U.S. patent number 3,778,850 [Application Number 05/255,056] was granted by the patent office on 1973-12-18 for automatic liquid dispenser for flush tanks and the like.
Invention is credited to James W. Bryan.
United States Patent |
3,778,850 |
Bryan |
December 18, 1973 |
AUTOMATIC LIQUID DISPENSER FOR FLUSH TANKS AND THE LIKE
Abstract
A liquid dispenser for discharging metered amounts of liquid
into a flush tank in response to the rise and fall of the tank
liquid level. The dispenser comprises a container having a
discharging neck portion provided with external screw threads, and
having a captive screw cap which has internal cooperable screw
threads and additionally has an internal annular captivating bead
spaced from its threads. The open end of the container neck
includes a resilient sealing lip which is engageable by a sealing
ring portion of the cap when the latter is fully threaded in or
down whereby the cap constitutes a sealed closure for the
container. As the cap is unscrewed, its captivating bead is forced
past the first of two spaced-apart annular beads on the container
neck, which now operate to restrict axial movement of the cap
between extended and retracted positions. For both of these
positions the cooperable screw threads of the assemblage are free
of each other. The cap has annular walls which define an air
chamber providing buoyancy when the cap is immersed in a liquid.
With the container inverted and the cap assembled thereto, the
latter is urged between extended and retracted positions in
response to changes in the level of the liquid in the tank.
Responding to a fall in the liquid level, the cap moves by gravity
to its extended position and a recess therein receives a
predetermined quantity of liquid from the container. As the tank
level rises, the cap is slowly urged by buoyant force to its
retracted position whereby liquid contained in the recess is
displaced therefrom, thus effecting a dispensing of the liquid into
the tank. In the retracted position of the cap, the bead thereof is
held in abutment with one of the spaced-apart neck beads to form a
seal and thus prevent leakage of the container contents into the
tank until the occurrence of the next change in tank liquid
level.
Inventors: |
Bryan; James W. (Madison,
CT) |
Family
ID: |
22966653 |
Appl.
No.: |
05/255,056 |
Filed: |
May 19, 1972 |
Current U.S.
Class: |
4/227.3; 248/692;
222/67 |
Current CPC
Class: |
E03D
9/037 (20130101); E03D 2009/028 (20130101) |
Current International
Class: |
E03D
9/02 (20060101); E03D 9/03 (20060101); A47k
013/30 () |
Field of
Search: |
;222/56,67,64,546,562,563,57 ;4/223,231,226,227,228
;248/359,360,311 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Reeves; Robert B.
Assistant Examiner: Stack, Jr.; Norman L.
Claims
I claim:
1. A liquid dispenser for flush tanks and the like, comprising in
combination:
a. an inverted container having a bottom discharge neck portion
provided with a longitudinal bore which communicates with its
interior, said neck portion having external screw threads,
b. a captive screw cap constituting a stopper, said cap being
adapted for loose movement on the neck portion, said cap having
internal screw threads cooperable and engageable with the external
threads of the container neck portion,
c. cooperable stop means disposed on said screw cap and container
neck portion for restricting axial movement of the cap between
extended and retracted positions on the neck portion wherein for
both said positions the screw threads of the neck portion and cap
are free of each other,
d. cooperable stopper means on the cap and neck portion, for
sealingly closing the latter when the cap is threaded fully
thereon,
e. valve means for sealing the neck portion and cap to each other
when the latter is in its retracted position, said valve means
enabling discharge of liquid to occur between the neck portion and
cap when the latter is out of said retracted position, and
f. floatation means on the cap, defining a float chamber when the
cap is inverted and immersed in the liquid of a flush tank, for
automatically shifting the cap from its extended to its retracted
position in response to a rising level of said liquid, said cap
shifting by gravity to its extended position as the liquid level
falls.
2. A liquid dispenser as in claim 1, wherein:
a. said cooperable sealing means on the cap and neck portion
comprises a resilient annular sealing lip adjacent the open end of
the container neck, and
b. an annular ring-like sealing portion on the cap adjacent the
threads thereof.
3. A liquid dispenser as in claim 1, wherein:
a. said floatation means comprises walls of the cap, forming an
inner chamber therein which is receivable in the neck portion of
the container, and further comprises additional walls providing an
annular outer chamber which surrounds the neck portion of the
container.
4. A liquid dispenser as in claim 3, wherein:
a. said additional walls are spaced apart and are annular and
concentric.
5. A liquid dispenser as in claim 1, wherein:
a. said screw cap has an annular guide portion,
b. said cooperable stop means comprising an internal annular bead
on said annular guide portion, and
c. a pair of spaced apart annular beads on said neck portion,
cooperable with and straddling said internal annular bead of the
cap guide portion.
6. A liquid dispenser as in claim 5, wherein:
a. said neck portion has longitudinally extending bearing ribs
disposed between said spaced apart annular beads, said bearing ribs
engaging the annular guide portion of the cap to prevent tilting
when the cap moves between its extended and retracted
positions.
7. A liquid dispenser as in claim 5, wherein:
a. said neck portion is constituted of yieldable plastic substance
and the annular beads thereof can yield inwardly under external
forces,
b. said cap bead being forcible past one of said beads of the neck
portion so as to be straddled by said spaced apart beads,
c. said cooperable screw threads being capable of shifting the cap
as it is turned, to force the bead thereof past said one bead of
the neck portion.
8. A liquid dispenser as in claim 5, wherein:
a. one of said spaced apart beads on the neck portion is continuous
and adapted to sealingly engage the bead of the cap to stopper the
container,
b. said other of the spaced apart beads having a relieved surface
to provide for passage of liquid between the cap and neck portion
when it is engaged with the cap bead,
c. the distance between said spaced apart beads determining the
volume of liquid which can flow from the container, and there-by
constituting a metering control.
9. A liquid dispenser as in claim 8, wherein:
a. the relieved surface of the neck bead comprises a plurality of
flats thereon,
b. said flats providing passages in the form of clearance spaces
between the relieved-surface bead and the cap when the latter is
out of its retracted position, whereby liquid from the container
can flow between the said neck portion and cap.
10. A liquid dispenser as in claim 1, wherein:
a. the floatation means of the cap comprises concentric spaced
apart annular walls thereof, surrounding the neck portion of the
container,
b. said neck portion of the container having longitudinally
extending bearing ribs engageable with the inner of said annular
walls of the cap to constitute a guide means for preventing tilting
of the cap when the latter moves between its extended and retracted
positions.
11. A liquid dispenser as in claim 10, wherein:
a. the inner of said annular walls has an internal bead slidably
engaged with said longitudinal bearing ribs.
12. A liquid dispenser as in claim 1, wherein:
a. said floatation means comprises an annular outer wall of the
cap, and an annular inner wall of the cap, and
b. said annular walls defining an air chamber providing a buoyant
force to said cap when it is immersed in liquid.
13. A liquid dispenser as in claim 12 and further including:
a. a transverse wall connected with said annular walls, all of said
walls constituting said air chamber.
14. A liquid dispenser as in claim 13, wherein:
a. all of said walls are constituted of molded plastic
substance.
15. A liquid dispenser as in claim 14, wherein:
a. said transverse wall has substantially the configuration of a
disc.
16. A liquid dispenser as in claim 14, wherein:
a. said transverse wall has an annular configuration.
17. A dispenser comprising in combination:
a. a container constituted as a bottle having a top, discharge neck
portion and having a bottom wall disposed oppositely to said neck
portion,
b. said bottom wall having a groove extending transversely from one
side of the container to the other,
c. said groove having opposite undercut side walls,
d. a side wall of the container adjacent the bottom wall having a
recess communicating with said groove, and
e. a slide, clamp piece having a flat body portion disposed in the
groove of the container bottom wall and slidable therein,
f. said clamp piece having respectively at its ends depending
extremities forming with the flat body a U-shaped
configuration,
g. one of said extremities being engageable with the wall of the
recess in the container side wall when the clamp piece is slide in
said groove to advance the other extremity away from the opposite
container side wall,
h. said other extremity when so advanced being spaced from said
opposite side wall to accommodate a support member from which the
bottle can be suspended.
18. The invention as set forth in claim 17, wherein:
a. said first extremity makes an acute angle with the body portion
of the clamp piece whereby the tip of said extremity effects the
engagement between the same and said recess wall.
19. The invention as set forth in claim 17, wherein:
a. the length of the clamp piece is substantially equal to the
width of the bottle measured parallel to the groove in the bottom
wall thereof, whereby the clamp piece can be slid so that is
extremities do not protrude substantially beyond the opposite side
walls of the container.
20. The invention as set forth in claim 17, wherein:
a. the bottle is constituted of blow-molded plastic, and
b. the clamp piece is constituted of formed sheet metal.
21. The invention as set forth in claim 17, wherein:
a. the side walls of the groove are yieldable to enable the body
portion of the clamp piece to be forced broadside into the groove
and retained by the undercut portions of the side walls of the
groove.
22. The invention as set forth in claim 17, wherein:
a. the depth of the recess is commensurate with the spacing between
said other extremity and said opposite side wall when the first
extremity engages the recess wall.
Description
BACKGROUND
This invention relates to automatic liquid dispensing devices, and
more particularly to dispensers of the type adapted to discharge
liquid from a container into a flush tank in response to the rise
and fall of the liquid level therein. In the past, a number of such
liquid dispensers have been proposed and constructed. Generally
with these constructions a container has a threaded closure cap
which is engageable with a cooperable threaded neck portion of the
container to provide a seal thereof during storage and shipping. In
some cases the neck portion has had a hollow threaded insert,
constituting one portion of a valve wherein the threaded cap, when
removed, could be inverted and forcibly engaged with the bore of
the insert to form therewith another valve portion. The cap usually
had some form of air chamber to provide buoyancy, although
frequently this chamber was not strictly sealed but merely
consisted of an inverted cup configuration whereby the buoyancy was
provided by trapped air.
These prior liquid dispensers had a number of distinct drawbacks.
For one thing, following removal of the cap (such as after storage
or shipping) there was necessary the reinsertion or assemblage to
the threaded insert of the neck portion. Frequently this method of
operation was not an obvious one to the unskilled user such as a
housewife, and often difficulty was encountered. Secondly, in most
cases a large number of molded parts was required (usually at least
three or four separate pieces) particularly where a separate
insert, threaded into the neck was employed. Moreover, the air
chamber that was needed, was often disposed near the bottom of the
movable valve member, and thus the buoyant force existed at a low
"float-center," which aggravated any tendency for the cap to become
cocked or tilted. Such tendency frequently resulted in binding or
jamming of the movable valve member. Also, in cases where an open
float chamber was employed, the valve cap had to be submersed in a
nearly vertical position to avoid permitting trapped air in the
chamber to escape and be displaced by water whereby it would
adversely reduce the float chamber buoyancy.
SUMMARY
The above drawbacks and disadvantages of prior liquid dispensers
are overcome by the present invention, which has for an object the
provision of a novel and improved automatic dispenser which is
especially simple in its construction, which has an absolute
minimum number of parts that can be easily and inexpensively
fabricated as molded pieces, and which is moreover particularly
simple to assemble and to use, thus enabling an unskilled person to
readily install and use the device. A related object of the
invention is to provide a liquid dispenser as above, which
comprises a one-part unitary cap that is normally held captive on
the container neck and that acts both as a sealing closure for the
container during storage and shipping, and as a metering and float
valve to dispense predetermined quantities of liquid into a flush
tank in response to the rise and fall of tank fluid contained
therein. The above objects are accomplished by a novel combination
of container having a neck portion provided with external screw
threads and, spaced therefrom, a pair of separated annular beads
disposed closely adjacent the container body. A unique screw cap
which has a captivating bead and internal screw threads provides a
sealed closure for the container when the threads are fully
engaged. The captivating bead is disposed adjacent the cap threads
and can be forced past the first of the annular neck beads as the
cap is unscrewed, so as to straddle the latter. The engagement of
the captivating bead with each of the annular neck beads defines
extended and retracted positions of the cap, respectively. The cap
further has a sealed air chamber which provides a buoyant force
thereto when it is immersed in liquid.
The cap when assembled to the inverted container suspended in a
flush tank thus constitutes a float valve which, in its extended
position, permits a predetermined quantity or charge of liquid from
the container to flow into a recessed portion of the cap. As the
cap is urged to its retracted position by a rising tank liquid, the
charge therein is displaced and flows between the container neck
portion and cap wall, and thence into the tank. In the fully
retracted position of the cap, the captivating bead is urged by
buoyant force against the innermost neck bead of the container and
thus provides a seal of the container contents until the next
succeeding tank cycle.
In the accompanying drawings, which illustrate the preferred
embodiments of the invention:
FIG. 1 is a side elevational view of the liquid dispenser of the
present invention, illustrating the container and screw cap
assembled thereto.
FIG. 2 is a fragmentary vertical sectional view of the dispenser
showing the threaded screw cap tightly engaging the corresponding
threads on the container neck, thus sealing the latter against
leakage for storage or shipping.
FIG. 3 is a view similar to that of FIG. 2, illustrating the cap in
a position hereinafter referred to as the retracted position,
wherein the threads thereof are disengaged from the container neck
threads.
FIG. 4 is a view similar to that of FIGS. 2 and 3, illustrating the
cap in a position hereinafter referred to as the extended position,
wherein the threads thereof are also disengaged from the container
neck threads.
FIG. 5 is a vertical sectional view of the threaded screw cap.
FIG. 6 is a bottom plan view of the screw cap of FIG. 5.
FIG. 7 is a fragmentary side elevational view of the container,
particularly illustrating the neck portion thereof.
FIG. 8 is a sectional view taken along the line 8--8 of FIG. 7.
FIG. 9 is an end elevational view of the container.
FIG. 10 is a bottom plan view of the container and a slider clamp
piece engaging the transverse bottom wall thereof, illustrating the
clamp piece as suspending the container from the edge of a flush
tank, in a typical installation.
FIG. 11 is a plan view of the container clamp piece.
FIG. 12 is a perspective view of the container clamp piece.
FIG. 13 is a vertical sectional view of a molded, one-piece screw
cap and closure member illustrating another embodiment of the
invention.
FIG. 14 is a top plan view of the alternate form of screw cap.
FIG. 15 is a vertical sectional view of a further modified screw
cap of the invention.
Referring first to FIG. 1 there is illustrated a liquid dispenser
for flush tanks generally designated by the numeral 10, comprising
a container 12 constituted as a bottle having a top discharging
neck portion 14, a body portion 6, and comprising a captive screw
cap 18 constituting a stopper thereof. The neck portion 14 is
provided with a longitudinal bore 20 which communicates with the
interior of the container, and has external screw threads 22. In
FIG. 2, the captive screw cap 18 has internal screw threads 24
which are cooperable and engageable with the external threads 22 of
the neck portion.
In accordance with the present invention, there are provided
cooperable stop means disposed on the cap and container neck
portion for restricting the axial movement of the cap between
retracted and extended positions, said positions being illustrated
respectively in FIGS. 3 and 4. The stop means comprises a pair of
spaced-apart annular beads 26 and 28 on the neck portion 14 of the
container, and an internal annular captivating bead 30 disposed on
an annular guide portion 32 of the cap 18. In FIG. 2, there is
further illustrated a cooperable means on the cap and neck portion
for sealingly closing the latter when the cap 18 is fully threaded
thereon, comprising a resilient annular sealing lip 34 adjacent the
open end of the container neck, and an annular ring-like sealing
portion 36 on the cap 18 adjacent the threads 22.
Further, in accordance with the present invention there is provided
novel floatation means on the cap 18, defining a sealed float
chamber when the cap is inverted and immersed in the liquid of a
flush tank, for automatically shifting the cap from its extended
position (FIG. 4) to its retracted position (FIG. 3) in response to
a rising level of the liquid. The said float chamber comprises
outer and inner annular walls 38, 40 respectively, and a transverse
wall 41, all defining an outer annular chamber 42 in the cap
surrounding the neck portion of the container. Also, an annular
wall 44 and a transverse wall 46 define an inner chamber 48 which
is loosely receivable in the longitudinal bore 20 of the neck
portion of the container.
The transverse wall 41 of the cap is of circular configuration and
can optionally be molded as a separate piece. It is provided with a
depending annular flange 43 having a bead 45, which is adapted to
be sealingly received in a groove 47 in the annular wall 38 of the
screw cap 16 and to be held captive thereby.
Referring now to FIGS. 9-12, the container 12 has a transverse
bottom wall 50 disposed oppositely to the neck portion 14, and can
be constituted of flow-molded plastic or other suitable resilient
material. As provided by the invention, the wall 50 of the
container has a groove 52 extending transversely from one side of
the container 12 to the other, the groove having opposite undercut
side walls 53 and 54, and the container side walls have recesses 55
and 55a respectively, communicating with the groove 52. A slider
clamp piece 56, illustrated in FIGS. 11 and 12, having a flat body
portion 57 and a pair of extremities 58 and 59 is slidably received
in the groove 52. The extremities 58 and 59 can be accommodated
respectively in the recesses 55a and 55. The clamp piece can be
constituted of formed sheet metal or molded plastic substance. The
side walls 53, 54 of the groove 52 are yieldable so as to enable
the body portion 57 of the clamp piece 56 to be forced broadside
into the groove and retained by the undercut portions of the side
walls thereof. As illustrated in FIG. 10 the extremity 59 of the
clamp piece is engageable with the wall of the recess 55 when the
clamp piece is slid to the position shown, wherein the extremity 58
is disposed away from the opposite container side wall. The
extremity 59 of the clamp piece is disposed at an acute angle with
respect to the body portion 57 as illustrated in FIG. 12, such that
the tip of the extremity engages the wall of the recess 55.
FIG. 10 illustrates a typical installation of the container 12 when
suspended from a support member 60 such as the wall of a flush
tank. It will be noted that the length of the body portion 57 of
the clamp piece is roughly equal to the width of the container or
bottle 12, the width being measured along the groove 52. By such an
arrangement, when the dispenser is not being used, as during
shipping or storage, the clamp piece 56 can be conveniently slid to
a position whereby neither of the extremities 58 or 59 extends or
protrudes substantially beyond the container side walls. At such
time as the dispenser is ready for use, the clamp piece 57 can be
simply and easily slid to the position illustrated in FIG. 10. The
depth of the recess 55 is thus seen to be commensurate with the
spacing between the extremity 58 and the adjacent side wall of the
container when the first extremity 59 engages the wall of the
recess 55.
The operation of the improved liquid dispenser can now be readily
understood. The container 12 is filled (at the manufacturer's
facilities) with the liquid intended to be dispensed (detergent,
deodorant, disinfectant, etc.). Screw cap 18 is then assembled onto
the neck portion 14 by gently forcing the internal annular bead 30
of the cap past the external screw threads 22 and annular bead 26.
The neck portion 14 is preferably constituted of yieldable plastic
substance, and the screw threads 22 and annular beads 26 and 28 can
yield inwardly under external forces. At approximately the point
where the cap bead 30 begins to engage the annular neck bead 28,
the corresponding screw threads 24 and 22 of the cap and neck
portions are almost but not quite brought into engagement. The cap
18 is now in the position illustrated in FIG. 3. The cap 18 can now
be gently urged further in the same direction to force the cap bead
30 past the neck bead 28, at which point the cap and neck threads
24 and 22 respectively become engaged, and the cap 18 can now be
screwed fully onto the neck, to the position illustrated in FIG. 2.
In this position, the resilient annular sealing lip 34 engages the
annular ring-like sealing portion 36 of the cap, thus constituting
cooperable means on the cap 18 and and neck portion 14 for
sealingly closing the latter when the cap is fully threaded
thereon. The dispenser may thus be stored and shipped without
danger of leakage with the cap fully threaded onto the neck as
illustrated in FIG. 2.
The liquid dispenser can be readily installed for use in existing
flush tanks with a minimum of time and effort. The clamp piece 56
is slid to the position illustrated in FIG. 10, to enable it to be
suspended from the support member or wall 60 of the flush tank. The
container 12 and captive screw cap are now inverted such that the
neck portion 14 is facing downwardly, and the screw cap slowly
unscrewed. As this is done, the cap annular bead 30 will become
engaged with the bead 28 of the neck portion 14. At this point the
cap threads 24 and neck threads 22 are still partially engaged, so
that further unscrewing of the cap will force the cap bead 30 past
the neck bead 28, whereupon the threads will become just
disengaged. The cap will now be in the position illustrated in FIG.
3 (the retracted position). In this position, the cap bead 30 and
neck bead 28 are closely engaged and thus provide a seal of the
neck portion 14. If the cap 18 is now released, it will fall (by
gravity) to its extended position (indicated in FIG.4. As this
occurs, liquid from the inverted container 12 will, by gravity,
fill the recess 64 in the cap until the level therein reaches the
level of the annular sealing lip 34 of the neck. The flow into the
cap will thereupon cease, since the flow of air into the container
which is necessary to displace the liquid being removed therefrom
is cut off when the liquid level in the cap reaches the sealing
portion 34 of the neck. The dispenser 10 can now be installed in
the flush tank in its inverted position as illustrated in FIGS. 4
and 10. As this is done, the cap 18 will become submerged, and the
buoyancy provided by the chambers 42 and 48 will urge the cap 18 to
the retracted position, indicated in FIG. 3. As the cap is moved
from its extended to its retracted position, the liquid which
heretofore filled recess 64 will become displaced by the annular
walls of the neck portion 14, and thus will be forced out through
the space between the annular wall 40 of the cap and neck portion
14. It is to be especially noted that, in accordance with the
present invention, the annular bead 26 has a relieved surface
comprising a plurality of flats 66, 68, 70 and 72, (FIGS. 7 and 8)
which provide passages in the form of clearance spaces between the
relieved surface bead 26 and the cap 18 when the latter is out of
the retracted position, and thus the bead 26 is unlike the bead 28
which is continuous and can sealingly engage the cap bead 30 when
the cap is in the retracted position.
Referring again to FIG. 7, the neck portion 14 of the container has
longitudinally extending bearing ribs, three of which are shown and
designated 75, disposed between the spaced apart neck beads 26 and
28. These bearing ribs are engageable with the cap bead 30 disposed
on the inner wall 40, and thus constitute an advantageous guide
means for preventing tilting of the cap 18 when the latter moves
between its extended and retracted positions. By the above
arrangement, any tendency toward cocking or tilting of the cap
along its path of travel is greatly minimized, and friction between
the cap and neck is also minimized due to the relatively small
areas thereof in direct contact with one another.
It can now be understood that under normal circumstances when the
flush tank is full, the screw cap 18 will be submerged in the tank
liquid, and the cap will be urged to its retracted position as
illustrated in FIG. 3 by a buoyant force due to the captive air in
the chambers 42 and 48. A predetermined volume of liquid will
occupy chamber 64 of the cap 18. In the retracted position, no
dispensing of the container liquid occurs, since the cap bead 30 is
sealingly engaging the neck bead 28 of the container. At such time
as the tank liquid begins to fall below the level of the retracted
cap, the cap will be urged by gravity to follow the falling level
until it reaches the extended position (FIG. 4). During this
transition, air which was drawn into the recess 64 from the flush
tank will displace liquid from the container, which liquid fills
the recess 64 until the level therein reaches the level of the
sealing lip 34 of the neck 14, at which time no further liquid from
the container will flow because the path of displacement air for
the container is now blocked by the liquid level in the cap recess.
Assuming that the tank has emptied, and the liquid level therein
now begins to rise, the cap 18 will eventually experience a buoyant
force which urges it from its extended position (FIG. 4) to its
retracted position (FIG. 3). During this transition, a quantity of
dispensing liquid equal in volume to the quantity that entered
chamber 64 during the previous transition (from the retracted
position to the extended position) will be displaced from the cap
recess 64 and travel in the spaces between relieved surfaces 66,
68, 70 and 72 of the bead 26 of the annular wall 40 of the cap 18,
in the direction of the arrows in FIG. 4, and thus out into the
tank. It is noted that the liquid cannot be forced back into the
container through the bore 20 during this transition because such a
flow would require a net displacement of air out of the container,
which clearly could not occur under these circumstances.
From the above it is clear that liquid from the container is
dispensed into the tank only during the transition of the cap from
its extended position (FIG. 4) to its retracted position (FIG. 3).
The quantity of liquid dispensed is dependent upon the spacing
between the beads 26 and 28. A large spacing therebetween will
permit a large volume of liquid to enter the recess 64 during the
transition of the cap from its retracted position to its extended
position. A correspondingly large quantity will then be displaced
by the container neck 14 and dispensed into the tank during the
transition from the extended to the retracted position of the cap
18. Thus, the spacing between the beads 26 and 28 constitutes a
metering control for the dispenser.
An alternate form of screw cap is illustrated in FIGS. 13-14,
wherein the cap is constituted as a single molded piece, and
designated generally by the numeral 18a. The screw cap has internal
screw threads 24a, an annular ring-like sealing portion 36a adapted
to be sealingly engaged by the resilient annular sealing lip 34 of
the container neck portion 14 when the cap is fully threaded
thereon, a pair of annular walls 38a and 40a and a transverse wall
41a. The transverse wall 41a has a depending flange 43a which is
formed as best illustrated in FIG. 14, and the latter has a bead
45a which is adapted to be sealingly received in the groove 47a of
the annular wall 38a. The wall 41a is fastened to the annular cap
wall 38a by means of an integral hinge 39a. Thus, when assembled,
the transverse wall 41a and annular walls 38a and 40a define an
outer air chamber 42a, and annular wall 44a and transverse wall 46a
also define an inner air chamber 48a. Annular wall 40a has an
internal annular bead 30a which functions in a manner identical to
that of the first-described screw cap 18.
A third form of screw cap 18b, considered the preferred form, is
illustrated in FIG. 15. The cap is provided with internal screw
threads 24b, annular walls 38b and 40b, and a transverse wall 41b
having substantially the configuration of a disc, all of said walls
defining a closed air chamber 42b which provides a buoyant force to
the cap when it is immersed in liquid. The cap is provided with a
resilient annular sealing lip 36b which is adapted to engage the
annular ring-like sealing portion 34 of the container neck 14. The
cap also has an internal annular bead 30b which can preferably be
integral with the transverse wall 41b. Transverse wall 41b is
further provided with an annular groove 74 which receives the edge
portion 76 of the wall 40b, and a shoulder portion 78 which closely
and sealingly abuts the edge of annular wall 38b.
There are a number of advantages in the above constructions. First,
the present invention employs a single screw cap as both a sealing
closure for the container to prevent leakage during storage and
shipping, and a metering and float valve to dispense predetermined
quantities of liquid from the container into a flush tank. Thus,
the number of separate parts required is kept to an absolute
minimum. Second, the operation and use of the dispenser is
extremely simple, due to the fact that the screw cap is held
captive and merely requires turning movement relative to the
container to ready the dispenser for use, without the necessity of
removing the cap and reinserting it in an inverted position as has
been the case in prior dispensers. Third, when the dispenser is
suspended in a tank, substantial portions of the air chambers 42 in
FIGS. 3-4, 42a in FIG. 13 and 42b in FIG. 15 are disposed high in
relation to the mass center of the respective cap. By the above
arrangement, the buoyant force which raises the cap to its
retracted position acts through a high point on the cap, and thus
the cap is "pulled" by the buoyant force rather than being "pushed"
thereby, this minimizing any tendency for cocking or tilting of the
cap during the transition from its extended position to its
retracted position.
From the above it can be seen that I have provided a novel liquid
dispenser which is simple in construction, reliable in operation
and can be readily installed and activated by unskilled personnel
whereby it represents a distinct advance and improvement in the
liquid dispensing art.
Variations and modifications are possible without departing from
the spirit of the invention.
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