US949451A - Electric burglar-alarm for vaults, safes, or the like. - Google Patents

Description

B. SERAGNOLI. ELEGTRIC BURGLAR ALARM FOR VAULTS, SAPES, OR THE LIKE.

APPLICATION FILED OOT,14, 1908.

Patented Feb. 15, 1910.

UNITED sTA'rn rATENT OFFICE.

ENRICO SERAGNOLI, OF ARENZANO, ITALY.

ELECTRIC BURGLAR-ALARM FOR VAULTS, SAFES, OR THE LIKE.

To all whom it may concern:

Be it known that I, ENRIGO SERAGNOLT, a subject of the King of Italy, residing at Arenzano, Province of Genoa, Italy, have invented new and useful Improvements in Electric Burglar-Alarms for Vaults, Safes, or the Like, of which the following is a specification.

This invention relates to that class of alarm systems, wherein the objects to be protected are surrounded by envelops, preferably made of metal and wherein said envelops are filled with a gaseous fluid of a pressure varying from the atmospheric pressure. It is customary in these systems to connect said envelops pneumatically with some contrivance which is adapted to close an electric alarm circuit when the pressure in the envelop is subjected to a change. It is obvious that by this means an effective protection of the objects is obtained as it is impossible to get at said objects without disturbing the equilibrium of the gas in said envelop.

For the purpose of improving the safety of the entire device it is customary to place the wires or portions of the wires of the alarm circuit in pipes which are pneumatically connected with the envelop and which for this purpose are made of thin metal, so that any attempt to disturb said alarm circuit will also require a breaking of those pipes and cause a disturbance of the equilibrium of the gas.

An object of this invention is to provide an arrangement for the conductors in the aforementioned pipes according to which a connection between the conductor and the pipe is obtained as soon as said pipe is crushed inwardly to a certain extent.

In the drawing a pipe with a plurality of branch pipes is shown in which conductors are disposed. One branch of the alarm circuit is formed by the conductors 13, 1 1 and 15 in the pipes, while the other branch of the alarm circuit is connected to the pipe 17 or the branches extending therefrom. It is evident to any expert skilled in the art that this circuit would be closed when any of the conductors would come in contact with the pipe. For the purpose of maintaining the conductors out of contact with the metallic conduits 16, 17 they must be insulated therefrom; It is obvious that the alarm circuit would not be closed between Specification of Letters Patent.

Application filed October 14, 1908.

Patented Feb. 15, 1910.

Serial No. 457,718.

the conductors and the conduit, under crushing of the conduit when said conductors would be surrounded by customary insulation. In this invention therefore the conductor or one of the conductors is bare and to protect it against contact with the metal conduit the insulation is accomplished by surrounding the same with a helically wound insulating member 18. The windings of said member are of a sufiiciently large pitch to leave relatively large portions of the conductor uncovered, so that said conductor is adapted to contact with the wall of the conduit when the same is crushed. When two or more conductors are disposed in the pipe, the insulating member may be replaced by a conductor insulated in the customary way by a coating of fabric or rubber or such like, said insulated conductor being wound about the bare conductor spirally and also leaving relatively large portions of the bare conductor uncovered. This is indicated in the part 16 of the conduit. In the portion 17 of the conduit a plurality of insulated conductors and one bare conductor are helically intertwisted leaving relatively large portions of the bare conductor uncovered, so that said bare conductor may contact with the wall of the conduit when the latter is crushed in.

It is obvious that by the means described under normal conditions the conductors are prevented from contact with the wall and that the alarm circuit is only closed when the conduit is crushed. By way of example an alarm circuit is shown comprising a plurality of conductors branched off or extended from the conductors in the various pipes and leading to some form of indicating signal apparatus 19, which in itself is very well known and does not form the subject-matter of this invention. The source of the current is indicated with 20, while an alarm bell, indicated by 21 is connected to the conduit by a wire 22. It is obvious that the arrangement of this alarm circuit may be subject to various changes.

I claim 1. In an electro-pneumatic alarm system the combination of a thin metal conduit, a bare conductor within said conduit, an insulating member helically surrounding said conductor leaving relatively large portions of the same uncovered, said conductor being adapted to contact with the wall of said conthe wall of said conduit, when the same is crushed and an alarm circuit including said conductor and said conduit.

In testimony whereof I have signed my name to this specification in the presence of 15 two witnesses.

ENRIGO SERAGNOLI. lVitnesses C. A. FERRAR,

Fro RINALDINI.

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