Seismic movement detector responsive in both vertical and horizontal planes

Claim 2

A warning device for detecting occurrence of seismic movements, comprising: a first pair of electric contacts, one of said contacts of said first pair being vibratile relative to a generally horizontal rest position, the other contact of said first pair being adjustably spaceable from said rest position; a second pair of electric contacts, in which one of said contacts of said second pair is vibratile relative to a generally vertical rest position, the other contact of said second pair being adjustably spaceable from said rest position; an electric circuit connected to both said pairs of electric contacts, said circuit being closed when a vibration of sufficient amplitude imparted by an earthquake to the vibratile contact of at least one of said pairs causes it to touch its corresponding adjustable contact; and at least one warning unit inserted into said circuit and energized by the closure of said circuit.

Claim 5

A device according to claim 1, wherein each said contact which is vibratile consists of a respective resilient metal strip fastened by one of its ends to said support.

Claim 8

A device according to claim 1, wherein said circuit comprises: a first electric input terminal (A) connected to one end of the primary winding (P) of a step-down transformer (15) while a second electric input terminal (B) is connected, through closure of a main switch (12), to the other end of said primary winding (P) of said transformer (15); a secondary winding (S) of said transformer (15) whose one end is connected to the vibratile contacts (3, 6) of the first and second pair of contacts and to one terminal of a pilot lamp (11), the other terminal of which is connected to the other end of said secondary winding of said transformer; a relay (C) with a coil terminating at each end at a respective stationary contact (16, 17), one contact (17) of said stationary contacts being electrically connected to the two adjustable contacts (4, 8) of the first and second pair of contacts and the other contact (16) of said stationary contacts being connected to the other end of the secondary winding (S) of said transformer (15), said relay (C) having additionally a first relay contact (18) and being connected to a first conductor (22) of an auxiliary line; a third relay contact (20) connected to said first electric input terminal (A) and a fourth relay contact (21) movable towards said third relay contact (20) and connected to a second conductor (23) of said auxiliary line, said auxiliary line (22, 23) being connected to terminals of a buzzer or bell (14) and of a warning light (13) and being connected to other warning units installed in other rooms of the premises.

Claim 9

A device according to claim 5, wherein the closure of one of the contacts (3, 6) which are vibratile causes a current to flow through said coil of said relay (C) thereby determining the closure of the first and second relay contacts (18, 19) and the third and fourth relay contacts (20, 21) respectively, thereby energizing said auxiliary line (22, 23) and consequently all the warning units connected to said auxiliary line.