GB541038A - Improvements relating to control devices for railway signalling systems - Google Patents

Abstract

541,038. Circuit controllers for railway traffic control systems. WESTINGHOUSE BRAKE & SIGNAL CO., Ltd. Jan. 20, 1940, No. 1247. Convention date, April 13, 1939. [Class 105] [Also in Group XXXVII] A circuit controlling device suitable for mounting on the control panel of a railway traffic control system such as described in Specification 499,340 comprises a longitudinally movable operating member 5 formed throughout its length of translucent insulating material such as quartz, glass, or suitable synthetic plastics adapted to transmit a luminous indication that the operation controlled by the device has been effected. As seen in plan, Fig. 1, a bracket 12 has an upturned end 11 secured to panel P by screws, not shown, the end also receiving a threaded bearing bush 9 which projects through the panel. One end of member 5 is secured in, and flush with the outer end of, a sleeve 7 slidable in bush 9. Its inner end is formed with a contact-operating cam 6, shown spherical, and is slidaply guided in bearing 16 fixed to the Bracket. Intermediate its ends member 5 has an integral enlargement 4 acting as a prism to direct light from one or other of selectively by illuminated lamps 29, usually red and green, through the visible outer end of the member. Sleeve 7 has an operating knob 8, removable to allow assembly on the panel, by which member 5 can be pushed or pulled, as required, from an intermediate normal position to which it is biased bv suitable means such as pairs of flat fixed springs 14 bearing against opposite faces of a flange 13 on the sleeve. Lamps 29 are enclosed in a cover 33 removably held on the bracket by spring clips 34, and their circuits, not shown, are controlled as part of the traffic control system. Three pairs of operated contacts are shown mounted on the bracket by spacing insulating blocks 24, and comprising fixed contacts 18, 19, 20, respectively, resting against fixed stops 18a, 19a, 20a, and cooperating with movable contacts 21, 22, 23. The free end of contact 21 carries an insulating member 28 resting against contact 22, which is extended and provided with a curved free end co-operating with cam 6. Contact 23 also has a curved free end co-operating with the cam. When knob 8 is pushed in, normally closed contacts 20, 23 remain closed, and normally open contacts 18, 21, 19, 22 are closed. When the knob is pulled, contacts 18, 21, 19, 22 remain open and contacts 20, 23 are opened.