Note: Descriptions are shown in the official language in which they were submitted.
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PLASTIC SPRING ASSEMBLY
BACKGROUND OF THE INVENTION
1. Field of the Invention.
The present invention relates to a trigger operated
5 dispensing de~ice for mounting to the top neck of a storage
container. Although such devices, known as trigger sprayers,
can be reused, often times they are disposed of.
The trigger sprayer includes a body, and a pumping
mechanism comprising a trigger movably mounted to the body, a
10 piston releasably coupled to the trigger and a cylinder in the
: body for receiving the piston for pumping fluid and defining a
- pumping chamber. The cylinder extends to a fixed back wall in
the body, whereby the space between the back wall and the inner
end of the movable piston defines a variable volume pumping
15 chamber. The cylinder has a fluid inlet valve and a fluid
outlet valve associated with the back wall;
- To facilitate disposal and/or recycling of the sprayer,
the trigger sprayer of the present invention is made of non-
metal, plastic or synthetic parts.
This is achieved by mounting a synthetic/plastic return
spring which forms part of the pumping mechanism between the
trigger and the sprayer body. This is also achieved by
providing plastic inlet and outlet flap valves associated with
the back wall of the cylinder.
25 2. Description of The Prior Art.
It is well known in the art of tri.gger sprayers to mount
a metal spring in a pumping chamber of a pumping mechanism in
a tri.gger sprayer. The spring acts against a piston coupled to
the trigger for urging the trigger to it's home, at rest,
30 position when the trigger i9 released.
Hereto~ore, it has also been proposed to provide plastic
springs or flexures in trigger sprayers. Some examples of
these previously proposed trigger sprayers are disclosed in the
following patents;
U.S. Patent No. Patentee
4,915,263 Corba
4,898,307 Tiramani
4,624,413 Corsette
4,593,607 Bennett
~0 4,273,290 Quinn
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4,241,853 Pauls et al.
4,191,3I3 slake et al.
SUMMARY OF THE INVENTION
According to the present invention there is provided a
trigger operated pumping mechanism for a fluid dispensing
device comprising a body adapted to be mounted to a container.
The pumping mechanism comprises: a cylinder in the body of the
dispensing device; a piston received in the cylinder; a trigger
10 movably mounted to the body and having a front side and a back
side, and being coupled to the piston; and a non-metal biasing
; mechanism for biasing the trigger away from the body to bias
the piston coupled to the trigger out of the cylinder, the
biasing mechanism including a separate, non-coiled, elongate,
15 generally flat, spring mechanism having elongate, opposed flat
surfaces and opposite ends and being positioned between the
body and the trigger; the trigger back side having a back wall
surface; and, the spring mechanism having one flat surface on
one end portion at one end of the spring mechanism positioned
20 adjacent the back wall of the trigger and having the other end
of the spring rnechanism positioned rearwardly of the trigger
and engaging against the body.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 i9 a perspective view of a trigger sprayer
constructed according to the teachings of the present
invention.
FIG. 2 i9 an exploded perspective view of the trigger
sprayer shown in FIG. l and shows a locking ring prior to its
30 detachment from a cylindrical base of the sprayer body.
FIG. 3 is a vertical sectional view of the trigger sprayer
in its at rest position where a spring between a trigger and
the sprayer body biases the tri~ger and a piston rod coupled
thereto to the most outward position.
' ` 35 FIG. 4 ig a vertical sectional view of the trigger sprayer
similar to the view shown ln FIG. 3 but showing the trigger
fully depressed.
FIG. 5 is perspective view of a non-metal trigger sprayer
spring assembly of the trigger sprayer shown in FIG. 1.
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FIG. 6 is a side view of the spring assembly shown in FIG.
5.
FIG. 7 is a top plan view of the spring assembly shown in
FIG. 5.
FIG. 8 is a top plan view of another embodiment of the
spring assembly constructed according to the teachings of the
present invention.
FIG. 9 is a side view of the spring assembly shown in FIG.
8.
FIG. 10 is a bottom plan view of the spring assembly shown
in FIG. 8.
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DESCRIPTION OF THE PREFERRED EMBODIMENT(S)
Referring now to the drawings in greater detail, there is
15 illustrated in FIG. 1 a perspectiv~ view of an all
synthetic/plastic trigger sprayer 10 coupled to a bottle 12.
An exploded perspective view of the parts of the trigger
sprayer 10 is shown in more detail in FIG. 2.
The trigger sprayer 10 includes a body 14, a nose bushing
20 16 at a discharge end 18 of the body 14, a nozzle tamper proof
pull away piece 20, a top portion 22 and a hand gripping
formation 24 extending rearwardly from the top portion 22 of
the body 1~ and then downwardly to a cylindrical base 26 of the
body 14. The base 26 is held by a locking ring 28 to a neck 30
25 of the bottle 12.
A trigger 32 having a front side 31 is pivotally mounted
to the body 14 by having two cylindrical pins 34, molded on the
top end of two opposed side walls 36 of the trigger 32,
inserted into two corresponding holes 38 in the body 14 of the
30 trigger sprayer 10.
As shown in FIG. 2, a plastic spring assembly 40 is placed
between the body 14 and the trigger 32 to urge the trigger 32
always back into its home position. Coupled to the trigger 32
is'a piston~2 having an outer piston rod 44 which connects
35 with the trigger 32 and an inner cylindrical end 46 which is
received in a cylindrical opening 48 in the body 14 for the
purpose oE varying the volume in a pumping chamber defined in
the opening 48.
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The trigger 32, the spring assembly 40, the piston 42 and
the cylindrical opening 48 form and define primary components
of a pumping mechanism 49.
A valve intake stem 50 is received into the bottom of the
5 cylindrical base 26 and has a dip tube 52 releasably fixed
thereto and depending therefrom for insertion into the bottle
2.
A safe and child resistant sprayer/bottle connection is
provided and includes locking tabs 53 with lug receiving
10 openings 54 formed in the cylindrical side wall of the
; cylindrical base 26 and locking lugs on the bottle neck 30 and
locked in place by the locking ring 28.
When the molded sprayer body is removed from a mold, the
locking ring 28, connected to the cylindrical base 26 of the
15 body 14 by six links, points, fillets or webs 57 which are
necessary for molding the locking ring 28 together with the
body 14, is broken away from the cylindrical base 26 by
breaking the fillets 57 and moved upwardly on the base 26.
During assembly of the parts of the trigger sprayer 10, the
20 locking ring 28 is moved downwardly over the cylindrical base
26.
A nozzle assembly 58 is provided and includes a rotatable
nozzle cap 60 having a forwardly extending cylindrical
extension 62. The nozzle cap 60 is mounted on the nose bushing
25 16 extending from a cylindrical por~ion 64 of the body 14 and
includes an annular band 66 for holding the nozzle cap 60.
Three different positions of the nozzle cap 60, a STOP
position, a SP~AY position, and a STREAM position are provided.
When the nozzle assembly 58 is mounted to the body 14, a
30 mounting block 67 of the piece 20 is snap fittingly received
through an opening o8 in the top portion 22. ~t the same time,
fork arms 69 of the piece 20 extend through notches 70 in the
top portion 22 and~or notches 71 in the top wall of the cap 60
between one of two flexible locking legs or prongs 72 and the
35 cylindrical portion 64 for securing the nozzle cap 60 in its
STOP position, thereby ensuring a tamper proof and child
resistant locking of the trigger sprayer nozzle assembly 58 to
the body 14.
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The nozzle assembly 58 is mounted on the discharge end 18
of trigger sprayer lo, as described above. The top portion 22
of the body 1~ extends rearwardly to a rear end 73 of the hand
gripping formation 24 and then slants forwardly and downwardly
from the rear end 73 to the cylindrical base 26.
The six contact fillets or webs 57 are uniformly
distributed around the lower end of the cylindrical base 26 and
are initially integral with the locking ring 28. During the
molding process, the contact fillets or webs 57 are broken and
10 the locking ring 28 is moved upwardly relative to the
cylindrical base 26. Later, when the locking ring 28 is moved .. `-`
downwardly on the base 26, an annular groove 74 within the ~ `
locking ring 28 snap-fittingly mates with an annular rib 75 on .---.. -
the base 26. The upper position of the locking ring 28 is the
15 pre-application-to-a-bottle position and the locking ring 28 ls
held in this position by frictional engagement of the inner ..
wall of the locking ring 28 with the rib segments 76 provided
on the outer cylindrical wall of the cylindrical base 26. The
upper, partially annular rib segments 76 on the outer
20 cylindrical wall of the cylindrical base 26 locate and to some
extent limit upward movement of the locking ring 28.
As shown in FIG. 3, molded within the cylindrical base 26
to a top wall 31~ of the cylindrical base 26 is a small
diameter seal ring 316. The seal ring 316 i9 designed to seal
25 against the inner diameter of the bottle neck 30. The seal
ring 316 has a bevelled end 318 at its lower side to facilitate
insertion of the bottle neck 30 into the base 26 and around the
seal ring 316.
Within the inner area of seal ring 316 is an opening 320,
30 having a shape according to the shape of the intake stem 50
which i.s generally oval in cross-section. The intake stem 50
is press-fitted into the opening 320 until ridges 322 on the
i.ntalce stem 50 snap into mating mounting groove~ on the inner
, su~l-face oE the wall of the opening 320. In this way, an air
3~ tight seal is provided. The diptube 52 is releasably fixed in
the center of the intake stem 50. The length of the diptube 52
depends on the size of the bottle 12. However, it is
recommended that the diptube 52 should extend to the bottom of
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the bottle 12 but shouldn't touch it.
The cylindrical opening 48 is located inside the body 14
of the trigger sprayer 10. The piston cylindrical end 46 fits
tightly into the cylindrical opening 48 to create a pumping
5 chamber 324 having a variable volume between a fixed back wall
326 of the cylindrical opening 48 and a rearwardly facing wall
328 of the piston cylindrical end 46. The fixed wall 326 of
the pumping chamber 324 has an inlet flap valve 330 situated in
the lower part thereof and an opening 332 in the upper part
lo thereof. An orifice 334 through a wall of the intake stem 50
: is located to mate or register with the inlet flap valve 330
- and to establish an inlet passageway. The inlet passageway is
provided by the hollow diptube 52, the intake stem 50 and the
orifice 334.
15The opening 332 is located to mate or register with an
outlet flap valve 336 on the top side of intake stem 50. Inlet
flap valve 330 and outlet flap valve 336 control the fluid flow
into and out of pumping chamber 324.
The trigger 32 is pivotally mounted on the body 14 of the
trigger sprayer 10 by inserting the two laterally extending
pins 34 on the upper part of the trigger 32 into the two
corresponding holes 38 in the body 14.
As shown in FIG. 4, the plastic spring assembly 40 has a
flat tapered end 410 press-fitted into a recess 412 in the body
25 14 located underneatll an inner end of the cylindrical portion
64 of the body 14. Another end 414 of the plastic spring
assembly 40 i~ placed in a trough-like space 416 in the back
side of the trigger 32 against a back wall 415. The plastic
spring assembly ~0 is bent and remains under stress to urge the
trigger 32 always back into its home position.
FIG. 4 shows the trigger sprayer 10 with the trigger 32
pressed in by the operator. The pressure in the pumping
chamber 324 opens outlet flap valve 336 so that the fluid can
Ielave pumping chamber 324. At the same time, the plastic
35 spring assembly 40 is bent and stressed even more, but it is
not stretched above its Hook limit, and the operator needs a
maximum force to keep the trigger 32 pressed in.
After the operator stops pressing trigger 32, the plastic
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spring assembly 40 urges the trigger 32 together with piston 42
bac~ into their home positions. While the piston 42 moves
back, a vacuum arises inside the pumping chamber 324. This
vacuum opens inlet flap valve 330 and sucks in fluid from the
5 bottle 12.
When the fluid is sucked out of the bottle 12, and because
the bottle 12 and the trigger sprayer lO connection is air
tlght, a vacuum arises within the bottle 12. To avoid a vacuum
within the bottle 12, a venting system is provided. The
10 venting system includes a vent hole 344 in the top wall 314 of
the cylindrical base 26. This part of the top wall 314 defines
- a ~all area between the lower side of the cylindrical opening
48 inside body 14 of trigger sprayer 10 and a cylindrical
cavity 346 within cylindrical base 26. When the trigger 32 is
lS fully pressed in, vent hole 3~4 is opened and a fluid
connection between the inside of the bottle 12 and the
atmosphere is established so that air is able to get into the
bottle 12. When the trigger 32 is not pressed in, e.g. when it
is in its home position, the vent hole 344 is covered by the
20 cylindrical end 46 of the piston 42 to close the vent hole 344
thereby preventing fluid from coming out of the bottle 12.
The pumping chamber 324 is designed so that, the ~dead
volume'~, i.e. the minimum volume of the pumping chamber 324, is
very small, 1/20 to 1/4 the full volume of pumping chamber 324.
25 With a small dead volume, only a very little amount of the
fluid or air i~ left in the pumping chamber 324, after the
trigger 32 is ~ully pressed in. This construction minimizes
the size o~ compressible air space inside the pumping chamber
324 and allows the trigger sprayer 10 to build higher
30 compression against the flap valve 330 during the priming of
the trigger sprayer lO. This minimized "dead volume" provides
for ~uicker priming of the trigger sprayer lO and higher vacuum
and high compression during the intake and ejection strokes.
Anotherl effect of the small "dead volume" is that the
35 pumping chamber 324 is filled up with fluid very quickly
therefore reducing the number of initial strokes required to
prime ~he trigger sprayer lO.
An outer end 510 of the piston rod 44 has a transversely
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located cylinder 512. The cylinder 512 is located transversely
to the longitudinal axis of the piston rod 44 between legs 513
and has an axially extending V in cross section slot 514 in the
middle thereof for receiving a pivot edge 516 of a hook member
5 517 extending between the sides 36 of the trigger 32. The hook
member 517 is part of a bearing formation 518 which is provided
on the backside of trigger 32 between the sides 36 and which
has an opening 519 through which the outer end 510 is received.
The cylinder 512 engages in the bearing formation 518 of the
10 trigger 32 and the sides of the V shaped slot 514 act as ~or
; form) stops to limit the rotational freedom of the connected
- parts.
The bearing formation 518, in combination with the V
shaped slot 514, establish a movable trigger 32 - piston 42
15 connection with limited, but sufficient, rotational freedom.
This enables the piston 42 to be moved within the pumping
chamber 324 while being pivotally connected to trigger 32 in a
simple and efficient manner.
The bearing formation 518 includes two rounded bearing
20 seating surfaces 520 adjacent the inner side of each side 36 of
the trigger 32 and between one side 36 of the trigger 32 and
the hook member 517 at the top of the opening 519 and between
one side 36 and a slot 521 on the bottom of the opening 519.
The cylindrical ends of the cylinder 512 seat and rotate on
these bearing surfaces 520.
Referring now to FIGS. 5, 6 and 7, the spring assembly 40
includes two leaf springs 610 and 612 which are connected
together at each end by a webbing 614 or 616. As shown in FIG.
6 the two springs 610, 612 are bowed slightly to form an upper
30 bowed spring 610 and a lower bowed spring 612. Each of these
elongate sprin~s 610, 612 are molded integral to each other and
then a separation or split 618 between them is formed by a
splitting process or cutting process. Alternatively, the
sp~ing assembly 40 can be a one piece molding comprising two
35 blade springs connected together at each end. Further, as
shown, each spring 610 and 612 is beveled at its ends as
indicated by reference numerals 620 and 621 for spring 610
adjacent to the respective webbing 614 or 616. Likewise the
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lower elongate leaf spring 612 is beveled at 622 and 623 to the
hinge or webbing 614 or 616 as shown.
Also, as best shown in FIG. 7, the end portions of each
spring 610, 612 are tapered toward the webbing 614 or 616 and
5 each spring 610, 6~2, is wider in a middle portion indicated by
reference numeral 625.
The lower elongate leaf spring 612 has a notch 626, 627
formed at each end thereof to define a shoulder 628 or 629.
The spring assembly 40 with the ends o~ the springs 610
10 and 612 formed in the manner described above define the mirror-
: image ends 410 and 414, each of which is configured to fit into
- the recess 412 with the shoulder 628 or 629 being adapted to
engage or hook with a shoulder adjacent the lower outer end of
the recess 412 as shown in FIGS. 3 and 4.
The leaf springs 610, 612 are made of glass fiber
reinforced plastic material such as a mixture of polypropylene
and polyamide (nylon) plus 30~ by weight glass fibers.
Another embodiment of a spring assembly 640 constructed
according to the teachings of the present invention is shown in
20 FIGS. 8, 9 and 10. The spring assembly 640 has opposite ends
642 and 644, only one of which, the end 642 is adapted to be
received in the recess 412. The spring assembly 640 includes
an upper or elongate blade or leaf spring 646 and a lower
elongate blade or leaf spring 648.
The ends 642 and 644 of the leaf springs 646 and 648 of
the spring assembly 6~0 are beveled and tapered as in the
spring assembly 40 shown in FIGS. 5-7. At the end 642, which
is received in the recess 412, a hinge or web connection 650 is
provided between the leaf springs 646 and 648. However, at the
30 other end 6~4 the leaf springs 646 and 648 are connected by a
cylindrical loop 652. The loop 652 is compressed when the
trigger 32 is pushed against the outer surface of the blade
leaf spring 6~6 adjacent the end 644 of the spring assembly
,~ 640.
As best shown in FIGS. 9 and 10, the lower leaf spring 648
has only one notch 654 on the outer surface thereof adjacent
the end 642. Also, spaced inwardly of the notch and extending
downwardly from the outer surface of the blade 648 is a small
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post 656 which serves to limit inward movement of the spring -
asse~bly-into the recess 412 and to limit downward movement of
the spring assembly 640 in use.
As shown in FIGS. 3 and 4, the spring assembly 40 or 640
is received between the bearing formation 518 and the back side
415 of the front wall 31 of the trigger 32 with the end 410 or . . -:
642 received in the recess 412 and the outer surface of the .-
upper blade 610 or 646 bearing against the inner wall surface
415 of the front wall 31 of the trigger 32 in the trough area .
10 416.
In use, the spring action is obtained by posit~oning the ---
end 410 or 642 in the recess 412, by positioning the spring -~
assembly 40 or 640 in the trough area 416 and between the
bearing formation 518 and the back side 415 of the front wall --- - `
15 31 of the trigger 32, and by the sliding action of the outer
: surface of the blade 610 or 646 adjacent end 414 or 644 against
the back side 415 of the front wall 31 of the trigger 32. ~:
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