GB372544A - Improvements relating to four-stroke-cycle internal-combustion engines - Google Patents

Abstract

372,544. Driving gear ; reversing. BONFA, A., 608, Umbilo Road, Durban, South Africa. April 27, 1931, No. 12447. [Classes 7 (ii) and 7 (v).] In four-stroke cycle engines wherein the piston drives the power shaft through gearing as described in Specification 346,592 the crank pin path describing a major hypotrochoidal curve due to rolling of pinions inside stationary internally-toothed wheels, the wheels 8, 9 are made adjustable by means of worm gear in order that the engine may be reversed ; by this means the clearance at the end 'of the exhaust stroke is made less than that at the end of the compression stroke for each direction of running. Two sets of cams-only one of which is shown -are formed on a sleeve 44 feather-keyed on a drum 11 on the main shaft; stops 43 limit the axial movement of the sleeve on the drum. The sleeve is held in one or other of its positions by a stirrup 54 held by a leaf spring 52 on the control rod 50. One or other of the spring- pressed catches 57, 58 enters a recess in the crank case to hold the stirrup, the catch being 'released by a spring-pressed lever 65 as the main shaft and drum reverse. In a modification the sleeve is made in two parts one carrying the inlet cams and the other the exhaust ; these two parts are adjustable angularly on the drum 11, their movement being limited by stops. According to the direction of rotation the two parts adjust themselves about the drum; the angular movements of the two parts are unequal.