Patent ID: 6422531
Filing Date: 2002-07-23
Classification: B60T,Y10T

Abstract:
A valve insert comprising:(a) a bushing assembly around which a plurality of annular flanges are formed with each of said annular flanges defining a groove in which an o-ring is secured and which allow said bushing assembly to fit snugly and sealingly within a suitable borehole, said bushing assembly defining (i) a longitudinal bore having an upper cavity, an intermediate cavity and a lower cavity, (ii) a vent port hole connected to said upper cavity and (iii) a first port hole connected to said lower cavity, said bushing assembly also having (iv) a lower spring seat formed circumferentially at a bottom of said upper cavity and (v) an annular valve seat formed circumferentially about said lower cavity, said annular valve seat featuring a raised inner portion tapering off at a predetermined angle to a sloped outer portion; (b) a piston assembly reciprocatable within said longitudinal bore between an open position and a closed position, said piston assembly comprising an insert piston and an annular sealing member, said insert piston having a head disposed in said upper cavity and a stem extending downwardly therefrom through said intermediate cavity, said head having an annular collar defining a groove in which a first annular seal is disposed to prevent leakage around said head, said stem deployed with a means for preventing non-longitudinal movement of said piston assembly as said piston assembly is moved longitudinally within said longitudinal bore and for preventing leakage around said intermediate cavity, said annular sealing member being secured to a bottom portion of said stem and having a flat surface for sealingly engaging said raised inner portion of said annular valve seat when said piston assembly occupies said closed position; and (c) a spring disposed around said insert piston and in compression between an underside of said annular collar and said lower spring seat, said spring for biasing said piston assembly in said longitudinal bore to one of (i) said closed position wherein said lower cavity is cutoff from a bottom area subjacent to said lower cavity and (ii) said open position wherein communication is established between said lower cavity and said bottom area.