GB305018A - Improvements in starting devices for internal-combustion engines - Google Patents

Abstract

305,018. Ingersoll-Rand Co., (Assignees of Rathbun, G. J.). Jan. 28, 1928, [Convention date]. Starting; reversing.-In a multi-cylinder fourstroke engine started by means of compressed air, manually controlled means are provided for rendering the admission valves inoperative at starting, while permitting normal operation of the exhaust valves, and compressed air is admitted to each cylinder at every revolution of the crank-shaft and is exhausted by means uncovered by the piston at the end of its stroke. As shown in Fig. 2 each cylinder head H has admission and exhaust valves J each actuated from an eccentric T on a half-speed shaft S through a push rod R and a rocker arm Q provided with a bearing fulcrum abutment Z. For starting, compressed air is admitted to the combustion chamber F of each cylinder in turn by a nozzle r provided with a check valve s, and the admission valves J are held closed by the admission of compressed air beneath pistons d in cylinders c. A plunger h on the piston d is normally held by a spring e in engagement with the free end of the abutment Z, which is pivoted at k and has an arm p engaged by a spring q to cause the abutment to follow the movement of the plunger h. When air is admitted beneath the piston d, the abutment swings out of the path of the rocker Q and the corresponding valve J is not opened. Exhaust of the starting air takes place normally on one instroke of the engine piston, and through a terminal port b at the beginning of the succeeding instroke. The valves and valve gear for controlling the supply of compressed air to the nozzles r and the cylinders c are shown in Figs. 4 and 5. A cam shaft w driven at engine speed carries forward and reverse starting cams 2, 3, Fig. 5, adapted to actuate valves 4, 12 through levers 5, 9 pivoted on a shaft 8 mounted on eccentric bearings in the casing v. By means of a handle 26 the shaft 8 is turned from a normal position, in which the valves are not actuated, into a forward or reverse starting position, in which one or other set of levers 5 or 9 actuates the valves 4 or 12 to admit air from a chamber 14 through chambers 20 and pipes t to the starting nozzles r of each cylinder in turn. At the same time, air is admitted through a chamber 32 or 35 and a pipe g to the cylinders c by one of the valves 30, 33, Fig. 4, actuated through levers 28, 29 by a cam 27 on the shaft 8.