US3736916A

US3736916A - Self-cleaning oven door structure

Info

Publication number: US3736916A
Application number: US00286450A
Authority: US
Inventors: J White
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1972-09-05
Filing date: 1972-09-05
Publication date: 1973-06-05
Anticipated expiration: 1990-06-05
Also published as: CA995533A

Abstract

An oven door of sheet metal construction having an outer door panel, an inner door liner and an inner panel that is adapted to be exposed to the internal oven temperatures. The inner panel is of shallow pan configuration with a peripheral flange that extends into a large opening in the inner door liner. A strip of gasket material encircles the inner panel and spaces the inner panel from the inner door liner in the manner of a thermal break. An insulation guard closes the inner panel to form a closed boxlike structure that is substantially filled with thermal insulating material. A cooling air channel is located between the insulation guard and the outer door panel so that currents of cooling air may pass up through the cooling channel.

Description

United States Patent 1191 White 1451 June 5, 1973 [54] SELF-CLEANING OVENDOOR 3,453,997 7/1969 Klepzig ..126/198 STRUCTURE 3,561,423 2/1971 Holtkamp ..126/198 Inventor: James A. White, Louisville, Ky.

General Electric Louisville, Ky.

Filed: Sept. 5, 1972 Appl. No.: 286,450

Assignee: Company,

, References Cited UNITED STATES PATENTS lO/l967 8/1968 6/1969 [57] ABSTRACT An oven door of sheet metal construction having an outer door panel, an inner door liner and an inner panel that is adapted to be exposed to the internal oven temperatures. The inner panel is of shallow pan configuration with a peripheral flange that extends into a large opening in the inner door liner. A strip of gasket material encircles the inner panel and spaces the inner panel from the inner door liner in the manner of a thermal break. An insulation guard closes the inner panel to form a closed box-like structure that is substantially filled with thermal insulating material. A cooling air channel is located between the insulation guard and the outer door panel so that currents of cooling air may pass up through the cooling channel.

5 Claims, Z'Drawing Figures PATENTEDJuu 5197s FIGJ BACKGROUND OF THE INVENTION A pyrolytic self-cleaning oven operates at oven temperatures as high as 950 F. as is described in the basic U.S. Pat. of Bohdan Hurko No. 3,121,158, which is assigned to the same assignee as is the present invention. Safety regulations of Underwriters Laboratories, Inc. are becoming more strict each year regarding the allowable surface temperatures present on the outer surface of the oven door during the self-cleaning operation. Therefore it is encumbent upon range manufacturers to continuously refine and improve their door designs to satisfy the needs of the range user. The door of a self-cleaning oven must be locked during the entire high temperature cycle; accordingly, it is important that the door be of high strength capability so that it will not warp and allow large amounts of the heat to escape from the oven nor allow the entrance of large amounts of air into the oven which could cause backfires to occur. Hence it is'necessary to design a rigid door of sheet metal construction to lessen the weight which at the same time will be rigid enough to function almost as a solid door. This door is' designed to offer excellent thermal isolation of the inner panel from the remainder of the door, while there is afforded high door strength even though the inner panel is mounted in such a way that it is allowed to expand and contract during the high temperature operation with a minimum of crazing of the porcelain enamel finish on the inner panel.

The principle object of the present invention is to provide an oven .door of sheet metal construction with high strength capability while at the same time having a reliable thermal break between an inner panel and the inner door liner which allows thermal expansion and contraction of the inner panel.

A further object of the present invention is to provide an oven door of the class described for use with a high temperature self-cleaning oven wherein an inner panel is supported in an opening in an inner door liner in such a way that the inner panel is allowed to expand and contract during the change of temperature within the oven without putting undue stresses or strains on the panel and on the porcelain enamel finish that is applied to the exposed surface thereof.

A further object of the present invention is to provide an oven door of the class described with an insulation guard that cooperates with the inner panel in such a way as to produce a box-like structure that is adapted to be filled by thermal insulating material to form a rigid structure with good thermal insulating characteristics. Y

SUMMARY-OF THE INVENTION The present invention, in accordance with one form thereof, relates to an insulated door construction for a high temperature oven where the door has an outer panel and an inner door liner that in turn supports an inner panel that projects into the oven and is exposed to the internal oven temperatures. The inner door liner has a large opening and the inner panel has a peripheral flange that just slips into the opening. A strip of gasket material encircles the peripheral flange of the inner panel and serves as a thermal break between the inner panel and the inner door liner. Fastening means extend through the peripheral flange and gasket material into the inner door liner. An insulation guard closes the inner panel to form a closed box-like structure that is substantially filled with thermal insulating material. A cooling air channel is located between the insulation guard and the outer door panel so that currents of cooling air may pass up through the cooling channel.

BRIEF DESCRIPTION OF THE DRAWINGS This invention will be better understood from the following description taken in conjunction with the ac companying drawings and its scope will be pointed out in the appended claims.

FIG. 1 is a perspective view of a free-standing domestic range having an oven door embodying the present invention, where the door is shown in its horizontal, fully opened position.

FIG. 2 is a cross sectional elevational view on an enlarged scale through the center of the door to show the general nature of the door construction.

DESCRIPTION OF THE PREFERRED EMBODIMENT Turning now to a consideration of the drawings and in particular to FIG. 1, there is shown for illustrative purposes a free-standing electric range 10 having a top cooling surface 11 with a plurality of surface heating elements 12, a baking oven 13 formed by a box-like oven liner 14 and a front-opening access door 16. Of course, this door invention is not limited to a use in electric free-standing ranges. The oven could be heated by gas, it could be a built-in wall oven or any other type of high temperature heated cavity. The oven cavity 13 is supplied with two standard heating elements; namely, a lower baking element 18 and an upper broiling element 19 located adjacent the top wall of the oven liner. The back edge of the cooking surface 11 is supplied with a backsplash 21 which supports a control panel including multiple selector switches 22 for the surface heating elements 12, and an oven selector switch 24, an oven thermostat" control 26 and finally an oven timer 28 for timing both the cooking operations as well as the oven cleaning cycles. Positioned beneath the oven 13 is a pull-out drawer 30 which is a storage drawer for cooking utensils and the like. However, in most gas ovens, this lower space is alloted to a broiler compartment.

The oven door 16 is hinged to the range body along the bottom edge of the door by means of counterbalanced hinge levers 32 such as are shown in the patent of G.R. Sherman, U.S. Pat. No. No. 2,873,737, which is assigned to the same assignee as is the present invention. An oven door latch handle 15 is shown at the front edge of the cooktop 11 for manipulation of a latch mechanism located beneath the cooktop for engaging the oven door 16 when it is in a closed position and locking it shut during the entire oven cleaning cycle. A suitable oven latch mechanism is shown in the patent of J. S. Fox, U.S. PatfNo. 3,367,697 of the present assignee. I

As is best seen in FIG. 2, the oven door 16 is of generally sheet metal construction having three main elements; an outer door panel 34, an inner door liner 36, and an inner panel 38 that is supported from the inner door liner. The outer door panel 34 is of shallow pan configuration by virtue of the fact that it has a slight rearwardly facing peripheral flange 41. The inner door liner 36 is also of shallow pan configuration, and it is edge of the door, while at the bottom of the door there is a tab and slot connecting relationship at 45 along most of the bottom edge of the door which prevents separation of the outer door panel from the inner door liner unless the screw fasteners at the top of the door are first removed.

The inner door liner 36 includes a generally rectangular outward embossment 47 which is adapted to project somewhat into a recessed front frame 49 of the oven body. Notice the boxl-like oven liner 14 has an outwardly turned front flange 51 which bears against the front frame 49 because the oven liner is pulled rearwardly into the oven body by tension means (not shown) such as J-bolts or the like as is standard practice in this art.

The inner panel 38 is of shallow pan shape with a front facing peripheral flange 55, and this inner panel is adapted to project into the throat of the oven liner 14 in the manner of a close fitting plug. The flat face of the embossment 47 of the inner door liner 36 is formed with a large opening or cut-out for accommodatingthe flanged portion 55 of the inner panel 38 therein, thereby substantially filling the opening. This opening is also provided with an inwardly turned, front facing peripheral flange 57 which closely parallels the peripheral flange 55 of the inner panel 38. This peripheral flange 55 of the inner panel is shown provided with an inner step 59 that extends completely around the inner panel so that the inner panel is of the correct size to fit within the throat of the oven liner l4. Wrapped around the peripheral flange 55 near the edge thereof is a strip gasket 61 of thermal insulating material such as woven fiberglass or the like. This gasket 61 has an enlarged exposed edge 62 that is adapted to seal against the front flange 51 of the oven liner when the door 16 is closed. The strip gasket 61 is sandwiched between the flange 55 and the generally parallel flange 57 of the inner door liner 36. Fastening screws 63 are threaded from inside the inner panel 38 and extend through the flange 55, the gasket 61 and the flange 57. There would probably be a minimum of two screws 63 on each side of the panel and possibly three on the top and bottom edges, but the number of such screws is not critical. However, it is well to realize that this type of inner panel construction and assembly allows for the expansion and contraction of the inner panel during the high temperature cycle as the strip gasket 61 almost serves as a somewhat resilient mounting means.

A sheet metal insulation guard 67 is provided to close the interior of the inner panel 38. This insulation guard happens to be assembled to an inwardly facing flange 69 of the peripheral flange 57 of the inner door liner 36 as by means of screws 71, as this is the best means of thermally isolating the inner panel 38 from the remainder of the metallic parts of the door 16. However, a modification would be to mount the insulation guard 67 from the other peripheral flange 55. By closing off the inner panel 38, this insulation guard 67 forms a strong box-like structure which goes far towards reinforcing the door into a very rigid structure. The interior of this box-like structure is substantially filled with thermal insulating material 75 of fiberglass or the like so as to retain much of the heat generated within the oven cavity and allow as little heat loss as possible.

Another expedient for holding down the surface temperature of the front face of the oven door is to provide natural convection air cooling within the door by creating air inlet openings 77 along the bottom edge of the I rearwardly facing flange 41 of the outer door panel 34,

as well as air outlet openings 79 in the top edge of the outer door panel 34. There is an air channel provided by the spacing of the insulation guard 67 back away from the outer door panel 34, thus this cooling air is able to pick up some of the heat stored in the thermal insulation and insulation guard 67 and serve somewhat as a heat exchanger to remove a portion of this heat by carrying it back into the kitchen. This air flow is primarily useful during the high temperature selfcleaning cycle although it also functions during normal cooling operation which makes for cool cooking as far as the outer temperature of the oven door 16 is concerned.

Modifications of this invention will occur to those skilled in this art; therefore, it is to be understood that this invention is not limited to the particularembodiments disclosed, but that it is intended to cover all modifications and equivalents which are within the true spirit and scope of this invention as claimed.

What is claimed as new and is desired to be secured by Letters Patent of the United States is:

1. An oven door comprising an outer door panel, an inner door liner and an inner panel all fastened together, the outer door panel having a rearwardly facing peripheral flange, said inner door liner having a front facing peripheral flange telescoped with the flange of the outer door panel, the inner door liner having a generally rectangular outer embossment, and fastening means for holding the inner door liner to the outer door panel, the inner panel being slightly smaller in size than said embossment and having a front facing peripheral flange which extends into a large opening in the embossment, said opening also having a peripheral flange generally parallel to the said flange of the inner panel, and a strip of thermal gasket material sandwiched between the peripheral flange of the inner panel and the peripheral flange of the large opening in the inner door liner, and a limited number of fastening means holding the two last mentioned flanges and the gasket together, said gasket also having an enlarged exposed edge encircling the inner panel and adapted to seal against an adjoining surface of an oven in the manner of a door sealing gasket, and an insulation guard within the'door attached to at least one of the inner panel flanges and the flange of the opening in the inner door liner to form a shallow box-like structure of high rigidity, and thermal insulation within this box structure, a cooling air char nel in the door between the insulation guard and the outer door panel with air inlet means along the bottom portion of the door and air outlet means along the top portion of the door so that currents of cool air may pass up through the cooling channel.

2. An oven door of sheet metal construction comprising an outer door panel, a spaced inner door liner and an inner panel that is adapted to be exposed to the high temperatures within the oven, and fastening means for holding the inner door liner and the outer door panel together, the inner panel being smaller in size than the inner door liner and having a peripheral flange, the inner door liner having a large opening for receiving at least a portion of the peripheral flange of the inner panel therein, a strip of thermally insulating gasket material encircling the peripheral flange of the inner panel, the large opening in the inner door liner having a peripheral flange around the edge of the opening that closely parallels the peripheral flange of the inner panel, and a plurality of widely spaced fastening means joining the two peripheral flanges with the gasket being sandwiched therebetween, said gasket also having an enlarged exposed edge encircling the inner panel and adapted to seal against an adjoining surface of an oven in the manner of a door sealing gasket whereby the door gasket serves as a thermal break between the inner panel and the remainder of the metallic door parts, thermal insulation within the door for retarding the conduction of heat therethrough, and an insulation guard of sheet form within the door supported from at least one of the said peripheral flanges to form with the inner panel a closed box structure, the said thermal insulation substantially filling this box structure.

3. An oven door as recited in claim 2 wherein there is a cooling air channel formed in the door between the said insulation guard and the outer door panel with air inlet means along the bottom portion of the door and air outlet means along the top portion of the door so that currents of cool air may pass up through the cooling channel.

4. An oven door of sheet metal construction comprising an outer door panel, an inner door liner and an inner panel, the outer door panel being of shallow pan configuration with a rearwardly facing peripheral flange, the inner door liner also being of shallow pan configuration with a front facing peripheral that telescopes with respect to the outer door panel flange, and fastening means for holding the outer door panel and the inner door liner together, the inner door liner having an outer embossment on its inner face with a large opening formed therein, the said inner panel being of shallow pan configuration with a front facing peripheral flange that is encircled by a strip of thermally insulating gasket material and fits within the said large opening, said gasket strip having an enlarged exposed edge adapted to seal against an adjoining surface of an oven in the manner of a door sealing gasket, and fastening means between the inner panel flange and the inner door liner whereby the door gasket serves as a thermal break between the inner panel and the remainder of the metallic door parts, and an insulation guard within the door supported from the inner door liner and closing the interior of the inner panel to form a closed box-like structure, and thermal insulation material substantially filling the said box structure.

5. An oven door as recited in claim 4 wherein the said large opening in the inner door liner has a front facing peripheral flange generally paralleling the peripheral flange of the inner panel, the said fastening means between the inner door liner and the inner panel being connected between the peripheral flanges of these two members.

Claims

1. An oven door comprising an outer door panel, an inner door liner and an inner panel all fastened together, the outer door panel having a rearwardly facing peripheral flange, said inner door liner having a front facing peripheral flange telescoped with the flange of the outer door panel, the inner door liner having a generally rectangular outer embossment, and fastening means for holding the inner door liner to the outer door panel, the inner panel being slightly smaller in size than said embossment and having a front facing peripheral flange which extends into a large opening in the embossment, said opening also having a peripheral flange generally parallel to the said flange of the inner panel, and a strip of thermal gasket material sandwiched between the peripheral flange of the inner panel and the peripheral flange of the large opening in the inner door liner, and a limited number of fastening means holding the two last mentioned flanges and the gasket together, said gasket also having an enlarged exposed edge encircling the inner panel and adapted to seal against an adjoining surface of an oven in the manner of a door sealing gasket, and an insulation guard within the door attached to at least one of the inner panel flanges and the flange of the opening in the inner door liner to form a shallow box-like structure of high rigidity, and thermal insulation within this box structure, a cooling air channel in the door between the insulation guard and the outer door panel with air inlet means along the bottom portion of the door and air outlet means along the top portion of the door so that currents of cool air may pass up through the cooling channel.