Electrical earthquake warning device has weight at end of freely suspended metal chain brought into contact with metal cylinder for closing warning circuit upon detection of earth tremor

摘要

The earthquake warning device has a voltage source coupled to 2 relatively spaced contacts bodies (56,70), which are brought into contact with one another upon detection of an earth tremor, for providing the current for an optical or acoustic signal source. One contact body is provided by a metal chain (40) which is freely suspended from one pole of the voltage source, with a circular metal weight (56) at its free end, the other contact body provided by a metal cylinder (70), enclosing the chain and coupled to the opposite battery pole.