GB144220A - Improvements in electric starting devices for internal combustion engines - Google Patents

Abstract

144,220. Imray, O., (Bosch Akt.-Ges., R.). Jan. 16, 1920. Turning-gear.-In an electric starter of the kind in which an electric motor is mechanically coupled to the engine on the closing of a circuit and is automatically uncoupled when the engine starts working, the starting-circuit is interrupted or short-circuited by electrically-operated means controlled by a source of current the pressure of which is dependent on the speed of the engine, so that the starting-motor cannot be operated when the engine is running. In the arrangement shown in Fig. 1. the starting-motor c is in a circuit adapted to be closed by an electro-magnetic switch b, which is operated when an auxiliary circuit including the coil f is closed by a switch g. The auxiliary circuit includes a spring arm k carrying a contact h<2> which normally engages a fixed contact h'. When the engine is running, it drives a dynamo l, the current from which ,energizes an electro-magnet o which attracts the contact h<2> and causes a break in the auxiliary circuit. The dynamo is connected to charge the battery a through an automatic switch p which breaks the connexion when the pressure of the dynamo falls below that of the battery. In a modification, Fig. 2, the part f<2> of the coil which operates the switch b is short-circuited by the closing of an electromagnetic switch h<1>, h<2> when the magnet o is energized, the remaining part f<1> of the coil being ineffective to operate the switch b. In another modification, the auxiliary circuit includes as auxiliary field winding, which shifts the armature of the starting-motor axially to bring a pinion on the armature shaft into engagement with the engine fly-wheel. The starting-switch may be in the motor circuit instead of in an auxiliary circuit.