507,005. Starting prime movers. SCINTILLA. Ltd. Sept. 3. 1937, No. 24107. Convention date. Sept. 4, 1936. [Class 38 (iv)] [Also in Group XXVII] In an engine starting and current generating installation, in which a starting motor 1 drives the engine shaft 18 through toothed reduction gearing having wheels permanently in mesh. and is driven as a generator at the speed of the shaft 18 when the engine is running, a rotatable member 12 of the gearing is held stationary during starting by an electromagnetic friction brake 24, and is afterwards coupled to the shaft 18 through an electromagnetic friction clutch 20. As shown in Figs. 1 and 2, the gearing comprises pinions 9, 10 rigidly connected to each other and rotatable in a carrier 7 keyed to the armature shaft 3 of the motor 1. The pinion 9 meshes with internal teeth 11 in the rotatable drum 12, and the pinion 10 with an internally toothed gear 14 connected by an elastic coupling with the engine shaft 18. The elastic coupling comprises compression springs 38 between abutments 35, 37 on a member 17 on the hub of the gear 14 and on a housing 36 integral with the shaft 18. The friction clutch 20 is connected to the drum 12 and to the armature 23 of an electromagnet 19 by pins 21 and is normally engaged with the gear 14 by springs surrounding the pins 21. During starting, the clutch 20 is disengaged by the alteration of the electromagnet 19, and the friction brake 24 is engaged with the drum 12 by an electromagnet 26. The control circuits of the starting motor and the electromagnets 19, 26 are indicated in Fig. 7. On closing a manual switch 56, a coil 55 actuates a switch 42 to close the circuits of the electromagnets 19, 26 and of a field wind. ing 43 in series with the motor armature 4. The friction brake 24 is thus engaged and the clutch 20 disengaged, so that the engine shaft 18 is driven through the reduction gearing. When the engine starts and picks up speed, a centrifugal member 27 oxi the shaft 3 engages a ring 31, which opens a switch 58 in the circuit, of the electromagnet 26, so that the brake 24 is released and the motor runs idle. On opening the manual switch 56, the switch 42 breaks the circuits of both electromagnets and the clutch 20 is engaged by its springs ; the gearing is thus locked and the motor driven from the shaft 18 as a generator at engine speed. A switch 46 controlled by a voltage coil 47 and a current coil 48 closes as soon as sufficient voltage is generated, and opens a switch 57 preventing the coil 55 from being switched into circuit while the engine is running. In modifications, (a) the coupling electromagnet is arranged to couple the drum 12 to the wheel 14 when switched on; the switch 42 controls separate contacts in the circuits of the two electromagnets, and a separate manual switch allows the coupling electromagnet to be switched off on stopping the engine ; (b) the brake is arranged to be released when the brake electromagnet is switched on ; (c) locking of the gearing is effected by coupling the drum 12 to the shaft 3 ; (d) the housing 36 is geared by a belt to the engine shaft.