Patent GB-190309496-A (GB)
Title: Improvements in the Generation, Distribution, and Control of Electric Currents and in Mechanism connected therewith, the Invention being particularly applicable to Train Lighting and like purposes.
Inventor: JUSTICE PHILIP MIDDLETON
Filed: 1903-04-27
Granted: 1903-06-11
Abstract: 9496. Justice, P. M., [Electric Car Lighting Co.]. April 27. Dynamos, driving; dynamos, regulating.-Relates to the generation, distribution, and control of current, particularly for use in train lighting and the like, where the generator is driven from a source of variable speed, such as the car axle, and secondary batteries supply current when the car is not running or running at a low speed. The generator is maintained at a substantiallyconstant speed, the transmission gear from the axle being varied by the agency of a medium such as oil controlled by suitable electrical devices connected in the circuit. In addition, regulating-resistances are included in the circuit and controlled by electromagnets. Fig. 2 shows the general arrangement. The generator a is driven from the car axle through the transmission gear b, the relative speed being controlled by admitting oil into the cylinder C. The oil pressure is maintained by a pump d driven by a motor g supplied with current from the circuit, and a valve m, governing the flow of oil, is controlled by a special arrangement of solenoids and cores more particularly shown in Fig. 3. The coil p is in shunt across the storage battery, the coil r in series with the lamps &c., and the coil s, which is wound in the opposite direction to the coils p, r, in series with the battery. The generator a is connected at the common point of the coils r, s, and the coils therefore operate the valve m so as to reduce the relative speed of the generator should the potential rise, or increase it should the potential fall. The oil tank f, Fig. 2, supplies the pump d, and receives oil returned by the controlling-valves. At z is a differentially-wound electromagnet for operating the switch y for connecting up the generator when its speed is sufficient to give the desired potential. A regulating-switch 2 is included in the circuit, and is controlled by the shunt solenoid 3, the core of which operates a valve 5 to admit oil to the cylinder as shown. The speed-regulating solenoids, Fig. 3, are fitted with two cores o, t adjusted in position by a spring and counterweight. To reduce the speed of the generator when the battery is fully charged and there is no demand for lighting-current, the upper core t is dropped by the action of the coil v in series with the lamp circuit and the coil x in series with the generator, and thus supplements the action of the core o. The pump d for pumping the oil to the pressure cylinder is driven by a motor g, the current for which is made or broken at the switch h. The switch h is closed to start the motor when the pressure falls below a limit, and is opened when the pressure rises. The variable-speed transmission gear is shown in Figs. 12 and 14. The axle 11 carries a cross-arm 12 attached by links 13 and ball or other universal joints 14 to a loose ring 15, which is attached by links 16 to the annular driver 17 mounted loosely on a sleeve 18. This sleeve 18 carries the annular driven part 20, and is geared to the generator. Wheels 22 mounted in a frame serve to transmit the motion, and by varying the position of the wheels the relative speed is varied. A spring 21 forces the driver against the wheels. Four of the wheels are mounted in a frame secured to the car body, and are geared together so that, on moving one by an arm, all are moved uniformly.