Patent GB-459305-A (GB)
Title: Improvements in engine starting mechanism
IPC: F02N99/00
Filed: 1935-07-09
Abstract: 459,305. Turning-gear. AIR-EQUIPEMENT, 64, Avenue Edouard-Vaillant, Billancourt, Seine, France. July 9, 1935, No. 19567. Convention date, July 24, 1934. [Class 7 (v)] In a starter for aircraft engines, comprising a flywheel 2 driven through a speed-increasing gearing and adapted to be coupled to the engine to be started, the flywheel 2 is driven by a small internal - combustion engine 9 permanently associated with the engine to be started. As shown, the engine 9 is mounted on a casing 10 enclosing the gearing 3 between the starter and the engine and secured to the casing 11 of the engine to be started. The engine 9 is coupled to a member of the gearing 3 by a clutch 12 actuated manually by means of a rod 13, and is started by a crankhandle 14. When the flywheel 2 reaches a predetermined speed, a centrifugal governor 17 driven from a member of the gearing 3 acts through a rod 16, a quick-release device 15 and a rod 8 to bring into engagement a clutch 6 coupling a screwed sleeve 5 to a shaft forming part of the gearing 3. A wheel on the shaft 1 of the engine to be started is then driven from the flywheel 2 through the gearing 3 and a pinion 4 threaded on the sleeve 5. The governor-actuated rod 16 may also disengage the clutch 12 between the engine 9 and the gearing 3 by means of a quick - release device 19 acting on a shoulder 20 of the rod 13 ; and the carburetter throttle of the engine 9 may be turned to the idling or stopping position by a lever 21 actuated by a shoulder 13a on the rod 13 and connected by a link 21<a> to the throttle lever 21<b>. When the main engine starts, the pinion 4 moves axially on the threaded sleeve 5 out of mesh with the engine gear and acts through a lever 22 and linkage 23, 24 to close the throttle of the engine 9 ; or it may act through the lever 19 or 21 or the rod 16 on a switch for cutting out the ignition. If the main engine fails to start and the flywheel 2 runs down, the clutch 6 connecting the sleeve 5 to the gearing 3 is released by the governor 17, leaving the pinion 4 in mesh with the engine gear. To prevent the re-engagement of the clutch 12 so long as the pinion 4 is in mesh, coaxially mounted levers 24<a>, 24b are connected by a spring 24<c>; the lever 24a is forked to engage a stud on the link 23 and the end of the lever 24b is in the path of a shoulder 24d on the rod 13 when the pinion 4 is in mesh, and prevents the actuation of the rod 13 to engage the clutch 12. Alternatively, a similar arrangement may prevent the operation of the starting- handle 14, or the throttle of the starting engine while the pinion 4 remains in mesh. A visible indicator 52 may show when the pinion is in mesh. To enable the engine 9 to be turned backwards to bring the pinion 4 out of mesh, the starting handle 14 may be adapted as in Fig. 4 it turn the engine 9 either forwards or backwards. The hub of the handle is movable axially between springs 34, 35 to bring teeth 30, 32 into engagement, for starting the engine or to bring teeth 31, 33 into engagement for turning the engine backwards to bring the pinion 4 out of mesh. To enable the main engine to be turned by hand from the handle 14, a hand-actuated rod 15<a> connected to the quick-release device 15 can be used to effect the engagement of the clutch 6. In a modification, Fig. 2, the control of the rod 16 from the engine 9 or the flywheel 2 is effected by means of a threaded shaft 26, driven from the engine shaft or the transmission gearing through worm or other reduction gearing 25, and actuating a half nut 27 engaging a fork 28 on one arm of a bell-crank lever 29 pivoted to the rod 16, so that the clutch 6 will be brought into engagement when the engine 9 or the flywheel 2 has made a predetermined number of revolutions. The nut 27 is supported by a guide bar 36 supported by levers 37, which can be lifted by means of a Bowden cable 39 to enable a spring 38 to return the nut along the bar 36 to its initial position. In a further modification, Fig. 3, an automatic change-speed gearing is interposed between the starting engine and the flywheel. Planet wheels 47 driven by the engine shaft 42 mesh with a wheel 40 connected to the flywheel and with a wheel 41, which can be coupled by a clutch 43, 44 either to teeth 45 on the casing or to a toothed disc 46 on the shaft 42. The clutch 43, 44 is shifted by a quick-release device 48 actuated from a cam 50 on the rod 16. The teeth 43, 45 are in engagement when the flywheel is being driven from the starting engine at reduced speed, and the teeth 44, 46 are in engagement, effecting a direct coupling between the flywheel shaft and the shaft 42. when the flywheel is starting the main engine. In a further form, the governor 17 can be disconnected from the rod 16 and connected to means for the control of an electric generator drivable from the starting engine.