Patent GB-190319172-A (GB)
Title: Improvements in Apparatus for Controlling the Working of Electrically Driven Cars.
Filed: 1903-09-05
Granted: 1904-09-01
Abstract: 19,172. Siemens Bros. & Co., and Lydall, F. Sept. 5. Motors, controlling. - Relates to apparatus for controlling electrically-driven vehicles or a train of such vehicles, and consists chiefly of the provision o n each vehicle of an automatic regulating-switch R, Fig. 1, which causes a gradual variation of the resistances in the motor circuits and thus prevents too sudden changes in acceleration and excessive currents on the line and in the motors. The automatic regulating-switch is worked by a pilot motor P having two opposing fields B, W, of which B is a shunt winding regulated by the mastercontroller M and a rheostat A, and the other W a series winding in the main motor circuit. As long as the field B is stronger than the field W, the pilot motor tends to reduce the regulating- resistance and to equalize the fields B, W. If the motor current becomes too strong, the field W causes the pilot motor P to reverse and to increase the regulating-resistance. Fig. 1 shows the mastercontroller M and its circuits together with the auxiliary circuits on one vehicle for operating the motor switches on that vehicle, and Fig. 2 the arrangement of the motor circuits and switches on one vehicle. A subsidiary controller H, Fig. 1, on each vehicle is operated by the pilot motor P together with the regulating-switch R, and is arranged to control the circuits through the actuating-coils of the switches p, p<1>, r, s, Fig. 2. The pilot motor P drives the regulating-switch R and controller H through a worm and worm-wheel P' and a magnetic clutch P', G, which is put in action by a coil D in series with the motor P, a spring D' being arranged to bring the switch back to the 'off ' position whenever the current fails. The switch R has two sets of resistances R', R', Fig. 2, and two brush arms b<1>, b<2> connected to semicircular contacts working against brushes S', S'. An ordinary reversing-switch K, Fig. 1, for reversing the motors A', A' is operated by magnet coils l<1>. l<2> in the controlling-circuit of the mastercontroller M, and is fitted with additional contacts k<1>, k<2>, k<3>, h<4> for making connections with the controller H and the magnet coil of the main circuitclosing switch t on each vehicle. The mastercontroller M is small, and has only five positions, corresponding to ' off,' 'forward series,' for- 'ward parallel,' 'reverse series,' and 'reverse ' parallel.' In the forward series' position, the current passes from the + lead and cut-out L<1>, through the coil and contact k<1> to the cut-off L' and-lead, thus operating the reversing-switch K. The current then passes from the coil l<1>, through the contacts k<2>, k<3>, coil of the switch t, controller H, coil r, and master-controller to the - lead, a derived circuit through the adjustable resistance A and field coil B receiving current at the same time. The switches t, r, Fig. 2, being now closed, and the switches p, P<1>, s being open, the current passes through the opposing field coil W of the pilot motor, motor cut-out c<1>, reverser contacts m, motor field F<1>, cut-out c', resistance R', switch r, resistance R', cut-out c<3>, field F', reverser contacts n, motor armature A', reverser contacts o, and cut-out c<2> to the cut-out L' and - lead, a derived current passing at the same time through the coil D, Fig. 1, and pilot motor P. The pilot motor P then gradually turns the brush arms b<1>, b', Fig. 2, through 180‹, end reduces the resistances R', R', Fig. 2, to nil. The controller H being turned through 180‹ at the same time, the switch s is closed, and the switch r opened. A stop E, Fig. 1, arrests the contact-arm b<1>, b<2> in this halfway position. If the master-controller is now advanced to the ' forward parallel ' position, the current passing through the coil S, which formerly passed to the - lead through the master-controller, is diverted through a coil which withdraws the stop E, and the controller H, continuing to move, opens the switch s and closes the switches p, p<1>. The motors A<1>, A<2>, together with their respective resistances R', R', are now connected up in parallel, and the pilot motor proceeds to reduce the resistances again to nil, the brush arms b<1>, b<2> being again arrested by the stop E after another 180‹ turn. When the master controller is turned to the 'off' position, the switches t, p, p<1> are opened if the motors are in parallel, and the switches t, s if in series, and, in either case, the coil D being de-energized, the spring D<1> returns the controller H and the brush arms b<1>, b<2> to their initial position. Auxiliary contacts c<3>, c<4> on the cut-outs c', c' are arranged to short-circuit the coil of the stop E when either motor is cut out, thus preventing the switch R from moving beyond the series position.