US1142094A - Protective duct for fire-detecting conductors. - Google Patents

Description

C. A. HARSCH.

PROTECTIVE DUCT FOR FIRE DETECTING CONDUCTORS. APPLICATION FILED APR. 11. 1914.

1,142,094. I Patented Jun e 8,1915.

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UNITED. sTAtrEs QFFIGE.

CHARLES A. HARSCH, OF NEW YORK, N. Y., ASSIGNOZB, IESNE ASSIGNMENTS, TO

THE FIRE DETECTING WIRE COMPANY, (INCH) 0? NEW YORK, N. Y., A COBI'OBA- TION 035 NEW' YORK.

PROTECTIVE DUCT FOB FIRE-DETECTING CONDUCTORS.

Specification of Letters Patent.

Patented June 8, 1915'.

Application filed April 11, 1914. Serial No. 831,266.

To all whom it may concern:

Be it known that I, CHARLES AUGUST HAnsoH, a citizen of the United States, residing in the city of New York, borough of the Bronx, State of New York, have made certain new and useful Improvements in Protective Ducts for Fire-Detecting Conductors, of which the following is a specification.

This invention relates to ducts for insulated electric conductors, separated by an easily fusible layer. 1

The object of the invention is to provide mechanical protection for electric conductors arranged in pairs, insulated from each other, and separated by an easily fusible metal, so that when heat is applied to a predetermined degree the fusible metal melts, expands, penetrates the insulation separating the conductors, and makes electrical connection between them.

Before my invention such conductors had been openly supported on the wall at or near the floor line and also at or near the ceiling, but in use they were liable to mechanical injury. To avoid this I provide a conduit or molding of heat conducting material such as sheet metal having thin walls, and these walls are perforated so that the heat has access to the insulated conductor directly throughthe holes in the molding and also by conduction and radiation through the metal wall of the duct.

The drawings illustrate the invention.

Figure 1 shows a form of duct suitable for attachment to a wall, either at the base board or at any point; the duct 0?, is made of sheet metal of high heat conductivity and is provided with perforations p; duct a? has a flange a with perforations s to receive screws or nails to attach it to the wall or base board; the perforations ;0 are shown in the front surface of the duct but it may be found more advantageous to provide perforations p on the lower side of the duct, as shown in the cross section Fig. 10. The cross section Fig. 2 shows the detail of Fig. l with fire detecting twin conductors c, in position.

The conductors 0, so arranged, are well known, composed of a core wire 10, having a fusible metal coating 11, of extremely low on the floor or where there is unusual liability to mechanical injury; this shows elongated perforations. In Figs. 7 and 8 I have shown the same duct with the round perforations p. In Figs. 9 and 10 I have shown the duct as formed for use as apieture molding; the duct has perforations g1) on its under surface and these may be either round or elongated, as already shown. The duct and the flange are made integral, of thin sheet metal, preferably of high heat conductivity. Both walls of the flange a are perforated at s as shown in Fig. 10. It has been found that this arrangement of duct has many features of merit; theduct is exposed to view; heated air raises the temperature of the sheet metal, the duct radiates heat internally, the heated air also affects the conductors directly, through the perforations, while the heated duct tends to protect the conductor from any cooling action due to occasional currents of air, at normal atmospheric temperature.

\\ What I claim is:

1. A duct formed of a material having high heat conductivity with a supporting flange, said duct and flange being in the form of a picture molding, in combination with a pair of insulated conductors fixed in close proximity with an intervening layer of metal having a low fusing point said conductor being located within said duct close to a series of perforations in said duct.

2. The combination of a duct formed of sheet metal having a high degree of heat conductivity, provided with a series of perforations in its exposed wall affording free access for air, and a pair of electric conductors located within said duct, said conductors being in close proximity, separated by a thin layer of insulating material and a thin layer of metal having a low fusing point.

3. The combination of a duct of sheet metal having a flange adapted for attachment to a support, said duct having perforations inits nemzepea.

ex osed surface edaptedte admit heated air said fusible material and said insulating to its interior, and e fire detecting conductormateriel,

iocated Within said duct and prptected there-= by, said conductor having an insulating me- CHARLES HARSGH' 3 terial and a material fusible at a low tem- Witnesses? peratu 'e, and'a complementary conductor W. B. VANSIGL separated from the first-named conductor by. OHN. M; NUGENT.

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