Patent GB-190417016-A (GB)
Title: Improvements in Control Systems for Electric Translating Devices, particularly adapted for use for Controlling Motors on Electrically Propelled Vehicles.
Filed: 1904-08-03
Granted: 1905-07-13
Abstract: 17,016. British Thomson-Houston Co., [General Electric Co.]. Aug. 3. Motors, controlling.-A series-parallel control system for multiple-unit electric traction embodies a master-controller and master reversing-switch and a series of electromagnetically-operated circuitclosers which by means of a shaft are arranged to close in a definite order to cut out resistance from the motor circuits automatically, and an electromagnetic device produces the paralleling of the motors. The arrangement of the apparatus for a single car with two motors is shown. If the master-controller H is moved to the position s, and the master reversing-switch RS is closed in the position n, a circuit is completed from the trolley T through the fixed contact-fingers h<1>, h, i<2>, i, train-line 4, magnet coil n', motor reversing-switch R<1>S<1>, resistance R', switch member G, magnet coil A, contact f<4>, and bridging-member f<1> to earth. The magnet coil n<1> draws the motor reversing-switch R'S' into the position shown, and the coil A is energized, its core raised, and the spring-pressed switch a<2> closed, this movement rotating the shaft J through the spring-pressed pawl a and cam a', the shaft rotating the sleeve K through the spring j or other strain-producing means. The bridging-piece of the automatic controlling-switch G, retarded by a dash-pot or other device, is raised, and traverses the stationary contacts shown. At the first contact, the coil E is substituted for a section of the resistance R' in the control circuit, causing the switches e<2>, e<3> to close, so that the motors M. M' are connected together in series with all the resistances R in circuit, the circuit of the coil r' being broken at the contact e' by the switch e<3>. The pawl e moves the cam e<1> another step, but the sleeve K can only rotate after the master-controller has been moved forward to the position s<1>, when the coil L is energized, the toothed wheel k released, and the switch member G further raised to substitute step by step for the resistance sections R' the magnet coils D, C, B which operate the switches d<2>, c<2>, b<2>, d<3>, &c., until finally the motors are directly connected in series with the mains. At the position p, the solenoid F is energized, and the piece f<1> bridges the contacts f<5>. The circuits of the coils A to E are now broken for a moment, and their switches consequently open and the shaft J returns to its 'off' position. The switch a<2> therefore opens and releases the selective device f, which is drawn upwards by a spring connecting it to the core of the coil F, and immediately the bridging-piece f<2> closes the circuit of the coil A, and the selective device f permits only the switches a<3>, a' to close. By this movement the shaft is rotated one notch, and the switch member G moved one step to energize the coil E and close the switches e<2>, e<3>, the motors now being connected in parallel and each having one half of the resistance R in series with it. When the mastercontroller is moved to its last position p<1>, all the resistance is gradually cut out of circuit. With excess current the cut-out O is operated. If the controller is turned to its extreme position at once, the above sequence of connections will ensue, parallel connection being impossible until all resistance is cut out in the series arrangement. The acceleration may be arrested by turning the controller from the position s<1> to the position s, or from the position p<1> to the position p. The direction of motion of the train may be reversed by throwing over the master reversing- switch RS.