Patent ID: 6948513
Filing Date: 2005-09-27
Classification: B60S,F16K,Y10T

Abstract:
1. A check valve for use in a section of a liquid flow pipe to control the flow of a liquid through said pipe, wherein said section having inlet and outlet ends with each having an opening through which liquid respectively enters and exits said section, said check valve comprising: a compression spring having upstream and downstream ends, wherein said spring configured so as to allow said downstream end to press against a portion of said section outlet end, a piston having bottom, top and outer side surfaces, said piston having a cavity that extends from said top surface and is configured to allow said spring to sit and be compressed longitudinally within said cavity with said spring upstream end resting on a portion of the bottom surface of said cavity, said piston having an opening in said side surface that connects said cavity and said outer side surface, said piston bottom surface having a sealing surface protecting outwardly therefrom with an outer boundary that is configured so as to allow said boundary to enclose said opening in said section inlet end, whereby when said piston bottom surface is pressed against said section inlet end by the action of said spring, said sealing surface seals the area around the opening of said inlet end so as to prevent liquid from flowing through said opening, wherein said piston being made from an elastomeric material so as to give said piston sealing surface the elastic properties necessary to allow said piston bottom surface to act as a seal for said inlet opening, and wherein said sealing surface is not a separate member that is inserted into said check valve.