Patent GB-190504529-A (GB)
Title: Improvements in the Control of the Electro-motors on Electric Railway Cars.
Inventor: LYDALL FRANCIS
Filed: 1905-03-04
Granted: 1905-09-07
Abstract: 4529. Lydall, F. March 4. Switches. - Relates to a master-control system for electric trains driven by alternating-current motors, in which a variable-ratio transformer, as described in Specification No. 23,398, A.D. 1901, in combination with an induction regulator and switches as described in Specification No. 1874, A.D. 1905, is used to regulate the voltage supplied to the motors. The improvements relate to apparatus for automatically operating the switches k<1>, k<2>, . . . k<9>, Fig. 1, and consist essentially of a pneumatic motor PM, Fig. 2, geared through the induction regulator IR to a barrel or the like B, on which are projections which operate the valves of the pneumatic cylinders in which the contactbars k<1>, k<2>, . . . k<9>, Figs. 2 and 3, move, the pneumatic motor being controlled by valves v<1>, v<2>, v<3>, v<4>, Fig. 4, operated by electro-magnets m<1>, m<2>, m<3>, m<4>, Figs. 1 and 4, which respectively open the valves for forward running, reverse the motion, govern the supply of air, and return the. barrel B to its ' off ' position. When the master-controller MC, Fig. 1, is operated, the contact-bar k<1> being in its raised position, the electro-magnets m<3>, m<5> are energized, thereby closing the switch CB and holding the valve v<3>, Fig. 4, in the position shown. The circuit through the train-wire. l<3>, switches k<3>, k<4>, . . . k<9>, and electro-magnets m<1>, m<4>. is then completed, and the valves v<2>, v<1> lowered from the positions shown in Fig. 4, and compressed air thus admitted through the valve v<4> to the cylinder z<1>. The pistons q<1>, q<2> are lowered, thereby setting the pneumatic motor for forward motion and admitting the compressed air to the motor through the centrifugal-governor throttle valve CG, which limits the speed of the motor. The barrel B, Fig. 2, turns and successively raises the contact-bars k<2>, k<3>. Directly the contact-bar k<3> rises, the circuit of the electro-magnet m<4> is broken, thereby closing the valve v<4> and stopping the motor. Further movement of the master-controller brings about the successive operation of the switches k<4>, k<5>, . . . k<9>, thereby impressing a graduallyincreasing voltage on the electric motors, which are connected through the leads X, Y, Z to the secondary S of the variable-ratio transformer asshown in Fig. 1. In the movement of the mastercontroller in the reverse direction, similar movements take plane, the electro-magnet m<2> being' energized and the valves v<1>, v<2> moved into the position shown in Fig. 4. The action of the induction regulator IR, whereby the voltage impressed on the electric motors is increased or decreased without opening or short-circuiting the intermediate convolutions of the secondary S of the transformer, is described in Specification No. 1874, A.D. 1905. When the master-controller is moved to its ' off ' position, the magnet m<3> becoming deenergized, the spring s<3>, Fig. 4, moves the valve v<3> to the right, so that compressed air passes through the valve V to the cylinder z<2> after depressing the valves v<2>, v<1>, and thence to the motor, which rotates until the barrel B reaches its ' off ' position, when the valve v closes.