Patent GB-475600-A (GB)
Title: Improvements in or relating to engine starters
IPC: F02N15/06
Filed: 1936-08-18
Abstract: 475,600. Connecting and disconnecting arrangements for friction gearing. GENERAL MOTORS CORPORATION. Aug. 18, 1936, Nos. 22778 and 22779. Convention dates, Dec. 5, 1935 and July 6, 1936. [Class 80 (i)] [Also in Group XXVII] An engine starter comprises a pair of driving discs 33, 34 adapted to be engaged with the opposite sides of a driven disc 35 independently of the operation of the starting motor, and independent connections between the driving discs and a shaft 30 driven from the starting-motor shaft 26, so that the pressure between each driving disc and the driven disc will be increased in response to operation of the motor and will be relieved when the engine becomes self-operative. As shown in Figs. 2 and 3, the shaft 30 is tubular, is splined at 31 on the starting-motor shaft 26 and is normally held by a spring 32 against the end of the bearing 25. The disc 33 is connected to the shaft 30 through a double screw-thread 36 and normally rests against a collar 37 on the shaft 30, but is pressed axially against the disc 35, owing to the thread 36, when the shaft 30 is driven by the starting motor. The disc 34 is the end face of a sleeve 34a connected to the shaft 30 by balls 38 occupying mating helical grooves in the sleeve and the shaft 30. External helical splines 41 on the sleeve 34a are engaged by the flange 42 of a sleeve 43 having slots 48 engaged by tongues on a disc 44 riveted on the end of the shaft 30. A flange 49 on the sleeve 43 is engaged by the bifurcated end of a lever 70 connected by a link 84 to the armature 82 of an electromagnet 75. The upper end of the lever 70 has a notch 71 urged by a spring 76 into engagement with a pin 72 on a bracket 73 on the electromagnet frame. On closing a switch 105 connecting a battery 101 to the ignition circuit 103 and to the electromagnet 104, the resulting movement of the lever 70 moves the sleeves 43 &c. bodily to the left to bring the disc 33 into engagement with the disc 35. Further movement of the lever 70 and sleeve 43 causes the sleeve 34a and disc 34 to be moved to the right by means of the helical connection 38 between the sleeves 34a, 30, rotation of the interconnected sleeves 30, 43 being prevented by the inertia due to the mass of the armature shaft 26 and parts rotatable therewith. When the disc 34 comes into contact with the disc 35, further movement of the lever 70 causes a contact 95 on an extension 85 of the armature 82 to close the circuit of the starting motor 20. The discs 33, 34 are then tightened by the helical connection 38 to transmit the drive. When the engine starts, this engagement is released. In a modification, Fig. 11, the driving discs 133, 134 each have an independent driving connection with the tubular shaft 130 splined on the armature shaft 126 of the motor. The disc 133 is fixed on a tubular hub 133a connected to the shaft 130 by a left-hand screwthread connection comprising a helical row of balls 136 held in spaced relation by a ball retainer 137 and engaging ball races in the hub 133a and in the tubular flange 130a of the shaft 130. The connection between the shaft 130 and the hub 141 of the driving disc 134 is a similar but right-hand screw-thread connection comprising a helical row of balls 138 and a ball retainer 139. Splines 144, 145 on the driving disc 134 and the hub 133a of the driving disc 133 ensure that each driving disc takes its share of the load while being pressed independently against the adjacent face of the driven disc 135. The means for moving the driving discs into engagement with the driven disc comprises a sleeve 153 engaging helical splines on the hub 141, the construction and the operation by means of a lever such as 70 being substantially the same as in Figs. 2‹and 3.