Abstract: An oscillating piston engine capable of running on a working fluid such as steam or compressed air comprises a bank of cylinders mounted for rotation in unison to turn a shaft in an engine block, pistons mounted for oscillation in the cylinders and rotatable in unison relative to the cylinders to turn another shaft in the engine block, control means operable in response to rotation of the cylinders for supplying and exhausting working fluid to and from opposite ends of the cylinders in alternating timed relation to cause the pistons to oscillate in the cylinders and pistons, and gearing means connecting the piston shaft and the cylinder shaft to an output shaft for converting the oscillating motion of the pistons and cylinders into unidirectional rotation of the output shaft.

Abstract: An oscillating piston internal combustion engine comprises a bank of combustion chambers mounted on the front of an engine block for rotation in an annular path to rotate an output shaft protruding from the rear of the block. Gearing inside the block converts oscillating motion of the pistons and cylinders into unidirectional rotation of the output shaft.