Gas operated switches

Abstract

Switches operated by gas, preferably controlled electrothermally, include a capillary tube closed at both ends with a conductive liquid piston dividing the tube into two chambers each filled with a non-oxidizing gas. A pair of electrical contact points are disposed within the capillary tube with the piston positioned to, at selected intervals, contact both points simultaneously. In one embodiment of the switches, a closed glass capillary tube contains a pair of aligned nickel wires with ends selectively contacted simultaneously by a mercury piston or globule providing a circuit-closing position for the switch. The switch is set in the circuit-closing position by applying heat to a non-oxidizing gas within one end of the capillary tube. The switch is then reset to a circuit-opening position at any desired time by applying heat to a non-oxidizing gas within the other end of the capillary tube. The non-oxidizing gas is heated by electrothermal means disposed at each end of and within the ends of the capillary tube. A barrier such as a collar disposed near the end of each of the wires is provided to prevent the mercury piston or globule from separating into a plurality of globules upon application of strong forces to the globule from either end of the tube.

Dependencies are inferred from the claim text.