US487285A - Electrical heater - Google Patents

Description

(No Medel.)

W. MITCHELL.

ELECTRICAL EEATEE. No. 487,285. y Patented Dee. 6, 189.2.

UNITED STATES PATENT OEEICE.'

IVILLIS MITCHELL, OF MALDEN, ASSIGNOR, BY MESNE ASSIGNMENTS, TO THE g AMERICAN ELECTRIC HEATING COMPANY, OF BOSTON, MASSACHUSETTS.

ELECTRICAL HEATER.

SPECIFICATION forming part of Letters Patent No. 487,285, dated December 6,1892.

Applio ation filed March l 5, 18 92.

T all whom, it may concern:

Be it known that I, WILLIS MITCHELL, a citizen of the United States, residing at Malden, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in lillectro-Magnetically Heated Stoves; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable 1o others skilled in the art to which it appertains to make and use the same.

This invention relates to stoves which are heated by electricity and electro-magnetic induction. To this end a stove is constructed of magnetic material, with cores or studs on which an electric conductor is Wound or electric heaters are tted, the said conductor or heaters being in electric circuit, so that a current passing through it or them will magnet- 2o ize the said stove. The latter may be applied to heating rooms, halls, or vehicles, to cooking, steam-generating, or any other purpose for which it is suited.

In the accompanying drawings, Figure l 2 5 represents a verticalsection of an electro-magnetic stove embodying my invention. Fig. 2 represents ahorizontal section of the same on the line :c .fr of Fig. I; and Fig. 3 represents a detail sectional view of one of the cylindril3o cal electric heaters employed, on a larger scale.

A designates the body of the stove, standing on feet c.. As shown, it is of cylindrical form and upright, but of course may be rectangu- 3 5 lar and horizontal or of any other construction which is suitable and desired. It is o1", magnetic material, preferably iron, and made in several sections, secured together by rivets b, that pass through inwardly-turned iianges 4o B on the side edges of the said sections.

These sections are provided with inwardlyextending studs or cores C, of magnetic material, the studs of each section being preferably integral therewith. On each of these studs is Iitted aheater D, of cylindrical form, similar to that shown and described in my previous patent, No. 457,362, and consisting of concentric insulating-cylinders cl, preferably of asbestus, having a Wire E Wound continu- 5o ously thereon to form successive concentric helices, the Wire at each Winding being pref- Serial No. 425,004. (No model.)

erably in a space about ten times its own breadth, this being found to give the best calorific results. Each heater is protected by a cap or casing d', and the Wire E passes from heater to heater, connecting the whole series. Vthen the circuit is closed, the current of electricity through the said wire not only heats the said studs and the body of the stove by the heat of resistance,but also magnetizes the said studs or cores and the magnetic body of the stove, so that additional heat, due to magnetic lag or hysteresis, is produced,especially when an alternating or interrupted current is employed.

Of course only a part of the stove may be .made of magnetic metal and provided with these studs and heaters; but better results will be obtained by the construction shown. By leaving it open at top and bottom, as illustrate'd, I allow the free passage of air, which is heated therein, beside the heating of the surrounding air, due to conduction and radiation. The studs may of course be external, but in that case will require additional covering or Will be unsightly and in the way. Therefore the internal studs shown are preferred. It would, however, be more or less difficult to cast the stove as an integral body with these inwardly-extending studs and have them all accurate in shape and position. Therefore the sectional construction is better whenthe stove is made of cast-iron. For a Wrought-iron stove the advantage of sectional construction is even greater. Of course the magnetization may be effected Without the especial heaters which I have shown; but these are found to be very convenient and eflicient. Nevertheless, a mere winding of Wire about the studs will be operative if there are studs enough.

A furnace or heater of any size may be made and operated in accordance with the same principle.

Having thus described my invention,what I claim as new, and desire to secure by Letters Patent, is-

l. A stove or furnace partly or wholly composed of magnetic material, provided with studs or cores of the same, in combination with Wire Wound on the said studs and conducting electricity, for the purposes set forth.

TOO

2. A stove orfurnace partlygorwhollycom: posed of magnetic material and provided with studs or cores of the same, in combination with electric heaters applied to the said studs and containing helices, whereby the said studs and the magnetic material ofk thestove are magnetized in order that the said stove may be heated by magnetic lag as Well as by resistance, substantially as set. forth.

3. A stove or furnace partly or Wholly composed of magnetic material and provided with inwardly-extending studs of the same, in combination with aWire woundthereon and foim1 ing part ot an electric circuit, substantially as set forth.

4. A stove consisting of several sections of magnetic material7 each section being provided With flanges for fastening and with in- ,presence of twowitnesses- WILLIS MITCHELL. Witnesses:

PELATIAH -RJ TRLPP, EDWIN W; PIERCE.

Images