GB472442A - Improvements in or relating to the starting of internal combustion engines - Google Patents

Abstract

472,442. Starting compression-ignition engines. INTERNATIONAL HARVESTER CO. OF GREAT BRITAIN, Ltd. (International Harvester Co.) July 24, 1936, No. 20559. [Classes 7 (ii) and 7 (v)] In an engine arranged to operate either at low compression on a volatile mixture with spark ignition, or at high compression on a non-volatile fuel with airless injection and compression ignition, a change-over device is actuated to alter the operation from the lowcompression cycle to the compression-ignition cycle upon the engine attaining a predetermined speed or temperature. A change-over device actuated in dependence on temperature includes a shaft 13, Figs. 3 and 5, connected by a lever 36 and link 35 to the shaft 33 of a valve operable to supply the inlet conduit 38 with air only or with mixture from a carburetter 331. The shaft 13 is also connected through worm gearing 21, 22 to a shaft 23 carrying cams 24 each operative through a floating lever 25 to open a valve 28 between an engine cylinder 29 and a supplementary chamber 30 fitted with a sparking plug 32 for ignition of the starting mixture. At starting, the shaft 13 is turned by means of a handle 15 into the position in which a catch 19 engages in a notch in a lever 20 pivoted on a bracket 17. The lever 20 is held by a spring 50 in engagement with a hook 48 on a lever 46 pivotally connected to the rod 44 of a heat-responsive device 41 in a pocket 42 adjacent to the opening 40 of the precombustion chamber 39. When a sufficient temperature is reached, the hook 48 releases the lever 20, which is moved by the spring 50 to free the catch 19 and allows the change-over shaft 13 to be moved by a spring 16 to bring the valves 28, 33 to the position for normal running with compression ignition. In a modification, Figs. 1, 2 and 4, in which the change-over device is dependent on engine speed as well as temperature, a rod 89 is slidable through the lever 20, which it engages by means of an adjustable nut 90 and a compression spring 103. Pivoted upon the lower end of the rod 89 is an extension 92 normally held by a spring 100 out of line with a tappet 87 reciprocated by a cam 86 driven through worm gearing 84, 83, 81, 80 from an engine-driven shaft 52 provided with cams 54 for actuating the fuel pumps 55. A governor 64 on the cam-shaft 52 controls the fuel pumps by varying the time of opening of a byepass valve 59, which is operated by a lever arm 60 rotatable on an eccentric 61 on a governor shaft 62, adjustment of the shaft 62 is effected by a bellcrank lever 76, Fig. 4, actuated from the governor 64 through a sleeve 71 and having an arm 78 provided with gear teeth engaging a bevel gear 79 on the shaft 62. When a sufficient speed is reached, a cam 95 on the shaft 62, acting through a shaft 93 and a tappet member 96, moves the extension 92 into line with the tappet 87. The rod 89 is then lifted by the cam 86, releasing the lever 20 if and when it is freed by the temperature-controlled hook 48. The temperature control may be omitted, the change-over device being actuated in. dependence only upon engine speed.