GB359710A - Improvements in and relating to starting and reversing mechanisms for internal combustion engines - Google Patents

Abstract

359,710. Starting and reversing. ROMEYN, J., 157, Rue de Fierlant, Brussels. Oct. 22, 1930, No. 31731. [Class 7 (v).] A multicylinder liquid-fuel engine is provided with a number of cam-operated starting-air valves 13 connected to corresponding check valves 20 on the cylinder heads and actuated by forward and reverse cams 8, 9 movable into active or inactive position by hand-controlled mechanism. When the mechanism is brought into a " stop " position, all the check valves are opened and the fuel pumps rendered inoperative, the check valves remaining open and the fuel pumps remaining inoperative when the starting controls are set for reversal, until the engine actually begins to run in the reverse direction, when the closing of the check valves and the starting of the fuel pumps is effected automatically. As shown in Figs. 1 and 2, the forward starting cam 8 is formed on a sleeve 5 movable axially on the cam shaft 6 by means of a lever 3 engaged by an eccentric 2 on a hand-controlled shaft 1. The reverse starting cam 9 is formed on a lever 10 pivoted on the sleeve 5 and engaging between collars 12 on the shaft 6. The shaft 1 carries a cam 25 for opening the main air valve 26 controlling the supply to the starting- valve chest 14, and a cam 30 acting through a lever 31 and plunger 33 on a valve 321, which admits compressed air through a manifold 37 and pipes 24 to act on pistons 23 on the stems of the check valves 20. The lever 31 is connected by a rod 32 to means for stopping the fuel pumps, or the air manifold 37 may be connected by a pipe 51 to a cylinder 49 in which is a piston 50 connected to such stopping means. A hand-lever 52 may also be provided for controlling the delivery of the fuel pumps. The lever 31 is also connected by a rod 38 to a slide 40 carrying a roller 39 for engagement by a cam 41 having swells 46, 47 and frictionally mounted on the sleeve 5. A fixed pin 45 engaging a slot in the cam 41 limits its angular movement on the sleeve. In the " stop " position shown in Fig. 1, the valves 32<1>, 20 are opened by the cam 30, the main air valve 26 is closed, and the starting- valve cams 8, 9 and the cam 41 are inactive. On turning the control shaft 1 to the left or right, the sleeve 5 is moved axially by the lever 3, bringing one of the starting cams 8, 9 into active position, and moving the cam swell 46, 47 out of the path of the roller 39, so that movement of the lever 31 to close the valve 32<1> and to bring the fuel supply into operation is not prevented ; and the main air valve 26 is opened by the cam 25, so that starting is effected. When ignition is effected, the valves 20 open only for a short period during expansion; on turning the shaft 1 into positions between the starting and stop positions, the main air valve 26 is closed and the pump delivery is controlled by the position of the cam 30. If the shaft I is brought into forward starting position while the engine is or has been running rearwardly, the cam swell 46 prevents the movement of the roller 39, rod 38, and lever 31, so that the check valves 20 remain open and the pumps are stopped. The main air valve 26 is opened, and the air admitted to the cylinders brakes and reverses the engine ; as soon as the cam 41 turns with the cam shaft, the swell 46 comes into a position in which it no longer prevents the pumps from operating or the check valves from closing. In a modification, the cam 41 is omitted and a shaft is driven from the cam shaft 6 through skew gears and is moved axially to a predetermined extent by the axial thrust of the gears ; the shaft carries a pair of cams, one or other of which acts on a device for preventing movement of the lever 31, when the control shaft is turned to reverse the engine, until the direction of rotation of the engine and of the cam shaft has been changed. In another modification, the lever for moving the cam sleeve 5 axially is actuated from the control shaft through pistons actuated by compressed air supplied by valves opened by an arm on the control shaft. In a further form, the starting valves are actuated by edge cams formed on the periphery of the sleeve 5 and having bevelled edges to facilitate the axial movement of the sleeve when one of the cams is in front of one of the rollers.