Automated fluid dispenser

An automatic fluid dispenser including a pump mechanism actuated by a piston movable between a first position, and a second position in which a fluid is dispensed. A conduit is coupled to the pump mechanism and couplable to a pressurized fluid source. A valve is carried by the conduit and is movable between an open position in which a pressurized fluid from the pressurized fluid source moves the piston to the second position, and a closed position stopping the pressurized fluid.

FIELD OF THE INVENTION
 This invention relates to devices for dispensing fluids.
 More particularly, the present invention relates to automated dispensing
 devices.
 In a further and more specific aspect, the instant invention concerns
 automatically dispensing liquid soap.
 BACKGROUND OF THE INVENTION
 Devices for dispensing fluids are well known and have been used to dispense
 liquid soaps, cleaning fluids, and condiments for many years. While
 capable of dispensing any fluid, the present invention is primarily
 concerned with dispensing liquid soap which will be the primary area of
 discussion.
 Liquid soap is typically dispensed by the reciprocal translation of a
 plunger which pumps liquid soap from a source and ejects it from an
 aperture. These dispensers require manual manipulation of the plunger.
 Such manipulation serves as a vehicle for transmission of bacterial and
 viral contaminants to subsequent users.
 There also exists pneumatically actuated and mechanically (motor/pump)
 actuated mechanisms for dispensing soap in response to a trigger signal.
 These devices require a relatively substantial amount of power, usually in
 the form of electrical power, to maintain the air or gas pressure
 necessary to operate the pneumatic dispenser or to operate a motor in a
 mechanical dispenser. Conventional electric power (120 volts AC) creates
 an electrical hazard in proximity to a wash basin, or the like, reducing
 the desirability of devices requiring large quantities of power.
 It would be highly advantageous, therefore, to remedy the foregoing and
 other deficiencies inherent in the prior art.
 Accordingly, it is an object of the present invention to provide a new and
 improved automatic fluid dispenser.
 Another object of the invention is to provide an automatic soap dispenser
 which requires very little electrical power.
 And another object of the invention is to provide an automatic soap
 dispenser which is self cleaning.
 Still another object of the present invention is to provide an automatic
 soap dispenser which is adjustable to dispense a pre-determined quantity.
 SUMMARY OF THE INVENTION
 Briefly, to achieve the desired objects of the instant invention in
 accordance with a preferred embodiment thereof, provided is an automatic
 fluid dispenser including a pump mechanism actuated by a piston movable
 between a first position, and a second position in which a fluid is
 dispensed. A conduit is coupled to the pump mechanism and coupiable to a
 pressurized fluid source. A valve is carried by the conduit and is movable
 between an open position in which a pressurized fluid from the pressurized
 fluid source moves the piston to the second position, and a closed
 position stopping the pressurized fluid.
 In a more specific aspect of the present invention, provided is an
 automatic fluid dispenser including a liquid soap reservoir, a soap
 dispensing fixture and a pump mechanism. The pump mechanism includes a
 housing defining a pump chamber having an inlet coupled to the liquid soap
 reservoir and an outlet coupled to the soap dispensing fixture. A first
 check valve is mounted in the inlet of the pump chamber for allowing
 liquid soap flow only into the pump chamber from the reservoir, and a
 second check valve is mounted in the outlet for allowing liquid soap flow
 only out of the pump chamber to the soap dispensing fixture. A piston is
 positioned within a bore in the housing for reciprocating motion between a
 first position in which the pump chamber has a volume and a second
 position in which the volume of the pump chamber is reduced. The pump
 mechanism further includes a biasing element biasing the piston into the
 first position. A conduit is coupled to the bore and coupled to a
 pressurized water source. The conduit directs pressurized water from the
 pressurized water source onto the piston. A valve is carried by the
 conduit and movable between an open position in which pressurized water
 from the pressurized water source moves the piston to the second position,
 and a closed position stopping the pressurized water. A water bleed is
 coupled to the bore between the piston and the valve. A sensor positioned
 proximate the fixture actuates a solenoid to move the valve to the open
 position. The valve is normally biased to the closed position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
 Turning now to the drawings in which like reference characters indicate
 corresponding elements throughout the several views, attention is first
 directed to FIGS. 1 and 3 which illustrates an automatic soap dispenser
 generally designated 10, carried by a sink assembly 12 displayed in
 phantom lines. Sink assembly 12 is of conventional design, and includes a
 counter top 14, a bowl 16 formed in counter top 14, and a faucet 18
 positioned to overhang bowl 16.
 Automatic soap dispenser 10 includes a pump assembly 20 coupled to a
 reservoir 22 by a conduit 24, and an outlet fixture 26 by a conduit 28. An
 actuating assembly controls the operation of pump assembly 20 by
 regulating a flow of pressurized water. Upon release of pressurized water
 to pump assembly 20 a quantity of soap is dispensed. The actuating
 assembly includes a sensor 30 mounted on or proximate fixture 26, a
 conduit 32 from a pressurized water source, and a valve 34 opened and
 closed by a solenoid 36 upon triggering of sensor 30. Additionally, a
 conduit 38 is coupled between pump mechanism 20 and an outlet of fixture
 26. As will be described presently, conduit 38 allows the elimination of
 water employed to operate pump mechanism 20. In the preferred embodiment,
 all of the elements described are mounted below counter top 14 except
 fixture 26 positioned to dispense soap over bowl 16, and sensor 30
 positioned on or proximate fixture 26.
 Referring now to FIG. 2, pump assembly 20 includes a housing 40 having a
 water inlet 42, a soap inlet 44, a soap outlet 46 and a water outlet 48. A
 bore 50 extends between soap inlet 44 and soap outlet 46, intersecting a
 bore 52 extending from water inlet 42 and terminating at closed end 54.
 Check valves 56 and 58 are formed at soap inlet 44 and soap outlet 46,
 respectively, to prevent back flow of soap. It will be understood that
 check valves 56 and 58 can be positioned anywhere along conduits 24 and
 28, respectively, Lo prevent backflow of material. A piston 60 is
 reciprocally movable within bore 52 between a forward stroke and a
 rearward stroke. A volume of a chamber 62, defined by bore 50 between
 check valves 56 and 58, and bore 52 at the intersection thereof, is
 reduced and increased by the movement of piston 60 between the forward
 stroke and the rearward stroke, respectively. As the volume is reduced,
 soap is expelled through check valve 58 into conduit 28. During the
 rearward stroke the volume is increase to a normal volume, creating a
 vacuum which draws soap past check valve 56 into chamber 62 from conduit
 24. The quantity of soap dispensed is dependent upon the size of chamber
 62 and the length of the stroke of piston.
 The forward stroke of piston 60 is produced by the release of pressurized
 water from conduit 32 by valve 34. Valve 34 is biased closed and is opened
 for a brief period by solenoid 36 and automatically closed. The surge of
 pressurized water drives piston 60 in the forward stroke. The water is
 then bled away through water outlet 48 and conduit 38. The bled off water
 can be disposed of in many different manners. Conduit 36 can direct the
 water directly to a drain pipe, mix the water with the dispensed soap,
 etc. In this embodiment, as can be seen in FIG. 4, the water is directed
 to an outlet 70 of fixture 26, which disposes of the water onto the side
 of bowl 16. This aids in washing any soap residue from bowl 16 after soap
 has been dispensed.
 Still referring to FIG. 4, fixture 26 includes a dispense outlet 72 coupled
 to conduit 28 by a channel 74. In the preferred embodiment, channel 74 is
 inclined from conduit 28 to outlet 72. The incline prevents liquid soap
 from dripping into bowl 16. Once the soap is dispensed any residual soap
 is prevented from exiting outlet 72 by the incline of channel 74.
 Referring back to FIG. 2, the force of the water acting upon piston 60 can
 be adjusted by positioning bushings 76 and 78 within water inlet 42 and/or
 water outlet 48. The amount of constriction produced by bushings 76 and 78
 will increase the force of the water from conduit 32 and reduce the speed
 with which the water is bled away. By adjusting these factors, less water
 may be needed.
 The rearward stroke is achieved by a biasing element 80 which forces piston
 60 into the rearward stroke. The rearward movement of piston 60 displaces
 the water which moved piston 60 in the forward stroke, through water
 outlet 48. In this embodiment, biasing element 80 is a compression spring
 carried within bore 52 between end 54 and piston 60. Piston 60 includes an
 adjustable stop 82 for varying a distance between the first position and
 the second position whereby the reduction of the volume of the chamber is
 adjustable. Stop 82 is preferably threadably engaged to the end of piston
 60. By adjusting stop 82 outward, the stroke of piston 60 is reduced
 thereby reducing the amount of soap dispensed. Conversely, by adjusting
 stop 82 inward, the stroke of piston 60 is increased thereby increasing
 the amount of soap dispensed.
 By employing a pressurized water source to power the dispensing of soap,
 large amounts of hazardous electrical power are not required. A small
 amount of power needs to be supplied to sensor 30 and solenoid 36, but
 battery power is sufficient for this requirement.
 Various changes and modifications to the embodiments herein chosen for
 purposes of illustration will readily occur to those skilled in the art.
 For example, while the preferred embodiment of the present invention is
 driven by pressurized water to dispense liquid soap, one skilled in the
 art will understand that substantially any fluid can be dispensed and the
 device can be driven by other pressurized sources. To the extent that such
 modifications and variations do not depart from the spirit of the
 invention, they are intended to be included within the scope thereof which
 is assessed only by a fair interpretation of the following claims.