GB190306367A - Improvements in Brake Apparatus for Electrically Propelled Railway and Tramway Vehicles. - Google Patents

Abstract

6367. Newell, F. C. March 29, A.D. 1902, [date applied for under Patents Act, A.D. 1901]. Electric locomotives and motor vehicles. - Relates to electric braking systems for electrically-propelled railway and tramway vehicles, and consists in connecting the braking- switch with the running- controller so that it cannot be operated except when the running-con. troller is in the zero position. Sparking at the brake switch is thus prevented. Fig. 1 shows a diagram of an arrangement having a series parallel controller 100, a reversing-switch 101, and a brake switch 102, in connection with which is fitted an electrically -actuated locking-device for preventing the brake switch trom being operated except when the controller 100 is in the zero position. The to king- device consists of a notched plate 111 fixed on the shaft of the brake switch, or other equivalent part, and engaged by the core or armature 109 of a solenoid or electromagnet 108 located in a shunt circuit 103. This shunt circuit is connected at one end to the line between the trolley 104 and the brake switch 102, its opposite end being connected to the terminal 105 of the line 106 at the cut-out switch 107 in the base of the running-controller. When the running-controller is moved to any of its series positions, the bars 113, 114, cross connect the contact-fingers 115, 116 so that while the main current is flowing to the motors, a small current also flows through the shunt circuit 103, by the wire 106 &c., which current energizes the electromagnet or solenoid 108 and locks the brake switch 102. When the controller is moved to one of its multiple positions, the contact bars 134, 135 cross connect the contact-fingers 115, 116 and give the shunt circuit a ground connection through the lead 137. When the controller is in its zero position, as shown in Fig. 1, the shunt circuit 103 is broken, thus leaving the brake switch free to be operated. When the brake switch is moved to the braking-position, as shown in Fig. 2, the motors are connected up to operate as generators in a local brake circuit including the brake magnet coils 150 and 151. Should the running-controller be accidentally moved from its zero position while the brake switch is in its braking- position, the shunt circuit is closed through the lead 106, contact bars, &c. and the brake switch is locked until the controller switch is returned to zero.