Valve assembly with silencer

Claim 1

A valve assembly with a silencer installation for controlling fluid flow therethrough comprising a pair of cooperating valve plates maintained in sliding contact with each other and movable relative to each other to control fluid flow through said valve assembly, inlet aperture means an outlet aperture means defined to extend through said valve plates, said valve plates being operable to effect alignment and nonalignment of said inlet and outlet aperture means in respective ones of said plates to control fluid flow through said valve assembly, silencer means for reducing noise in the operation of said valve assembly, said silencer means comprising a flow impeding member movable between a first position in abutting contact with one of said plates and a second position spaced away from said one plate, said flow impeding member being configured to overlie at least said inlet aperture means to substantially impede fluid flow at least through said inlet aperture means when in said first position and to substantially decrease the impedance to fluid flow through said inlet aperture means when in said second position, and spring means applying a resilient force urging said flow impeding member against said one plate into said first position to impede said flow, said spring means being constructed to allow said flow impeding member to be urged away from said one plate toward said second position by fluid pressure through said inlet aperture means overcoming the resilient force of said spring means.