Method and apparatus for dispensing a fluid using a fluid-operated timer
FIELD OF THE INVENTION 
     The Invention relates generally to fluid-operated timers, and more particularly to automatic hydraulic timers utilized to dispense a predetermined amount of cleaning solution by regulating the flow of a solvent to a concentrated cleaning chemical. 
     BACKGROUND OF THE INVENTION 
     Fluid-operated timers are well-known devices. Generally, a fluid-operated timer is a device which utilizes a &#34;control fluid&#34; to determine or measure a period of time. A fluid-operated timer can be mechanically coupled to a valve such that when a preselected period of time elapses the timer causes the valve to either open or close, thereby regulating the flow of a fluid. As recognized by those skilled in the art, a portion of the regulated fluid can be used as the control fluid for the timer. The present invention is generally directed to such a fluid-operated timer. 
     The control fluid or regulated fluid associated with a fluid-operated timer could be a liquid or a gas. The present invention, however, is particularly directed to a liquid-operated timer which is mechanically coupled to a valve suitable for controlling the flow of a liquid, wherein a portion of the regulated liquid is used as the control liquid. 
     A preferred embodiment of the invention is a hydraulic timer apparatus which is coupled to a hydraulic valve suitable for controlling the flow of water from a source to a utilization point. The preferred timer apparatus stops the flow of the regulated liquid after a predetermined period of time. 
     At least two hydraulic mechanisms have been used to prevent the flow of a liquid through a conduit after a predetermined period: (i) float valves and (ii) restricted return flow valves. A float valve utilizes a tank and float wherein the tank retains fluid and the increasing amount of fluid retained supports and moves the float upward. The float is operatively engaged to a normally-open valve such that when the float has risen a preset distance the valve is closed. An example of this type of timer valve is described in U.S. Pat. No. 2,973,781. The liquid which is subject to control by the normally-open valve is the same liquid which is accumulated by the tank and used to close the valve. One disadvantage associated with this type of valve is that the liquid must be manually drained from the tank in order to reset the valve for a subsequent operation. 
     A restricted return flow valve includes a normally-closed valve which is manually opened. Return of the valve to its normally-closed position is impeded by a fluid which enters a chamber when the valve is manually opened. The valve closes when the chamber fluid is forced out of the chamber through an orifice. An example of this type of hydraulic timer valve is shown in U.S. Pat. No. 2,549,909. One perceived disadvantage of this type of timer valve is that it must be manually actuated in order to open the normally-closed valve and initiate the timing process. 
     In some situations it is desirable to have a timer valve which is entirely automatic in that it can cycle repeatedly without requiring human intervention. Thus, one of the drawbacks associated with prior art hydraulic timers is that they must be manually actuated or reset for each operation. 
     In an attempt to address this problem, automatic electrical timers have been utilized to regulate the flow of a fluid through a conduit. Such timers are certainly capable of completely automatic actuation and reset. However, electrical timers also have drawbacks which include: (1) they are difficult to install and repair as they must be connected to a source of electricity; (2) they are relatively expensive compared to hydraulic timers; and (3) they are safety hazards, especially when used near water. 
     Therefore, a substantial need exists for a simple, safe, completely automatic mechanical hydraulic timer valve. Such a valve could be advantageously utilized to control the amount of a liquid allowed to flow through and contat a cleaning chemical. 
     This need is fulfilled by the hydraulic timer of the present invention. It automatically and mechanically (not electrically) actuates upon the onset of flow of the regulated liquid and automatically and mechanically resets when the flow of regulated liquid through the hydraulic timer valve is shut off. 
     SUMMARY OF THE INVENTION 
     The present invention includes an automatic reset fluid-operated timer valve which includes a biased bearing arrangement sealingly engaged within a housing. The bearing arrangement preferably includes a larger bearing element, a smaller bearing element, and means for uniting the larger and smaller bearing elements The elements of the bearing arrangement preferably divide the housing into a pressure chamber and a flow chamber wherein the pressure chamber is defined by a first end of the housing and the larger bearing element and the flow chamber is defined by the smaller bearing element and the second end of the housing. 
     The bearing arrangement is preferably biased towards the first end of the housing or, in other words, biased in favor of a large flow chamber and a small pressure chamber. The pressure chamber has at least one port for allowing fluid to both enter and exit the pressure chamber. The flow chamber has at least one inlet port for allowing fluid to enter the flow chamber and at least one outlet port for allowing fluid to exit the flow chamber. 
     In operation, a preferred embodiment functions as follows: fluid is allowed to concurrently flow into the pressure chamber via the pressure chamber port and into and out of the flow chamber via the flow chamber inlet and outlet ports. Because the bearing plate defining the pressure chamber is larger than the bearing plate defining the flow chamber, the fluid pressure exerted upon the larger bearing plate coerces the bearing arrangement counter to the force exerted by the biasing means and towards the second end of the housing (thereby creating a larger pressure chamber and a smaller flow chamber). Fluid flow through the flow chamber is subject to being impeded by the smaller bearing element when the smaller bearing element is coerced far enough towards the second end of the housing to block either the flow chamber inlet port or the flow chamber outlet port. 
     The pressure chamber and flow chamber are preferably open to the atmosphere so that when fluid flow into the hydraulic timer device is stopped, the biasing means may return the bearing arrangement to its normal position by evacuating the fluid in the pressure chamber into the atmosphere, thereby resetting the hydraulic timer for another use. The fluid allowed to escape into the atmosphere may be (i) drained away, (ii) returned to the fluid flowing to a utilization point via the flow chamber if the utilization point is open to the atmosphere or preferably (iii) mixed with the fluid flowing to a utilization point via the flow chamber at the first utilization point. 
     The hydraulic timer may be used for dispensing a predetermined amount of a cleaning solution wherein the cleaning solution is formed by impinging a fluid upon a cleaning chemical. The hydraulic timer valve controls the amount of cleaning solution by controlling the amount of fluid allowed to contact the cleaning chemical. 
     &#34;Utilization point&#34;, as used herein, refers to the point wherein the fluid flowing through the hydraulic timer (i.e., the regulated fluid controlled by the hydraulic timer) is used. There may be more than one utilization point and multiple utilization points may be in series or parallel. 
     As utilized herein, &#34;cleaning chemical&#34; refers to those chemicals utilized in the washing and cleaning of wares, textiles, floors, etc. Examples of such cleaning chemicals include detergents, bleaches, softeners, soaps, etc. 
     As utilized herein, &#34;solvent&#34; refers to those liquids commonly used as solvents including both organic and inorganic solvents with reference made to water as the most common solvent. 
     While the following description refers to a solvent mixed with a cleaning chemical, the invention is not limited to the dispensing of &#34;solutions&#34; in the strict sense of the word. Mixtures, slurries, emulsions, suspensions and the like are also contemplated for this use of a hydraulic timer device. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     FIG. 1 shows a schematic view of a preferred dispenser system including a timer valve of the present invention, wherein the timer valve is open and beginning its closing process. 
     FIG. 2 shows a schematic view of the system of FIG. 1, wherein the timer valve is closed and beginning its opening process. 
    
    
     DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
     The Drawing shows a schematic view of a cleaning system 10 which includes a water supply 12, a cleaning chemical dispenser 14, and a sink 18. The chemical dispenser 14 preferably contains a cleaning compound 16 which is in solid, granulated or powdered form. U.S. Pat. Nos. 4,063,663 and 4,426,362, incorporated herein by reference, describe powdered and block detergent dispensers, respectively, which may be used as the cleaning chemical dispenser 14 shown in the Drawing. The system 10 provides means for combining water or any other solvent and compound 16 to produce a liquid cleaning solution which is directed to a utilization point 18 which could be a ware-washing sink 18 or the like. 
     Between and in fluid communication with the water supply 12 and the cleaning chemical dispenser 14 is a water supply line valve 20 and a normally-open hydraulic timer valve 22. Altnough the timer and valve portions of the timer valve 22 could be separate but interconnected components, the preferred embodiment is a device wherein the timer and valve are integral components as further described below. 
     The water supply 12 is preferably a pressurized source of water, wherein when the water supply line valve 20 is open, water can flow from the water supply 12 through the valve portion of hydraulic timer valve 22 and to the cleaning chemical dispenser 14. A water supply line 24 on the outlet side of the water supply valve 20 is connected to both a pressure chamber 26 and a flow chamber 28 of the hydraulic timer valve 22. In line 24a between supply valve 20 and pressure chamber 26 is an adjustable flow control valve 35. 
     A water supply line 30 runs from the flow chamber 28 to a nozzle 32 within the dispenser 14. A drain line 34 is connected at one end to the bottom of dispenser 14; the other end is located above sink 18 so that the cleaning solution will fall into the sink 18. Completing the basic hyraulic circuit is a sink fill line 38 which vents line 24 to the sink 18. 
     Thus, pressure chamber 26 and flow chamber 28 are open to the atmosphere so that when fluid flow to the hydraulic timer valve 22 is stopped by closing the water supply line valve 20, a biasing means or compression spring 36 may reset the hydraulic timer valve 22. Although the line 38 empties into the sink 18, in general the pressure chamber 26 could be vented in any fashion which would allow the biasing means or spring 36 to reset the timer valve 22 once the supply valve 20 is turned off. For example, the fluid vented to the atmosphere could be drained away or returned to the drain line 34 of the dispenser 14. 
     The cleaning chemical dispenser 14 preferably includes a canister 40 which contains a source of solid cleaning chemical. As FIGS. 1 and 2 illustrate, the solid cleaning chemical can be in the form of a cleaning chemical cake 16 located toward the top of the canister 40. As mentioned above, the water supply line 30 preferably terminates with a spray nozzle 32 located within the canister 40. The spray nozzle 32 is aimed towards the detergent cake 16 such that when a water spray 42 issues from the nozzle 32 it impinges and dissolves a portion of the cleaning chemical 16. The resulting cleaning chemical solution flows downward through canister 40 and is directed by drain line 34 to a utilization point or sink 18. 
     As described above, the hydraulic timer valves 22 controls the flow of water from the water source 12 to the cleaning chemical dispenser 14. The hydraulic timer valve 22 preferably has a bearing arrangement 44 having a larger bearing element 46, a smaller bearing element 48, and means 50 for uniting the larger and smaller bearing elements while maintaining a void between the elements. The bearing arrangement 44 is preferably slideably and sealingly engaged within a housing 52 wherein the housing 52 and the bearing arrangement 44 define three separate and distinct chambers: (i) the pressure chamber 26, (ii) a central chamber 54, and (iii) the flow chamber 28. The pressure chamber 26 is defined by the first end 56 of the housing 52 and the larger bearing element 46; the central chamber 54 is defined by the larger bearing element 46 and smaller bearing element 47; and the flow chamber 28 is defined by the smaller bearing element 48 and the second end 58 of the housing 52. The hydraulic timer valve 22 contains a biasing means or compression spring 36 for biasing the bearing arrangement 44 towards the first end 56 of the housing 52, thereby biasing the hydraulic timer valve 22 towards the open position (i.e., allowing fluid flow therethrough) and towards having a larger flow chamber 28 and a smaller pressure chamber 26. 
     Further regarding the timer valve 22, the pressure chamber 26 has a port proximate the housing first end 56 for allowing fluid to enter and exit the pressure chamber 26. The flow chamber 28 has an inlet port connected to line 24b and an outlet port connected to line 30 for allowing fluid to enter and exit the flow chamber 28, respectively, thereby allowing the continuous flow of fluid through the flow chamber 28. The pressure chamber 26 and the flow chamber 28. The pressure chamber 26 and the flow chamber 28 are interconnected with the water source 12 via the water supply line 24 so that water can flow into the pressure 26 and flow 28 chambers. 
     As discussed above, the pressure chamber 26 and flow chamber 28 are preferably vented to the atmosphere so that when fluid flow into the hydraulic timer valve 22 is stopped by closing the water supply line valve 20, the spring 36 may reset the hydraulic timer valve 22. Venting could be accomplished in various ways, and the invention is not limited to venting the liquid to the sink 18 as shown in FIGS. 1 and 2. 
     In the preferred embodiment, the bearing arrangement 44 includes a larger cylindrical piston 46, a smaller cylindrical piston 48 and a piston rod 50 connecting the larger 46 and smaller 48 pistons wherein the ratio of the larger piston surface area to the smaller piston surface area is about 10:1 to about 1.5:1, and preferably about 4:1 to 2:1. 
     The pressure 26 and the flow 28 chambers are preferably right angle cylinders sized to create a fluid-tight seal about the larger 46 and smaller 48 pistons, respectively. 
     The elements of the hydraulic timer valve 22 may be made from any durable, formable and impermeable substance, examples of which are metals such as polyethylene and polypropylene. Of course, the materials must be compatible with the solvent (e.g., water). A preferred material is polypropylene due to its ease of manufacture, durability, and resistance to corrosion. 
     It should be noted that a pressure regulating valve (not shown) could be included in line 24 of the system 10 in addition to the control valve 35 to better control the amount of solvent permitted to impinge on detergent cake 16. 
     In operation, the water supply valve 20 is opened to allow water to flow through the water supply line 24. Water concurrently flows into the pressure chamber 26 and the flow chamber 28. The water flowing into the flow chamber 28 is immediately directed out of the flow chamber 28 through the flow chamber outlet line 30 and to a utilization point (herein the cleaning chemical dispenser 14). Because the bearing element or piston 46 defining the pressure chamber 26 is larger than the bearing element of piston 48 defining the flow chamber 28, the introduction of water into the pressure chamber 26 coerces the bearing arrangement 44 counter to the force exerted by the spring 36 and towards the second end 58 of the housing 52, thus creating a larger pressure chamber 26 and a smaller flow chamber 28. When enough water has been introduced into the pressure chamber 26 to move the smaller bearing element 48 over either the flow inlet port connected to line 24b or the flow outlet port connected to line 30, flow through the hydraulic timer valve 22 to the cleaning chemical dispenser 14 is impeded and eventually prevented. 
     Referring to FIG. 1, those skilled in the art will recognize that the resistance to flow provided by line 38 must be sufficient to direct a portion of the flow through valve 35. The flow resistance of line 38 can be adjusted by simply varying the length of line 38 or by adjusting a valve (not shown) in the line 38. 
     Following closure of timer valve 22, water continues to flow into the pressure chamber 26 until the bearing apparatus 44 is depressed towards the second end 58 of the housing 52 as far as the water pressure, the spring 36 and the second end 58 of the housing 52 will allow. FIG. 2 shows the valve 22 in this state. All of the water flowing through the water supply line 24 will then flow through line 38 to the atmosphere discharge point above sink 18 until the water supply valve 20 is closed. 
     When the water supply valve 20 is closed water will no longer flow through the water supply line 24 and the spring 36 will coerce the bearing arrangement 44 towards the first end 56 of the housing 52, thereby forcing water held within the pressure chamber 26 out through lines 24a and 38. FIG. 2 shows the timer valve 22 in its fully closed state immediately after the spring 36 begins to move the bearing arrangement 44 toward the first end 56 of the housing 52. The timer valve 22 is shown in its fully reset state in FIG. 1. The arrows in FIGS. 1 and 2 indicate the direction of water flow through lines 24, 30 and 38 depending on whether the valve 22 is in the process of closing (FIG. 1) or opening (FIG. 2). 
     The description presented above is given to aid in the complete nonlimiting understanding of the invention. Since many variations and embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.