region under the
poppet 150 from which region the flow passes down
through the sealing conduit 190, through the fixed
supply conduit 120, and into the container 26.
If the primary piston 82 is permitted to
rise (for example, above elevation Y in FIG. llA),
then the spring 240 will simultaneously urge the
j 15 sealing conduit 190 and poppet 150 upwardly together
in the spaced-apart relationship shown in FIG. llA
with the poppet 150 continuing to close off the
discharge passage 98.
However, if the primary piston 82 is
subsequently forced further downwardly in the pump
, chamber 80, the poppet 150 again seals against the
top of the sealing conduit 190 so that additional
,
downward movement of the primary piston 82 again
begins to pressurize the pump chamber 80. If and
when the maximum design pressure is again attained in
. the pump chamber 80, the poppet 150 is again forced
i away from the primary piston 82 to permit further
discharge of the liquid from the pump.
. It will be appreciated that the sealing
conduit 190, owing to its frictional engagement with
the fixed supply conduit 120 during operation of the
pump, will remain in place on the supply conduit 120
during pre-discharge pressurization of the pump
chamber 80 even if the pump 20 is inverted. Thus, if
the container ls inverted prior to spray dischrrge,
--" 1323618
-
-26-
pressure cannot be inadvertently vented to the
container so long as the piston 82 is continuously
depressed to seal the poppet 150 against the sealing
conduit 190 while the pump chamber is being
S pressurized--even at very low pressures.
The downward stroke of the primary piston 82
is mechanically terminated at the maximum stroke
length illustrated in FIG. 12. At the bottom of the
stroke, the primary piston 82, with the poppet 150
seated therein and the sealing conduit 190 sealingly
engaged with the underside of the poppet 150, has
moved sufficiently downwardly in the pump chamber 80
so that the sealing conduit top cross wall 222 abuts
the open top end 121 of the fixed supply conduit
120.
Of course, it will be appreciated that a
sufficient amount of spray may have been generated
long before the primary piston 82 would reach the
bottom of ~he maximum permissible stroke illustrated
in FIG. 12. In such a situation, the finger force on
the top of the actuator button 90 would typically be
released before the full stroke condition had been
attained. In any case, release of the finger
pressure from the actuator button 90, at the end of a
full down stroke or at any intermediate stroke
position, permits the spring 240 to return the pump
20 to the fully raised, inactive position.
--Refilling Of The PumP
FIG. 13 illustrates the pump 20 just after
the finger pre~sure on the actuator button 90 has
been released and just after the primary piston 82
has begun moving upwardly in the pump chamber 80 in
response to the biasing force of the spring 240
:
,:
~ 1 3236 1 ~
-27-
pushing the poppet 150 against the primary piston
82. As the poppet 150 moves upwardly, the sealing
conduit 190 initially remains frictionally engaged
with the fixed supply conduit 120 so that the poppet
150 separates from the top of the sealing conduit 190
to the extent permitted by the lost motion
arrangement (i.e., until the sealing conduit 190 is
engaged by the spring 240). Communication is thus
established between the container 26 and the pump
chamber 80.
As the upper end of the spring 240, sealing
conduit 190, poppet 150, and piston 82 move upwardly
together, the volume under the piston 82 continues to
increase. This lowers the pressure in the chamber
80. As a result, the container liquid which is at
substantially atmospheric pressure, flows up the
suction tube 30 over the top of the sealing conduit
190, and into the pump chamber 80 to refill the
chamber as indicated by the flow arrows 297 in FIG.
13. Liquid continues to flow from the container 26
' into the pump chamber 80 until the primary piston 82
reaches the fully elevated position.
Near the end of the return stroke of the
primary piston 82 to the fully elevated position, the
bottom end of the sealing conduit 190 separates from
the fixed supply conduit 120 (FIG. 8), and additional
liquid fills the pump chamber 80 through that
separation space.
In some prior art accumulative pump
constructions which are capable of dispensing more
than small amounts of liquid, refilling of the pump
chamber typically is dependent upon a differential
pressure-actuated construction, such as a flapper
valve, or a ball valve, or the like. In accordance
with the present invention, a non-differential
` 1323618
,
-28-
pressure mechanism, which is entirely mechanically
operated, is provided. This positive~ mechanical
opening of an entry passage into the pump chamber
from the supply source assures proper and rapid
5 refilling under all conditions and circumstances.
--Venting Of The Container
Whenever liquid is drawn from the container
26 up the suction tube 30 into the pump 20,
atmospheric pressure must be maintained over the
remaining liquid in the container 26 so as to cause
the liquid to flow into the pump 20. To this end,
ambient atmosphere is permitted to flow into the
container 26 whenever the primary piston 82 is
located below the fully elevated rest position. As
explained above in detail in the section entitled
nDescription Of The Components And Arrangement Of The
Components," the diameter of the upper part of the
primary piston stem 86 is smaller than the diameter
of the lower part of the stem 86 so that ambient air
> can flow between the collar 38 and the piston stem 86
when the piston 82 is depressed. The ambient air
then flows into the container 26 through the
passageways in the collar 38 as previously described
in detail with reference to FIG. 13. Since the top
of the container interior is in communication with
ambient atmosphere when the primary piston 82 is
depressed below the fully elevated position, there
will always be sufficient pressure in the top of the
container 26 to force the liquid into the reduced
pressure region of the pump chamber 80 whenever the
primary piston 82 begins to return to the fully
- elevated position.
.~
,
"", . .
:'
-' 13~618
-29-
--Venting And Priming Of The Pump Chamber
~, The pump 20 of the present invention has a
novel and effective means for venting air from the
pump chamber to aid in priming the pump chamber 80
whe~ liquid is initially absent from the pump chamber
80. In particular, when the primary piston 82 is
initially forced downwardly in the pump chamber 80
, containing no liquid, the air and/or vapor in the
chamber is compressed. However, owing to the large
volume of the pump chamber 80 and to the highly
compressible nature of the air and/or vapor, the
pressure build-up on the top of the poppet piston
surface 172 is not sufficient to overcome the force
1~ of the spring 240. The discharge passage 98 in the
Y~ primary piston 82 thus remains closed.
s However, when the finger force on the
actuator button 90 is released at or near the bottom
, of the maximum stroke of the piston 82, the poppet
150 moves away from its sealing engagement with the
top of the sealing conduit 190 (i.e., to the same
spaced relationship as illustrated in FIG. 13). The
pressurized air and/or vapor is then forced under the
poppet lS0 lopposite the direction of the liquid flow
arrows 297 in FIG. 13), over the top of the sealing
; conduit 190, and down through the suction tube 30
into the top of the container 26 above the liquid
therein.
This thus relieves or vents the pressure in
, 30 the pump chamber so that the chamber will be able to
subsequently receive the initial flow of liquid to be
-~ dispensed into the chamber as described in detail
hereinafter.
' The pump 20 is adapted to be primed without
a venting aid which disrupts the sealing engagement
J
r
1323618
-30-
as between the sealing conduit 190 and the fixed
- supply conduit 120 at the end of the stroke. It will
be appreciated that this venting action is
accomplished without the use of the prior art types
of venting structures which have been built into the
pump chambers for otherwise bypassing or interrupting
- the sealing engagement between pressurizing parts at
the end of the pressurizing stroke. This use of the
venting structure of the invention permits priming
with partial (less than full) strokes (while pumps
using prior art types of venting aids do not so
permit), and also this use of the structure of the
invention permits the use of the pump assembly for
variable reduced outputs. Variable reduced outputs
may be provided by changing the button skirt len~th
to shorten the stroke length or by various other
means to shorten the stroke length. Other such means
include lengthening pin 230 or inner conduit 246 to -
shorten the stroke length. Venting will still be
achieved effectively with short stroke pump
assemblies, whereas it would not be if a typical
prior art venting aid operable only at the end of the
full stroke was used. Reduced output by simply
pressing with reduced length strokes manually is
~ 25 possible with the structure of the pump disclosed
I herein.
With the pressure vented from the pump
chamber 80, liquid will be able to enter the
chamber. In particular, continued upward movement of
the components of the pump 20 tends to draw in some
liquid from the container 26. After a few full
length strokes of the primary piston 82, a sufficient
amount of air has been vented from the pump chamber
80 and a sufficient amount of liquid has been drawn
35 ~nto the pump chamber 80 so th~t subGequent strokes
.
'
1 3:236 1 8
result in the discharge of a fine mist spray in the
manner that has been previously described in detail.
--~ In other prior art constructions, such as in
the types of pumps disclosed in the previously
discussed U.S. Patent No. 4,025,046, an especially
^ effective or tight seal must be employed
;` circumferentially around the main piston where the
main piston engages the interior cylindrical side
surface of the pump chamber. The sealing forces must
be relatively high because a relatively strong vacuum
(reduced pressure) is drawn in the pump chamber as
the main piston returns to the elevated (unactuated)
position. The relatively great vacuum continues to
be drawn as the main piston moves upwardly until the
lS poppet sleeve slides off of the top of the suction
conduit near the end of the pump return stroke. At
i this point, the relatively strong vacuum in the pump
chamber permits the exterior ambient air pressure to
- fill the pump chamber and reduce the vacuum therein.
1 20 Since the container liquid cannot be drawn into the
:' pump chamber until near the end of the upward stroke
, of the pump when the poppet disengages from the
' sealing conduit, the very strong vacuum exists during
,:~
most of the upwardly moving return stroke of the main
piston. This strong vacuum creates a pressure
i differential across the seal between the main piston
and the inside surface of the pump chamber, and this
seal is susceptible to air in-leakage from outside of
the pump.
In practice, commercial pumps fabricated in
; accordance with the teachings of the U.S. Patent No.
4,025,046, typically include a special upper seal
configuration which seals the main piston tightly
against the inside surface of the pump chamber and
which, necessarily, imposes a greater friction load
. . .
.s
,, .
. ,
.,
,~ . .
~ 1323618
on the pump actuator. Thus, the spring within the
pump must be strong enough to return the pump
actuator to the fully raised position in opposition
to the great frictional force between the main piston
and the pump chamber wall as well as in opposition to
the pressure differential being created as the piston
moves upwardly. Since the spring must necessarily be
sized to provide a sufficient upward force, the force
required to press the actuator down against the force
of the spring is also necessarily greater. In some
situations, for instance where the pump is to be
actuated by a young child or an elderly person having
reduced finger strength, such a pump may be difficult
to operate effectively.
lS In contrast with pumps fabricated in
accordance with the above-discussed U.S. Patent No.
4,025,046, pumps according to the present invention
may use a relatively weaker spring and may therefore
be more readily operated by young children or elderly
persons. A weaker spring may be used in the pump of
the present invention because the sealing force
between the primary piston 82 and inner surface of
the pump chamber 80 may be considerably reduced as a
result of a considerably reduced amount of vacuum
i 25 (reduced pressure) that is created inside the pump
chamber 80 as the primary piston 82 moves upwardly on
the return stroke.
The pump of the present invention operates
effectively by drawing less vacuum within the pump
chamber 80 because the poppet 150 moves upwardly away
from its sealing engagement with the top of the
sealing conduit 190 when the finger force on the
actuator button ~0 is released. Thus, the liquid
from the container flows up the suction tube 30, over
the top of the sealing conduit 190, and into the pump
-., ~, ,. ~ -
~ . . . .
132361~
--33--
chamber 80 to refill the chamber almost immediately
after the force is removed from the button 90 which
permits the primary piston 82 to begin to move
upwardly to the fully elevated position. Thus, if
5 the force is removed from the actuator button 90 when
the primary piston 82 is at or near the bottom of the
downstroke, the refilling of the pump chamber 80
begins when the primary piston 82 is still
substantially at the lowermost position within the
10 pump chamber.
As the primary piston 82 rises in the pump
chamber 80, the incoming liquid is being forced into
the pump chamber 80 underneath the primary piston 82
at substantially atmospheric pressure. Thus, the
15 vacuum (reduced pressure) that is drawn within the
pump chamber 80 beneath the primary piston 82 remains
relatively low. Since the vacuum beneath the primary
piston 82 remains relatively low, the differential
between the pressure in the pump chamber 80 beneath
20 the primary piston 82 and the exterior ambient
atmospheric pressure above the primary piston 82
remains relatively low. Since there is a relatively
low pressure differential across the primary piston
82, the sealing forces between the primary piston 82
25 and the wall of the pump chamber 80 can be relatively
low. Thus, the force of frictional engagement
between the primary piston 82 and the wall of the
pump chamber 80 can be relatively low. Since the
frictional engagement force is relatively low, the
30 force of the spring 240 may also be relatively low.
The spring need only overcome the relatively low
frictional force and the relatively low pressure
differential force resulting from the relatively low
vacuum in the pump chamber. The use of a relatively
~3~3618
-34-
weak spring 240 permits the pump to be more readily
. actuated by a child or elderly person.
It will be readily observed from the
foregoing detailed description of the invention and
from the illustrated embodiment thereof that numerous
variations and modifications may be effected without
: departing from the true spirit and scope of the novel
. ,
concepts or principles of this invention.
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