US678887A - Resistance device. - Google Patents

Description

- No. 678,887. Patented July 23, IQOI.

' c. w. LARSON.

RESISTANCE DEVICE.

(Application filed Jan. 18, 1900.)

(No Model.)

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CARL l/V. LARSON, OF SCI-IENECTADY, NEYV YORK, ASSIGNOR TO THE GENERAL ELECTRIC COMPANY, OF NEW YORK.

RESISTANCE DEVICE.

SPECIFICATION forming part of Letters Patent No. 678,887, dated July 23, 1901. Application filed January 18,1900. Eerial No. 1,847. (No model.)

To all whom it nut/y concern:

Be it known that I, CARL W. LARSON, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Resistance Devices, (Case No. 903,) of which the following is a specification.

This invention relates to an electric resistance device adapted to have an extraordinary large current capacity in proportion to its size.

Figure 1 is a perspective View, Fig. 2 a longitudinal section, and Fig. 3 a transverse section, of one form of a device embodying the features of the inventiomof which other forms may be constructed without exceeding the limits of the invention.-

A is a support formed in a single piece of iron or other suitable material, preferably having a large capacity for heat. The sup port is formed with suitable projections or corrugations D to increase the heat-radiating surface.

B indicates resistance-conductors, such as rods of amorphous carbon, which are located in perforations in the support or casing A and are provided with a thin sheath of incombustible insulation D, such as mica. This sheath is preferably about one thirty-second of an inch in thickness. The ends of the rods are incased in caps E, of conducting material, such as copper, of any suitable construction, to which the line and interconnecting wires W are attached. The caps E are also covered with the sheath of mica. Other means for connecting the wires W to the resistance-conductors may be employed, such as spreading out the cable and binding the ends about the conductor with a Wire. In any case it is desirable to inclose the connecting means within an insulating-sheath.

The rods B are held in the support A by means of a suitable plastic heat-conducting and electric insulating material F, such as a mixture of Portland cement and sand or Portland cement alone, which is placed in the enlargements G of the perforations in the sup port and when it sets holds the carbon rods securely in place and excludes air, thus preventing deterioration of the carbon rods.

carbon rods provided at their ends with means for connecting them with the outside leads, a thin sheath of incombustible heat-conducting and electric insulating material surrounding said rods and connecting means, said parts being retained within abody of metal byasuitable plastic heat-conducting and electric insu lating material.

4. An electric resistance, which comprises a metallic body provided with a plurality of perforations, a carbon rod in each perforation, copper caps on the ends of the rods, connecting-wires secured to the ends of said caps,- a thin sheath of incombustible heat-conducting and electric insulating material which surrounds the rods and caps, and a plastic heat-conducting and electric insulating material which surrounds the sheath and retains the rods in the perforation of the casing.

5. An electric resistance comprising ame tallic body provided with cavities, resistanceconductors in said cavities, and plastic material adapted to secure said conductors within said cavities by mechanically interlocking with said body.

l 6. An electric resistance comprising a metallic body having a large radiating-surface, said body being also provided with cavities, each of which has more than one diameter, carbon rods in said cavities, and a heat-conducting electric insulating cement filling the space between said conductors and said body.

7. An electric resistance, which comprises carbon rods provided with a thin sheath of incombustible heat-conducting and electrioinsulating material substantially as described, copper caps on the ends of the rods, connectlug-wires secured to the ends of said caps, said rods being retained within a body of metal by a suitable plastic heat-conducting and electric insulating material.

8. An electric resistance, comprising a metallic body provided with a plurality of perforations, a carbon rod in each perforation and having reduced ends, copper caps having holes fitting the reduced ends, the outer surfaces of the caps being flush with the surfaces of the rods, connecting-wires secured in the ends of the caps, a thin sheath of incombustible heat-conducting and electric insulating material which surrounds the rods and caps, and a plastic heat-conducting and electric insulating material which surrounds the sheath and retains the rods in the perforation of the casing.

9. A resistance device comprising carbon rods surrounded by a sheath of incombustible electric insulation which is in turn surrounded and secured Within a support by means of a plastic material.

10. An electric resistance comprising a metal casin g,resistance-conductors in the easing, a thin sheath of mica surrounding each conductor, and a material filling the spaces between the resistance-conductor and the easing, to insulate them from each other, convey heat from one to the other, hold the com ductors secure Within the casing, and exclude air from the conductors.

In Witness whereof I have hereunto set my hand this 16th day of January, 1900.

CARL W'. LARSON.

Witnesses:

BENJAMIN B. HULL, MABEL E. JAcoBsoN.

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