Air cooled exhaust valve

Claim 1

A fluid cooled valve construction for an engine, said engine having a housing, said valve construction comprising: a valve having an elongated stem and an enlarged valve head connected to one end of the stem, means for axially slidably mounting said stem in said housing, a source of pressurized fluid, fluid passage means formed in the housing, said fluid passage means being fluidly connected at one end to said pressurized fluid source and fluidly connected at its other end to an annular opening around said valve stem adjacent said valve head whereby fluid flows through said opening along said valve stem and across one axial end of the valve head to thereby cool said valve, wherein a portion of said passage means is formed through said mounting means, and said mounting means further comprises an outer tubular sleeve positioned in a bore in said housing and an inner tubular member positioned within the interior of said sleeve and adapted to slidably receive the valve stem therethrough, wherein at least a portion of the outer periphery of said tubular member is spaced from the inner periphery of said sleeve to define a first portion of a fluid passageway therebetween, said first portion of said passageway being open at one end to the annular opening, and wherein said tubular member terminates short of said annular opening whereby a second portion of said passageway juts radially inwardly along said valve stem to provide a continuous flow of pressurized fluid along said valve stem and across one axial end of the valve head.