Patent ID: 6142111
Filing Date: 2000-11-07
Classification: F01B,F02B

Abstract:
A power machine comprising:a cylinder having a bore formed therein;two pistons, each having a respective piston head and a piston rod connected thereto, said pistons being disposed in said bore with said piston heads in opposed facing relation with respect to each other with said respective piston rods extending in opposite directions and being constructed and arranged to synchronously reciprocate within said bore in opposite respective directions;a transmission mechanism for converting linear reciprocating movement of said two pistons into a rotating movement;structure defining a generally enclosed space on a piston rod side of each of said piston heads outside a range of motion of each of said piston heads; anda closing mechanism associated with each said space and constructed and arranged to close said space during at least a portion of each cycle of operation of said piston, each of said closing mechanisms comprising at least one valve for opening or closing said generally enclosed space.