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Publication numberUS2488622 A
Publication typeGrant
Publication dateNov 22, 1949
Filing dateOct 25, 1946
Priority dateOct 25, 1946
Publication numberUS 2488622 A, US 2488622A, US-A-2488622, US2488622 A, US2488622A
InventorsJoseph Giorgianni
Original AssigneeJoseph Giorgianni
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Fault indicator for closed circuit installations
US 2488622 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

Nov. 22; 1949 J. GIORGIANNI 2,488,622



Joseph Giorgianni, Providence; m1: Application October 25, 1946, Serial No. 705.559.

ZiGlfiilflSa. (Cl. 177-311) The present invention relates to normally closed c ircuit installations such -as burglar alarinu syste-ms andthelike, and has specific reference toan indicatorfor detecting and localizing-defectsinthe lineand the-- installation parts.

The principal object of the invention is :to provi'd'eaz positive indicator which localizes the dee feet, and I thus'permits-quick" repairs to bemadei Another object of the invention is to provide a localizing indicator which operates only when an open or an intermittent break occurs in a closed circuit system, and remains in indicating position until released manually.

With the above and other objects and advantageous features in view, the invention consists of a novel arrangement of parts more fully disclosed in the detailed description following, in conjunction with the accompanying drawings, and more specifically defined in the claims appended thereto.

In the drawings:

Fig. 1 is a diagrammatic view of a portion of a normally closed electric circuit having a local alarm point, a novel indicator being included for disclosing a local break;

Fig. 2 is a plan view of the face of an electric meter which is modified to lock the needle in place after registering a circuit break; and

Fig. 3 is a detail on the line 3-3 of Fig. 1 showing a preferred arrangement for exerting a locking action on the meter needle.

It has been found desirable to provide a positive indication of a local break in a normally closed circuit installation, such as is commonly used for burglar alarms and the like. These systems usually have a series of local alarm points, such as windows, doors and other openings, and it often happens that one or more Of the local points is disturbed sufficiently by local atmospheric conditions to break the circuit and thus set off the alarm. However, since there is no actual visible break, an exhaustive search is required to find out where the disturbance or break occurred, and complete re-wiring is frequently necessary, as the trouble often corrects itself before the investigation and the check up are made. A closed circuit burglar alarm system of standard type, for example, includes a relay for controlling the alarm, the relay normally receiving a constant flow of current from the source of supply, which flows through a number of separate alarm points through switches, lines, and tinfoil back to the source of supply. When a pronounced break occurs at any alarm point the difficulty thusbecomes neicfissarytocheck eachalarm point;


Ihave; found'fitifeasible to .connectanindicator ff he. lt'aletyp across each. alarm, pointinstallation, the' preferred" indicator being a fl'ash" bulb. When an intermittent break occurs within any of the installations, the current passes through the flash bulb at that installation. which cannot carry the line current and therefore burns out. The particular defective installation is thus positively identified, and repair of the break is rapid, as no other installation need be tested.

Referring to the drawings, the line If), H is conveyed through an alarm point or installation by connections l2, l3 and M, the alarm point being in series with an alarm relay in the usual manner, to provide a normally closed electric circuit which operates the alarm whenever the circuit is broken. I have connected an indicator IS in parallel with the alarm point, whereby it normally receives insuflicient current for registering but receives full line current if the circuit at the alarm point becomes broken. The indicator 15, which preferably is a flash bulb, then burns out, and thus positively indicates the local installation where the current was broken. Instead of a flash bulb, any similar positive indicator which normally is not operated when placed in parallel with a local alarm point circuit, may be used, such as for example, a visible type fuse or a relay or circuit breaker.

For certain local installations a voltmeter or ammeter may be placed in the alarm point circuit, the parts being so arranged that when a break occurs and causes the meter needle to move, the needle is releasably retained in moved position until manually released, thus givin a positive indication which localizes the break.

One preferred manner of register-locking a meter needle in place is shown in Figs. 2 and 3, wherein the meter I6 is provided with the usual indicating needle l1, and a tension wire I8 is fastened at one end l9 to the meter face, and is connected to a coil spring 20, the outer end of which is also fastened to the meter face as indicated at 2|, whereby the wire l8 extends across the path of travel of the needle in frictional contact therewith. The tension of the wire I8 on the needle is adjusted so that the needle will move when a break in the closed circuit at the can be visually located, but a minor break caused alarm point occurs, but will be frictionally held 3 so as not to swing back to its initial position until the wire I8 is manually lifted or its tension otherwise released sufficiently to permit the needle to swing to its original indication for the normally closed circuit.

It is thus clear that I have provided an indicator for visually disclosing a break in a local alarm point installation, which is physically changed, as by burning out or by moving, whenever a break occurs in the normally closed electrical circuit of the installation.

Although I have described specific constructional arrangements for positively indicating a local break in a normally closed electrical circuit, it is obvious that other arrangements for obtaining the desired indication may be utilized, within the spirit and the scope of the invention as defined in the appended claims.

I claim:

1. In an alarm apparatus, in combination, a current source, wiring including alarm sections in a normally closed circuit, an alarm, a relay in series with the normally closed alarm section circult and operable on opening of the circuit of an alarm section to actuate the alarm, and an inz.

dicator in parallel with each alarm section, said indicator being unaffected by the normally closed circuit and physically effected upon breaking of its alarm section circuit by passage of full circuit therethrough.

2. In an alarm apparatus, in combination, a current source, wiring including alarm sections in a normally closed circuit, an alarm, a relay in series with the normally closed alarm section circuit and operable on opening of the circuit of an alarm section to actuate the alarm, and an indicator in parallel with each alarm section, said indicator being unaffected by the normally closed circuit and physically efi'ected upon breaking of its alarm section circuit by passage of full circuit therethrough, said indicator including an indicating fuse.


REFERENCES CITED The following references are of record in the tile of this patent:

UNITED STATES PATENTS Number Name Date 378,078 Barnes Feb. 21, 1888 659,499 Ullman Oct. 9, 1900 1,158,146 Olney Oct. 26, 1915 1,927,370 Kriegstedt Jan. 12, 1932 2,159,751 saul May 23, 1939 2,279,394 Fountain Apr. 14, 1942

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US378078 *Sep 26, 1867Feb 21, 1888 Conductor for electrical fire-alarm systems
US659499 *Nov 17, 1899Oct 9, 1900Isaac W UllmanSignal system.
US1158146 *May 21, 1913Oct 26, 1915Harry W OlneyElectric burglar, fire, and general alarm.
US1927370 *Jan 12, 1932Sep 19, 1933Engineering Appliance CorpFuse plug
US2159751 *Jun 22, 1935May 23, 1939Bell Telephone Labor IncSignaling system
US2279394 *May 8, 1941Apr 14, 1942William FountainClosed circuit alarm
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2599623 *Aug 30, 1950Jun 10, 1952Forrester Herman GClosed circuit fire and burglar alarm
US2985870 *Oct 28, 1953May 23, 1961Lindberg Jr John EEngine analyzer for detecting temperature with transducer and circuits
US4176350 *May 18, 1977Nov 27, 1979Patterson Billy JIndicator to show whether a switch has opened
US5134248 *Nov 13, 1990Jul 28, 1992Advanced Temperature Devices, Inc.Thin film flexible electrical connector
U.S. Classification340/511, 340/524, 340/550, 340/652
International ClassificationG08B29/00, G08B29/10, G08B23/00
Cooperative ClassificationG08B29/10, G08B23/00
European ClassificationG08B23/00, G08B29/10