Patent ID: 6416034
Filing Date: 2002-07-09
Classification: B60T,Y10T

Abstract:
A vent 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 be incorporated within a suitable borehole, said bushing assembly defining (i) a longitudinal bore having an upper cavity, an intermediate cavity and a lower cavity and (ii) a first port hole connected to said lower cavity, said bushing assembly also having (iii) a lower spring seat formed circumferentially at a bottom of said upper cavity and (iv) an annular valve seat formed about said longitudinal bore that faces downward to a bottom area subjacent to 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 having a head disposed in said upper cavity and a stem extending downwardly therefrom through said lower 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 having a bottom portion to which an annular sealing member is secured, said annular sealing member having a flat upper surface for sealingly engaging said raised inner portion of said annular valve seat when said piston assembly occupies said closed position; (c) a means for preventing non-longitudinal movement of said piston assembly as said piston assembly is moved longitudinally within said longitudinal bore of said bushing assembly; and (d) 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 to (i) said closed position wherein said annular sealing member is pulled upward against said annular valve seat to cut off communication between said lower cavity and said bottom area and away from (ii) said open position wherein pilot pressure acting on a control surface atop said head overcomes said spring and forces said annular sealing member downward off of said annular valve seat to establish communication between said lower cavity and said bottom area.