GB1239815A - Tristable indicator - Google Patents

Abstract

1,239,815. Indicator systems; rotating display devices. D.B.A. 30 July, 1968 [31 July, 1967], No. 36200/68. Headings G4F and G5O [Also in Division H1] A revolving drum indicator capable of two actuated positions and one rest position is geared to a pivoted armature that responds to the signal appearing on one of two electromagnets, the system having a spring return to the rest position. In Figs. 4, 5 contacts 4 supply the electromagnets 16, 17 having cores 14, 15 and polepieces 18, 19 respectively. An armature 21 pivoted at 20 is attracted by that magnet energized by a signal, its subsequent movement also moving indicator drum 6, being engaged to it via the teeth at 22 and 11. The pin 12 joining pinion 11 and the drum is inserted between pegs 13. Outside rim 6C of the drum is transparent having information written on it that is illuminated by lights 10 and seen through window 12. The drum 6 is returned to its rest position by a return spring 23 engaging the outside edges of pegs 13. An extension a of the plate A provides the stops defining the limits of drum movement.