GB534801A - Improvements in internal combustion engines - Google Patents

Abstract

534,801. Two-stroke engines; valves. Mc- CARTHY, J. J. Jan. 8, 1940, No. 435. [Classes 7 (ii) and 7 (vi)] In an engine having opposed pistons 16, 20 working in a cylinder 10 open at both ends to the atmosphere and having inlet and exhaust ports 11, 12 in its wall, the piston 20 works in a skirt 17 on the piston 16, exhaust ports 27 in the piston 16 register with the cylinder ports 12 when the pistons are in their outer dead-centre position, and an exhaust valve 31 in the piston 16 is opened by the abutment of the valve stem 38 against a stop formed by the face 41 of an adjustable plug 40. As shown, the skirt 17 has intake ports 18 adapted to register with the ports 11 and ports 19 adapted to register with fuel injectors 80. Air entering inlets 43 in the cylinder head 35 is caused by a baffle 48 to pass over cooling ribs 50 on the piston 16 and over the part 49 of the valve stem. The air then passes through a conduit 46 to a supercharger supplying air under pressure through. a conduit 47 to the inlet ports 11. The valve 31 and its seat 30 are made of heat-resistive material and the valve is normally held on its seat by a spring 34. The impact of the valve stem 38 on the stop 46 is cushioned by a dashpot having fluid inlet and outlet ducts 61, 62 communicating with the space above the valve stem through a check valve 72 in the plug 40 and through a port 76 controlled by the valve stem. The pistons 16, 20 are connected to opposed cranks on a crankshaft and a number of cylinders may be cast in a block.