Patent GB-190309806-A (GB)
Title: Improvements in Emergency Brakes for Railway and Tramway Vehicles or Trains
Inventor: CAROLAN EDGAR ALFRED
Filed: 1903-04-30
Granted: 1904-03-24
Abstract: 9806. Carolan, E. A., [General Electric Co.]. April 30. Electric locomotives and motor vehicles.-Relates to means of the type described in Specification No. 19,562, A.D. 1902, for automatically controlling motors and power-actuated brakes in case of emergency, and consists mainly of mechanism by which the brakes are applied when the operator ceases to depress a knob on the motor-controlling handle whatever may be the position of the handle. The application to an electrically-propelled vehicle or train in which the brakes are actuated by compressed air is described, and the brake system employed is that in which compressed air is stored in a reservoir and is allowed to pass to a brake cylinder by means of a valve when it is desired to apply the brakes, but the automatic system may also be employed. The valve in the casing P for applying the brakes is operated by the movement of a spindle 34, against which presses the lower end of a lever p pivoted to the controller casing A. The upper end of the lever projects into the path of a lug q in a cam f carried by a sleeve F which can turn on the shaft D secured to the handle E. When the knob E' is depressed by the operator against the action of the spring E<3>, a bolt G is slid downwards to lock together the sleeve F and shaft D, but, when the knob is released, the spring E<3> presses upwards the knob and bolt to release the sleeve, which is then rotated by a spring F' to bring the lug q into contact with the lever p and so to operate the valve in the casing P to apply the brake. To release the brakes, the operator turns the handle E into the " off " position and depresses the knob E<1>, by which the inclined lower end of the bolt G slightly turns the sleeve F to the lug q from the lever p and then locks together the sleeve and shaft. The sleeve F can be fixed with the brakes in the released position by turning the reversing-switch R, S from either of its operative positions, in which one of the recesses t, Fig. 4, engages with the projection w<1>, into its neutral position, in which the smaller recess t<1>, Fig. 3, engages with the projection. In the latter case, the projection moves the spring-pressed arm so that the parts w<2>, x on the arm lock into corresponding parts u, y on the sleeve F and so fix it. The cam f engages an arm h on the rock-shaft H, which has an arm h<1> carrying an insulating-block H<1> provided with two spring contact-fingers, which co-operate with stationary contacts to form a double-pole switch I for closing and opening the power circuit when the shaft H is rocked. The casing P contains two valves 21, 29, Figs. 7 and 8, so arranged that, when the spindle 34 is forced inwards against the action of the spring 32, the chamber 24 is exhausted to the atmosphere through the passage 27 and exhaust port 30 Since the passage 25 in the valve 21 is small compared with the exhaust port 30, the pressure in the chamber 26 will open the valve 21 against the action of the spring 23 and connect the pipe 20 from the source of compressed air with the pipe 19 leading to the train-pipe.