Abstract:
A flow washer in the form of a disc constructed of flowable-under-pressure, flexible, resilient material and having a plurality of closely spaced thin fins extending radially inwardly from an outer wall and terminating short of the disc&#39;s center to cooperatively define an axial orifice inwardly thereof. A method of making the flow washer is also disclosed.

Description:
BACKGROUND OF PRIOR ART 
     Flow washers are conventionally utilized in water discharging conduits in an effort to control the flow of water therethrough so as to make the flow volume more uniform under various or varying source pressure conditions. Such flow washers are frequently utilized under such varying conditions in combination with timers, in an effort to dispense a predetermined quantity of water where such is desired, as in washing machines. Since city water pressures vary between 15 p.s.i. and 120 p.s.i., the flow volume through a given valve will vary widely, absent such a flow washer. 
     Flow washers presently in common use are generally discs constructed of a flexible resilient material and having a central orifice extending therethrough, the washer distorting to different extents under different pressure conditions and thereby reducing the size of its orifice as the source pressure is elevated. As a consequence, some measure of control is accomplished at the higher pressures, but at the lower ranges of pressure, such flow washers are inadequate in that they do not readily provide for an adequate flow therethrough. Thus, for such flow washers, at lower source pressures ranges, the volume of flow is substantially less than that which will be permitted to pass at more elevated source pressures and therefor, it is impossible to properly time such a machine so as to insure that the desired amount of flow will result at both low and elevated source pressures. My invention is directed to solving this problem in a simple and relatively inexpensive manner. 
     BRIEF SUMMARY OF THE INVENTION 
     My invention provides an essentially uniform flow over a wider and important range of source pressures. As a consequence, my flow washer, when used in combination with a timer, will provide essentially a uniform volume of flow over the entire normal range of source pressures. I accomplish this by constructing the flow washer differently so as to inherently increase, as a result of its structure, the amount of water which is permitted to pass, therethrough throughout the lower ranges of source pressure. In other words, I have provided a flow washer with different structural characteristics which causes a greater flow to pass therethrough at lower pressures. 
     I do this by defining the orifice of the flow washer with a plurality of closely adjacent but spaced radially and axially extending fins which are supported by an annular outer wall. At lower pressures, the water readily flows through the narrow slots which separate the fins, as well as through the central orifice. At higher pressures, however, the thin fins deform and gradually close off the slots therebetween, through which water will flow at the lower pressures. As a consequence, I am able to substantially increase the flow at such lower pressures by, in effect, increasing the effective size of the orifice, in that the liquid is permitted to flow through the slots as well as through the orifice thereby raising the flow volume to the same level as that reached at higher source pressures. At higher pressures, the fins deform and close off the slots and the disc in general is compressed so that the main orifice is diminished, thereby reducing the size of the path through which the liquid may flow and controlling that flow at a uniform volume. 
     Thus, it is an object of my invention to provide a flow washer which will permit essentially equally high volumes of flow therethrough at low source pressures as at high source pressures. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a plan view of my novel flow washer as viewed from the outlet side; 
     FIG. 2 is a vertical sectional view taken through one of my flow washers mounted in functioning position within a conduit, to effectively regulate the flow volume therethrough. 
     FIG. 3 is a chart diagram illustrating the flow volumes at varying source pressures through flow washers as heretofore known; and 
     FIG. 4 is a chart diagram illustrating the flow volumes at varying source pressures through my new flow washer. 
    
    
     DETAILED DESCRIPTION OF INVENTION 
     The preferred embodiment of my invention is shown in FIGS. 1-2, herein. As shown, it is comprised of a flow-control member in the form of a disc 5 having an axially extending orifice 6 which is defined by a plurality of radially extending fins 7. These fins 7 are separated by slots 8 which are preferably of uniform width. As shown, the fins 7 are carried by an outer annular supporting wall 9 which has radial dimensions approximating those of the fins 7, and which supports the fins 7 at its inner diametrical surface. The free inner end portions of the fins 7 are radiused slightly adjacent the inlet side 10 of the disc as at 11 to produce a more uniform flow. 
     FIG. 2 shows a conduit 12 having a groove or flow washer seat 13 formed therein to receive and hold such a flow control member, the arrows showing the direction of flow therethrough. As shown, the conduit is beveled at 45° as at 14, 15 at opposite sides of the disc and is comprised of sections 16, 17 which are secured together in any simple conventional manner (not shown). Such connections are conventionally utilized on conduits where there is need for such flow control as in wash machines, shower heads, etc. 
     Also, as shown in FIG. 2, the orifice defining portions of the disc 5 adjacent its outlet side 18 increase slightly in radius at a 45° angle as at 19 and then extend parallel to the axis of the orifice again as at 20. This increase in radius is provided to insure that any material left at the parting line will be located outside the flow of liquid therethrough and thus will not disrupt the flow stream. 
     The disc 5 is preferably made of a flowable-under-pressure, flexible, resilient elastomeric or plastic material. Among such materials are an ethylene propylene diene monomer, a silicone, or a nitrile. The material should have a hardness range of 30-95 durometer Shore A, preferably 50-70 durometer Shore A. The material is highly resistant to deterioration which otherwise may result from prolonged periods of time within water. 
     The market demand is principally for flow washers having an outer diameter of 0.680 inches, which is standard in that 85-90% of the flow washers currently sold are of this dimension. 
     There is a limited demand for flow washers having O&#39;D&#39;s as low as 0.300 inches and some may go as low as 0.200 inches. The bulk, however, have O&#39;D&#39;s approximating 0.680 inches which is the dimension of the disc 5 shown herein. The axial dimensions of the disc 5 are preferably within a range of 0.095-0.150 inches. 
     The radius of the orifice 6 may and does necessarily vary, depending upon the flow volume desired. I prefer, however, to maintain the length of the fins 7 at or about 0.100 inch and the radial dimensions of their supporting annular wall 9 at the same dimension. Thus, a disc having a 0.100 radius orifice will have a 0.300 overall radius, a disc having a 0.150 inch orifice radius will have a 0.350 inch overall radius, and a disc having an orifice with a 0.200 inch radius will have an overall radius of 0.400 inches. 
     As shown, the slots 8 which are cut in the disc 5 are 0.012 inches in width. They are preferably uniform in width within a range of 0.010-0.020 inches, and extend radially as shown. The preferred width range is 0.0125 to 0.0165 inches. The slots define the fins 7 therebetween, the latter having dimensions of 0.002-0.007 at their inner free end tips and substantially wider dimensions at their base, as shown. 
     It will be noted that the radial length of the fins 7 approximates the radial dimensions of outer wall 9 as well as the radius of the orifice 6. The supporting wall 9 may be thicker but should not be lesser in radial dimensions than those of the fins. The lengths of the fins 7 are preferably within a range of 0.070-0.130 inches. 
     The slots 8 can be cut through a molded preform disc 5, made of one of the materials hereinbefore defined. The fins 7 and the slot 8 must be narrow as defined, in order to function properly. It is impossible however, to cut such slots by mechanical means because the radially deformable material from which the disc is made will flow. I have found, however, that through the use of a Laser beam, I can cut such narrow slots and define such narrow fins. It is impossible to mold such fins because the portions of the mold which would define the same will collapse at standard molding pressures. 
     It will be readily seen that at low pressures, the slots 8 remain defined, with the result that a greater volume of liquid may pass through the orifice 6 and slots 8 of the disc then could otherwise flow through only its orifice. As the pressures raise, however, the fins 7 deform and close off the slots 8 so that all of the liquid must pass through the disc orifice. As the pressure mounts, the disc deforms further to restrict the orifice itself, in the same manner as heretofore occasioned in the use of conventional flow washers. As a result of the above action, such a flow-washer produces a uniform flow volume over a wider range of pressures, as shown by the charts of FIGS. 3 and 4. This is particularly evident in the lower pressure ranges where there presently is the greatest need for improved performance. 
     Reference to FIG. 3 shows the flow volume in gallons per minute when using a flow washer commonly in use today and prior to my invention. It will be seen that at pressures of 45 p.s.i., and greater, the flow is fairly uniform at 6 gallons per minute. Below 45 p.s.i., however, the flow volume drops off markedly so that at 20 p.s.i. it permits only 5 gallons per minute and at 15 p.s.i., it permits only 4.5 gallons per minute. 
     Reference to FIG. 4 shows the flow volume of my new flow washer at such low pressures at substantially higher levels. Thus, at 20 p.s.i., there is a flow of 7 gallons per minute and at 15 p.s.i. there is a flow of 6.7 gallons per minute. At 20 p.s.i., and for all pressures thereabove, there is a uniform flow of approximately 7 gallons per minute. 
     From the above, it can be seen that I have provided a flow washer of new design and material which markedly increases the flow of liquid permitted therethrough at the lower end of the pressure level range of conventional city water sources. This is particularly important for use wherein valves are coordinated with timers to control the length of time a valve is opened, such as in washing machines, where a predetermined volume of water needed. This is also of particular value in irrigation, wherein currently efforts are being made to greatly reduce the pressures needed, to 30 p.s.i. in order to conserve energy. 
     In considering the invention, it should be remembered that the present disclosure is illustrative only and the scope of the invention should be determined by the appended claims.