Abstract: A pressure fluid driven piston and cylinder engine capable of providing high torque output at any engine speed for direct connection to a vehicle or machine to be driven. The engine may be used for any purpose, but is especially advantageous for powering an automotive vehicle. The engine does not require a transmission due to its ability to provide, in itself, a high torque at any engine speed and the ability to provide forward and reverse drive and neutral and park functions. The engine has at least a pair of piston and cylinder power units with pistons which move in an opposing manner to transmit power from elongate gear racks, respectively, on the piston rods to an outer pinion gear portion of respective conventional roller clutches. The roller clutches, in turn, change the reciprocating movement of the power units into unidirectional rotation of the drive shaft. Constant leverage is exerted by the pistons on the drive shaft throughout their power strokes by use of this gear and rack arrangement.

Abstract: A piston-cylinder device, such as a Rankine cycle engine, is provided with one or more variable displacement cylinders and variable stroke pistons for accommodating loads of variable torque. Cylinder displacement is varied by a movable cylinder head internally of the cylinder and auxiliary to a fixed cylinder head, and piston stroke is varied by a variably fulcrumed lever linking piston connecting rods with a crankshaft. For the engine particularly, load torques are continually sensed and cylinder displacement adjusted accordingly. In turn, the position of the movable cylinder head is continually sensed, and the lever fulcrum adjusted accordingly.