US460980A - Electric heating-core for smoothing-irons - Google Patents

Description

(No Model.) 2 Sheets-Sheet 1.

W. MITCHELL. l ELECTRIC HEATING GORE FOR SMOOTHING IRONS.

Patented Oct. I3, 1891'.

lNvENToR WITNESSES s venus co., mow-urna., wsu

2 She W. TCHELL. ELECTRIC HEATIN RE POR SMOOTHING IRONS.

SI1 8 C UNITED STATES PATENT OFFICE.

IVILLIS MITCHELL, OFVMALDEN, ASSIGNOR. T() THE BUTTERFIEIiD-MITCHELL ELECTRIC HEATING COMPANY, OF BOSTON, MASSACHUSETTS.

ELECTRIC HEATING-CORE FOR SMOOTH'ING-IRONS.

SPECIFICATION forming part of Letters Patent No. 460,980, dated October 13, 1891.

Application led March 24, 1891.

To all whom, t may concern:

Be it known that I, XVILLIs MITCHELL, a citizen ofthe United States, residing atl Malden, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Electric Heating- Cores for Smoothing-Irons; and I do hereby declare the following to be a full, clear, and exact description ot'the invention, such as Io will enable others skilled in the art to which it appertains to make and use the same.

The chief object of this invention is to provide a new core for the wire of electric heaters which shall separate the cols or spi- Pals thereof absolutely and insula e them from each other, while holding each in its proper position. .2

To this end my invention consists, mainly,`\ in a block or solid piece'ot soapstone or otherl 2o` insulating material in any suitable form,l1avfr ing grooves for the wire eut in its sides `or ends or both. This core is especially designed for use in bed-warmers, flat-irons, cylindrical smoothing devices, cooking utensils, and other small articles, but of course is not confined thereto.-

In the accompanying drawings, Figure l representsaperspective viewof my improved core, having grooves in its sides and the heating-wire wound thereon, but partly broken away. Fig. 2 represents a similar View of a block having grooves in its sides, but not in its ends, the wire being wound endwise as well as crosswise, and broken away to show the grooves. Fig. 3 represents in perspective as a modification a cylindrical core having circumferential grooves. Fig. 4. representsa side elevation ot' the same with the wire wound thereon. Fig. 5 represents a perspective view of another modification, having a fiat form, with the wire wound in grooves in its sides and partly broken away. resents a metallic shell, open at one end to receive this latter core and constituting with it an electrically-heated griddle. Fig. 7 rep- Fig. S represents a heating-cylinas determined by experiment.

ience both ends ot the Wire leave the core or Fig. 6 repi Serial No. 386,204. (No model.)

der constructed as in Fig. 3 and coated with pulverized soapstone and asbestus; and Fig.

f) represents a hollow {lat-iron body adapted to receive a modified form of core, also shown in said figure.

' In the said drawings, A designates the heating-wire which forms part' ot an electric circuit, and B the core on which it is wound. This core is preferably of soapstone, but may 6o be of any other solid insulating material. As shown in Fig. l, a continuous helical groove B is made in its sides to receive the wire, said groove being of suflicient depth to hold the wire spirals in their proper position and the interval between one spiral of the groove and the next on either side being such as to insure the best heating action ot the electric current passing through the wire,

For Couven-7o block at thc same end, one end ot' the wire passing thereto through a short oblique inner passage c from the nearer groove and the other end of the wire being passed through 7 5 a longitudinal inner passage CZ, extending from end to end ot the said core or block. This construction is repeated in Fig. 5, except that the groove is broken into a number ot parallel grooves, occupying the same posi- .8o tion, by the ungrooved edges ot the flattened core, these being too narrow to need grooving. The form shown in Figs. 3 andhas the continuous groove ot Fig. l, and also the passages c d, arranged correspondingly to those S5 above described, the chief difference being that the core in the one case is a rectangular cubical ligure, whereas in the other it is cylindrical. This cylindrical core has gudgeons c screwed into its ends, they being available 9o for suspending it under car-seats or suspend- /i'ng it in bearings on standards D, as shown in Fig. S. A coating C ot mingled asbestus and pulverized soapstone is given to it, as

`shownin this latter iigure, and becomes as 9`5 har/d as the core itself, practically embedding the Wire therein and hiding it. To apply this coating mix together approximately equal parts of pulverized asbestus and pulver-ized soapstone, with enough of any adhesive maroo terial to form a paste or mortar. Then heat the soapstone core by the electrical current.

'Then turn oftl the' said current and spread the aforesaid mixture on the said heated core. The heat will cause it to harden, forming the desired coating; or, as shown in Fig. 7, a heating-core having one of the forms above described may be heavily painted over and used as a bed-warmer or foot-warmer or forany other heating purpose. It is preferably provided with a handle E; or, as shown in Fig. 6, a fiat hollow case F, having one end fopen, may receive the fiat form of core shown in Fig. 5 and be used with it as an electric griddle. Legs g are provided, giving this article a table-like appearance.

As shown in Fig. 2, a block of the form shown in Fig. l may be grooved spirally endwise as well as around its sides. The grooves of each set cut through those of the other set, so that neither is strictly continuous. The lengthwise grooves o are deeper than the grooves h to avoid contact of the coils of wire with each other and consequent short-circuiting. I wind the wire first in the lengthwise grooves o and then back on the sides of the block or core in the grooves l) to the end of the block Where the winding began. A short passage m from the last lengthwise groove o on the right to the nearest crosswise groove l) extends through one corner of the block and allows-this transfer of the wire from one set of grooves to the other, the direction of winding, as in the other figures, being indicated by arrows.

Heating-cores constructed as hereinbefore described are capable of being used in a great variety of ways and with many kinds of covering or incasement. A few of these have herein been explained and illustrated; but such a core, wherever used, is a part of my invention. It dispenses with all other insulation and holds the wire absolutely in its position and arrangement of greatest efficiency.

Of course the core may have the same grooved construction without being madeof insulating material and will answer well if the Wire is coated. The grooves are arranged to hold each spiral of the wire in a space or interval about ten or twelve times its own width, varying more or less according to the work to be done.

Any form of core shown may of course be coated like the cylinder shown in Fig. 8, or painted like the bed-warmer shown in Fig. 7, or put into a hollow casing, as suggested by the hollow griddle-shell in Fig. (i or the fiatiron body of Fig. 9, which last receives a core of the form shown also in said ligure. This receso core is' rounded at the iippeiv corner' of oneJ1 end to' tit the end of the cavity in the shell; Otherwise it has substantially the construction shown in Fig. 1.

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

l. In combination with a wire forming part of an electric circuit and wound in a heating coil or spiral, a solid core of insulating material which is grooved to receive the said wire and provided with a passage permitting the return of the wire to the end of the core where the winding began, substantially as set forth.

2. In combination with a wire forming part of an electric circuit, a core or block which is provided with a set of spiral grooves running crosswise anda similar set running lengthwise, the wire being wound first in one set of grooves and then in the other, for the purpose set forth.

3. In combination with a wire forming part of an electric circuit, a core which is provided with a set of grooves running crosswise and a set running lengthwise of the said block, one set of grooves being deeper than the other set, and the said wire'being wound first in the deeper grooves and afterward in the shallower ones, substantially as set forth.

4:. In combination with a wire forming part of an electric circuit, and a grooved core ou which it is wound, a coating of powdered soapstone and asbestus for the outside of the said core and wire, substantially as set forth.

5. In an electrically-heated utensil, the combination of a non-metallic bar or core inclosed within the body of it, and a wire forniing part of an electric circuit, which is wound on said core, each spiral-of the wire being in a space or interval about ten ortwelve times its own width, more or less, according to the work to be done, substantially as set forth.

6. A grooved core, in combination with a wire wound thereon in -the groove or grooves thereof and forming part of an electric circuit, the said core being provided withv a pas sage through a part of it for one end of the said wire to extend outward from the grooves through one end of the said core, substantially as and for the purpose set forth.

In testimony whereof I affix my signature in presence of two witnesses.

WILLIS MITCHELL. Witnesses:

ARTHUR B. SMITH, WILLIAM P. CUTLER.

IOO

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