SUMMARY OF THE INVENTION

The present invention relates to a flush valve of the type used in commercial washrooms and in particular to an improved flexible diaphragm assembly for use in such a flush valve.

A primary purpose of the invention is a flush valve of the type described which has an improved diaphragm assembly, substantially reducing the number of components within the flush valve, thereby reducing piece-part costs, labor assembly costs and inventory costs.

Another purpose is a reliably operable flexible diaphragm assembly of the type described in which all of the parts are formed of a suitable plastic.

Other purposes will appear in the ensuing specification, drawing and claims .

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is illustrated diagrammatically in the attached drawing illustrating a preferred embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention is assigned to the assignee of U.S. Pat. No. 4,327,891, Sloan Valve Company, of Franklin Park, Ill., which manufactures and sells flush valves for use in commercial washrooms of several types, including those sold under the trademarks ROYAL and CROWN. The '891 patent shows a flush valve of the type sold under the trademark ROYAL and the present invention is specifically directed to a diaphragm assembly which may be usable in the flush valve of the '891 patent. The diaphragm assembly is substantially improved over that shown in the prior art, particularly in reducing the number of parts, and in forming the diaphragm assembly out of parts which may be easily molded from one of the new generation of plastics, specifically a plastic sold by DuPont under the trademark HYTREL.

In the drawing, the flush valve has a generally hollow body 10 which includes an inlet connection 12, an outlet connection 14 and a handle coupling connection 16. The top of the valve body is closed by an outer cover 18 and an inner cover 20. The inlet portion of the valve is separated from the outlet portion by a valve seat 22 formed at the termination of an inwardly-extending annular body flange 24.

The valve is actuated by an operating handle 26 which is fastened to the valve body 10 by means of coupling nut 28. The handle is connected to a plunger 30 which extends into the interior of the valve body. Plunger 30 is guided and supported by a bushing 32 and restored by a spring 34. A rubber sealing cap or grommet 36 is snapped on the end of bushing 32 and prevents leakage outward from the handle opening.

Positioned within the flush valve body 10 is a diaphragm assembly indicated generally at 37 which includes an annular flexible diaphragm 38, having an enlarged portion 40 at its periphery which is fixed to the flush valve body between inner cover 20 and an annular shoulder on the flush valve body. Diaphragm 38 may have one or more reinforcing rings 42 positioned intermediate the central area of the diaphragm and the enlarged portion 40. Reinforcing rings 42 may extend axially from both sides of diaphragm 38.

Integral with diaphragm 38 and a part of the diaphragm assembly 36 is a barrel 44 which is integrally molded to the diaphragm as at 46. The diaphragm and inner cover 20 define an upper chamber 48. There is a bypass orifice 50 in the wall of barrel 44 directly adjacent diaphragm 38 and a seal ring 52 extends about the barrel in a groove 54, with the seal ring in part masking the bypass orifice, but permitting the passage of water therethrough.

Barrel 44 has a portion 56 of reduced inner and outer diameter. On the inside of the barrel there is a relief valve seat 58 formed at the end of the portion of reduced diameter and on the exterior of the barrel there is similarly positioned a small groove 60 which contains a seal ring 62 which closes upon valve body seat 22 when the flush valve is in the closed position of the drawing. The barrel may have a plurality of axially-extending flow control slots 64, if desired.

Positioned within barrel 44 is a relief valve 66 which has a stem 68 positioned for contact by plunger 30. The enlarged body 70 of the relief valve has an outwardly-extending flexible lip 72 which is in sealing engagement with the interior of the barrel. Spaced from lip 72 is a second outwardly-extending lip 74 which has a lower surface thereof positioned upon barrel relief valve set 58 when the flush valve is in the closed position of the drawing.

The operation of the flush valve is as follows:

The drawing illustrates the closed position. Water from inlet 12 will normally seep through bypass orifice 50 into upper chamber 48 above the relief valve. Since the surface area subjected to inlet water pressure is greater on the upper side of the diaphragm than on the lower side, water pressure holds the diaphragm on valve seat 22 and water pressure also holds the relief valve on barrel relief valve seat 58. When a user pivots handle 26 in any direction, plunger 30 moves inwardly, tilting stem 68, which has the effect of unseating the relief valve from barrel seat 58 and, at least in part, moving annular sealing lip 72 away from the interior surface of barrel 44. This relieves the pressure in upper chamber 48 and causes the diaphragm assembly consisting of the diaphragm, barrel and relief valve to raise up, thereby creating a direct connection between inlet 12 and outlet 14.

When the diaphragm assembly so moves, relief valve 66 will again close on relief valve seat 58, closing off the upper chamber. Water seeping through orifice 50 will, in time, cause the diaphragm assembly to return to the closed position of the drawing. This provides a measured volume of water for flushing a toilet or urinal.

Even if handle 26 should be held in an operable position, the diaphragm assembly will still close upon body valve seat 22. The holding open of the handle assembly will maintain the position of plunger 30 beneath valve stem 68, but there will still be a seal between the exterior of the relief valve and the interior of the barrel because annular lip 72 will always bear against the interior of the barrel, except at that instant when the relief valve is unseated at initial operation of the flush valve.

Preferably, the diaphragm and barrel, as well as the relief valve, are formed of a suitable plastic and the plastic HYTREL manufactured by DuPont has been found to be satisfactory, although the invention should not be limited to any particular plastic. By forming the barrel and diaphragm as a single unit, there is a substantial reduction in the number of parts of the diaphragm assembly, when compared with the flush valve shown in the above-mentioned '891 patent. The same is true of the relief valve. The savings brought about by a reduced number of parts is substantial. Less parts must be manufactured, there is a substantially reduced time for assembly and a substantial reduction in the number of parts which must be inventoried for repair, all leading to flush valve equally efficient in operation with flush valves in the prior art, but vastly less expensive to manufacture.

The use of plastic components provides a flush valve in which the internal parts thereof will have a substantially extended life, when contrasted with prior art flush valves having a number of metal fittings.

Although the invention shows a single stress control ring molded into the diaphragm, there may be more than one such ring, and those portions of the ring extending away from the diaphragm on opposite sides thereof, instead of being aligned, could be offset.

Whereas the preferred form of the invention has been shown and described herein, it should be realized that there may be many modifications, substitutions and alterations thereto.