GB377368A - An improved method of and means for starting internal combustion engines - Google Patents

Abstract

377,368. Starting ; turning - gear. JUNKERS, H., 21, Kaiserplatz, Dessau, Anhalt, Germany. June 4, 1931, No. 16307. [Class 7 (v).] To assist an engine over compression points when it is being turned by a starting-device or by the admission of compressed air to the engine cylinders, additional energy is furnished intermittently to the engine shaft from an elastic member such as a spring or a compressed-gas cushion. In one form, Fig. 7, an engine 20 is provided with an electric starter 25, and the engine shaft 21 is connected at starting by a clutch 27 to a crank shaft 1 connected to a piston 14 acting upon a spring 16 in a cylinder 15. The spring 16 is compressed during the outstroke of the engine piston and returns the energy thus stored to the engine shaft on the compression stroke. For a singlecylinder four-stroke engine, the crank shaft 1 is driven through gearing at twice the speed of the engine shaft. In a modification, Fig. 12, a cam 2 on the engine-driven shaft 1 engages a roller 3 on.the rod of a piston 4, which compresses air in a cylinder 5 and is returned by the air pressure when the engine piston 52 is on the compression stroke. Compressed air is admitted to the cylinder 5 by a cock 8 and pipe 75 from a starting-air receiver 60 ; when starting has been effected, the air in the cylinder 6 is allowed to escape through an outlet 9 by turning the cock 8. For multi-cylinder engines, the cam 2 has two or more swells, or is mounted on a shaft driven at reduced speed from the engine shaft. Starting-air is supplied from the receiver 60 to the engine cylinder through valves 62, 67 actuated by slidable cams 64, 68 on the engine crank shaft 53. The spindle 63 of the valve 62 has a bore 71 which connects the pipe 66 to the atmosphere when the valve 62 is closed. At the beginning of the outstroke of the engine piston 52, the valves 62, 67 admit compressed air to the engine cylinder ; the valves 62, 67 then close and the air expands in the cylinder, while the piston 4 compresses air in the cylinder 5. On the return stroke of the engine piston, the valve 67 is opened and the air in the engine cylinder is exhausted through the pipe 66 and bore 71, the piston 4 exerting a drive on the shaft 53. In another form, Fig. 13, starting-air is admitted to the cylinder 51 by a valve 80 and exhausted through the hollow spindle 81 of the valve 80 by a valve 82, the stem of which is provided with a piston 84 co-operating with outlet ports 87 in the spindle 81. Springs 88, 89 are provided and the valves are actuated by a cam 91 through a lever 92 pivoted at 93 on a lever 95 movable to put the valves into or out of use. The starting cycle is similar to that described for Fig. 12.