Patent GB-572702-A (GB)
Title: Improvements in starters for internal-combustion engines
IPC: F02N13/00
Filed: 1941-03-19
Abstract: 572,702. Turning - gear. COSTA, H. DA, and PLESSEY CO., Ltd. March 19, 1941, No. 3781. [Classes 7 (iii) and 7 (v)] An engine starter comprises an auxiliary internal-combustion engine 10 for turning the engine to be started through a reduction gear train and a cartridge-operated device 30 for starting the auxiliary engine. As shown, the shaft 12 of the engine 10 carries a flywheel 19 and is geared through a change-speed gear 21 ... 24, gearing 35, 36, a friction clutch 38, and planetary gearing 40 ... 45 to a dog clutch 50 engageable with the engine to be started. The changespeed gear comprises pinions 21, 22 slidable on a splined sleeve 20 for alternative engagement with pinions 23, 24 on a lay shaft 25 carrying a pinion 35 which meshes with an internally toothed wheel 36 on a driven shaft 37. The clutch 38 couples the shaft 37 to a sleeve 39 integral with a sun pinion 40 meshing with planet wheel 41 on a carrier 42 integral with a second sun pinion 43 ; this meshes with planet wheels 44 on a carrier 45, and both sets of planet wheels mesh with fixed internally toothed rings 46, 47. The carrier 45 has a tubular extension with spaced inclined ramps 48 engaging with teeth 49 on the inner end of the dog clutch 50, so that initial rotation of the i carrier 45 engages the clutch 50 with the engine to be started ; the clutch 50 is then driven through abutments 52 on the ramps 48. The cartridge-operated device consists of a cylinder 30 and a piston 31 connected to a crank 32 rotatable on the layshaft 25 and coupled to the shaft 12 through a free-wheel device within a gear 33'meshing with a gear 34 formed on the shaft 12. The cylinder 30 is connected by a pipe 53 to a cartridge-firing chamber, which may have an automatic feeding and firing mechanism such as that described in Specification 513,179 or 562,807, [Group XXI]. The auxiliary engine may be provided with a floatless carburetter 55, Fig. 3, the air supply to which is initially strangled by a valve 58 afterwards opened by the action of crank-case pressure through a bleed passage 67 on a piston 62 ; a control valve 65 is interposed between a non-return valve 66 and the passage 64 to the crank case 17. A single switch or control member may be arranged to close a relief valve 68 on the crank case, to switch on the ignition and open a fuel valve for the auxiliary engine, and to operate the cartridge feeding and firing mechanism; the control may be mechanical, electric, hydraulic or pneumatic. Firing of a cartridge causes the piston 31 to turn the shaft 12 through the free-wheel and gearing 33, 34, and when the engine 10 is thus started it is effective to start the main engine through the change-speed gear 21 ... 24, lay shaft 25, gear train 35 ... 47 and dog clutch 50. In a modification, Fig. 4, the flywheel 19 on shaft 12 of the auxiliary engine is allowed to reach an appreciable speed before the load is applied. Pins 84 on the flywheel engage in slots 85 in centrifugal clutch plates 81 normally retracted by springs, and driving through frictional engagement with the flange 83 of a disc 80 connected by a dog clutch 86, 87 to a sleeve 20 carrying the gears 21, 22, the sleeve 20 being movable axially to change the gear ratio. The clutch 81 may be hydraulic instead of centrifugal.