GB190605263A - Improvements in and relating to the Control of Electrically-propelled Vehicles. - Google Patents

Abstract

5263. British Thomson-Houston Co., and Hopps, B. March 3. Sparking, preventing.-In controlling electric motors for propelling vehicles, where the current is supplied by a generator driven by a petrol engine or other prime - mover carried by the vehicle, the changes of connexion from series to parallel, and other changes involving the breaking of large currents, are accompanied by cutting- down of the field strength, which is restored in the running positions. In one form of apparatus for this purpose, the driving-motors M, M' and the generator G, which may have a separate exciter E, are connected through a controller C, placed near the motors in order to obviate long lead - wires. The controller C has movable contacts on a shaft A actuated by the driver's handle L which is caused to describe a compound or zigzag movement by a slotted and notched plate P, the handle being hinged to the shaft as shown. The component motion at right-angles to the shaft A turns the controller successively to its series and parallel positions, the arrangement being preferably such that forward connexions are made by moving the handle in one direction, and reverse connexions by the contrary movement. A spring B constrains the handle, which on moving from the middle ' off ' position falls first into the series notch ps and afterwards into the parallel notch pp, or if the reverse movement is made the handle enters the reyerse notch pr. The component motion of the handle about its hinge actuates, by means of an integral extension l, a rod s linked to the switch S controlling the field resistance R, which is thus inserted into the field before each change of connexions and cut out again afterwards. The alteration of field resistance may be effected by other mechanism than that described, e.g. by means of contact-studs on the controller casing traversed by a sliding arm. The checking of the driver's lever at the respective contact positions may be effected by a pawl carried on the lever and capable of release by hand.