摘要 |
An electro-mechanical auxiliary knob structure, releasably attachable to a rotatable knob of a valve, to annunciate an open condition of that valve operated thereby. The auxiliary knob pivots relative to its attachment structure to switch electric circuitry carried within the auxiliary knob to annunciate last knob motion in the direction causing valve opening. The auxiliary knob is particularly adapted for use on valves of compressed gas tanks used in gas welding.
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