GB154705A - Improvements in or relating to fuel-injection mechanism for internal-combustion engines - Google Patents

Abstract

154,705. Bush, H. D., and Merton, H. Sept. 2, 1919. Reversing.-The invention relates to engines of the type in which cam-actuated pumps inject the fuel directly into the cylinder, and reversal is effected by injecting fuel early in the compression stroke so that ignition and combustion take place during that stroke. According to the invention, the forward and reverse cams are formed on a sleeve slidable on, but rotatable with, the cam shaft, and are each formed with two driving faces, one of which (the rear face) actuates a feedpump when the cams are set for reverse running and until the engine is reversed, after which the other face (the front face) becomes normally operative. Two other cams, one hand-controlled and one governor-controlled, regulate the stroke of the feed-pumps, and, when the hand control is operated to reverse the engine, the pumps are held out of action by a spring detent device until the speed of the engine has fallen sufficiently, whereupon a governor-controlled device releases the detent. Fig. 1 is a longitudinal section on the line 1-1, Fig. 2, and Fig. 2 is a transverse section on the line 2-2, Fig. 1, of the mechanism for a four-cylinder engine having one fuel-pump for each cylinder. The pumps 11, 12 are operated by bell-crank levers 22, 23 provided with rollers 26 adapted to contact with cams 16, 17, 18, 19 arranged in pairs on a sleeve 20 slidably adjustable on the cam shaft 15. One cam of each pair actuates two pumps when running ahead, and the second cam of the pair actuates the two pumps when running astern. The other ends 27, 28 of the bell-crank levers 22, 23 overlap and rest against a longitudinal member 45 carried by an arm 44 loosely mounted on a shaft 38. A shaft 30, vertically above the cam shaft 15 and driven by a hand-control lever 33 through gearing 32, rotates a sleeve carrying the hand-control cam 34, and also rotates a step cam 46 which rocks the reversing-lever 48 connected to the sliding camsleeve 20. The governor-control cam 35 is loosely mounted on the shaft 30 and is actuated by the governor 42 through the linkage 41, 40, 39, toothed sector 37, and pinion 36 on the cam-sleeve. Both cams 34, 35 are adapted to bear upon the member 45 and thereby to rock the bell-crank levers 22, 23 more or less away from the cams 16 - - 19. Each cam 16 - - 19 is formed with two working faces such as f, r. When the hand-control lever 33 is moved to reverse the running, the cam 34 depresses the member 45 and throws the feed pumps out of action. The member 45 is thereafter held down by a spring-actuated detent 51 until released by an arm keyed to the governoractuated shaft 38 when the speed of the engine is suffciently reduced. The rotation of the handcontrol shaft 30 also causes the cam 46 to rock the lever 48, and shift the sleeve 20 of the pumpactuating cams. If the pumps were previously driven by the front face f of one cam of each pair, the displacement of the sleeve 20 causes the pumps to be driven by the rear face R of the second member of each pair until the engine reverses, when the front face F of the second member becomes normally operative. Other means may be employed for rendering the appropriate cams 16 - - 19 operative.