GB142795A - Improvements relating to electric motors for starting internal combustion engines - Google Patents

Abstract

142,795. Bosch Akt.-Ges., R. May 5, 1919, [Convention date]. Turning-gear.-In an electric motor for starting internal-combustion engines, an automatic switch a, adapted first to supply a weak current to the motor and then to be automatically changed over to supply a full working current, is secured to a support d attached to the commutator bearing of the motor c. In the form shown, the switch u and the commutator b are enclosed by a removable cap i with an opening closed by a readily detachable cover k allowing access to the switch. The cable terminals 1, 2, 3 and contact plates 4, 5, 6 indicated in the circuit diagram, Fig. 5, are mounted upon a plate g and extension g', Fig. 1, and the leads are inserted through insulating tubes h<1> in the support d. On closing the starting-switch D, Fig. 5, current from the battery B is supplied through the coil M of the switch a to a field winding H of high resistance and to the motor armature A. The armature moves axially to bring a starter pinion into mesh with the engine fly-wheel, and a flange o on the armature shaft engages a lug p and moves the contact member t of the switch a near enough to be attracted and held by the switch magnet. The member t then bridges the contacts 4, 5, 6 and current is supplied to a low-resistance field winding E of the motor and also to an auxiliary ignition-device V and coil P.