Patent GB-190305286-A (GB)
Title: Improvements in Pneumatic Systems of Motor-control.
Inventor: CAROLAN EDGAR ALFRED
Filed: 1903-03-06
Granted: 1904-04-06
Abstract: 5286. Carolan, E. A., [General Electric Co.]. March 6. Electric locomotives and motor vehicles; switches.- Relates to systems of motor control, and more particularly to systems of train control in which a number of motor controllers located on electrically-propelled vehicles coupled together to form a train are operated simultaneously by pneumatic pressure from any desired point on the train by means of a motorman's valve. Fig. 1 represents diagrammatically a single car equipment of the pneumatic control apparatus, and Fig. 2 a modification ; 1, 2 are the train pipes, m the means for connecting them to the corresponding train pipes on the adjacent cars, A an electricallydriven aircompressor, B the reservoir, C the motor controller, and RS the current reversing switch. The controller C is actuated through the rack and pinion 30, 31, from the fluid-operated piston 23, the spring 37 returning the controller to the "off " position when the cylinder D is exhausted. The compressed fluid is admitted to the train-pipes 1, 2 by one of the hand actuated valves V, V<1>. Fig. 11 shows a plan of one of these valves, the upper casing 74 being removed, and Fig. 12 a plan with the disc valve v<2> also removed. Figs. 10 and 13 show sectional elevations taken at right-angles to each other. These valves consist of two parts, a disc valve v<2> operated by the handle h<2>, and a plug valve v<1> operated by the handle h<1>. The plug valve is provided with a groove 77 having enlarged ends 78 in which the elongated valve spindle 75 is adapted to operate. The end of this spindle is so constructed as to form an interlock between the two valves, and only allows the valve v<1> to be moved when the handle h<2> is in the "off " position, or vice versÔ. The disc valve v<2> has two apertures 72, 85 and an under-cut channel 84 which slide over ports 71, 70, and the exhaust port 88 in the valve seat. The passages 70, 71 are connected to the train-pipes 1, 2 by the apertures 79, 80 or grooves 81, 82 in the reversing plug valve v<1>. When the valve v<2> is moved into the position shown in Figs. 10 and 11, the compressed fluid passes from the supply pipe 3 to the pipe 2, along pipe 5, through the open valve 11, and in the form shown in Fig. 1, into cylinder F by forcing the valve 15 against the spring shown. The opening of the valve 15 closes the valve 12, the two valves being connected by the rod 13. The piston 17 is then moved to the right-hand end of the cylinder, the switch RS reversed, and the compressed fluid allowed to pass to the cylinder D through the normally-open valve 22. The controller drum is then moved to the end of its series positions when the projection 28, which works in the slotted bar 27, moves this bar forwards against a spring, thas closing the valve 22 and stopping the piston 23. The motorman then further rotates the disc valve v<2> so that the channel 86 registers with the part 70. Compressed fluid then passes to the train-pipe 1, along the pipes 6, 7, 9 to the cylinder E, thus raising the looped rod 32 and with it the rod 27. This liberates the projection 28 and allows the valve 22 to re-open, the controller being then moved into its parallel positions. The part 26 of the rod 27 is made of magnetic material, and with the coil b, which is placed in the motor circuit, as shown in Fig. 16, forms a current-limiting device. The direction of movement of the car is determined by which train-pipe 1 or 2, or which cylinder F or G, the compressed fluid is first supplied to, and this is determined by the position of the plug valve v<1>. To return the controllers to their "off " position, the pipes 1, 2 are exhausted byturning the valve v' until the passage way 84 registers with the ports 70, 71 and the exhaust passage 88. In the modification shown in Fig. 2, the valve 55, which is in the form of a hollow tube and is moved backwards and forwards by the compressed fluid, controls the admittance of the fluid to the cylinders F<1> and E by its four ports. Connected with the cylinder D is an oil reservoir D<1>, the oil in which transmits the pressure of the compressed fluid to the piston 23. Fig. 8 shows a controller equipped with this operating mechanism. To avoid the reversing of the motor connections if the "series" pipe were to break while the controllers are in their parallel position, an automatic valve 95, Figs. 12, 13, and 14, is used, which will, simultaneously with the breaking of the " series " pipe, exhaust the " parallel" pipe. This valve works in a chamber which is connected by the passages 91, 90 to the passages 71, 70 respectively. Upon starting the motors, compressed air is always admitted first to the passage 71, and the piston 95 is then driven against the spring 96 into the position shown. If the "series" pipe should become broken, the spring 96 pushes the piston past the openings 90, 94, thus allowing the "parallel" pipe to exhaust. Fig. 15 shows an enlarged view of the circuit-breaking device R, Fig. 2, which breaks, or completes, the motor circuit when the pressure in the chamber D' is below, or exceeds, a prearranged amount. One set of contacts 101 are mounted on a toggle joint 103 operated by the piston 107. When the pneumatic pressure is sufficiently great, the pistons 116 and 107 are forced into the position shown. The switch is then closed, and is prevented from opening by the catch 113. If the pneumatic pressure falls below a certain limit, the piston 116 is forced forwards, the piston-rod knocking the catch 113 and releasing the piston 107. The switch then opens rapidly under the influence of the springs 105, 108.