Patent GB-190419574-A (GB)
Title: Improvements in Electric Motor Control Systems.
Filed: 1904-09-10
Granted: 1905-08-10
Abstract: 19,574. British Thomson-siouston Co., [General Electric Co.]. Sept. 10. Motors, controlling.- A multiple-unit motorcontrol system for electrically - propelled vehicles, which may be applied to the present standard controllers, comprises a hand-operated mastercontroller electrically connected t o two electromagnets which operate, through ratchet - wheels &c., a series-parallel controller and a reversing- switch, whereby, as one of the magnets is energized and deenergized, the motor controller receives a step-by-step rotation. The equipment, which must be duplicated for other cars, is shown diagrammatically for a single car in Fig. 7, where four train-wires are used. If the master-controller C be moved to its first forward position, a circuit is closed from the trolley T through the contacts c<1>, c<4>, trainwire 2, magnet winding D, interlocking switch L, brush m<2> (which bears upon a contact M carried by the series-parallel controller B), and brush m<5> to earth X. The core D is attracted, shifting the switch N and rotating the shaft d and the lever e, which causes the pawl E, guided by the roller e<2>, to engage the ratchet-wheel F and move the controller to the first position, while at the same time the projection on the lever G engages the pin i on the lever I. which is attached to the shaft of the reversing - switch J. The switch J is in this way turned to its forward position, and the pin on the lever G rotates the loose member K so as to move away the spring - pressed lever G<1> from the member L. The switch L is so arranged that the circuit of the magnet winding D is maintained closed during the movement of the reversing-switch, and, in combination with the coil O and the contactor o, the switch L assures that the reversing-switch shall have reached its proper position before the motor circuit is closed. In the second forward position, the magnet winding D<1> is energized and rotates the sleeve d<1> on the shaft d, moving the pawl E<1> into engagement with the ratchet-wheel, and moving the controller B one more step. The reversing- switch J is unaffected by this movement, while the switch N' is moved, breaking the circuit of the winding D', the spring-pressed &c. core of which returns to the position shown, whereupon the circuit of the winding D' is again energized by the switch N'. In this manner the circuit of the winding D<1> is made and broken, notching the controller step-by-step to its various positions, until the brush leaves the contact M (which is shown developed), when the winding D<1> is de-energized, and the controller B stopped. In the third position, the coil P is energized, the bridging-memberp is raised, and the switch L is connected to earth, while in the fourth position the winding D' is again energized and the notching-up process is resumed, moving the controller through its remaining positions until, finally, the contact M leaves the brushes. Fig. 8 shows a similar arrangement, in which two trainwires only are necessary, further contacts being provided on the switch L, an additional brush m<6>, a contact M of different shape, and two additional contacts for the bridging-piece p, while one pair of stationary contacts for the switches N, N' is omitted. The first two portions of this arrangement correspond with the first two of the arrangement just described, but, in order to continue the notching-up process, the master-controller must be moved back from the position 2 to the position ] and then restored to the position 2. This allows the armature of the coil P to fall, thereby closing a circuit for the magnet winding D<1> so that the notching-up continues as in the first modification. The mechanical construction of the various parts, the functions of which have been described, is shown in Figs. 1 to 6. The core of the winding D', Fig. 4, carries a pin n<2> which engages a hole in the lever N' which carries the roller n<3> engaged by the spring-pressed member n', which gives the switch-arm N<1> a quick-break movement. The member I, Fig. 5, is secured to the shaft of the switch J, while the member K is loosely mounted on the shaft and has a projecting portion k<3> which, when the member K is rotated, engages the lever G or G', pushing it outwardly so as to prevent it from engaging the member 1. The contact M, instead nf being carried by the motor controller, is shown, in Figs. 1 and 2, as pivoted and carrying the roller M' engaging the cam M<1>, so that, when the controller B is rotated, the desired movement of the contact M is obtained. The casing of the automatic switching-devices is so shaped that it will fit upon the casing V of the standard street car equipment now in use, and, by securing the different shafts as shown, this equipment may be adapted for use in a train-control system.