US3450126A - Windowed door for self-cleaning oven - Google Patents

Description

June 17, 1969 A. w. voNDERHAA WINDOWED DOOR FOR SELF-CLEANING OVEN Filed Feb. 21, 1968 INVENTOR ARTHUR w. VO/VOERHAAR aZM/MMQM Fm fT'TORNEYS United States Patent C US. Cl. 126-200 4 Claims ABSTRACT OF THE DISCLOSURE A self-cleaning oven door having a window and a removable pad applied to the inside of the door to prevent heat loss and to shield the window during high temperature cleaning of the oven. The pad is hollow, contains insulation material, and is interlocked with the oven controls so that a heat cleaning cycle cannot be initiated unless the pad is properly in place on the door.

Disclosure This invention relates to a windowed door assembly for ovens in which cleaning of the interior surfaces is accomplished by heating the oven to a temperature substantially above the normal range for cooking and the like.

As explained in U.S. Patent No. 3,311,106, the first self-cleaning ovens produced for domestic use could not be equipped with conventional windowed doors in view of the very high heat energy produced in the cavity in the cleaning cycle, the oven operating at a temperature above 750 and usually close to 1,000 E, and the patent presents a new construction for such a door which includes a protective shutter for the window. The window in this construction has at least two glass panes and the shutter can be moved from a concealed position within the body of the door to a visible position between the panes to act as a reflective shield during the high temperature cleaning operation. Guides must be provided to ensure proper movement of the shield, special snubbers and detents are required, and an exteriorly accessible actuating handle is needed, all adding considerably to the complication and cost of the door.

It is a primary object of this invention to provide an improved windowed oven door assembly which is effective in retaining heat within the oven cavity during selfcleaning operation.

It is a principal object of this invention to provide an improved windowed oven door assembly in which the window is more efliciently shielded from the high heat energy during cleaning to effect a safe operation.

Another principal object of this invention is to provide such a door construction which is substantally less complicated and costly than the door described in the aforesaid patent.

Other objects and advantages of the present invention will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawing setting forth in detail a certain illustrative embodiment of the invention, this being indicative, however, of but one of the various ways in which the principle of the invention may be employed.

In said annexed drawing:

FIG. 1 is a perspective view of a self-cleaning oven range equipped with a windowed door in accordance with the present improvements;

FIG. 2 is a sectional view of the door detached from the oven and approximately at the plane of the line 22 in FIG. 1; and

FIG. 3 is a further fragmented section proximately by the line 3-3 in FIG. 1.

Referring now to the drawing in detail, the illustrated range structure, apart from the oven door, serves only as an illustrative embodiment of conventional construction. It comprises a free-standing cabinet 10, an oven 11 within the same, and a cook top 12 having a plurality of surface heating devices 13. The oven door 14 is of the drop indicated aptype and hinged to the cabinet at its bottom edge by a hinge means, also conventional, including lever arms 15-. A handle 16 is shown projecting from the cabinet above the oven, and this handle is the actuator of a combination mechanical and thermal door latch as described in the pending Anderson application Ser. No. 561,851, filed June 30, 1966, assigned to the assignee of the present application. Such latch mechanism is actuated when a heat cleaning cycle is to be carried out and it operates an interlock switch which must be thus operated before the cycle can be initiated; a bimetal locking device precludes release of the latch when the oven temperature is above a predetermined degree as a further safety feature.

For purposes of the present application, it is also significant to note that such combination latch mechanism includes a hook arm which enters a slot 17 at the top inside of the door when the latter is closed to engage about a keeper within this part of the door and, also, that the latch is of the type which cannot move to the full closed or latched position unless the hook arm engages and experiences some restraint by the keeper in the closing action. Reference may of course be had to said Anderson application for further description of the latch mechanism. The actuating handle 16 will be above the top of the door in the closed condition of the latter. The door comprises an outer liner 18, which is flanged rearwardly about the periphery and has a flanged rectangular opening 19. The main body of the door is completed by a forwardly flanged inner liner 20 which also has a rectangular opening 21, but of somewhat smaller dimensions than the outer liner opening as illustrated. A double-paned window sub-assembly is mounted within the door at these openings and comprises first and second glass panes 22 and 23, respectively, separated by a spacer channel 24 and enclosed by a continuous outer channel 25. A trim frame 26 is added at the outer or front door opening 19, and it will be seen that the inner liner is flanged inwardly at its opening 21 and carries a continuous seal 27 which bears against the inner glass pane 23. A liner shield 28 is applied to the inner door liner 20 as shown to provide an added thickness over the major area of the door. The outer and inner door liners are joined conventionally by screws, as typically indicated at numerals 60; similarly, the liner shield 28 is attached to the inner liner 20 by a plurality of screws, not shown, and it will be seen that this shield is drawn to provide an inturned outer edge 29 and a compound flanged rectangular opening 30 in register with the inner liner window opening 21.

A main oven gasket 31 extends continuously about the outer edge portion of the shield and with such edge 29 engaging the gasket intermediate its width and thereby being insulated from the inner door liner. Such main gasket is also engaged by channel retainers 32 secured suitably to the inner liner for clamping of the gasket as shown interiorly of the liner shield 28.

It will be further seen that the inner edge of the shield at opening 30 is also thermally isolated from the inner liner by the interposition between the two of a high temperature resilient gasket 33. The main body of the door defined by the outer and inner liners is filled as indicated with glass wool insulation 34, and the additional interior a space 35 provided by the liner shield is also filled with such insulating material. The main gasket 31 is of course exposed about the liner shield to engage and seal the front frame of the oven when the door is closed.

The construction thus far described constitutes a basically complete windowed door in the condition in which it will be used during normal cooking operations in the oven and, of course, affording the desired view of the interior with the door closed. When a cleaning cycle is to be undertaken, a removable pad designated generally by reference numeral 36 is applied to the inside of the door as will be described in order to protect the window from the high heat energy produced in the cavity and to contain the energy within the oven.

The pad body is formed of a first rectangular sheet 37 with a peripheral flange, a stepped intermediate frame member 38 and a second rectangular sheet 39 also flanged, but of smaller size than the first. Such pieces are assembled and suitably held together in the manner illustrated to form a hollow body the peripheral wall of which has first and second steps 40 and 41, respectively, with a high temperature sealing gasket 42 clamped between the pieces 38 and 39 in exposed overlying relation to the second step 41.

The dimensioning is such that the pad 36, which may be filled with suitable insulation such as glass wool, nests within the window opening of the liner shield 28 and projects partially as well into the opening 21 of the inner door liner. The first or outer step 40 of the pad when applied to the inside of the door thus overlies the shield 28, while the gasketed second step 41 bears against the inner shield flange 43 about such opening 21.

This removable pad will, as noted, be used only when the high temperature operation is undertaken for cleaning of the oven and it will normally be stored, for example, conveniently in the utility drawer 44 below the oven. The pad when applied must be held in place and, in the illustrated embodiment, the retention is provided by a strap 45 secured to and extending outwardly at a slight angle as indicated from the frame piece 38, approximately at the top center of the same, and by two turns respectively in the lower corners of the pad. These turns each include an exposed head 46 to be turned by hand, a shaft 47 which extends through the pad at the first outer step section 40 of the same, and a lug 48 at the opposite projecting shaft end. The liner shield 28 has a slot 49 at the top center for insertion of the pad strap 45 and two lower corner slots 50 respectively to receive the lug ends of the turn shafts. It will be apparent that the pad is accordingly fixed in place by first inserting the top portion and the strap, then bringing the body into the flush position causing the turn lugs to enter the shield slots provided for the same, and then operating the turns by hand to engage the lugs behind the shield.

The door assembly also desirably includes an interlock feature to preclude initiation of the high temperature cleaning operation unless the pad is applied to the door, and such interlock in the illustrated range very simply utilizes the earlier mentioned latch mechanism by adjusting the door keeper for the same. With particular reference to FIG. 3, an interlock angle 51 is used within the door in lieu of the usual keeper, and this angle is arranged for engagement and movement by the top retaining strap 45 of the removable pad 36. The angle 51 is guided by a track 52 attached to the inner surface of the inner door liner 20, with one end 53 flanged and extending through a slot 54 in such liner to the space between the liner and the shield 28 where strap 45 enters the same, and the other strap end 55 being movable across the door latch slot 17 which receives the hook arm of the mechamsm.

It will be apparent from FIG. 3 that when the door is upright or closed and the pad is detached, the interlock angle 51 will slide down sufficiently to withdraw its upper end from the latch slot 17. However, when the pad is properly applied, the strap 45 engages the angle 51 and moves it relatively outwardly so that its upper end portion bridges the slot 17 and is thereby in position to serve as the keeper for the latch mechanism. Since, as explained earlier, the latch cannot be fully closed without engagement of a keeper, and the interlock electrical switch in the control circuit of the range will not be actuated to permit initiation of the heat cleaning cycle unless the latch is fully closed, it will be clear that placement of the pad is a condition upon commencement of such operation.

It is to be understood that the described interlock is preferred in the illustrated range primarily by virtue of the availability of the described latch mechanism for the same, and that the range controls can be conditioned in other ways to make the cleaning cycle similarly dependent upon the proper application of the pad to the inside of the door.

The structure disclosed is obviously uncomplicated and economical, and yet it provides very efiicient operation of the oven and protection for the window. In this last connection, it is significant to note that the pad is of appreciable thickness and, filled with glass wool, represents a substantial thermal insulating mass, and also that the pad is applied so that no glass surface is exposed to the energy in the cavity in the high temperature operation. The pad is thus more than a simple reflective shield and fully conceals and protects the window in particular contrast, in both respects, to the described other arrangement of a reflective shutter used between the glass panes.

Further, and very importantly, the action of the pad as a heat barrier provides the advantage of containing the high heat energy within the oven. Heat dissipation through a window may be so great as to prevent the door and perhaps even the oven itself from reaching a cleaning temperature and the structure of the door assembly of this invention is such as to eliminate these problems. While the inner surface or sheet 37 of the pad will attain a selfcleaning temperature, the isolation provided by the material and configuration of the pad in such sealed engagement with the door, will prevent undesirable heat transfer through the window aperture.

It will also be evident that the new door and pad combination can be utilized with a three pane window, if desired, with a third pane added at the inside generally in the manner disclosed also in Patent No. 3,311,106. With such modification, the thickness of the removable pad would be reduced appropriately by eliminating the inner sheet 39 and making the frame 38 the inner pad liner or closure. This would of course obviously accommodate the third pane mounted as in the patent, and in such case the added pad gasket 42 might also be eliminated as unnecessary.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

I, therefore, particularly point out and distinctly claim as my invention:

1. A windowed door for a self-cleaning oven, comprising outer and inner door panels together forming the body of the door and having laterally spaced window openings in register, a window assembly mounted in said body at and closing said openings, said window assembly including at least two spaced-apart glass panes, a pad applied to the inside of the door and fully covering the window assembly for shielding of the same from the oven cavity during high temperature cleaning operation thereof, the pad being removable from the door for viewing through the window assembly during other oven operation, latch means in the door having operative and inoperative conditions of adjustment, and means responsive to application of the pad to the door to adjust the latch means from its inoperative to its operative condition for latching of the door.

5 6 2. The combination set forth in claim 1, wherein the overlies the inner panel and another part extends into pad is hollow and filled with thermal insulation material. the recess adjacent such inner pane.

3. The combination set forth in claim 1, wherein the latch means includes a keeper portion for engagement References Cited with a latch member, the door having an opening to re- 5 UNITED STATES PATENTS ceive such member and ad uStment of the latch means moving said keeper portion relative to such opening. 2,963,019 12/ 1960 Domsky 126-2()0 4. The combination set forth in claim 1, wherein the 2,859,744 11/1958 Hadley 126-200 XR glass pane at the inside of the door is recessed relative 3,311,106 3/1967 Baughman et a1 126-200 to the inner panel, the pad has appreciable thickness, and 10 the periphery of the pad is stepped so that an outer part KENNETH W. SPRAGUE, Primary Examiner.

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