GB190302564A - Improvements relating to the Brake Apparatus of Electric Railway and Tramway Vehicles - Google Patents

Abstract

2564. Johnson-Lundell Electric Traction Co., [Lang, J. G. V.]. Feb. 3. Electric locomotives and motor vehicles.-The brakes are normally held off, but are applied automatically when the speed increases beyond that due to the position of the controller, or on failure of the regenerative motors to act as brakes, or when the controller is in the off position. In the diagram, Fig. 1, the needle a of a voltmeter, supplied by a generator D driven from the axle or motor, causes the pivoted frame a<5> to work over the contacts a<1> ... a<4>, which are connected with corresponding contacts b<1> ... b<4> swept by a pointer on the controller handle B. The needle is insulated from the frame, and normally is held against the stop a<7> thereon, but, if the speed increases unduly, the needle comes against the uninsulated stop a<6>, carrying the frame forward, and completing a circuit through a switch C, which controls the mechanical brake system. As shown, the brakes are held off by a small motor E, but the switch may operate a valve in a pneumatic-brake system. The needle a may be worked from a mechanical speed governor instead of an electric governor, and a battery used to supply current for the switch C. The contact b x at the " off " position of the controller may also be connected to the needle, so that the brakes go on when the main current is cut off.