US1782787A - Armored conductor - Google Patents

Description

Nov. 25, 1930. J. E. 'MCAULIFFE 1,732,787

7 ARMORED GONDUCTOR Filed May 1. 192a ATTORN EY Patented Nov. 25, 1930 UNITED STATES PATENT OFFICE,

JOHN E. mcAULIEEn oE BROOKLYN, NEW-YORK, ASSIGNOR 'ro TRIANGLE coNnUrr coMrANY, or BROOKLYN, NEw YORK, A CORPORATION on NEW YORK ARMORED CONDUCTOR Application filed May 1,

. This invention relates to armored conductors but more specifically to an insulated conductor enclosed in a spirally wound metal armor.

The object of the invention is to provide in an armored cable of the type above set forth an electric conductor located between the insulation and the metal armor and contacting -with the convolutions of the armor so that said conductor functions to carry the current and bridge any gaps in the convolutions of the armor, should the conductors be short circuited through the armor for any reason.

In the present type of armored cable, if one of its conductors is grounded on the armor and the armor is compelled to carry the current, it may heat to such a point that a fire hazard is the result. If the armor is perfectly made so that metal contact is had throughout all points of contact of the con-- volutions, an electric current will pass longitudinall through the armor and blow a fuse before there can be any fire hazard. If, on the other hand, the armor be imperfectly made or imperfectly installed or injured in any way, there is a possibility of a gap or gaps between the convolutions of the armor and 1n such an event the current will follow the spiral path of the metal forming the armor, $0 that a resistance will be provided to generate heat and constitute a fire hazard.

It is therefore thebroad purpose of my invention to provide-what maybe termed a safety device, located within the armor, and constituting an electric carrier which will compel the current to travel longitudinally of the armor in the event of short circuiting and which will bridge any gaps whichmay exist between the convolutions of the armor.

This safety conductor need not be of the fullcurrent carrying capacity of the cable as it is to be understood that the armor itself will carry the major portion of the current and the safety conductor is only to insure a bridging of any gaps which may exist between the convolutions of the armor.

- With these and other objects in view, the

- invention consists in certain novel features of construction and combinations and arrangements of parts, which will be more fully 1928. Serial No. 274,343.

an ordinary wire or maybe any suitable current carrying device which extends lon tudinally of the armor and is in contact with the inner faces of all the armor.

This conductor 4 has no function except. when for some reason or other the current enters thearmor, as, for example, when the insulation is bad or burned out or injured for some reason and there is a short circuit or ground through the armor. In such an event the electric conductor 4, or safety device as I term the same, contacts with all the convolutions of the armor and compels the current to travel longitudinally of the armor, the armor itself functioning also as a current carrier and preventing any possibility of the electric current following the convolutions of the armor.

The electric conductor 4 need not be of the full current carrying capacity, although it might be if desired, but the function of this conductor is to compel the current to flow longitudinally of the armor, and the conductor may be slightly embedded in the insulation, as shown in Figure 2.

It is of course needless for me to explain in detail the many adaptations of this device in connection with difierent types of fuse, but it is a fact that the current will in any event of short circuiting or grounding flow through the metal of the armor for a certain length of time before a fuse is blown; and to compel the current to flow longitudinally of the armor and not follow the convolutions 0f the convolutions of thereof is the broad idea of my invention which I desire to cover by a patent.

I therefore do not wish to be limited to specific details of construction and combinations and arrangements of parts but-desire to cover the idea broadly as more fully hereinafter expressed in the appended claims.

I claim:

1. The combination with an insulated conductor and a spirally wound metal armor around the insulation of the conductor composed of interlocking turns, of a safety conductor constituting an electric bridge located inside of the armor,insulated from the firstmentioned conductor, and contacting with substantially all of the turns of the armor, said armor tightly embracing said insulated conductor and said safety conductor.

2. The combination with an insulated conductor and a safety conductor, of a spirally wound metal armor composed of interlocking turns enclosing said insulated conductor and said safety conductor under pressure,

said safety conductor contacting with substantially all of the turns of said armor to constitute an electric bridge.

3. In an armored electric cable the combination with a plurality of insulated electric conductors and a bare electric bond 'wire disposed in longitudinal relation, of a spirally wound metal armor of interlocking-turns tightly embracing said conductors and bond wire so that the bond wire is partially impressed in said insulated conductors and held in contact with the turns of the armor.

Signed at Brooklyn, N. Y., in the county of Kings and State of New York, this 26th day of April, 1928.

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