Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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TITLE OF THE IN~tENTION
FLUID DISPENSER
BACKGROUND OF THE INVENTION
This invention realtes to automatic
dispenser~, in particular for dispensing liquid
detergents, soaps and germicides. A need has long
existed for a~dispenser that would release a measured
: quantity of soap or other material without the need
~or the user to depress a button, move a handle or
tbe like. The handling o~ such actuators of
conventional dispensers by a number o~ users spreads
disease causing micro-organisms and creates an
unsig~tly appearance around the dispenser actuator.
T~us~ a dispenser that would release a predetermined
quantity o~ liquid soap or t~e like in response to
: the presence of a hand or other receiving object
placed under the dispenser outlet would eliminate the
aforementioned disadvantages of conventional
dispensers.
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Therefore it is an ob~ect o~ t~is invention
to release soap, detergent, or other liquid or
semi-solid materials (~ereina~ter termed fluid) in
response to the mere placement of a ~and or other
receiving object within the proximity of t~e
dispenser outlet.
It is a furt~er object of t~is invention
t~at a predetermined quantity of ~luid (~ereinafter
termed a portion) be released from the dispenser upon
eac~ instance of use.
Further, it is an object of this invention
that t~e dispenser be adapted to the use of a
disposable fluid container which can be placed within
t~e dispenser, and that such a disposable container
be integrally connected to disposable valve means and
outlet means. In t~is manner, t~e entire wetted
pathway from the container through t~e outlet means
may be discarded after t~e emptying of the container,
thereby minimizing t~e opportunities for a build-up
of micro-organisms.
It is a furt~er object of t~is invention
t~at tbe dispenser contain a proximity detector means
of an electrical nature, and t~at said proximity
detector means consumes a minimum of electric power,
t~ereby allowing the use of disposable or
recbargeable batteries.
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DESCRIPTION OF THE DRAWINGS
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Figure l is an overall view of an embodiment
o~ the dispenser.
Figure 2 is a view from beneat~ the
dispenser.
Figure 3 is a side view o~ the dispenser
s~owing a sectional view of internal components.
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Figure 5 is a perspective view s~owing t~e
container pressure plate raised.
Figure 4 is a perspective view s~owing the
pressure plate lowered in its position on t~e
container bag.
Figure 6 is a block diagram of t~e
electronic circuits of the dispe~ser.
SUMMARY OF THE INVENTION
T~e instant invention is directed to a fluid
dispenser comprising:
(a) a flexible container for a fluid, integrally
connected to valve means and outlet means:
(b) means for imparting a squeezing force to said
flexible container;
(c) and proximity detector means connected to means
for opening and closing said valve means.
DETAILED DESCRIPTION ûF THE INVENTION
T~is invention is particularly directed to a
fluid dispenser whic~ contains an electric power
source, an electronic proximity detector, a means for
holding and supporting a ~lexible, disposable bag
container, an actuator w~ic~ opens and closes a
disposable valve w~ic~ is part of t~e container
assembly, and a pressurizing means w~ic~ applies a
~orce to t~e top of t~e bag, moving fluid from t~e
bag throug~ t~e valve when t~e valve is open.
In a preferred embodiment of this invention,
t~e power source for t~e dispenser is a dry-cell
battery, allowing location of t~e dispenser
anyw~ere. T~e proximity detector employs very s~ort
pulses of in~ra-red radiation w~ic~ are directed
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downward in a beam aimed toward the area under the
dispenser outlet, and in association with a detector
o~ lnfra-red radiation whic~ is designed to pick up
reflected light from a hand or other receiving ob~ect
placed below the outlet. When the detector picks up
a light signal (it is energized continously in order
to be in constant readiness), it~is converted to a
timed pulse which is transmitted to the actuator,
opening the valve. A predetermined interval later,
another timed pulse is sent to the actuator, closing
the valve. The fluid container is a flexible bag
which lies in a horizontal postion on a shelf above
the detector. T~e valve means and outlet means are
also disposable and are attac~ed to t~e bag, hanging
below it. In order to provide a substantially
constant flow rate from t~e container, a spring-
driven pressure plate presses gently on top of t~e
bag and is arranged to press with gradually
increasing force as t~e bag empties, compensating for
t~e naturally slowing flow of t~e unassisted bag
under this condition. This combination of constant
flow rate and predetermined open time for the valve
yields portions of uniform size.
~eferring now to the drawings, Figures 1 and
2 show two views of the dispenser, and in both of
t~em the front side o~ t~e dispenser is on t~e le~t,
and a wall mount is on the right. The dispenser may
be mounted to a wall by means of bracket 3. Fluid is
dispensed from outlet 4 which protrudes through
dispenser bottom at 1. The proximity detector means
uses two infra-red devices- emiter means 5 and
detector means 7. Bot~ of these are aimed optically
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downward in t~e same direction so t~at any ob~ect
near the dispenser and illuminated by the beam from 5
will reflect a portion of t~is illumination back to
detector 7.
Figure 3 s~ows a sectional view o~ the side
of the dispenser. Any flexible material may be
employed to create a flexible con~tainer. The
flexible container is supported by s~elt` 13.
Preferred materials for the container include rubber
and ~eat-sealed plastic sheet material. Flexible
outlet tube 4 is sealed to t~e flexible container and
leads to the bottom area of the dispenser as s~own.
A simple and preferred valve and actuator mec~anism
consists of a pinc~ing means coupled to a special
solenoid actuator. In Figure 3 t~e pinc~ assembly is
comprised of fixed pinc~ jaw 17 and movable p$nch jaw
16. One suitable solenoid mec~anism 15 is shown in
Figure 3, and is based on the Model 589R bistable
impulse relay manufactured by t~e Potter and
Brumfield Division of AMF Corporation. In t~is
mechanism, each pull stroke o~ the solenoid plunger
causes pin 27 to travel toward the ~eel-end 28 of t~e
solenoid. In t~e position shown in Figure 3 the pin
thus moves within t~e upper leg of t~e vee-slot in
cam 29. W~en t~e pin reaches t~e end of t~e slot
(t~e position s~own in Figure 3) t~e cam 29 is
rotated clockwise~ causing t~e pinc~ valve to close
t~roug~ t~e action of link 32 and movable jaw 16.
W~en t~e solenoid is de-energized, an internal spring
(not shown) moves pin 27 back to a position at the
apex of the vee slot in cam 290 T~e next time the
solenoid is energized pin 27 traverse-~ the lower leg
of t~e vee slot, at t~e end of w~ic~ cam 29 is caused
to rotate counter-clockwise, opening t~e pinc~
valve. Thus, successive electrical
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actuations of t~e solenoid alternately open and close
the pinch valve. This is important~ because any
required quantity of fluid may be dispensed by only
two very s~ort impulses -- one to open t~e valve and
t~e other to close it. Using a Potter and
Brumfield-type device, an electrical impulse lasting
only 0.1 second is needed ~or eac~ transfer of the
cam ~rom one position to t~e ot~er. Since a typlcal
; fluid-dispense event may require as muc~ time as
several seconds, t~e use of an impulse solenoid of
this nature saves a great deal o~ electrical energy
from the battery.
T~e electronic circuit 18 of Figure 3,
powered by battery 14, converts t~e signal picked up
by detector 7 to a short -- e.g. O.l second --
opening pulse. A pre-set interval later, t~e circuit
sends an identical pulse to t~e solenoid, closing t~e
valve. This pre-set interval is t~e primary control
wit~in the dispenser for the amount of fluid
2~ dispensed. It is also an exact control, provided
t~at the flow rate t~roug~ the valve is constant. If
the bag container is simply resting on shelf 1~, with
only gravity providing pressure on the fluid or its
container, t~e flow rate will decrease from its
maximum value w~en t~e cDntainer is full, to zero
w~en the container is empty. Thus it is necessary to
; provide an additional means for gradually increasing
pressure on t~e bag container as the container is
gradually emptied during the any successive
wit~drawals of fluid from the dispenser. In this way
the naturally decreasing bydrostatic pressure caused
by the ~eight of the fluid level in the bag can be
compensated by the aforementioned increase in
pressure applied to the bag.
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Figures 4 and 5 show t~e general arrangement
of the dispenser parts. In particular, Figure 4
s~ows that the flexible bag 19 lies under a pressure
plate 11 w~ic~ is attac~ed in a pivoting manner to
axle 26. This axle, in turn, is solidly attac~ed to
a straig~t lever 30 and a triangular lever 20. T~ese
two levers are attac~ed together-by a shaft 31 w~ic~
is free to rotate in holes or bearings which are an
integral part of t~e dispenser framework (not
s~own). Extension spring 24 is attac~ed to t~e
dispenser framework at 25 and to the triangular lever
at 22. In t~e position shown in Figure 4 t~e spring
is attempting to cause counterclockwise rotation of
t~e triangular lever, and hence a downward motion on
the pressure plate. Referring still to Figure 4, if
one were to raise t~e pressure plate until t~e
centerline of spring 24 passed directly over t~e
centerline of shaft 21, t~en the spring would exert
no torque on the triangular lever and t~ere would be
no force exerted downward on t~e pressure plate.
T~us it can be seen that, as t~e pressure plate moves
downward from a "dead-center" position, t~e
centerline of t~e spring moves away ~rom its position
directly over t~e centerline of s~aft 21 and this
causes a progressively increasing torque to be
applied to t~e triangular lever. The foregoing
statement is strictly true only w~en t~e spring is
long enoug~ to provide a decrease in force along its
own axis, as the triangular lever moves
counterclockwise, whic~ is less t~an t~e increasing
torque effect caused by the increase in distance of
the spring centerline from the centerline of shaft
21. In practice this is a very simple conditon to
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meet, since t~e total travel of t~e pressure plate issmall and the effect of s~ortening t~e spring as the
~luid leaves t~e container is very muc~ less than the
effect of increasing the moment-arm in the mec~anism,
or t~e distance from t~e spring centerline to the
centerline of s~aft 21. As an essential feature of
the present invention, it is only necessary to
provide a means for increasing pressure-plate force
whic~ is substantially equal to the decreasing effect
of progressively-decreasing ~ydrostatic pressure
occuring as t~e container is emptied.
Figure 3 reveals t~at the dispensed ~luid
touches only the disposable flexible container 19 and
tbe flexible outlet tube 4. T~us t~ere is no
clean-up needed when an empty container is replaced
by a full one, t~e entire fluid flow pat~ being
replaced and renewed w~en the container, assembly is
replaced. In order to permit easy replacement of the
container ~ixed pinc~ jaw 17 may be adapted to be
swung out of tbe way during container and outlet tube
replacement. It is clear t~at alternative valve
mec~anisms may be used, as long as t~ey are
disposable and adapted to operate in association wit~
solenoid 15. A poppet or movable-~lap type o~ valve,
~or example, may be used. Also, a rotary valve may
be employed, deriving its actuation from t~e angular
motion n~ the cam 29. As an alternative valve
mechanism, t~e resilient tube 4 may be bent to
provide a kink seal. The minimum angle to provide a
kink seal is defined for each resilient material and
can be accomplis~ed by any mec~anism t~at bends t~e
tube to t~e required angle.
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Use of the pressure plate 11, also gives
rise to a simple indicator for t~e quantity o~ ~luid
in t~e container. This is done, for example, by
mounting a graduated dial (not s~own) on s~aft 31.
T~e angular position of the dial is a direct
indication of the amount of fluid in t~e bag.
Alternatively, a switc~ or other electrical
transducer may be mounted in cooperation with the
levers 20 or 30 so t~at upon approaching a nearly
empty condition of the container the position of the
lever is sensed by the switch, lig~ting a lamp or the
like.
A major objective of the present invention
is to reduce the electrical energy required for
continuous dispenser use. Two major components of
electrical consumption are present; (1) the valve
solenoid and (2) t~e light emitter portion of the
proximity detector. Valve solenoid power consumption
~as been lowered appreciably by the use o~ a bistable
device, as explained above. To reduce energy
consumption of t~e other component, this invention
employs a far lower pulse frequency and pulse duty
cycle than are use~ in ot~er proximity detectors used
~or general industrial pu~poses. Pre~erred values
are near 5-20 pulses per second and a duty cycle o~
near 0.007. Also, t~e lo~est effective emitter
current is used. Figure 6 shows the block diagram of
t~e electronic circuits of the dispenser. Reflected
radiation is rece~ved by the p~ototransistor, w~ose
signal is amplified and then separated from anbient
light in a level clipper. The resulting signal is
fed to the 0.1 second pulse generator which causes
the solenoid to stroke and open t~e valve. An
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auxiliary switch on the solenoid causes, through
feedback path A, a variable timer to generate a
"valve-open" interval, at the ~nd of which a signal
is sent to the same 0.1 second pulse generator,
stroking the solenoid again and closing t~e valve.
An additional circuit path B stops the interval timer
if t~e hand is removed prematurely from below t~e
dispenser and immediately causes a solenoid pulse
which closes the valve before the normal open
interval has transpired.
An additional means for lowering consumption
of electrical energy may be employed as an addition
to t~e preferred embodiment of this invention. T~is
is an additional circuit, not shown in t~e Figures,
which senses the presence or absence of general room
illumination in the location of t~e dispenser. In
operation, a simple power-transistor gate, actuated
by a cadrnium-sulfide photoresistor located on or near
the exterior o~ the dispenser, s~uts down the
dispenser electronics until such time as the room
lig~ts are turned on again. In, for example, an
industrial situation wherein only a single-shift
schedule is being worked, t~e battery life in the
dispenser would be approximately tripled over that
obtained without this feature.
