GB697841A - Improvements in or relating to internal-combustion engines mounted in vehicles - Google Patents

Abstract

697,841. Starting; valves and valve-gear; cylinders. LOWE, P. A., and LOWE, B. Aug. 22, 1950 [Aug. 23, 1949], No. 21821/49. Classes 7 (ii), 7 (v) and 7 (vi) A spring-loaded valve 13 in each cylinder may be temporarily held open to allow air compressed in the cylinder during enginebraking to pass through a check valve 38 in a pipe 43 to a receiver 44, the compressed air in which can be automatically re-admitted to the engine cylinders during a stage of the piston operation which is determined by the setting of a single angularly-adjustable member. The valves 13 are opened in succession, in a multicylinder engine, by cams 33 on a manually rotatable shaft 32 and each valve stem 20 is housed in a valve-guide 27 passing through a cylinder head cooling chamber 18 and held in position by a cap 22 bolted thereto and carrying a guide member 23. The check valves 38 may, when desired, be opened and closed in timed relation with the piston strokes so that the compressed air in the receiver 44 may be used for supercharging or for starting purposes. A bellcrank lever 47, actuated by a cam 51 driven by a chain gear 53, Fig. 2, from the engine cam-shaft 54, normally idles in a slot 49 of a member 48 attached to the valve 38. The lever 47 and cams 51 are carried by a lever 55 which may be moved angularly. about the shaft 54'to bring the lever 47 into a position to cause, timed opening of the valve 38. When the engine is under heavy load, the valve 38 is brought into operation to supply compressed air to the cylinder during the compression strokes for supercharging, the valve 13 being opened by the compressed air. For starting, the input sprocket of the chain drive 53, which is helically splined to shaft 54, is moved endwise by a lever 57 which re-times the cams 51 so that the valve 38 is actuated to supply starting air to the cylinders on their working strokes. In a modification, Fig. 3, the pipes 58 leading from the valves 13 are connected to a rotary valve 61 having ports 63 which connect the pipes 58 in succession to a pipe 69 leading through a check valve 73 to the receiver 44. The valve 73 may be opened manually to allow air to be supplied to the cylinders, a sleeve 66 around the valve 61 being angularly adjustable by a lever 68 to time the valve to supply the air for supercharging or for starting. Means are preferably provided connecting the shaft 32 to a fuel control lever to shut off the fuel supply when the engine is being used for braking, and the adjusting'levers 57, Fig. 2, and 68, Fig. 3, are preferably interconnected with the shaft 32 so that they cannot be operated when the valves 13 are open during engine-braking.