US3439668A - Oven door construction - Google Patents

Description

April 22, 1969 c. w. TlLUS OVEN DOOR CONSTRUCTION Filed Sept. 23. 1966 FIG.5

United States Patent 3,439,668 OVEN DOOR CONSTRUCTION Carl W. Tilus, Mansfield, Ohio, assignor to Westinghouse Electric Corporation, Pittsburgh, Pa., a corporation of Pennsylvania Filed Sept. 23, 1966, Ser. No. 581,582 Int. Cl. F24c /02 US. Cl. 126190 4 Claims ABSTRACT OF THE DISCLOSURE This invention relates generally to oven door construction and in particular to an improved door seal construction.

While a construction according to the invention is applicable to other types of ovens, it is especially useful with those ovens adapted to undergo a heat-cleaning cycle involving oven temperatures substantially above the usual cooking temperatures, and accordingly will be described principally in that connection.

Sealing of the door of heat cleaning ovens is critical within limits since high temperatures must be maintained to effect the cleaning (too great a fiow of air into the oven would increase the difficulty of obtaining the high temperatures), but some air must be introduced to permit more complete oxidation of the material being burned from the interior oven surfaces. A woven glass fiber material lends itself to use as a gasket for the door seal because of its ability to withstand high temperatures while retaining adequate resiliency for sealing purposes. However, its use also poses problems stemming from the characteristics of the fibers and of the fabric woven from the fibers. Essentially, the difficulty experienced with woven glass fiber material is that it does not facilitate the usual type of mechanical mounting because of its lack of mechanical integrity, its flexural weakness and lack of sufiicient permanent rigidity to make it self-supporting. Woven asbestos material has much the same character as woven glass fibers with respect to this invention, and, accordingly, is also applicable for use.

The general object of this invention is the provision of an oven door construction in which the deficiencies of the woven fiber gasket are minimized by virtue of the mounting arrangement according to the invention.

In accordance with the invention, the gasket material comprises a woven fiber sleeve which is slipped over a wire frame which gives the sleeve its general configuration. The sleeve and contained frame are then adapted to be held in the proper place on the inner face of the oven door by being disposed in captured relation between the peripheral edges of a muffle panel and an inside corner formed by shoulder means on the rear face of the inner panel. The wire frame is sized relative to the shoulder means on the inner panel and to extend along the inner margin of the sleeve and form, in effect, a thickened bead portion along the margin. It is this head so formed which is captured and retained between the inner panel shoulder means and the mufile panel edge flange. The mufiie panel is fastened to the inner panel so that the gap between the mufile panel flange and the opposing ice surface of the inner panel accommodates a double thickness of the sleeve without fracturing force being exerted upon the gasket material, but with the gap being limited sufficiently to prevent the escape of the bead. Thus the sleeve is held in a generally flattened condition with its major width portion (outside of its inner margin) exposed around the perimeter of the muffle panel. Thus when the door is moved into a closed position the exposed portion of the gasket moves into sealing engagement with the oven liner throat.

The construction is such that the wire frame may be simply fastened to the inner panel at the two ends of the frame. Other than this fastening, the remainder of the gasket is held in place by virtue of the fastened relationship between the muflle panel and the inner panel of the door.

An embodiment of the invention will be described by way of example in connection with the accompanying drawing wherein:

FIGURE 1 is an isometric view of a cooking range having an oven door construction according to the invention;

FIG. 2 is a partly-broken face view of the inner face of the oven door;

FIG. 3 is a sectional view corresponding to one taken along the line IIIIII of FIG. 2;

FIG. 4 is a view of the wire frame over which the gasket is slipped;

FIG. 5 is a sectional view corresponding to one taken along line VV of FIG. 2 and showing the end fastening arrangement;

FIG. 6 is a sectional view corresponding to one taken along the line VIVI of FIG. 2 and showing the means for fastening the mufile panel to the inner panel.

Referring to FIG. 1, the range illustrated may be considered to be of the type provided with an oven adapted to undergo a heat cleaning operation in which food residue is burned out of the oven by subjecting the oven to high temperatures substantially above those encountered in normal oven cooking operations. The front face of the oven cavity 10 is adapted to be closed substantially by the oven door 12. The main parts of the door of immediate interest include an outer panel 14, an opposing inner panel 16, a muffie panel 18 which generally overlies the central area of the inner panel, and the sealing gasket 20 which borders all of the edges of the muffle panel except for a part of the edge adjacent the hinged edge of the door.

The throat of the oven cavity is defined by generally outwardly-directed flanges 22 of the oven liner. These include portions projecting slightly forwardly of the bordering front face of the range body to form a rim. When the oven door 12 is closed the gasket 20 is correspondingly moved into engagement with this rim along all but a part of the bottom side where the gasket on the door is omitted. As shown in FIG. 2, the gasket 20 extends around the bottom corners from the sides and then terminates under the mufi le panel 18. Thus where the gasket is omitted an air inlet slot is provided adjacent the bottom edge of the door when closed to permit a limited quantity of air to be admitted into the oven when the door 12 is closed. The admission of this air is desirable both during normal cooking operations and during heat cleaning operations in the oven.

The inner panel 16 (FIGS. 2 and 3) has an overall generally rectangular shape and is provided with a central, generally rectangular cutout area defined by the inner peripheral flanged edge 24. A raised inner border on the inside face of the inner panel encompasses the cutout area and provides a shoulder 26 against which the inner border of the gasket 20 seats when the gasket is assembled to the door. This shoulder 26 extends without interruption along the three sides of the cutout area of the inner panel. Along the hinged edge of the door the shoulders jut inwardly toward the cutout area to provide a pair of recesses 28 into which the ends of the gasket and framing wire is secured. These recesses are completely hidden by the mufile panel when it is applied.

The muflle panel 18 is a generally rectangular sheet which is drawn or otherwise formed in the shape of a shallow flat-bottomed pan with peripheral flanges 30 which overlap the shoulders 26 of the inner panel with a limited width space between the flange 30 and shoulder 26 to accommodate the beaded or enlarged inner border 32 of the gasket 20.

The gasket 20 is an open-ended, woven glass or asbestos fiber sleeve which is generally circular in its unstressed form but, as supported and held in the construction according to the invention, takes a flattened form. The currently preferred glass fiber material is able to withstand high temperatures without deterioration, but, as noted, tends to abrade easily as a result of the natural character of the glass fibers which make up the material. The sleeve is long enough to extend from one recess 28 adjacent one corner of the muflle panel (FIG. 2), around three consecutive sides, and then terminate at the other recess (not shown in FIG. 2).

To hold the shape of the gasket, a wire frame 34 shaped as in FIG. 4 is used. The loops 36 at each end are accommodated in the recesses 28 of the inner panel and a sheet metal screw 38 (FIG. is turned through the gasket end and loop 36 into the inner panel to hold the Wire frame and gasket in place before assembling the muflle panel 18. A washer 40 is also preferably used with the sheet metal screw to distribute the loading on the gasket fabric.

The wire frame 34 is sized so that with the gasket pushed down into a flattened condition, the wire extends around the inner margin of the gasket and forms the enlarged, head 32 which seats in the limited width space between the shoulders 26 of the inner panel and the peripheral flange 30 of the muffle panel.

The gasket is retained in its flattened cross-sectional shape by the mufile panel peripheral flange 30. It is preferred that the size of the gap between the flange edge and the opposing face of the inner panel be equal to, or slightly greater than, a double thickness of the gasket material. To hold the muffle panel relative to the inner panel with this gap size, a bracket 42 (FIGS. 2 and 6) is provided between each corner of the muflle panel and the inner panel. As shown in FIG. 6, the brackets 42 are of a generally saddle-shape with wings which are secured by welding or otherwise bonding them to the hidden face of the muflle panel 18. The bight portion of the bracket is secured to the inner panel 16 by a screw fastener 44. In this way the panels are held together with the proper spacing provided for the gap in which the gasket lies.

The gap is of course less than the diameter of the bead 32 formed along the inner border of the gasket by the wire frame 34 with the gasket material encompassing the frame. Accordingly, the bead prevents the gaskets from being pulled out from underneath the muflie, and the relationship between the flange and the facing portions of the inner panel hold the gasket in its properly flattened shape without damage to the gasket material. It will also be appreciated that heat conduction from the muflle panel to the inner panel is limited, as a practical matter, to the paths provided by the brackets.

By way of summary then, a door construction according to the invention is such that the characteristics of the woven fiber gasketing material may be taken advantage of, but with the construction being such that the disadvantages of this type of material, with respect to problems encountered in typical mounting arrangements, are substantially minimized.

I claim as my invention:

1. In an oven door construction:

an inner panel including shoulder means raised from the exposed face of said panel and generally encompassing a central area ofsaid inner panel;

a muflle panel overlying said central area and having peripheral flange means directed toward said inner panel, said flange means lapping said shoulder means slightly outwardly therefrom to define a limited width space therebetween, said flange means further defining a gap with the portion of the opposing face of said inner panel immediately outwardly from said limited width space, said gap having a transverse dimension substantially less than the transverse dimension of said limited width space;

a flexible tubular gasket having a length suflicient to follow the major portion of the central area perimeter with the inner margin of the gasket disposed in said limited width space, and the remainder of said gasket extending outwardly through said gap and being exposed beyond the perimeter of said muflle panel;

a wire frame extending longitudinally in said gasket inner margin to form an enlarged bead portion confined in and substantially occupying said limited width space.

2. A door construction according to claim 1 wherein:

said shoulder means includes interrupted portions located to register with the ends of said wire frame to provide spaces for fastening the ends of said wire frame to said inner panel in a hidden position beneath said muflle panel.

3. A door construction according to claim 1 wherein:

said gasket is of woven glass fiber material.

4. A door construction according to claim 3 including:

means for securing said muffle in spaced relation from said inner panel with said gap defined between the edge of said muflle panel peripheral flange and the opposing face of said inner panel, said gap being less than the diameter of said gasket head, but at least as great as the double thickness dimension of said gasket material so that head is retained and the exposed portion of said gasket material is held in generally flattened condition but is not subjected to abrasive clamping by said muflle panel flange.

References Cited UNITED STATES PATENTS 3,099,259 7/1963 Newell 126-190 2,219,962 10/1940 Reynolds et al 49479 2,665,458 1/1954 Wilcox 49-479 3,127,890 4/1964 Mills 126-200 KENNETH W. SPRAGUE, Primary Examiner.

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