Metering unit

Claim 1

A metering valve unit comprising a sleeve member having an axially extending bore and at least one transverse bore communicating with said axially extending bore, said axially extending bore having one end adapted to be connected to a water supply conduit and said transverse bore being adapted to be connected to an outlet conduit, a valve stem being retained in said axially extending bore for slidable movement between an open position and a closed position in which a resilient seat washer seals said one end of the axially extending bore, spring means biasing said stem toward the closed position, means for manually moving the stem to the open position and regulating means for regulating movement of said stem from the open position to the closed position, said regulating means comprising an annular cup washer secured to said stem and disposed within an annular liquid-filled chamber formed between said stem and sleeve, said chamber being divided into first and second portions by said cup washer and said first and second chamber portions being interconnected by passageways within said stem, one of said passageways containing a compressible wad of porous material, whereby movement of said valve toward the open position causes said cup washer to collapse to allow liquid to move from the first portion of the chamber to the second portion whereas movement of the valve toward the closed position causes said cup washer to seal said second portion of the chamber from the first portion of the chamber and force liquid to flow from the second portion of the chamber through said passageways and said compressible wad, flow through said compressible wad regulating closing time of the valve, including adjustable means for compressing said compressible wad to thereby adjust the rate of closing of said valve and wherein said passageways communicate with a check valve which, when open, connects said passageways to said outlet whereby, if the valve expands when subjected to hot water, some liquid may escape from said chamber via said passageways and check valve to prevent seizing of the valve.