Relay visible position indicator - has arm pivoted on coil, moved by armature one end, indicating position at other end

摘要

The relay with a visible position indicator has a cover (4) with a lens shaped window (4) through it, so that the end (9) of a swinging arm (5) inside can be seen. The arm is a swinging arm, resting on top of the coil (1) and moved by the action of the armature (3) above it. This arm is of a resilient plastics material and is formed by two V-shaped parts. The larger V (5a) carries the indicator part (9), and has a return spring (12) holding it down. The smaller V (5b) the other end has it apex (11) nesting on the coil, forming the pivot point of the whole arm. A number of alternative designs incorporate alternative return springs. The spring may be a resilient extension of the arm itself, at the other side of the pivot point. It may be a spring retained between the arm and the armature, or a wire spring attached to the frame.