Abstract:
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.

Description:
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. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing and further and more specific objects and advantages of the instant invention will become readily apparent to those skilled in the art from the following detailed description of a preferred embodiment thereof taken in conjunction with the drawings, in which: 
     FIG. 1 is a perspective view of an automatic soap dispenser according to the present invention as it would appear installed on a sink; 
     FIG. 2 is a sectional perspective view of the pump mechanism taken along line  2 — 2  of FIG. 1; 
     FIG. 3 is a side schematic view of the automatic soap dispenser according to the present invention; and 
     FIG. 4 is a sectional side view of the dispensing fixture of the present invention. 
    
    
     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.