Note: Descriptions are shown in the official language in which they were submitted.
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BACKGROUND OF THE IN~'ENTION
Field of t~e' Invention
A common problem with liquid spraying devices of the hand-
operated type is the need for relief of the negative pressure
created in the closed container on which the device is used as
liquid is pumped. The vacuum created is relieved by venting
atmospheric air into the container to displace the liquid dis-
pensed. Various ways to do this have been proposed in the art
and, in general, usually involve separate or discrete valve means
; 10 with or without a vent passage, and more often than not, are
difficult to construct and are expensive. In addition, prior art
devices are often cumbersome to use and operate.
It is also very important that the device not leak when the
trigger or actuator is at rest and the container and sprayer are
laid on a side or even inverted such as might be the case in
normal use in spraying or in shipment where a full container
might be supplied with the device when sold.
Desc'ription'of the Prior'Art
A number of patents have been issued on trigger-piston type
hand sprayers useful for dispensing liquid from containers. For
example, a particularly useful, and perhaps the basic, trigger
type sprayer is disclosed in U.S. Patent 3r061,2Q2, i~sued on
October 30, 1962 to Tracy B. Tyler ~herein venting is provided
by means of a separate valve biased in the normally open position.
Other patents disclosing similar sprayers also using discrete
valve means for venting are U.S. Patent 3,650,473, issued on
March 13, 1972 to Carl E. Malone, U.S. Patent 3,685,739, on Au~ust
22, 1972 to Vance R. Vanier, and U.S. Patent 3,780,951, on December
25, 1973 to Richard T. Powers. The first mentioned Malone patent
vents in a manner similar to the T~ler device while the patent
to Powers shows an atmospheric vent through the body of the spray-
er where it attaches to the container but has a collar which is
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screwed down by the operator into an annular slot to close it o~
and thus prevent leakage of liquid from the container. Second
mentioned patent to Vanier utilizes a vent passage which allows
atmospheric air to flow through the sprayer's lower body past a
resilient, conically-shaped hollow valve into the container.
In U.S. Patent 3,8~0,157, issued on October 3, 1974 to J.
F. Hellenkamp, a trigger operated sprayer is disclosed which dif-
fers from the sprayers of the afoxementioned patents in that a
plunger, or piston is mounted with its axis vertically aligned
and movable off a sealing collar to permit venting of a container
; and is an example of a lever or trigger operated vent device, as
is U.S. Patent 3,749, 290, issued on July 31, 1973 to L.A.
Micalleff, which discloses a deformable diaphragm pump system
wherein a venting surface is unseated to permit atmospheric pres-
sure to be applied to the interior of the container. Other
patented devices having venting means are U.S. Patent 3,701,~78,
issued October 31, 1972, U.S. Patent 3,762,647, issued October 2,
1973 and U.S. Patent 3/770,2Q6, issued November 6, 1973 to T.
Tada; U.S. Patent 3,768,734, issued Octobex 3Q, 1974 to I.O.
Anderson, Jr., et al; and U.S. Patent 3,820,721, issued on June
28, 197~ to J.F. Hellenkamp.
The present invention provides a simple, efficient, relative-
- ly inexpensive and easy to use venting system and includes an
automatic drain back feature in a pleasantly appea~ing structure
which operates during pumping and spraying and ~ithout the employ-
ment of additional parts or component mechanisms.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to
provide a vent system for a manual, trigger operated sprayer
which is simple in construction, efficient in operation, and is
easily and economically manufactured.
It is another object of the present invention to provide
a manually operated trigger sprayer which employs no separate or
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discrete mechanisms or other parts ~or venting the container on
which it is mounted, nor additional components operatively
associated therewith.
It is still another object of the present invention to pro-
vide a manually operated, trigger sprayer of the foregoing type
wherein liquid which may leak by a seal element may be drained
back into the container rather than being permitted to leak from
the sprayer.
~ ccording to the present teachings, a manually operated
lQ liquid dispenser is provided which is adapted to be attached
to a container holding liquid to be dispensed and comprises
component retaining body means, the bulk of which is located
outside of the container when attached thereto, an outwardlY
opening bore defined within the interior of the component re-
taining body means, a piston which is shiftable within the bore
and bounding a variable compartment with the bore, inlet and out-
let means disposed within the component retaining body means for
delivering liquid into and out of the compartment bounded by the
piston and bore, operating means which includes a tigger normally
actuated by the application of substantially horizontal force by
the fingers thereto for shifting the piston within the bore be-
tween a normal non-pumping position and a pumping position, vent-
ing means ex~ending through the body means and opening, at one
end, into the bore, and a single unit providing seal means for
the venting means and the compartment, the seal means comprising
~ pair of spaced apart seals integrally molded with the piston,
- the seal means in normal non-pumping position, preventing commun-
ication to the ambient air from the venting means and th~ compart-
ment, thereby forming a positive closure for the container, the
seal means in pumping position permitting free communication be-
tween the venting means and the ambient air.
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Other objects and advantages of the present application
will be apparent from the detailed description and drawings which
follow.
BRIEF DESCRIPTION OF THE DRAWI~GS
Figure 1 is a sectional elevation of a preferred embodi-
ment of the invention showing a trigger operated
pump mechanism in its at rest or non-pumping
condition;
Figure 2 is a sectional elevation, similar to Figure 1
of another embodiment of the invention.
DETAILED DESCRIPTION AND OPERATION OF THE INVENTION
With reference to Figure 1, a trigger type, manually oper-
ated sprayer 10 comprising a housing or component retaining body
lQ-a hav~ng a cylindrical, hollow pump chamber or bore 11 closed
at its upper end but in communi`cation through its side wall by
means of an exit or outlet passage 12 connected to a chamber 13
in a nozzle 14. Nozzle 14 has an exit orifice or "spray" nozzle
opening 15. An inlet passage 16 provides communication between
pump chamber or bore 11 and an inlet valve chambQr 17 in a intake
body portion 17-a. Chamber 17 contains, in sealing relation on
a valve seat 19 therein, a ball check 18 in an inlet passage 20.
A liquid pick-up~ or dip tube 21 is fitted in air-tight relation
and extends downwardly from body portion 17-a into a container
23 terminating near the bottom thereof (not shown). A container
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cap 22 is attached to body 10-a on body portion 17-a and is
adapted to be clamped or screwed down onto the threaded neck psr-
tion of container 23 in liquid-tight relation therewith. A ring
or lip seal 24 is formed on the bottom surface of body portion
17-a and mates with the top surface of container 23.
Slidably positioned for reciprocation in chamber or bore
11 is a plunger assembly 25 comprising a hollow piston 25-a and a
carrier piece or holder 25-b. Ho:Lder 25-b has a recess 25-a on
one end which engages an extension 27-a of an actuating trigger
27 mounted on body 10-a by means of a pivot or pin connector 29.
Piston 25-a is fitted into a second recess in holder 25-b in the
opposite end thereof, and in the embodiment shown, comprises a pair
of spaced apart, annular circumferentially extending seals 30
and 31, the former preferably being a lip sealing angularly,
rearwardly extending and sealingly contacting the wall of bore
11, whereas seal 31 preferably has a rounded, substantially cir-
cular appearance, also sealingly contacting the wall of bore 11.
A compression spring 26 axially ~iases plunger assembly 25 in a
direction away from or out of bore 11, spring 26 being mounted
in bore 11 between the closed end thereof at one end and the
hollow interior of piston 25-a, the parts described being arranged
such that when at rest, as shown in the drawings, spring 26 may
be under some slight compression~ As is apparent from Figure 1,
when trigger 27 is actuated and pivoted about pin 29, plunger as-
sembly 25 and piston 25-a reciprocate in bore 11 compressing
spring 26 to initiate and maintain pumping operation of sprayer 10.
As mentioned above, in its preferred form piston 25-a is
providea with spaced apart, peripheral lip seal 30 and annular,
circular seal 31 which sealingly engage in sliding relation the
inner wall of bore 11. In the at rest or non~pumping position
as shown in Figure 1, seals 30 and 31 are separated by a peri-
pheral space or groove 32 and straddle the opening or entrance
33-a to a vent passage 33 formed in body 10-a in a bottom wall
of chamber or bore 11. Passage 33 extends from space or groove
32 to one or more vertical passages 34 (one only shown in the
Figures) formed in body portion 17-a and provides fluid communi-
cation to the interior of container 23 from space or groove 32
permitting, as will be seen, venting of container 23.
Once again referring to Figure 1, it should be readily
apparent that the present invention includes within its scope and
is just as readily operated with a single seal on piston 25-a,
which, preferably, would be forward lip seal 30. In this instance
in the at rest position shown in Figure 1 (and Fig. 2~, piston
25 may be positioned in chamber 11 so that seal 30 is in juxtaposi-
tion with opening or entrance 33-a of passage 33, by which is
meant that seal 30 would normallyr when in the at rest position
of piston 25 Cor 125 of Fig. 2~, be in a position proximate to
entrance 33-a o~l ei~her~s;de thereof~ in or on top of said entrance
33-a. It would, of course, be preferred in a single seal arrange-
ment that seal 30 (or seal 130 of Figure 2~, be juxtaposed
with entrance 33-a on the trigger 27 side thereof to retain the
"no leak" advantage previously referred to and described. How-
ever, operationally, the objecti~ve of venting would still be
achieved with a single seal 30 (or 130~ even if said seal is ar-
ranged in a normally at rest position in juxtaposition on the
opposite side of opening 33-a or on top of said opening. In these
latter arrangements, however, some leakage may be expected in some
situations such as when sprayer 10 and container 23 is inverted
or laid on its side. It is, of course, possible to modify sprayer
10 somewhat to avoid this eventuality in any of several well-
known ways (not shown~. For example, passage 33 may be formed
as a capillary tube of fine diameter whereby liquid leakage which
might occur will be insignificant, yet air passage will be unin-
hibited. Another means for obviating or mitigating against such
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76~8
possible leakage is the use of materi~ls ~lell-kno~rn to those
skilled in the art in passage 33 which pe~m~t gas or air flow but
inhibit or prevent li~u~d flow. Lastly mechanical devices such
as check valves (not shownl may be employed in passage 33 or
34 to prevent liquid out flow while still permitting air flow in
the opposite direction to vent conta~ner 23.
In operation of the Figure 1 or preferred embodiment of the
inventionr container 23 is filled with liquid and sprayer 10 is
attached by clamping or scre~ing downcap 22 onto the neck of
container 23 with dip tube 21 extend~ng below the liquid surface.
A liquid~tight seal is obtained b~ seal ring 24 on the top surface
of container 23 when cap 22 is screwed down or otherwise clamped
on the neck thereof. Sprayer 10 is no~ ready for spraying liquid
by grasping container 23 in the hand pistol gxip fashionr the
fingers gripping trigger 27. Trigger 27 is squeezed forcing
plunger assembly 25 and piston 25-a into bore 11 pressurizing the
air therein and forcing ball 18 to close against seat 19. Air '
; in chamber or bore 11 flo~s into exlt or discharge conduit 12 and
into chamber 13 of nozzle 14 forcing a slidable valve member 35
therein to move leftwardly. Fluid flo~s around valYe member
35 through the radial passages formed between the vertical wall
35-a and ridges 35-b on the end of member 35 and is discharged
in a spray through nozzle 14 orifice 15. ~hen trigger 27 is
released, piston 25-a and plunger 25 moves oppositely or leftwardly
under the force of compressed spring 26, and trigger 27 returns
to the "at rest" position shown. This action causes an expansion
or increase in volume of chamber 11 and a slight vacuum develops~
which opens ball check 18 and forces val~e member 35 in nozzle
14 to close against a seat 36 in ch~mber 13. Simultaneously
liquid is drawn up into bore 11 through tube 21, chamber 17 and
inlet passage 16. Seal 30 on piston 25-a prevents liquid leak-
age from chamber or bore 11, however should leakage occur liquid
will flow back into container 23 through passages 33 and 34 from
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:
annulal^ space 32, being prevented from flowing out of sprayer 10
by seal 31. Subsequent squeezing and releasing of trigger 27
repeats the above cycle except liquid is now being pumped and
sprayed from container 23.
It is, however, necessary that atmospheric air be allowed
to enter contalner 23 to make up for the volume of liquid drawn
therefrom and equalize pressure therein. If venting is not allow-
ed for, a vacuum will develop in container 23 and either liquid
spray will cease or container 23 will tend to deform and/or col-
lapse. The provision of vent passage 33 and passage 34 connected
thereto in the wall of chamber or bore 11 and body portion 17-a
respectively, permits venting communication between the interior
of container 23 and the atmosphere to be established. When annular,
spaced apart seals 30 and 31 are used on piston 25-a and straddle
the entrance 33-a to vent 33, when trigger 27 is squeezed and piston
25-a moves into chamber 11, seal 31 will pass beyond opening or
entrance 33-a to passage 33 and container 23 is vented to the
atmosphere. It can be seen therefore, that the location of en~
trance 33-a to passage 33 between seals 30 and 31 in annular space
32, and closely adjacent to seal 31, permits yenting of container
23 during the pumping or spraying stroke, yet in the non-pumping
or "at rest" position, a positive closure for container 23 is
simultaneously also provided.
Referring now to Figure 2, an additional embodiment is dis-
closed wherein a one~piece piston and plunger device 125 is shown.
Piston or plunger 125 is preferably a single molded piece including
the spaced apart, annular, circumferentially extending seals or
sealing surfaces 130 and 131 separated by the peripheral, or an-
nular recess 132, and, as shown in Figure 2, is in the at rest
position. In this position, seals 130 and 131 straddle opening
or entrance 33-a vent passage 33 as in the preferred, Figure 1
embodiment. In all other respects as to construction and
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operation,~ ~he Figure 2 embodiment is identical with the Fiyure
1 invention. In addition, while not shown herein, it is evident
that seal 130 could also be formed, as by molding and the like,
as a lip seal for enhanced sealing quality usually characteristic
of this type seal and, due to less friction between seal and wall
would provide faster return of the pump and trigger to the at
rest position by compressed spring 26.
It should~also be understood that a single seal element
device, similar to that previously disclosed is applicable to
this embodiment and such is fully contemplated. Also piston or
plunger 125 can be molded with suitable annular grooves (not shown)
in which O-ring type seals or the like, can be installed in place
of the shown seal elements 130 and 131 with comparable beneficial
results. In addition, the sealing elements associated with the
piston can also be located in bore 11 remaining stationary rela-
tive to piston 25 when the latter is reciprocated. In short,
any number of methods can be employed to provide the necessary
sealing between piston and bore in chamber 11 and will occur to
the skilled artisan. Similarly, leakage if apparent, can be
dealt with in accordance with the known methods, previously de-
scribed.
It is expected that the invention hereinabove described
will be constructed of thermoplastic materials by any of the
usual and well-known processes, for example, blow molding, injec-
tion molding, casting or the like, depending on materials used
and sprayer qualities desired. Examples of suitable materials
useful in carrying out the invention include any of the well-
known plastics such as polystyrene, polyvinylchloride, polyure-
thane, the polyolefins, polyamide, polyacetate, polycarbonate,
polyester and the many possible mixtures or blends thereof.
A preferred material is the polyolefin,polypropylene, which has
many desirable qualities including being resilient and is thus
particularly useful for sealing elements or devices and for the
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pistons 25-a and 125. Other suitable materials include natural
rubber, synthetic rubber, acrylonitrile-~utadiene styrene (ABS)
and mixtures of these and other materials. Each material will
be selected in accordance with good engineering practice to maxi-
mize quality and minimize cost and expense.
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