Patent GB-493402-A (GB)
Title: Improvements relating to power transmission by electrical means
IPC: H02P9/00
Filed: 1937-11-09
Abstract: 493,402. Transmitting mechanical power. SEBREV SOC. D'ETUDES ET DE BREVETS. Nov. 9, 1937, No. 30771. Convention date, Sept. 25. Addition to 484,436. [Class 38 (iv)] The system described in the parent Specification is modified by dividing the motor group into at least two subgroups, each with its separate exciter regulated and reversed by an independent changeoverswitch, whereby the power available may be divided equally or unequally among the sub-groups or the motors may be adapted to act as brakes. When two sub-groups or motors are arranged on opposite sides of a vehicle, ship, &c., steering may be effected by differential driving or braking or by a combination of both. The Figure shows, in connection with a motor vehicle, only those parts of the original system which have been modified. The two subgroups, each consist of a single motor 165 and 166 associated respectively with exciters 281 and 28, having fields 173<1> and 173, reversed and regulated independently by controllers 50<1>, 50 associated with adjustable resistances 167<1>, 167. The fields 173<1> and 173 are also adjusted conjointly with the control of the prime mover, for instance the throttle of an internal-combustion engine, by resistances 10<1> and 10 which are moved by the rod 75 simultaneously with the resistance 9 in the circuit of the field of the generator exciter 27. The fields are all supplied from the battery 29, 30. The exciting fields 173<1>, 173 are also regulated by resistances 55<1>, 55 when the brake pedal is depressed. When the controllers 50<1>, 50 are in their central position, a circuit is completed through coil 59 whereby switch 25 is operated to connect the main circuit of the motors 165, 166 to a braking resistance 26. These are the conditions for starting the engine as described in the parent Specification. Accelerating.-The engine is accelerated by the accelerator pedal, not shown, and the controllers 50<1>, 50 are adjusted in the direction of the arrows for forward movement. The coil 59 is thus de-energized so that motors 165, 166 are then connected to the generator and are in series with one another. When the controllers 50<1>, 50 are moved right forward and the accelerator pedal is fully depressed for maximum power, sectors 183<1>, 183 on the switches engage contacts 39<1>, 39 while contacts 136 and 137 meet. A circuit is thus completed through coil 181 of the change over switch 169 thereby placing the motors in parallel. Any substantial increase in road resistance restores the series arrangement. Reverse running is similar but there is no provision for the high speed parallel arrangement of the motors. Braking.-When the brake pedal is depressed, lever 95 is moved to engage the righthand row of fixed contacts. Interlocking mechanism also ensures that the accelerator pedal is raised. The motors are then connected to the braking circuit including resistance 26 by switch 25 and their braking effect is regulated by the excitation of the exciting fields 173<1>, 173. Each of the fields depends upon the corresponding resistance 55<1> or 55 and 101 or 10 ; also by inversion of the controls upon resistance 167 or 167<1> of the opposite switch. By regulation of controllers 50, 50<1>, the one motor sub-group may brake while the other is accelerating, or both may accelerate or brake differentially. In a modification, each sub-group consists of two motors and the four motors may be utilized in series, in parallel or in series-parallel.