Patent ID: 6216647
Filing Date: 2001-04-17
Classification: F02B,F02F,F05C

Abstract:
A free piston internal combustion engine, comprising:a combustion cylinder having an inside surface; anda piston reciprocally disposed within said combustion cylinder, said piston including a piston head and a plunger rod attached to said piston head, said piston head including a cap and a metallic skirt attached to said cap and interconnecting said cap with said plunger rod, said cap and said skirt being connected together in a manner such that said cap is capable of moving a limited extent in a radial direction relative to said skirt, said cap and said skirt having a first cap diameter and a first skirt diameter, respectively, at a non-operating temperature, said first cap diameter being greater than said first skirt diameter, said cap having an outside surface lying closely adjacent to and defining a bearing surface with said inside surface of said combustion cylinder, said cap consisting essentially of a non-metallic material.