Valve assembly and valve member therefor

Claim 1

A valve assembly for controlling unidirectional flow of fluid under pressure through fluid moving structures comprising: a. a seat member having a seat face and an unimpeded flow passage therethrough, said fluid flow passage having a mouth at said seat space and a guidable bore portion extending from adjacent said seat face; b. a valve seat at said passage mouth and seat space, said valve seat having a surface on a radius defining a convex curve connecting the seat face and the surface of the flow passage at said passage mouth; c. a cage member secured to the seat member and having a cage face in opposed relation to the seat face and spaced therefrom; d. said cage member having a guide bore therein extending from said cage face and aligned with said valve seat and guide portion of said flow passage, said guide bore terminating in a closed end; e. a valve member for said valve seat and having a head with a seat engaging portion of a spherical curvature, said valve head and valve seat curvatures being convex in opposite direction; f. said valve member having a guide structure extending from said valve head, said guide structure having a plurality of circumferentially spaced portions in sliding engagement with a surface defining the guide bore portion of the seat member; g. a cylindrical stem extending from said valve head in a direction opposite to said guide structure, said stem being in sliding engagement with a surface defining the guide bore of the cage member; h. a spring member in the guide bore of the cage member and having ends engaging the valve member and guide bore end to resiliently urge the valve head into seating engagement with the valve seat; i. a vent passage extending from the closed end of the guide bore of the cage member to the exterior thereof for restricted fluid flow to and from said guide bore between the valve stem and closed end thereof.