US1028107A - Electrically-heated culinary apparatus. - Google Patents

Description

W. S. HADAWAY, JR. & E. E. ROSE. ELEOTRIGALLY HEATED CULINARY APPARATUS.

APPLICATION FILED OUT 8, 1910.

Patented June 4, 1912.

ATTORNEY UNITED STATES PATENT OFFICE.

WILLIAM S. HADAWAY, JR., 0F

OF PITTSBURGH, PENNSYLVANIA, ASSIGNORS EAST ORANGE, NEW JERSEY, AND EDWARD E. ROSE,

TO WESTINGHOUSE ELECTRIC &

MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

ELECTRICALLY-HEATED CULINARY APPARATUS.

Specification of Letters Patent.

Patented June 4, 1912.

Application filed October 8, 1910. Serial No. 586,081.

The object of our invention is to provide a device of the above-mentioned character which shall be simple and durable in construction and eflicient in operation.

It is well known in the art that the efliciency and the life of a heater unit are greatly increased by subjecting it to pressure, and our invention embodies simple and inexpensive meansfor obtaining the desired conditions.

In the accompanying drawing, Figure 1 is a view, partially in elevation and partially in section, Fig. 2 is a plan view, with a portion broken away, and Fig. 3 is a seetional View, on the plane IIIIII of Fig. 1, of a device constructed in accordance with our invention. Figs. 4: and 5 illustrate two steps in the process of seaming the outer and inner shells together, whereby a pressure upon the heater element is secured, as hereinafter described, and Fig. 6 is a sectional view of a modified form of heater unit.

Referring to the drawings in detail, the device comprises, essentially, an inner receptacle or shell 1, of thin heat-conducting material, an outer shell 2 which is also formed of thin heat-conducting material and is adapted to fit tightly over the inner shell, a circular band 3 which surrounds the upper portion of the inner shell, and a heater unit 4, which is assembled between the bottom' walls of the aforesaid shell members and is maintained under pressure.

The inner shell 1 is, in general, of cylindrical shape, the upper rim of which is turned over, to form a double seam 6 with the upper edge of the circular band 3, in order to securely fasten the two members together. The outer shell 2 is substantially of the same form as the inner shell, and is adapted to fit tightly over it. A channel or recess 8 is provided in one side of the,

outer shell 2 to accommodate the leads to the heater umt 4', and the outer shell is also provided with a suitable bracket 9 upon which a plurality of plug terminals 10 and 11 are mounted.

The heater unit 4 may be of any suitable construction, but preferably comprises a slotted resistance ribbon 14:, wound into a flattened helix about an insulating disk 15 which is provided with notches 16 to hold the ribbon in position. Inasmuch as the arrangement and structure of the resistance ribbon are shown and described in detail in Patent No. 890,856, granted, June 16, 1908, to the Hadaway Electric Heating & Engineering Company, a further description is not considered necessary.

'Ribbon connections or leads 17 and 18 are connected to the heater unit 4 and extend up through the recess 8 in the outer shell to the plugterminals 10 and 11, said leads being suitably insulated from each other and from the adjacent walls by means of strips of insulation 19.

In assembling the heater unit, insulating disks 21 and 22 are placed upon the respective sides of said unit to separate the resistance ribbon 14 from the containing vessel. Pressure plates or disks 23 and 24 are also placed upon the respective sides of the heater unit, in order to reinforce and lend rigidity to the thin bottom walls 25 and 26 of the outer and inner shells,re-

spectively.' Having assembled the heater unit and the insulating disks and pressure plates, the upper edge 27 of the outer shell 2 and the lower edge 28 of the circular band 3 are seamed together in such manner as to secure and maintain a considerable pressure upon the heater unit.

In some instances, it may be expedient to assemble the component parts of the heater into an incased, self-contained unit, as shown in Fig. 6, in order to hold the parts together and provide a single structure which would materially facilitate the preliminary handling and treatment of the heater unit before it is associated with the containing vessel. Referring particularly to .Fig. 6, itwill be observed that the resistance ribbon 14 and the insulating disks 15, 21 and 22 are assembled as hereinbefore described. Furthermore, an incasing sheath 29 is provided which envelops these parts and thus forms a simple and self-contained 'unit. The incasing sheath 29 is preferably constructed of aluminum or sheet copper, although any suitable material may, of course, be employed.

In order to set forth more clearly the method of seaming the outer shell and circular band together, whereby a pressure is exerted upon the heater unit, attention is directed to Figs. 4 and 5, which show two steps in the seaming process. Before assembling any of the parts of the device, the lower edge 28 of the circular band 3 is turned out at substantially right angles and the upper edge 27 of the outer shell is similarly turned back, but in a less degree, as shown in Fig.4. The circular band 3 and inner shell 1 are then secured together at the top by the seam 6, as previously noted; the

heater unit 4 is assembled and placed in position wit-h the insulating disks 21 and 22 and the pressure plates 23 and 24, in the bottom of the outer shell 2; the ribbon connections 17' and 18 are disposed within the recess 8 and the inner shell 1 is placed in position.

If the incased type of heater, such as shown in Fig. 6, be employed, it may be assembled as a single unit between the pressure plates 23 and 24 in the bottom of the shell 2. Moreover, if desirable, said pressure plates may be suitably secured together on opposite sides of the sheathed heater unit, in such manner as to effect some initial pressure on the heater element before it is placed in position and is subjected to the'final pressure by means of the seaming process. Having assembled the heater, as a whole or in parts, pressure is then applied to the upper edge 6 of-the inner shell 1 and a the two shells are forced together, thereby causing the edges 27 and 28 of the outer shell and circular band, respectively, to take the positions shown in Fig. 4. With the pressure still applied, the extremity of the upper edge 27vof the outer shell is turned.

over the projecting edge 28 of the circular band, as shown in Fig. 5. The final step in the process consists in forcing up the seam,

now partially formed, into'engagement with the ClICtllELP- band, whereby a tension in the outer'shell is produced and a drawing 1 action effected, which exerts and maintains a considerable pressure upon the heater element, as will berea-dily understood. If desired, the. seam may then be brazed inorder to form a particularly rugged andv durable I structure. Furthermore, those skilled in the art will readily'understand that the-heater unit 4 may be so constructed that either the whole or apart thereof maybe disposed between the side walls of the outer and inner shells, instead of being located entirely in termediate the bottom walls, as hereinbefore shown and described.

I Although we have shown and described our device as equipped with a single heater unit and as adapted for but a single heat, it is evident that a plurality of heater units may be similarly assembled and that two or more heats may be readily obtained, if desired.

It will, of course, be understood that the device shown and described is onlyillustrative of a specific application of our invention to culinary apparatus and thatour in vention may be readily adapted to other commercial devices.

Modifications of thedevice shown may be effected without departing from the spirit and scope of our invention, and such modifications are intended to be covered by the appended claims. x

We claim as our invention:

1. The combination with an inner receptacle/of relatively thin heat-conducting material, a two part outer shell of substantially the same form and adapted to surround said receptacle, of a suitable heater unit and insulation therefor disposed between said receptacle and said shell, the adjacent edges of the parts of said outer shell being folded together to exert pressure upon the heater unit.

thin heat-conducting shells, the one fitted within the other, an insulated heater unit assembled between the bottom walls of said shells, and means for maintaining a pressure on said heater unit, of rigid pressureplates or disks disposed on the respective sides of said heater unit to reinforce the relatively flexible bottom walls of said shells.

3. A vessel comprising outer and inner shells having their edges folded together and aheater element disposed between the walls of said shells, the side wall of the outer shell comprising two parts that are seamed together in such manner as to exert a: pressure 011' the heater element.

4. The combination with two similarly shaped receptacles, the one fitted within the other, of heater elements in the form of insulated flattened helices disposed between the bottom walls of said receptacles and maintained under pressure by a double seam 2. The combination with two relatively I which draws and secures said receptacles together.

5.2 vessel comprising ,two shells or receptacles of substantially the same form, fitted the one within the other and secured together by a seam, and a heater unit or resistance. ribbon in the form of an insulated flattened helix maintained under pressure between the bottom walls of said shells, a

narrow space or recess being provided be-' tween the side walls of said shells in which the heater connections are disposed and the outer shell being provided with suitable circuit terminals.

6. A vessel comprising an inner receptacle of relatively thin heat-conducting material, an annular band of sheet metal surrounding the upper portion of said receptacle and secured to it at its upper edge, an outer shell of materially less depth which fits closely about said receptacle and is provided with suitable circuit terminals, and a heater unit comprising a strip of resistance ribbon wound about a notched insulating disk in the form of a flattened helix and suitable insulation therefor disposed between the bottom walls of said receptacle and said outer shell, the heater connections extending to the circuit terminals in 'a recess provided between the side walls of the inner receptacle and the outer shell, and said heater unit being subjected to pressure by the drawing action of a double seam which secures said annular band and said outer shell together.

7. A vessel comprising an inner receptacle, an outer shell, and an insulated heater unit disposed between said receptacle and said shell, the peripheral wall of said shell having a fold to exert pressure upon the insulated heater unit. 8. A vessel comprising outer and inner shells and a heater element disposed between the bottom walls of said shells, the side wall of the outer shell being provided with a folded and brazed seam to exert a pressure upon the heater element. 7

9. The combination with a self-contained heater unit comprising a resistance element, insulation therefor, an enveloping sheath to hold said element and insulation together, and pressure plates disposed on the respective sides of said enveloping sheath and secured together to produce a slight initial pressure upon said resistance element, of an inner shell and an outer shell between the bottom walls of which said heater unit is located, said shell embodying peripherally disposed means for compressing said heater unit between said bottom walls.

In testimony whereof, we have hereunto subscribed our names this 30th day of Sept,

WILLIAM S. HADAWAY, J R. EDWARD E. ROSE.

Witnesses:

ISABEL C. TERRY, B. B. HINES.

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