Patent ID: 7377249

Claim:
A gas-exchange valvetrain for controlling the flow of gas between a gas manifold and a combustion cylinder of an internal combustion engine, said valvetrain being supported by a valve train housing of the engine, comprising: a) a valve chamber in communication with said gas manifold; b) a port configured for passage of gas between said valve chamber and said combustion cylinder; c) a valve seat surrounding said port and facing away from said combustion cylinder; d) a first bore formed coaxially with said port and valve seat; e) a poppet valve head slidingly disposed in said first bore for reciprocally moving through said valve chamber into and out of mating contact with said valve seat to vary gas flow between said combustion cylinder and said valve chamber; f) an abutment disposed at an end of said first bore; g) a scissor mechanism pivotably attached at a first end to said poppet valve head and disposed between said poppet valve head and said abutment which, when said scissor mechanism is fully extended, defines a rigid linear strut for urging said poppet valve head in a direction toward said combustion cylinder into a valve-closed position against said valve seat, and when collapsed urges said poppet valve head in a direction away from said valve seat into a valve-open position; and h) an actuator mechanism for actuating said scissor mechanism.