GB190706812A - Improvements connected with Railway Signal Semaphores. - Google Patents

Abstract

6812. Panton, J. A. March 21. Lamp signals; semaphore signals. - Electric incandescent lamps are placed in a semaphore arm, and exhibit a red or green light according to the position of the arm which may also be arranged to reverse its face when raised or lowered, the face presented when raised being red, and the reverse face white or green. The arm A, Fig. 1, carries lamps B, C of the straigh tfilament type, which are contained in semicircular reflector cases D, the beadings E of which contain the circuit wires. Platinum wires F support the filaments. The positive lead of lamp B is led to a contact-piece G, and that of the lamp C to a contact-piece H. When the arm is raised, the piece G makes contact with the piece 1 attached to the post K, thus illuminating the red lamp. When the arm is lowered, the green lamp is illuminated by the contact of the pieces J, H. The plungers L of spring buffers M prevent jars and limit the positions of the arm. A modification in which the arm has its faces reversed in moving is shown in Fig. 2. The spectacle casting is made in two pieces N, O, and the arm A is bolted to the piece O, the trunnion P of which is journaled in the casting N, and by means of the bevel-pinion R meshes with the rack S. Lamps B, C are placed on either side of the arm, and the positive lead of the red lamp B is connected to the piece G, which is normally situated immediately behind the strip H, and thus to the contact strip I. When the arm is lowered, the lead of the green lamp C connects through the piece H with the contact strip J. The contacts I, J arrest the movement without shock by their elasticity. In another form, the centre portion of the arm, with the lamps, alone rotates, a trunnion being provided at the outward end, and the outer part, of the arm acts as a frame ; or a single lamp with a case coloured half red and half green may be rotated in a central aperture, thus showing red or green according to the position of the arm. This lamp may be provided with a fixed reflector placed inside the glazed lamp casing. Rows of small lamps arranged in series may be used instead of the straight-filament lamp.