Abstract: According to the invention, the valve comprises a cylindrical body (21) in a housing (21), for receiving one end of a return spring while the end is in contact with the case. The valve also includes two ribs (22, 23) for connection to a sealing plate (25) contacting the inner surface of an annular chamber (27) above an opening (26) thereof. The annular chamber is arranged to shorten the distance between the valve and the corresponding transfer port. The air valve of the invention is for spark ignition engines, in particular two-stroke engines.

Abstract: In a two-stroke internal combustion engine with an engine block including a crankcase and a cylinder housing receiving pistons which are connected to a crankshaft by crosshead rods with crossheads guided for linear movement with the piston and a connecting rod extending between the crosshead and the crankshaft, wherein the cylinders have walls with inlet and outlet slits disposed above the bottom dead-center position of the piston and providing for communication between the cylinder and inlet and outlet channel structures formed in the cylinder housing around the pistons, the engine block consists of a cylinder housing and a crankcase joined along a dividing plane extending across the engine block below the lowest piston ring when the piston is in its bottom position and the cylinder housing includes channel structures which are open toward the dividing plane and have walls extending inwardly and have inner surfaces in engagement with the piston for guiding said piston and to form, with the piston skirt, the

Abstract: In a port-controlled two-stroke internal combustion engine with an engine block comprising a crankcase and a cylinder block including pistons connected to a crankshaft by crosshead rods with crossheads guided for linear movement with the pistons, and connecting rods extending between the crossheads and the crankshaft a partition structure is arranged between the crankcase and the cylinder block and includes hollow cylindrical sleeves which project axially into the cylinders to a point closely adjacent the undersides of the piston tops when the pistons are in their bottom dead center positions and the sleeves are spaced from the cylinder walls to form between the sleeves and the cylinder walls annular spaces for receiving the depending skirts of the pistons.

Abstract: Internal combustion engine apparatus includes a dual piston with a plurality of intake ports having reed type check valves.

Abstract: An engine driven reciprocating air compressor. The engine is operated in a through scavenge two-stroke mode. The engine has opposed pistons reciprocating in opposition in a cylinder, the pistons being rigidly connected to respective compressor pistons working in compressor cylinders. A crankshaft rotates about an axis perpendicular to and intersecting the engine cylinder axis. The piston pairs are directly coupled to the crankshaft by connecting rods. The crankshaft synchronizes the piston pairs, defines their strokes, and provides rotary motion for auxiliary devices. The connecting rods and crankshaft are lightweight and do not transmit full engine power. The piston pairs are provided with inward return energy from a flywheel on the crankshaft and air trapped in compressor cylinder clearance volumes. The inward faces of the compressor pistons may be used to compress fuel/air mixture to the scavenge pressure.