GB436675A - Improvements relating to electrically operated changing display indicators - Google Patents

Abstract

436,675. Changing signs. SIEMENS BROS. & CO., Ltd., Caxton House, Tothill Street, Westminster, BROOME, J. H., 80, Leyland Road, Lee, and WOOD, A. F., 145, Kidbrooke Park Road, Blackheath, both in London. June 21, 1934, No. 18372. [Class 3 (i)] In electrically - operated indicators each of a plurality of display prisms 2 has a coaxial shutter 5 which is brought over the prism to conceal same during the whole period while being turned and, optionally, when out of use. The shutters are provided with counterweights 6 and are coupled together by links 7. One of the shutters is directly driven by a rod 8 provided with a pin 9 which is introduced into, and removed from, a thread groove, having a self-entering end, continuously rotated by an electric motor. The movement of the pin 9 is controlled by an electromagnet 11 which when energized brings the pin into the groove, and when de-energized allows a spring 15 to remove the pin and the shutters to cover the displays by gravity or spring tension. The actuation of the prisms is effected by chains engaging the driven side of an electromagnetic clutch, the driving side of which is connected to an electric motor through reduction gearing. As many as may be necessary of the prisms and shutters are provided with commutators of the brush and ring type or with cam circuit makers and breakers, and each display may be controlled by a key through a relay. A further contact of the relay may operate a master relay which in turn closes the circuit of the motor, the prism turning until the clutch circuit is opened by the appropriate commutator or cam. In this position a shutter commutator operates to uncover the display. Each possible circuit for the shutter includes a make contact for the appropriate relay and a commutator contact, and also a break contact for each of the other display relays, so that if one of the latter relays is operated the shutter circuit cannot be completed. Lamps may be automatically lit to indicate that a shutter is closed or open. The displays may be on slats carried by endless bands passing over rollers, and the shutters themselves may bear display matter. Specification 432,735 is referred to.