GB497900A - Improvements in or relating to the control of internal combustion engines - Google Patents

Abstract

497,900. Regulating; re - admitting exhaust gases. HAPKINS, D. N. Feb. 28, 1938, No. 6280. [Classes 7 (ii) and 7 (vi)] During overrunning, the flow of mixture to the engine cylinders is prevented by an auxiliary throttle valve which is closed bv the action of the suction on a diaphragm carrying a valve which is moved to transmit the suction to a piston connected to the auxiliary throttle. A block 22 inserted between the carburetter and the intake manifold carries an auxiliary throttle valve 50 mounted on a shaft 51 connected by rods 55, 37 to a piston 32 in a cylinder 31. During overrunning with the main throttle closed, the suction in the intake manifold, transmitted through passages 70, 85, moves a diaphragm 79 carrying a valve 76 to the left to establish communication between the passage 70 and the cylinder 31 ; the suction then moves the piston 32 to shut the valve 50, and simultaneously a piston 40 connected to the piston 32 uncovers an annular groove 44 to admit exhaust gases, delivered past a filter 39, through a passage 42 containing an adjustable valve 63 into the intake manifold. When the main throttle is opened, a cam plate 102 adjustably connected to the control arm 16, opens a ball valve 99 to admit air through a passage 93 to the cylinder 91 to permit the valves 50, 40 to return to their normal positions. To prevent stalling, an orifice in the valve 50 maintains a small depression in the carburetter when the valve 50 is closed when the main throttle is opened. An auxiliary diaphragm 91 prevents leakage around the valve 76. Specification 454,615 is referred to.