Atmospheric closure mechanism

Claim 1

An atmospheric pressure actuable valve closure apparatus for closing a partially evacuated conduit, comprising a housing having a fluid passageway therethrough including inlet and outlet ports and a closure passageway angularly intersecting said fluid passageway including an open ended closure member chamber at one side of said fluid passageway and an impact chamber at least partially disposed at the other side of said fluid passageway; flange means adjacent said inlet and outlet ports for mating with a said conduit; an impact absorbing cushion in said impact chamber; a closure member in said closure member chamber movable toward said cushion to a closed position blocking said fluid passageway; a mounting plate secured to said housing extending across the open end of said closure member chamber having apertures therethrough for communicating ambient pressure to said closure member chamber; a shaft secured to said closure member extending through one of said apertures; a retaining pin adjacent said shaft for normally retaining said shaft and closure member in an initial open position; electrically actuable, explosive means for moving said retaining pin to release said shaft; latch means adjacent said shaft for locking said shaft and closure member in a closed position responsive to movement of said closure member to said closed position; and sealing means for impeding fluid passage between said partially evacuated conduit and said closure member chamber.