Abstract:
A self cleaning liquid soap dispenser which rinses the internal parts of the soap dispenser each time soap is ejected from the nozzle. The dispenser, being adapted to be connected to a pressurized water line comprises: a liquid soap tank containing liquid soap, a piston terminating in a nozzle, a cylinder which slidingly receives the piston, and a valve inside the cylinder, for providing selective communication between the dispenser and the pressurized water line. Whenever the piston will be pressed against the valve, pressurized water from the water line will rush into the piston pushing the soap in the cylinder out through the nozzle. The pressurized water will rinse the valve, the cylinder, the nozzle and the piston.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to liquid soap dispensers which are installed in sinks or wherever there is a water line and which are provided with a refillable soap tank. This invention provides an apparatus which will self clean each time the dispenser is used, keeping the device free of hard soap clots or dirt. Thus this device will prevent the malfunctions that occur in conventional liquid soap dispensers that are caused by the accumulation of hard soap inside the valves second cylinder and piston. Also, this invention will provide means for diluting the soap prior to its ejection, thus providing a single mechanism that wets the sponge and ejects the soap. 
     2. Description of the Related Art 
     Prior art provides liquid soap dispensers to be used in sinks where the soap tank is mounted below the sink and a plunger projects above the sink to be pressed each time soap is needed. The major problem all such soap dispensers have lies in the innate quality of liquid soap--its tendency to dry and plug the piston, prevent valves from moving and sticks the piston to the cylinder. Thus most such dispensers do not eject soap each time the plunger is pressed and consequently require regular cleaning. 
     SUMMARY OF THE INVENTION 
     My invention is an apparatus which can clean itself each time the dispenser is used. The device is adapted to a pressurized water line, which will provide pressurized water to wash the cylinder piston and all the valves situated between the water line and the soap tank. In a first position, the device can be in used as a regular soap dispenser, ejecting soap exclusively. In a second position, the device can eject soap and continuously eject pressurized water to clean the valves, cylinder the piston and the piston passage. In a third position, the device can eject soap and a limited amount of water. The device has either a single function for cleaning, in which case the soap will be diluted minimally, or the device can serve a second function which is a mechanism for providing water and soap in one step, in which case the soap can be diluted further, to different extents. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 illustrates the apparatus where the plunger is not pressed. 
     FIG. 2 illustrates the apparatus where the plunger is pressed to a second position which allows continuous water flow. 
     FIG. 3 illustrates the apparatus where the plunger is pressed to a third position which allows minimal water flow. 
     FIG. 4 illustrates the apparatus with a dual diameter cylinder and a dual diameter piston. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 will illustrate the apparatus which consists a soap tank T, having an opening O at the top to allow refilling the tank with soap. A plug L is adopted at the top exterior of the tank. A plunger B has a bore BB through it terminating in a nozzle Z. The nozzle Z is projecting out from the tank T through opening O. A button A is mounted on the plunger B for pressing the plunger B down. A spring J1 is placed below button A which will return plunger B to a none pressed position after button A is released. A projecting member M is mounted on the tank T to act as a stopping device: preventing button A from being pushed down against plug L, and therefore preventing plunger B from traveling down all the way. A piston PP having a bore H through it is mounted at the bottom of plunger B, bores BB and H forming a continuous passage for fluid to flow. A sleeve S is mounted in the tank T below the opening O for receiving and passing the piston PP. The lower portion of sleeve S is a cylinder CC for closely receiving piston PP. The bottom tip of piston PP is grooved to allow water to enter into piston PP when piston PP is pressed against valve V2 [to be described below]. Cylinder CC is connected to a valve body G, which is adapted to be connected to water line WW via adapter LL. A valve V1 seated on seat S1 at the lower end of piston PP allowing fluid to move in one direction--up from cylinder CC into piston PP and out of nozzle Z. Valve V1 will block the soap from going back to the tank T once button A will be released. The bottom of cylinder CC comprises a valve seat SU where valve V2 is mounted. The lower part of valve body G has a seat SL where valve V3 is mounted. In between valve seat SU and valve seat SL there is an intermediate valve seat SI. An expansion spring J2 is urging valve V2 and valve V3 against seat SU and SL respectively. Valve V2 prevents soap from entering into water line WW. Valve V2 provides a way for water from water line WW to enter and accumulate in valve body G between seats SL and SU, keeping the water pressure in valve body G almost equal to the water pressure in water line WW. 
     When the apparatus is installed, soap is filled in the tank T through hole O. Soap will fill cylinder CC, bore It of piston PP and part of bore BB in plunger B. Piston PP will slide in the upper portion of sleeve S. Water pressure from water line WW will overcome the expansion force of spring J2 and push valve V3 away from seat SL, allowing water to rush to valve body G to fill it until the water pressure in valve body G will almost equal to the water pressure in water line WW. 
     In a first position, the dispenser can be used to dispense just soap. As can be seen from FIG. 1, if plunger B is depressed into cylinder CC such that valve V2 is not moved by piston PP, the presence of piston PP is cylinder CC causes an increase in pressure in cylinder CC which causes soap in cylinder CC to move valve 1 and cause soap to be spat out of plunger B. 
     As illustrated in FIG. 2, when member M is adjusted to a first position, such that button A can only be depressed part of the way, spring J1 compresses, and plunger B pushes piston PP into cylinder CC finally to push valve V2 away from seat SU. In this second depressed position valve V2 is in between seat SU and seat SI. This will allow water from valve body G to rush into the bore H of piston PP, by moving valve VI away from seat S1. Water will not enter into tank T, it will only enter into bore It since piston PP and cylinder CC are slidingly fit, and also due to the presence of O ring OO. As water is leaving valve body G, water from water line WW will enter via valve V3 to equalize pressure between the water line and valve body G. Thus, so long as button A is depressed, pressurized water will continue flowing up bore BB. This will allow for a continuous cleaning of the piston, cylinder and valves, if required. 
     FIG. 3 will illustrate the apparatus when member M is adjusted to a second position which will allow button A to be fully depressed against plug L. In this third depressed position plunger B will push valve V2 away from seat SU and against seat SI. When valve V2 is seated on seat SI it prevents the water from water line WW from entering into valve body G. Consequently only a limited amount of water will clean the system. Only the pressurized water from valve body G will burst into bore H and will push the soap in bore BB out of nozzle Z. This second depressed position will provide a feature that will enable the user to have a minimal amount of water diluting the soap where the amount of water is sufficient to clean the system. 
     When the button A is released, spring J1 will expand, pulling plunger B up and out of cylinder CC, returning plunger B to slide in sleeve S. As plunger B moves up it will release its urging pressure off of valve V2, allowing the valve to return to seat SU. Once again water from line WW will overcome the force of spring J2 so that water will enter valve body G, leaving the system ready for further use. 
     FIG. 4 will illustrate a dual diameter cylinder and dual diameter piston which will minimize the force needed to remove valve V2 from seat SU, and minimize the distance plunger B will need to travel in order to eject the maximum quantity of soap from the nozzle. Since pressurized water from water line WW is acting on valve V2, forcing it against seat SU, the user will have to overcome this opposing force when pressing button A. To minimize this force, the surface of valve V2 must be minimized. Thus, a small diameter cylinder CC is preferable at the bottom, with a corresponding small diameter piston PP. At the top, on the other hand, a large diameter cylinder CC1 is preferable, and correspondingly a large piston PP1 is necessary. Since the distance the plunger needs to travel should be minimized--in order to exert the least amount of work, and since the quantity of soap to be ejected should be sufficient, the upper cylinder CC1 should have a large diameter but be short. When the plunger B is not pressed, the upper piston PP1 will be maintained above the sleeve S to allow soap from the tank T to enter into the cylinders CC and CC1. These two pistons PP and PP1 can be built from one unit or from two units--in which case the small-diameter piston will slide in the large-diameter piston--where the small diameter piston is connected to plunger B. The large-diameter piston can slide up and down the small-diameter piston. The small-diameter piston will have a stopper above and a stopper below the large-diameter piston. When the plunger will be depressed it will move the upper stopper against the large-diameter piston pushing the piston down, and when the plunger will be released, the lower stopper will urge the large-diameter piston up, cuasing the large diameter piston to slide up. When plunger B is not pressed, soap will enter into the cylinders via the space between the pistons. When the plunger B will be in a depressed position it will move the upper stopper against the larger-diameter piston acting as a valve which closes off communication of soap from the tank to the cylinders. As plunger B moves further down, the upper stopper will compress the soap in the cylinders causing the soap to be pushed out through the bore in piston PP. 
     This specification is only one way of building this apparatus and is not intended to be an exhaustive description or the only description of how to build an apparatus that has a self cleaning mechanism.