Patent GB-538438-A (GB)
Title: Improved power-transmitting arrangement for motor-driven vehicles
IPC: H02P9/06
Filed: 1939-04-24
Abstract: 538,438. Motor vehicles. PIEPER, H. April 24, 1939, Nos. 12322 and 12323. Convention dates, April 27, 1938 and July 20, 1938. [Classes 79 (ii), 79 (iii) and 79 (v)] [Also in Group XXXV] Power-transmitting means for motor vehicles comprise an internal combustion engine, adapted to be coupled with either of the vehicle axles, and an electric motor which is supplied with energy by the engine and is mechanically coupled to one of the vehicle axles. A buffer battery may be associated with the motor. The gear ratios between the engine and the two axles may be different, so that the engine may drive the vehicle at different speeds according to which axle is driven. A change-speed gear may be provided in the drive to either axle so that the gear ratios between the engine and the' axles may be equalized. Further, if the engine is non-. reversible the axle gears may be such that the engine, drives them in opposite directions and a reversing gear may be dispensed with. Braking may be effected by connecting the engine simultaneously to both axles. In the construction shown in Fig. 1 an internal-combustion engine 1 can drive the front axle 14 through a clutch 17 and bevel gear 16, and can drive the rear axle 7 through a clutch 6, gearing 13, the shaft M of an electric motor 3, a magnetic clutch 8, free wheel clutch 9, reversing gear 10 and bevel gearing 12. The motor 3 can be supplied with electricity either by a dynamo 2 or by a buffer battery 4. With the clutch 6 engaged and the clutches 8, 17 disengaged the engine 1 may be started by the motor 3. To start the vehicle the clutch 6 is engaged, the clutch 17 is disengaged and the reversing gear is put in forward gear (say); the engine and motor then drive the rear axle as soon as the clutch 8 is engaged automatically by a relay 25 energized when either the motor speed or the counter E.M.F. of the motor has reached a predetermined value. When the vehicle is in motion the drive may be transferred to the front axle 14 by disengaging clutch 6 and engaging clutch 17. The motor 3 may be automatically switched in and out by means depending on the accelerator pedal 22 and the motor or vehicle speed. The motor circuit is completed through moving contacts A, B, contact A being actuated by the accelerator pedal and contact B through a lost-motion device 23 by a centrifugal governor 26 driven by a shaft 5 driven by the motor. The motor circuit may include a time relay and indicating device in order to limit the period during which the motor is in use. This relay may also change the gear ratio between the engine shaft and an intermediate shaft carrying the clutches 6, 17. The motor may be permanently connected to the battery, a centrifugal regulator being provided which switches resistances into the motor exciting circuit as the speed increases. In the construction shown in Fig. 2 the engine 102 may be coupled to the front axle 106 by a magnetic clutch 108 or to the rear axle 105 by a clutch 107, these clutches being controlled by switches 136, 137. A dynamo-electric machine 109, capable of acting either as a generator or a motor, is mounted on the shaft 110 driving the front axle and is connected to a battery 104. A small charging dynamo 103 is provided connected to the battery by an automatic switch 117. The machine 109 may be shunt wound but preferably has a series winding 111 and a shunt winding 112. The series winding is controlled by an automatic switch 113 which switches in the maximum series excitation as soon as, due to the slowing down of the machine 109, the battery delivers current thereto. The shunt winding 112 of the motor is controlled by a pendulum switch 114 which cuts out resistances 115 when the vehicle is going downhill and inserts resistances when going uphill, a reversing switch 116 being placed in one or other position 116a, 116b according to the direction of travel of the vehicle. The engine throttle 126 is controlled by an hydraulic servo-motor 124 having inlet and outlet valves 120, 121 actuated by an electromagnet 118 spring-loaded at 127 and having a winding 128 in series with the motor 109 and a shunt winding 129. The two windings act in the same sense when the battery is being discharged and in opposition when it is being charged, the result being that the fuel supply to the engine is cut down when the vehicle reaches a predetermined speed. The circuits of the clutches 107, 108 are in parallel with the motor 109 and are controlled by the motor switch 132 and its resistances 133. When the motor 109 is working as a generator it is desirable to disconnect the engine 102 from the axles and to cut down its fuel supply, in order that the mechanical resistance of the engine may not consume a part of the regenerative energy. For this purpose the magnet 118, when the battery is being discharged, closes the clutch circuit through a flexible contact 138, so that when the motor 109 acts as a generator the magnet moves upwardly, breaks the clutch circuit at 138, and cuts down the fuel supply to a minimum as determined by an adjustable stop 141 in the servo-motor 124.. A plurality of engine and motor units may be employed.