US1613770A

US1613770A - Electric heating device

Info

Publication number: US1613770A
Application number: US49990A
Authority: US
Inventors: Reichold Ludwig
Original assignee: FITZGERALD Manufacturing CO
Current assignee: FITZGERALD MANUFACTURING Co
Priority date: 1925-08-13
Filing date: 1925-08-13
Publication date: 1927-01-11
Anticipated expiration: 1944-01-11

Description

V' 1,613,770 Jan. 11, 1927. L' REICHOLD ELECTRIC HEATING DEVICE Filed Augufift 13J 1925 Patented' Jan. 1l, 1927.

UNITED STATES PATENT OFFICE.

LUDWIG REICHOLD, OF WINSTED, CONNECTICUT, ASSIGNOR TO THE FITZGERALD MANUFACTURING COMPANY, 0F WINSTED, CONNECTICUT, A CORPORATION 0F CONNECTICUT.

ELECTRIC HEATING DEVICE.

applicati@ mea august 1s, 192s. sum m. 49,990.

This invention relates to improvements in electric heatinedevices, and more particularly to'such p ates of the hot plate type yfor domestic use. l

It has heretofore been sought to construct electric heating devices which may have the heating element brought into close proximity to the surface to be heated, and in which the resistance wires are protected and insulated in a satisfactory manner. The great difficulty of the' previous constructions has been the fact that the heating element wires were not brought into sufliciently close proximity with theplate toy bc heated, but were held at a distance therefrom, and in par ticular were subject to physical deterioration by abrasion. Furthermore, in such devices it was dilicult to maintain the proper plane relation of the heating element wires with regard to the plate to be heated.

According to the present invention. a very simple and cheaply constructed assembly is provided which may be easily assembled and dismounted at need, and yet which presents the heating element wires in close and positive relation with regard to the plate.

One form of execution of such a' structure is shown on the accompanying drawings, in which:

Fig. lfis an elevation of a wafile `iron employingheating elements according to the present invention.-

Fig. 2 is a longitudinal section of the device substantially on line 2-2 of Fig. 3, but showing the other parts in position. g'

Fig. 3 is a 'plan of the base plate, with the heating element wire in position thereon.

This electric heating device has the hot plate section proper with waflle iron studs thereon atone face, and on the other face a stud 2 with a threaded bolt 3 extending there from, the stud heilig arranged substantially at the center of the plate vand projecting at right angles therefrom.

A disk of mica 4 has a central aperture which closely fits the stud 2, and is received tightly against the surface of the plate 1. This disk serves bothv as electrical and mechanical'protection for the heating element.

The heating element assembly has the base plate 5 of relatively thick metal. AAIt is of substantially circular form, with a central aperture 6 therein to adapt it to be placed over and around the vstud 2. A flattened Gil and are held spaced therefrom by smaller disks 12 of similar material. The preferred method of mounting thesedouble washer as- .semblies is by providing a small hole in the plate 5 at the point Where they are to be located; a hollow rivet 11a is then passed through the plate 5, the asbestos sheet 10, and the

disks

11 and 12, and clinched in posit'on` thus holding the members firmly and ixedly assembled to form a unitary and rigid Whole.

The terminal bolts 13 and 14 for the heating elementwires are mounted upon the sheet of mica 15, and are separated from the plate 5 by a series of mica washers 16 which are received in two holes 17 formed in the plate 5, as may be seen from Fig. 2. These mica washers are substantially the same diameter of the holes and when the bolts are drawn tight they, by their natural irregularity of outline in the usual process of manufacture, are held in frictional and overlapping relation with regard to each other and to the plate, so that the terminal bolts are fixed in position.- In addition to this method of holding the terminal bolts 13 and 14 in place, the mica sheet- 15 projects under the asbestos sheet 10, and is held thereby as well as by the rigidity of the heating element wire itself. n practice it has been found that a very rigid assembly 1 vhen this plate 5 with the asbestos sheet wir 7 has a central hole 26 to enable it to fit over and around the threaded bolt 3. A nut 27 is employed to force the ldome into contact with the plate 5, as shown in Fig. 1. It will bev noted that the edge 28 of this domeshaped cup 25 engages the plate intermediate the central aperture 6, andthe outer edge of the same.

This device has been shown andv described as being applied toa wafle iron, but it will be understood that it is of far wider application. In the particular forni illustrated in Fig. 2 the rear side of the element is shown as covered and protected by a cap 30 which iits the rebated edge 31 of the plate l, and is held in fixed relation to the other elements by a nut 32.0n the threaded bolt 3. The plate may have` the hinging lug 34 formed integrally therewith; so that two such eley ments may be assembled, as shown in Fig.

Cal

1, and mounted uponv a suitable standard 35 with base 36. The lower element A is fastened to the standard 35, while the upper element is hinged to the lower at C and has the lifting handle D for easy and safe operation.

Obviously, modifications smay be made from the particular embodiment represented within the scope of the appended claims.

I claim:

1. In an electric heating device, a heating element assembly consisting of a rigid metal base plate, an insulating sheet upon said base plate, insulating spacing and holding washers on said insulating sheet, metal rivets passing through said late, said sheet, and said washers to fixed y connect the same, terminal bolts secured to and insulated from said base plate, and a heating element passing from one terminal bolt to another in zig zag manner around said washers and held by said bolts and washers in iixed relation to said b ase plate.

2. In an electric heating device, a heating element assembly having a base plate with apertures therein, an insulating sheet on one side of said base plate, a terminal boltpassing through said sheet and one of the apertures, and mica washers substantially of the size of the aperture and disposed about said bolt and in said aperture and extending beyond the'same, whereby said bolt upon being drawlitight clamps said washers into locking engagement with ythe said base plate and prevents movement of said bolt with regard to said plate.

3. In an elect-.ric heating device, a heating plate, a clan'iping bolt extending from said heating plate, a mica sheet loosely locate-d upon said plate and around said bolt; a heating element assembly consisting of a base plate, an insulating sheet on said plate, spacing and holding washers on said sheet, rivets passing through said plate, Said sheet and said washers to fixedly connect the same, an insulating terminal sheet on said plate, terminal bolts mounted on said terminal sheet, and a heating element` passing from'one terminal bolt to another in zigzag manner around said washers; a

Aspherical dome-shaped cup having anl aperture for said clamping bolt and engaging said base plate intermediate the center and the edge, a nut .on said bolt to clamp said heating element` assembly into close and fixed relation with said heating plate, and a protec'tiner cap inclosing the heating element assembly.

In testimony whereof, I aiix my signature.

5- LUDWIG REICHOLD.