Self-energizing valve

Claim 1

A self-energizing pilot valve for a gas powered driving unit adapted to convert gas pressure into rectilinear motion comprising a main casing, an inlet valve body mounted in said casing; said inlet valve body defining an interconnected spool chamber and a valve chamber, spool means slidably mounted in said spool chamber and including a rearwardly projecting tip having a closed flat end surface, a pilot valve housing having a stepped end mounted in said valve chamber, said pilot valve housing defining a stepped blind bore pilot valve body chamber, and gas feed means leading to said pilot valve chamber, said gas feed means comprising a gas passageway defined by said pilot valve housing, a filter chamber defined by said pilot housing communicating with said passageway and a port defined by said pilot valve housIng leading from said filter chamber to said pilot valve chamber, an O-ring mounted on said stepped end of said pilot valve housing, said O-ring being adapted to prevent the flow of gas past the forward face of said housing and to direct the flow of gas into said gas feed means, a pilot valve body slidably mounted in said pilot valve chamber and including a stop means to engage the step of said stepped blinde bore, said pilot valve body defining a throughgoing central bore to allow gas flowing from said pilot valve chamber to pass therethrough, said pilot valve body having a raised flat annular lip end means to seat against said flat end surface of said spool means to prevent the flow of gas through said central bore and an annular channel having an O-ring seated therein to prevent the flow of gas past the exterior of said pilot valve body and spring means mounted in said blind bore pilot valve chamber, said spring means being seated in one end of said blind bore pilot valve chamber and abutting an end of said pilot valve body.