Patent GB-189824700-A (GB)
Title: Intercommunication in Railway Trains.
Inventor: LANGDON WILLIAM EDWARD
Filed: 1898-11-23
Granted: 1899-11-23
Abstract: 24,700. Langdon, W. E. Nov. 23. Signalling and communicating on trains.-Relates to means for electrically communicating between the passengers, guards, and driver of a railway train. The circuits are preferably arranged on the balanced current system, the wires being connected between the carriages by means of the coupling shown in Figs. 1 and 2. Each lead is connected by two plates a, a<1>, which are insulated from the corresponding plates of the other lead by interposed blocks of ebonite. The slit projection c and recess b of each plate are adapted to enter and receive the corresponding recess and projection of the plate to which it is coupled. Each member of the coupling is enclosed in a protecting-hood G and tube H, Fig. 4, the hoods being connected like an ordinary brake coupling. Fig. 6 shows the passengers' operating -switch, as arranged to be operated by a pull in one direction only. By pulling the cord &c. F, the block E on the rod C connected to the cord actuates the lever G by means of the inclined projection e', and causes it to make contact with the spring i, so closing the alarm circuit. The rod C also raises a semaphore mounted on the side of the carriage, to show where the alarm was operated. The lever G drops into the notch e<11> in the block E, and locks the switch, without breaking contact with i. The switch is re-set by means of a railway key, perforated at e, Fig. 11, to pass over the pin r in the keyhole in the lever Q. An arm P on the spindle of the lever G lies in a gab in the lever Q, so that, when the latter lever is operated by the key, the former is raised, and allows the rod C and block E to be returned by the spring D, and the semaphore to be lowered. The semaphore is retained in its lowered position by a pair of spring catches, until it is again operated. When the key is withdrawn from the lever Q, the lever G falls and breaks the circuit. The switch is protected by a cover held in place by a screw, which is formed with a head adapted to be operated by the key, Fig. 11. In a modified form of switch, adapted to be operated by either of two cords F extended in opposite directions, the circuit is closed by a contact-arm, on a drum operated by the cords, entering between two springs in the signalling-circuit. The switch is locked by a projection on a spring-controlled lever entering a recess in a disc on the drum spindle, and is released by the re-setting key. Between the compartments, the cord &c. passes through tubes A, B, Fig. 12, as indicated in Speci6cation No, 12,230, A.D. 1897. Springs D are fixed in these tubes to prevent the cord, after having been pulled, from being pushed back into another compartment. Fig. 13 shows the arrangement employed for enabling the alarm steam whistle on the engine to be operated, either electrically. or by the ordinary mechanical communication cord K. The whistle spindle is coupled to the spindle C, on which the lever armature B of the electromagnets A is loosely mounted. The spindle C has an arm D, which is normally locked, against the action of the spring d<1>, by the catch E. When the electromagnets are energized, the catch is released by the arm b on the armature B, and allows the spring d' to open the whistle. The cord K is connected to a lever G, having a pin g, which bears on the extension e of the catch, so that the catch is released when the cord is pulled. The electromagnets A are conaected up to the electric communication mains, in such a manner that a battery is not required on the engine.