US1279252A - Resistance element. - Google Patents

Description

J A. CAPP.

RESISTANCE ELEMENT.

APPLICATION man APR. 1a. 1916.

1,279,252. Patented Sept. 17,1918.

ALLOY 0F/R0/V, NICKEL, MANGANESE h IDA/6111101:

O n a s @Wi His A om g.

cost of the process, and hence STATES PATENT OFFICE.

Jomt A. canyon COMPANY,

scmmnt'ranr, NEW YORK, assxanon roommmx. Emerald a conroaarron or NEW YORK.

RESISTANCE ELEMENT.

To all whom it may concern.- Be it known that I, JOHN A. Our, a citizen of'the United States, residing at Schenectady, county of Schenectady, State. of.

8 New York, have inventedfcertain new and useful Improvements in Resistance Elements, of which the following is a specification.

My invention relates to resistance elements or the like, and more especially to resistance elements in which the resistance wire is inclosed in a metallic sheath, with an intervening layer of heat conducting and 7 electric insulating material between the two.

Resistance elements of this character have hitherto been proposed which are made from an ingot comprising a metal tube of steel other material, a central core of suitable material which for heating 'work and the like should have a high specific electric resistance, and a layer of powdered refractory heat conducting and electric insulating material compacted between thecore and the sheath. After the ends of the ingot are stopped with washers or swaged or rolled to a size to give to the core wire the required resistance. The details of manufacture of sheathed wire of this character are fully set forth in a patent issued to Chester N. Moore, August 11, 1914, Serial N 0. 1,107,233, and need not here be morefully discussed, except to explain that between each few passes it is necessary to thoroughly anneal the wire; otherwise the core wire be- It comes so hard that further reduction becomes impractical. Many of the best resistance materials require a considerable amount of annealing, and as this is a rather expensive process, it adds materially to the to the expense of the finished sheathed wire.

My present invention has for its object the provision of sheathed wire of the general character discussed above, in which the core I wire is made of a material that is particularly well suited to undergo the operations necessary for its manufacture without an excessive amount of' annealing and which has at th ejsaine time a high specific resistance, so

0 that the material is particularly applicable to heating and other work where'ahigh re sistance is required. I havefound that an alloy containing, or composed of, iron, nickel, and manganese is particularl well l suited for this purpose. Alloys 0 iron plugs, the whole is.

Specification of Letters Patent. P t nt t, 17, 1913, Y Application filed April 1a, 1916. serial m. 92,057,

and nickel have hitherto been used resistance elements,. and manganese has commonly been present in such alloys in small proportions, for example one per cent. or less, and in such proportions it has the' effect of hardening the alloys. I have found, however, that when the maganese 1s present in such alloys in substantial proportlons, that it not only raisesthe resistance of the alloy, butthat it has the unexpected result of increasing their malleability and ductility so that, because of their malleability, they do not require an exce s sive amountof annealing between the successive passes in the rolling or swaging machine in order to prevent their becoming unduly hard, and because of their ductility they may be extended to the required length and be kept substantially, uniform in crosssection. At the same time, the manganese imparts to the alloys greatly increased electric resistance, which makes the same particularly suitable for heating and other high resistance Work. I have found the following composition satisfactory for the core wire:

Iron 55% Nickel 35% Manganese 10% It will be understood, however, that while I have given the composition that I prefer in practice, that the percentage of the vari- 'ous constituents may vary and still come within the scope of my invention.

Referring, now, to the drawing, the figure shows, partly in longitudinal section and partly in side elevation, a section of sheathed Wire, embodying my invention and provided with a terminal. The core wire is indicated by the numeral 1, and is formed at the end with an enlarged terminal 2 of the character shown in Whitney Patent #1,095,502;which was issued April 14, 1914.

The core wire is inclosed by a tubular metalmade is rather readily oxidized when exposed to the atmosphere at high temperatures, and is, therefore, unsuitable for heating device, and other resistance work 5 where the resistance element is run at ared heat and exposed'to the atmosphere' When the material, however, becomes the resistant element of sheathed wire, this property of rather readily oxidizing is of 10 no consequence, since the atmosphere is ex- What I claim as new and desire to secure by Letters Patent of the United States, is,- 1 1. A reduced sheathed wire comprising.

a high resistance core wire including in its composition iron, mckel and manganese, a

. sulating material withm compacted tubular metallic sheath inclos' said core 28 wire, and an intervening layer 0 compacted powdered insulating material within which the resistance element is embedded;

2. A reduced sheathed wire comprising a high resistance core wire including in ts 8 0 composition iron and nickel, and manganese in excessiof one per cent., .a tubular metallic sheath inclo'sin'g said core wire, and an in-y tervening layer of compacted powdered inance element is embedded. v

3.. A reduced sheathed wire comprisingia resistance core wire composed substanh gh .tla 1y of iron fifty-five per cent., nickel thirty-five per cent., and manganese ten per 40 cent., a tu ulan metallic sheath inelosing said eorewire, and an intervening -layer of.

gowdered insulating material withm whic the resistance element is embedded.

In witness whereof, I have hereunto set my hand this 17th day of A ril, 1916.

JO A. CAPP.

which the resist-ti

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