Patent GB-190324796-A (GB)
Title: Improvements in or relating to Motor Controllers and Emergency Brakes for Railway and Tramway Vehicles or Trains.
Filed: 1903-11-14
Granted: 1904-10-06
Abstract: 24,796. British Thomson-Houston Co., [General Electric Co.]. Nov. 14. Electric locomotives and motor vehicles. - Relates to means for automatically controlling motors and power-actuated brakes on electricallypropelled vehicles or trains in the event of the driver or motorman being suddenly incapacitated. The means are especially intended for fluid-pressure brakes arranged on either the "straight" or the automatic system, and are described as adapted to the "straight " system. An emergency valve P, Fig. 1, for admitting compressed air from the main reservoir to the train-pipe is connected with the controller handle E in such a manner that it is opened automatically whenever the pressure of the motorman's hand is removed from the knob E<1> on the controller handle in any other than the " off " position. The valve P is a relay valve, and is shown separately in Figs. 5 and 6. It consists of a large valve 23, normally held on its seat by the air pressure and by a spring 25, and of a small valve 30 which, when opened by the release of the controller handle, allows air to escape from a chamber 26 above the valve 23 more quickly than it can enter by a small passage 27 in a piston-like extension of the valve. The valve 23 is then opened by the compressed air acting on the underside of the piston, so as to allow a free passage of the compressed air to the train-pipe. When the normal action of the controller is restored, the valve 30 is closed again by its spring 32, and the valve 23 by its spring 25. In order to prevent this emergency valve from being rendered ineffective by the driver's valve being inadvertently left at the " quick release " position, the driver's valve is fitted with a spring device for moving it back from the "quick release" position if the driver lets go of the valve handle with the valve in that position. The driver's valve consists of a rotary disc 56, Fig. 7, held on its seat by a spring 66, and centered by a stud 59. A port in the valve can be set to connect the train-pipe port 17<a>, Fig. 8, either with the pressure-pipe port 18<a>, or with the release port X' communicating with the atmosphere. The dotted lines ES, SS, R, and QR indicate the positions of the valve handle 70 for " emergency "stop," "service stop," "release," and "quick "release." In the "release" position, only a small part 57<1> of the valve port overlaps the train-pipe port 17<a>, and the amount of leakage allowed is not sufficient to prevent the application of the brakes by the emergency valve. A lug 74, Fig. 10, on the valve handle moves between stops 76, 77 on a sleeve 69, Fig. 7, which is mounted on the valve cover, and is capable by turning through a small angle limited by stops 72, 78, Fig. 10, engaging a stop 73 on the cover. When the valve is moved from the release" to the "quick release" position, the stop 78 on the sleeve 69 is moved against the stop 73 by the valve handle, but, on releasing the handle, a spring 71, Fig. 7, turns the sleeve 69 together with the valve spindle and valve back to the " release " position. The controller is of the known construction, in which the pressure of the driver's hand on a knob E', Fig. 1, on the controller handle E lowers a bolt G in the handle spindle D into engagement with a spring-controlled sleeve F, which operates the emergency valve P and the cut-out switch I when the handle E is released in any other than the "off" position. With the handle E in the "off position, and the reversing-switch RS in the neutral position, the sleeve F is held by its spring with a projection f<4>, Fig. 2, against a stop 47 on a bar 46 connected to a lever 40 engaging a cam on the spindle of the reversing-switch. If, however, the reversing- switch is in one of its operative positions, the sleeve F can turn back against a stop a<1> on the casing and operate the emergency valve by means of a projection 39 and a lever 38. The notch f<2> in the sleeve F, which is engaged by the bolt G, is bevelled, and the end of the bolt G is also bevelled, so that, on depressing the knob E<1> when the handle E is in the " off " position, the sleeve F is moved away from the stop a<1> into-the position shown in Fig. 2, and the emergency valve allowed to close. The cut-out switch I is opened by a cam f on the sleeve F acting through a rock-shaft H controlled by a spring h<3>. The controller cylinder B, Fig. 1, is connected by gearing C, C' with the spindle D, and the reversing-switch RS has the usual interlock W with the spindle D.