US2253384A - Oven door construction - Google Patents

Description

Aug. 19, 1941. L LQWN AL I 2,253,384

OVEN DOOR CONSTRUCTION Filed Jan. 4, 1939 3 Sheets-Sheet 2 mvEmons WITNESSES:

Zasrilauzr arra Aug. 19, 1941 OVEN DOOR CONSTRUCTION Lester E. Lown and Edwin H. Lockwood, Mansfield, Ohio, assignors to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application January 4, 1939, Serial No.v249,181

3 Claims.

Our invention relates to ranges and more particularly to methods of making a range-oven door.

It has been a common practice in the construction of present day range-oven doors to form individual inner and outer panels. The panels have then been individually finished in, say, vitreous enamel. These panels have then been rigidly secured together by being attached to suitable brackets, supports, etc.

By reason of being attached to such brackets and supports, it has been practically impossible to obtain a true alignment of the various parts. This condition, in turn, prevents some of the doors from making a good seal with an oven lining. In addition, the multi-handling of the various parts and the enameling of the two separate panels greatly increases the cost of such doors.

In contrast with this method of construction, which required the use of brackets, etc., if such doors were made without the use of internal brackets and if fabricated in such a manner that they could be enameled in one operation after being assembled, the cost of such door structure would be greatly reduced.

It is, therefore, an object of our invention to provide an oven door formed of two panels rigidly attached together without the aid of supporting brackets, supports, etc., and which can be completely assembled before being enameled.

A further object of our invention is to provide a rugged, simple, inexpensive door structure which is capable of making a good seal with an oven lining.

Another object of our invention is to provide a method of making a rugged, inexpensive, twopiece, heat-insulating door structure from two panels without the use of any internal supporting brackets.

Other objects of our invention will either be pointed out specifically in the course of the fol lowing description embodying our invention, or will be apparent from such description.

In the accompanying drawings:

Figures 1 and 2 are perspective views of the oven rear panel and front panel, respectively.

Figs. 3, 4, 5, 6, 7 and 8 are perspective views illustrating various steps in assembling the door construction embodying our invention, and

Fig. 9 is a partial perspective view illustrating the door construction embodying our invention.

Referring to the accompanying drawings, we show a rear panel in and front panel H, which are, through a series of steps hereinafter described, assembled into a rigid, inexpensive door structure It having hinge members l5 rigidly attached thereto.

Referring particularly to Fig. 1, the rear panel I 0 includes a plurality of upstanding sides It and front and back edges I1 and I1, respectively, extending outwardly from the main, or central downwardly depressed, portion l8, notched portions 20 located at the front portion of the sides It as seen in Fig. 1, and an elongated substantially rectangular aperture 22 positioned in the front upwardly curving surface of the central portion l8 (see Figs. 1 and 3). The rear panel i0 is formed from a single sheet of enameling metal and is preferably formed by means of a combination punch and die press operation. The edges I6, I! and I1 are formed substantially normal to the panel l0 and are of a substantially uniform depth. The centrally depressed portion l8 covers nearly the entire surface thereof. The portion 18 is positioned within the panel ill to give added strength thereto and to give an enlarged central hollow space for the insulating material.

The front panel I2, in this instance, comprises a substantially flat sheet of enameling metal having a continuous upturned edge 24 located around the edge thereof. The edge 24 is substantially normal to the surface of panel I2 and has substantially the same depth as the edges l6, I1 and ll of the rear panel I0. In addition, the peripheral shape of the front panel I2 is substantially the same as that of the rear panel l0. However, the front panel I2 is slightly larger than the rear panel l0 so that the edges 24 thereof will fit over the outside surface of the edges l8, l1 and ll of the rear panel ill in a contiguous manner, as hereinafter described.

The front panel l2, like the rear panel I0, is also preferably formed from a simple press operation. However, it is to be understood that both the fron t and rear panels I 2 and I0, respectively, may be formed in any other desired manner.

After he rear panel i 0 has been formed, a plurality of outwardly extending protrusions or projections 26 are formed within the rear edge H of the rear panel ill. The protrusions 26 are relatively small in shape and extend only a small distance beyond the rear surface of the rear edge H, see Figs. 3 and 6. The projections-2B are formed in the rear edge ll of the panel ill to permit a fusion between such edge and a corresponding edge on the front panel l2 by projection welding, as hereinafter described.

The hinge members I! are preferably formed from an enameling metal and comprise an irregularly shaped leg I9 including a latching portion 2I a pivoting portion 21, and an irregularly shaped= supporting portion 29. The supporting portion 28 is bent substantially 90 to the leg I8 and is adapted to fit within the notches 28 in the rear panel I8, as hereinafter described.

The supporting portion 28 includes a plurality of spaced inwardly extending ears 3I, see Figs. 5 and 7. The ears 3I have substantially the same configuration as the side and front portions of the centrally depressed portion I8 of the rear panel I8 and are formed in such a manner as to fit within the respective lower corners thereof.

The two hinges I5 are, in this instance, attached to the rear panel I8 as follows. Each hinge has its bent or supporting portion 29 placed over the edge of the corresponding side notch 28, with the spaced ears 3I resting on the corresponding curved side and front portions of the depressed central portion I8, near one of the front (or bottom) corners. There is thus one hinge I5 at each front (or bottom) corner, with the two portions 21 and 28 disposed externally of the door panels in a suitable position for proper hinge action with the oven door frame (not shown) as will be understood.

After the formation of the front panel I2 and rear panel I8, as hereinabove described, the door structure is assembled substantially as follows.

The hinges are attached to the rear panel by being positioned upon a suitable jig or support 28, the back panel I8 being then located upon such jig or support and over the hinges I5, whereupon suitable clamps 38 rigidly attach the back panel I8 to such jig 28, the upper end of the hinges extending out through the notches 22. The jig 28 accurately positions the hinges I5 with respect to the back panel I8 in a predetermined manner, and through the cooperation of the clamps 38, retains such rear panel in a fixed position.

Suitable electrodes 32 are then brought in contact withthe hinge I5 and the panel I8 so as to spot weld a portion of the hinge I5 to the panel I8. The hinges I5 are thus accurately positioned and rigidly attached to panel I8. After being attached to the panel I8, as described, the clamps 38 are removed and the panel is likewise removed from the jig 28, permitting the welding tools 32 to spot weld the ears 3| of the hinges to the central portion I8 of the panel III. The hinge member I5 is thus rigidly attached to the rear panel I8 of the door structure without the need of any supporting brackets or auxiliary members.

The rear panel I8 is then placed over a suitable wide fiat stationary welding tool 34 (Fig. 6) and hangs upon such welding tool by means of the rear edge II'. Therefore, it is obvious that the protrusions 26 in the rear edge II will be substantially in line with the welding tool 34 and will extend upwardly therefrom. The front panel I2 is then positioned in front of the welding tool 34 with an edge 24 thereof located over and upon the rear edge ll of the rear panel I8 in a contiguous manner. A suitable holding and gauging tool 35 is then fitted down over the cooperating front panel I2, welding tool 34 and rear panel I8. The tool 35 insures proper physical relationship between the rear panel I8 and the front panel I2, as well as holding the panels in a fixed position. The welding tool 34 is thus located between such panels and in contact with th ear edge ll of the rear panel I8. After the panels I8 and I2 have been positioned upon and rigidly clamped to the lower welding tool 34, the upper movable welding tool 38 is lowered substantially in line with the lower welding tool 34 and the projections 28. The upper welding tool 36, after contacting the edge 24 of the front panel I2, applies pressure and a welding current to the panels I2 and I8. The welding current then fuses the contacting edges of the rear and front panel together. Thus, the rear edges of the front and rear panels I2 and I8, respectively, are rigidly attached together by means of projection or protrusion welding. However, it is to be understood that such edges may be joined together in any other suitable manner.

After having the rear edges of the panels I8 and I2 fused or rigidly attached together, the structure is removed from the lower welding tool 34, whereupon the front panel I2 will be substantially ajar or inclined with respect to the rear panel I8 (see Fig. '7). In other words, the rear and front panels I8 and I2, respectively, are sprung apart from each other while being rigidly attached to the rear edges as hereinabove described.

The front portions of the rear and front panels I8 and I2, respectively, are then positioned upon a suitable jig 44 and are held together by means of a clamp 48. The clamp 46 is preferably fixed with respect to the jig 44 so as to retain the front edges of the panels I8 and I2 in a given predetermined fixed position (see Fig. 8). An irregular arcuately shaped welding tool 38 is then passed through the substantially rectangular shaped aperture 22 in the rear panel I8 and positioned within the space between the rear and front panels. The irregular shaped welding tool 38 is of such a configuration and predetermined thickness as to permit such tool to be located along the inside of the front edge. In addition, the predetermined thickness of the welding tool 38 ensures the front edges of the panels I8 and I2 being spaced a given distance. The tool 38 thus cooperates with a movable welding tool 48 to spot weld the side and front cooperating edges of the structure to form a solid functionally integral door structure, and cooperates with the jig 44 and clamp 46 to ensure the front portions of the panels I8 and I2 being spaced a predetermined amount.

The functionally integral door structure I4, comprising the front panel I2, rear panel I8, and hinges I5, may thus be treated as a unitary member or structure I4. The door structure may now be enamelled or painted without any danger of the finished coat being marred or destroyed. The enameling is performed in the usual manner and covers the whole structure.

It is, therefore, obvious that the door structure I4 at this point includes an enameled or painted rear panel I8 and a front panel I2 rigidly attached together at their cooperating edges with a hollow space therebetween and suitable hinge members I5 located at both ends thereof. Suitable insulating material 42 is then positioned within the space between the two panels I8 and I2. The insulating material 42 may be any suitable powdered or finely divided insulating ma.- terial which may be positioned therein through the aperture 22 in the rear panel. After the insulating material 42 is positioned and packed within the space between the panels I8 and I2, a suitable cover plate 23 is positioned over the apertur 22 and rigidly attached thereto by means of suitable screws 25 (Fig. 9). It will be noted that this plate 23 is located at the bottom of the finished door, where it is inconspicuous in service.

At this point or prior to the filling of the insulating material 42 within the hollow space betweentfie panels l and i2, a suitable handle may be located on the front portion of the door structure 14 in any desired manner, such as by means of elongated bolts which may extend through the door structure M or which may be rigidly attached merely to the front panel I2 of such structure.

It is, therefore, obvious that a door structure [4 formed in such a manner will constitute a functionally integral structure, the parts being rigidly attached together without the use of any internal brackets or supports or the like. In addition, such structure is rigidly assembled before being enameled. Further, by being formed in such a manner, the door structure may be built to specific physical specifications, permitting such structure to fit tightly against any desired oven wall structure.

Various changes may be made in the method of making the device embodying our invention without departing from the spirit and scope thereof, and We desire, therefore, that only such limitations shall be placed thereon as are imposed by the prior art and the appended claims.

We claim as our invention:

1. The method of making a two-piece bracketless door structure which includes the steps of forming a separate rear panel and front panel with depending edges, providing projections along one edge of the rear panel, placing an edge of the front panel over the corresponding edge of the rear panel in contact with the projections with a welding tool located between the panels, holding said panels in an ajar position upon said welding tool, applying a pressure and a welding current to the panels in line with the projections for fusing the panels together along one edge of each, and applying welding current to the remaining contiguous edges while holding said panels together in their closed position.

2. The method of making a bracketless door structure comprising a front panel and a rear panel, which includes forming the panels with depending edges, forming outwardly extending projections in one of the edges of one of the panels, attaching hinge members to one of the panels, placing said one edge upon a welding tool with the panel being located on one side of such tool, placing a corresponding edge of the other panel upon such edge in a contiguous manner with said other panel being positioned upon the opposite side of the same tool from the first panel, applying pressure and a welding current to the contiguous edges to fuse them together, holding the panels together and applying a spot welding current to the remaining edges by inserting a welding tool through an aperture in one of the panels, filling the space between thepanels with heat insulatingamaterial, through. said iprture, covering said aperture, and applying a decorative coating to the entire'struoture..

"3';*The-,method of making a door structure which includes th'e'steps of bending over edges on all sides of a front panel and a rear panel, placing a corresponding bent-over edge of each of the panels in overlapping contacting relation upon a welding tool with one panel in front of and the other in back of the same tool, holding said panels in an ajar position upon said welding tool with said overlapping edges as the pivotal area, applying pressure and current to the overlapping edges for fusing them together, closing the panels to cause overlapping of the corresponding remaining bent-over edges of the panels, and applying welding current to said remaining edges while in their closed position.

LESTER E. LOWN. EDWIN H. LOCKWOOD.

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