Patent GB-190819397-A (GB)
Title: Improvements in or relating to Railway Air-brake Systems.
Inventor: CHRISTIE NORMANBY CONSTANTINE
Filed: 1909-04-13
Granted: 1910-03-24
Abstract: 19,397. Christie, N. C., and Henderson, W. April 15, 1909. Brakes.-In an alarm for fluid-pressure brakes for railway vehicles, in which an electric bell is placed in the engineer's cab to indicate whether any angle-cocks have been left closed after the train is assembled, means are provided for silencing the alarm during shunting - operations and for automatically returning the indicating-device to normal position when the hand-lever operating the engine whistle is moved. The alarm may be operated either by closing a normally open circuit, or by opening a normally closed circuit. The invention also comprises details of construction of the apparatus. Two electric leads 43, 23, Fig. 1, are provided on each vehicle, one of which is formed by the train-pipe, and the leads are coupled at the same time as the hose connexions. The ends of the train-pipe 43, Fig. 3, are connected to the coupling heads 14 by an electric lead 41, while the lead 23 is connected at each end of the vehicle to an insulated collar 2 secured to the angle-cock 1. The lead is continued from the collar through the hose 24 and is connected to an insulated plate 15, Fig. 17, on the coupling-head 14. The plates 15 carry spring-pressed contacts 17, which engage when the hose-pipes 24 are coupled. Two continuous leads are thus formed throughout the train, which are connected at the front of the engine when the angle-cock is closed by an arm 13, Fig. 4, of the handle 12 of the cock contacting with a plate 8 secured to the insulated collar 2. One terminal of the battery 21 is connected to the insulated collar 2 on the angle cock at the rear of engine while the other terminal is connected through the electric bell 34 to the train-pipe on the engine. When any cock is left closed after the vehicles are coupled, the circuit of the bell is completed through the arm 13 on the handle of the cock and the contact plate 8. In order to allow the cock at the rear of the train-pipe to be closed without ringing the bell, the lead 23 after passing through an indicator 25, Fig. 1, is divided, and the ends are connected to contact plates 33, Fig. 6, of a switch 26. A brass disk 31 is carried by a rod 29, the end of which engages in a cam-shaped slot formed in an arm 37 carried by a spindle 36. The opposite end of the spindle is secured to a dummy coupling 35, which, when coupled to the free hosepipe section 24, turns the arm 37 to withdraw the disk 31 from between the plates 33 and break the circuit. In order to prevent the bell from ringing during shunting operations, a switch 42, Fig. 21, similar to the switch 26 at the rear of the train, is provided in the engineer's cab and may be opened by moving the hand lever 44 to the right. The switch is closed automatically when the engineer moves the lever 46 to sound his whistle before starting the engine. In a modified form, the circuit throughout the train is normally closed, and the break of the circuit which occurs when one of the angle-cocks is left closed after the hosepipes are coupled, de-energizes an electro-magnet 48, Fig. 8, in the circuit. The armature 49 is then pulled over by a spring and completes the electricbell circuit in the cab. Switches, similar to the switches 26 above described but with reverse movements, are provided in conjunction with the angle-cocks at the front of the engine and at the rear of the train to render the closing of these cocks inoperative. A wire gauze woven into the hose-pipes may form the electric connexion between the ends of the train-pipe and the coupling- heads. The electric conductors may be used to signal or telephone between different parts of the train.