Snap action tilt actuated mercury switch

Claim 1

A tilt actuated conductive liquid switch comprising: an elongated envelope of electrically insulating material sealed off from the atmosphere, a pair of electrodes each supported on and within the envelope and providing conductive means which extends through the envelope to terminals outside the envelope providing electrical connection to said electrodes, their electrodes and their supporting structure being arranged in a vertical plane during operation to extend from one end side-by-side into the envelope generally in the direction of elongation, the lower one of said electrodes projecting further into the envelope than the higher one and terminating in a blunt termination, such that in the selected operating orientation the envelope is arranged generally horizontally with the lower electrode projecting furtherest into the envelope beneath the other electrode, and a mass of cohesive conductive liquid within said envelope, the mass being sufficiently great and the position of the lower electrode being such as to require penetration by the lower electrode as it passes to contact the shorter higher electrode and sufficiently small to clear both electrodes except when tilted with the electrode and lowered, the blunt termination on the lower electrode being of sufficient area in a transverse direction opposed to liquid movement and proper shape to effectively block passage of the liquid mass until the liquid surface tension effect thereof is overcome by the component of weight opposed to it, in order to provide a snap action effect.