Patent GB-190301095-A (GB)
Title: Improvements in Electric Lighting Systems.
Inventor: ELROY JAMES FINNEY MC
Filed: 1903-01-15
Granted: 1903-11-26
Abstract: 1095. McElroy, J. F. Jan. 15. Casings; dynamos, regulating ; motors, controlling. - Relates to the general construction and arrangement of apparatus for lighting when the dynamo runs at variable speeds, as in the lighting of rail way vehicles, a dynamo driven from the car axle supplying the current with the aid of storage batteries. Fig. 1 shows the arrangement for regulating the dynamo A. a, b are the mains, B the storage battery, L the lamps, and F the reversing-switch. A resistance Ris placed in the shunt field, and varied by an arm K moved by a motor M. The motor is started or reversed by the switch G, which is controlled by a solenoid C acting on a core c. The solenoid is in a shunt circuit, and the motor is started when the potential varies. The reversing-switch F, for maintaining the direction of the current constant when the direction of the car is reversed, is shown in detail in Figs. 3 and 4. The dynamo casing 0 is extended, and contains a switch and operating- mechanism. The armature shaft H carries a flanged disc S fitted with a spring pawl S<2> adapted to take in a notch in a disc T<1>. The disc T' has a limited rotary movement, a pin 22 on it working in a slot in a fixed disc T<2> which disc is formed with a cam surface for lifting the pawl S<2> out of the notch when the disc T' has moved sufficiently. The pin 22 is connected by the rod R<3> to the switch, and the starting of the armature shaft throws the switch into the proper position. The current in the dynamo field magnet is maintained in the same direction by taking it from the mains at points outside of the reversing-switch. When the armature shaft rotates at high speed, the pawl S<2> is prevented from rubbing on the cam disc T<2> by the centrifugal action. An automatic switch for connecting or disconnecting the dynamo with the circuit when the potential has reached the limits is provided. Instead of fitting a dynamo on each car, a single dynamo on the locomotive may be employed, with a storage battery and regulator on each car. In cars such as sleeping cars, where it is desired to cut out the lamps in groups, special regulators are employed, such as is partly shown in Fig. 6. L', L<2> are two groups of lamps. The potential magnet C has two windings, and controls the automatic connection switch D by mechanism not shown, and also the contacts Y', Y<2>, Y<3>, Y<4> for starting or reversing the motor M, operated by the battery, which operates the regulating switch arm K and cuts in or out the resistances R' in the lamp circuits and the resistance R' in the field-magnet circuit of the dynamo A. The contacts are arranged so as to prevent the continued flow of battery current through the motor M after the arm K is turnel 'off.' A centrifugal governor M<3> controls the speed of the motor by breaking circuit when the speed is excessive. A cam W<2> on the switch spindle serves to operate the arm K<6> and put additional tension in the spring Q<1>, so as to alter automatically the regulating effect when the dynamo is running or stopped.. A set of lamps L<3>, such as vestibule lamps, may be arranged in shunt of the switch D, and light up when the train stops, say at a station, the battery then discharging through the dynamo armature. The connections are arranged to maintain a current from the battery through the armature when the dynamo is at rest.