GB476367A - An improved internal combustion engine with two pistons acted upon by the same impulse - Google Patents

Abstract

476,367. Two-stroke engines. RIS, A. April 23, 1937, No. 11626. Convention date, May 6, 1936. [Class 7 (ii)] In a valveless engine having two pistons acted upon by each impulse and controlling the cylinder inlet and exhaust ports, the auxiliary piston which controls the inlet port makes four unequal strokes, one of which is a driving stroke,. while the main piston which controls the exhaust port makes two strokes of equal magnitude, and the auxiliary piston at the dead centre point following the driving stroke does not expose the inlet port which is only exposed after the scavenging stroke during a succeeding stroke of greater amplitude. The crank-shaft 8 drives at twice its speed a shaft carrying a crank 15 on which is pivoted a connecting rod 14; the other end of the connecting rod 14 is pivoted to the free end 13 of a floating lever 12 carrying at its other end the auxiliary piston 7, the lever being fulcrumed about a crank 17 on a shaft driven at crank-shaft speed. In operation, as the main piston 6, plotted on the curve a, Fig. 1, descends from the position of Fig. 2, the auxiliary piston as shown by the curve b, descends rapidly to the point c in the cycle where ignition occurs. Both pistons drive the crank-shaft until the exhaust port 2 is opened by the main piston. The auxiliary piston now descends rapidly with a much longer stroke to expel the burnt charge at the point e in the cycle and, as the main piston rises, the auxiliary piston rises to its highest point at f to uncover the inlet port. The amplitude of the smaller stroke of the auxiliary piston is about half that of the stroke of the main piston.