Patent GB-665242-A (GB)
Title: Improvements in heavy duty engine starter gearing
IPC: F02N15/06
Filed: 1949-08-02
Abstract: 665,242. Turning-gear. BENDIX A VIA. TION CORPORATION. Aug. 2, 1949 [Aug. 9, 1948], No. 20130/49. Class 7(v) In an engine starter gear including a sleeve 2 splined on the power shaft 1 and a pinion 5 slidably journalled on the power shaft for longitudinal movement into and out of mesh with a gear 7 of the engine to be started, a barrel 11, associated on the one hand with a driving slip clutch having teeth 21, 24 arranged to slip over each other when a predetermined load is exceeded and on the other hand with a dental over-running clutch, there is provided yielding means, such as spring discs 17. to compress the over-running clutch and to resist slippage of the driving clutch; the two clutches may have a common intermediate member 22 slidably journalled on the power shaft. A driven clutch member 8 is attached to the inner end of the pinion 5 whilst the barrel 11 surrounds the flange 3 of sleeve 2 and the member 8 and forms a thrust bearing for the latter. The flange 3 has lugs 13 engaging slots 14 in the barrel which slots are also engaged by lugs 16 on a driving clutch member 15 whilst initially compressed spring discs 17 are located between the flange 3 and member 15. The intermediate clutch member 22 is journalled on an inwardly extending part 23 of the pinion bushing 6 and is provided with teeth 24, 25 to engage similar teeth 21, 26 on the driving and driven clutch members, respectively. A split spring ring 27 which bears frictionally in a groove 28 in extension 23 has an inclined slot 29 formed in one end whilst a pin 30 fixed to clutch member 22 has an inwardly extending portion 31 which projects into the slot 29. In operation, a manually or otherwise operated shift fork 36 engages the pinion 5 and engine gear 7 so that rotation of power shaft 1, and hence barrel 11, is transmitted to clutch members 15 and 22 so that the latter, by means of the pin 30 and slot 29, is rotated and thereby moved axially into engagement with clutch member 8 to crank the engine. Any overload causes the teeth 21, 24 to be forced apart until it is possible for members 15 and 22 to slip. When the engine starts the members 22 and 8 separate and allow the pinion to over-run. In a modification, the discs 17 may be adjusted by a ring and a screw thread on the barrel. The pin and slot connections for moving the intermediate clutch member is replaced by straight spring-loaded guiding pins and a spring- ring friction connection between the driven and intermediate clutch members, the engaging movement of the intermediate member being entirely axial. Rotation of the intermediate member is initially resisted by the friction spring-ring and so causes the clutch comprised between the driving and intermediate members to slip and thereby effect engagement of the latter member with the driven member. In a further modification, the intermediate clutch member comprises two -parts, one part engaging the driving clutch member and having integral therewith a screw shaft whilst the other part is formed as a nut on the screw shaft so that a screw-jack action between these parts effects engagement of the intermediate and driven clutch members.