US1378515A - Electric heating device - Google Patents

Description

A. F. BERRY. ELECTRIC HEATING DEVICE. APPLICATION FIlED DEC.26, 1912. RENEWED SEPT. 8, 1920.

'l,378,5 1 5. Patented y 17, 1921.

Fi Z /0 x; 2 H v I [Q Q Q Q Q QQ /5 h; 16 F /'4 Inventor Arthur Francis Berry,

His Attorneg.

- ARTHUR FRANCIS BERRY, OF LONDON, ENGLAND, ASSIGNOR COMPANY, A CORPORATION I OF NEW YORK.

UNITED STATES PAATVE Nr' OFFICE.

T0 GENERA]; ELECTRIC ELECTRIC IiEATING DEVICE.

To alZ'wko'in it may concern: I

Be it known that I, ARTHUR FRANCIS BERRY, a subject of the King of Great Britain, residing at London, Englanchhave invented certain new and useful Improvements in Electric Heating Devices, (if which the following is a specification.

This invention has reference to electrical heaters of the kind comprising perforated plates or grids and bare resistance elements arranged beneath the same, and designed for heating or boiling water, for cooking and the like purposes, and. it has for its object the provision of electrical heating apparatus of this kind having greater eificiency, utility and durability than such apparatus as heretofore constructed.

For this purpose an electric heater made in accordance with my invent on comprises a metal plate having comparatively large openingsseparated by ribs or bars, and, a

' bare resistance elemelit i hat. inay-be bent t6 a coiled, zig-zag or equivalent-shape and is carried by' and below the plate by holders of insulatingmaterial secured to the ribs or bars which are constructed in such a manner as toshielcl the holders and adjacent portions of the resistance element from contact Fig. 3 is a section on the line 3 3 of Fig. 2; Fig. 4 is a view similar to Fig. 2,'but par' with liquid that may boil over from the ves- .sel being heated, or which may become spilled therefrom in any way, so that deterioration of the insulating quality of the holders andrapid destruction of the holders and of the adjacentfportions of the resistance element shall be prevented and the efli-.

ciencyand durabilit of the heating unit maintained. The res stance element may be connected at different points along its length to terminals combined with a switch so that one, two or more sections of the element y be used at will to varythe heating efi'ect groduced, to suit requirements.

" In the accompanying illustrative draw' ings, Figure 1 is a plan view of an. electric heating device embodying my invention; Fig. 2 is a section on the line 22 of Fig. 1;

tially in elevation showing a slightly'modi fied form of support for the heating ele ment; F igfio is a detail view of a section of an insulating supporting strip and Figs. 6,

'7 and 8 are detail views of modifications.

Referring now to the drawings, a-plate 10 is provided with openings 11 which are prefbe unevenly I Specification of Letters Patent. I Patented May 17, 1921, 1 Application filed December 26, 1917, SeriaI No. 208,782. Renewed September 8, 1920. Serial No. 409,032.

erabliyg sector shaped and separated by ribs 12. ported, beneath the plate by the ribs, from which the same is insulated. The resistance element .which may be helically' wound, is formed into several convolutions which may spaced apart as described in my British Patent #467 2 of 1909, so as to insure the plate being uniformly heated. Theresistance element .is supported by insulating strips 14 vertically disposed and preferably formed of micat Thesestrips are fixed in recesses 15 formed on the underside of the plate beneath the ribs.

The strips are preferably secured in position by wedges 16 (see Fig. 3) ohe on either bare resistance element 13 is supside of the strip, which are also formed of insulating material. Inthe form of my invided with registering holes 17 in which the ""resistance" element 'is disposed. In order to insert the resistance element 'si'dewise into these holes, slits 18 are provided which extend from-the holes to the lower edge'of the strips and in order to lock the resistance element in position, the slits in the two pieces leading to the opening are angularly arranged. Ihstea'd of arranging the slits in thestrip at the lower edge of the piece as just described, they may be arranged in the upper portion as shown in Fig. 6. In order to prevent any liquid or other material that is being treated on the plate; from coming into contact with the members which support the resistance element, flanges 19 are provided beneath the plate at the inner and outer portions of the supports from which the liquid may drip. r

Figs. 7 and 8 show a modified arrangement in which each of the two strips of mica are formed with reversely arrangedslots 20, the inner holes of which are curved and are armed with semi-circular metal "guards 21.

The arrangement is such that after the convolutions of the resistance element have been placed in the slots when the strips of .mica

are apart, the strips are then brought to-.

gether with the slots registering as shown in Fig. 8 andcircular metal lined holes will be. provided for supporting the convolutions of conductor, the adjacent guards 21 forming, in effect, a series of metal eyelets. One pair of strips of mica and two lengths of mica wedges may be used for each rib as already described in connection with Fig. 2 or several lengths of strips 14 and several lengths of mica wedges may be used for each rib as shown in Fig. l. The terminals for'the'heating unit are indicated by the reference characters 22, 23, 24 and 25 which are connected to conductors 26, 27, 28 and 29,respectively.

While I have described my invention as embodying a concrete structure and as operatingin aspecific manner in accordance with the provisions of the patent statutes, it should be understood that I do not limit my invention thereto, since various modifications thereof will suggest themselves to those skilled in the art without departing from the spirit of my invention, the scope of which/isset forth in the annexed claims.

Vhat I claim as new and desire to secure by Letters Patent of the United States, is: 1. An electric heater comprising a bare resistance element, means carrying said element, and a metal plate provided with openings separated by ribs covering said means.

2. An electric heater comprising a bare,

resistance element, means carrying said element, and a metal plate provided with openings separated by ribs supporting and covering saidmeans.

3. An electric heatercomprising a metal plate provided with openings separated by ribs vertically disposed, insulating strips secured to the under side of s'aid ribs and formed with holes, and a bare resistance element disposed within said holes, the ribs covering said insulating strips.

4. An electric heater comprising a metalance element disposed within said holes, the

insulating strips being provided with slits extending from said holes to the edge ofthe strips by which the resistance element may be inserted within the holes.

6. An electric heater comprising a metal plateprovided with openings separated by ribs, a bare resistance element carried beneat the plate by said ribs and insulated therefrom and flanges secured to the under side of the plate adjacent to the resistance element.

In witness whereof, ll -havehereunto set my hand this sixth day of December, 1917.

ARTHUR FRANCIS BER-RY.

Images