US3439669A - Supporting means for shutter of oven door window - Google Patents

Description

April 22, 1969 w. K. WINKLER 3,439,669

SUPPORTING MEANS FOR SHUTTER OF OVEN DOOR WINDOW Filed Feb. 1, 1968 Sheet of 2 FIGI INVENTOR. NH-LIAM K. W) NKLER BY o Hxs ATTORNEY April 22, 1969 w. K. WINKLER 3,439,669

SUPPORTING MEANS FOR SHUTTER OF OVEN DOOR WINDOW v ma Feb.- 1, 1968 Sheet 3 of 2 INVENTOR. W\LLIAM K. WlNKLER H vs ATTORN-EY United States Patent 3,439,669 SUPPORTING MEANS FOR SHUTTER OF OVEN DOOR WINDOW William K. Winkler, Anchorage, Ky., assignor to General Electric Company, a corporation of New York Filed Feb. 1, 1968, Ser. No. 702,221 Int. Cl. F24c 15/04 US. Cl. 126-200 4 Claims ABSTRACT OF THE DISCLOSURE This invention relates to an oven door that has a window sealed with transparent panes. The door may be used with a high temperature, self-cleaning oven, where it would be necessary to provide the window with a shutter to close the window when the oven is operating on a self-cleaning oven cycle. The shutter may be retracted into the door structure during normal clocking operations, and raised to a closed 'position when the oven is to be operated at a high temperature. The shutter has handles at the top corners, and the inner surface of the door has slots through which the handles extend so the handles are accessible on the inner side of the door. A gravity actuated catch member is positioned within the door near the top thereof for automatically engaging the handle after the door is opened and the shutter is raised to its closed position for supporting the shutter in place.

Cross-reference to related art This invention is a refinement of the detent system for supporting the shutter in the windowed oven door of Patent No. 3,311,106 of Howard B. Baughman and Kermit B. Keeling, Sr., which issued on Mar. 28, 196 7 and is assigned to General Electric Company, assignee of the present invention. Moreover, the particular shutter shown in the present application is described in the pending patent application Ser. No. 644,257 of William K. Winkler and Eugene E. Pickerrell entitled Track System for Shutter of Windowed Oven Door which was filed on June 7, 1967, now Patent No. 3,396,717 and is likewise assigned to the assignee of the present invention.

Background of the invention Housewives have become accustomed to the convenience of a window in their oven door so that they may observe the food while it is being cooked. This avoids the necessity of opening the oven door in order to judge the degree of doneness of the food. However, in recent years housewives have been given the opportunity of owning a self-cleaning oven that operates on the principal of pyrolysis for decomposing the food soil and grease splatter that accumulate on the oven walls during normal cooking operations. Such a self-cleaning oven is taught in the patent of Bohdan Hurko No. 3,121,158 which is likewise assigned to the assignee of this invention. Such self-cleaning ovens operate at a high temperature range above the normal cooking temperature range of between 150 F. to 550 F., generally above a temperature of about 750. The conventional windowed oven doors were not usable in self-cleaning ovens for confining the increased amount of heat energy to the oven cavity, and hence they were omitted in the early models of selfcleaning ovens in order to take full advantage of the self-cleaning oven feature. The above-cited Baughman et a1. Patent 3,311,106 teaches the use of a movable shutter built into the door structure so that in one position the shutter blocks the window opening and serves as both a thermal radiation barrier and a visual barrier during the high temperature operation. During normal 3,439,669 Patented Apr. 22, 1969 "ice cooking operations this shutter will be retracted into the door structure so that the window will provide the convenience of the oven door windows in standard ovens. The shutter of the present invention is designed to be supported in its raised position by a gravity actuated catch member where no spring devices are involved, where the expansion of the shutter when exposed to high temperature does not effect the holding force of the catch, and whereby no force applied to the shutter can override the catch and permit the shutter to be lowered during the high temperature self-cleaning operation.

Summary of the invention The present invention, in accordance with one form thereof, relates to a door construction for a high temperature oven where the door includes a window opening that is closed by a plurality of transparent panes that are sealed along their periphery to the door structure. A manually movable shutter is located within the door, and in one position the shutter blocks the window opening and in a second position the shutter is retracted into the door structure. Track means in the door support and guide the shutter. The shutter includes handles at the top corners thereof, and the inner door panel is provided with slots so that the handles may extend outwardly therethrough and be accessible on the inner side of the door. A catch member is positioned in the door near the top thereof for automatically engaging a handle after the door is opened and the shutter is raised to its closed position for supporting the shutter in place.

Brief description of the drawings My invention will be better understood from the following description taken in conjunction with the accompanying drawings and its scope 'will be pointed out in the appended claims.

FIGURE 1 is a side elevational view of a free-standing range with a self-cleaning oven having a windowed oven door embodying the present invention with parts broken away and others in cross-section to show the main ele ments of the oven as well as to show the appearance of the inner surface of the door with the handles of the shutter extending out through vertical slots in the inner door panel as well as the release means for the catch member so that the shutter may be lowered when desired.

FIGURE 2 is a fragmentary plan view on an enlarged scale through the top left corner of the range of FIGURE 1 taken on the lines 22 thereof showing the three panes of high temperature transparent glass which are sealed over the window openings in the inner and outer door panels, as well as the shutter sandwiched between the first and second innermost panes, and having an outwardly extending handle which extends out through a slot in the inner door panel torender the handle accessible so that the shutter may be engaged and raised and lowered when necessary. This view also shows a pivoted catch member which is capable of engaging the handle after the door is opened and the shutter is raised to its topmost position.

FIGURE 3 is a front elevational view taken on the lines 33 of FIGURE 2 with the front half of the door removed to expose the shutter and illustrate the manner of supporting and guiding the shutter on a track system. The view also shows a mechanical interlock system which is operated by the shutter in its raised position and cooperates with an oven door latching mechanism to insure that the oven door may not be latched unless the shutter is supported in its raised position blocking the Window opening.

FIGURE 4 is a fragmentary, side elevational view 3 taken on the lines 4-4 of FIGURE 3 with parts broken away to show the pivoted catch member with a camshaped hook portion engaging the handle of the shutter. FIGURE 5 is a fragmentary plan view taken on the lines '5-*5 of FIGURE 1 showing the oven door latch mechanism in its un'latched position.

Description of the preferred embodiment Turning now to a consideration of the drawings and in particular to FIGURE 1 there is shown for illustrative purposes a free-standing electric range having a top cooking surface 11 with a plurality of surface heating elements '12, a baking oven 13 formed by a box-like oven liner 1'4- and a front-opening, drop-door 15. While the oven door of the present invention is shown as being installed on an electric oven, it will readily be apparent to those skilled in this art that the invention is not limited to use with an electric oven. I may be used just as well with an oven heated by gas or perhaps other heat energy sources. It could also be used with a built-in oven or in fact any type of high temperature cavity. The oven cavity is supplied with two standard heating elements; namely, a lower baking element 16 and an upper broiling element 17 located adjacent the top wall of the oven liner. There is also a mul'lion heater 24 which encircles the front portion of the oven liner 14 and serves to replenish the heat lost through and around the door during the heat cleaning operation to obtain generally uniform wall temperatures throughout. The back edge of the top cooking surface 11 is supplied with a backsplash 18 which supports a control panel on which is mounted control components 19 such as an oven selector switch, an oven thermostat, oven timer and the like. The surface heating units 12 are controlled by multiple pushbutton switches 20 located in the two side arms of the cooktop. Preferably, the oven heating elements 16-, 17 and 24 and their control switches, an oven thermostat and oven timers will be arranged and operated as described in the aforementioned Hurko patent to provide the normal cooking operations as well as the high temperature oven cleaning operation. Positioned beneath the oven 13 is a pull-out drawer 22 which is a storage drawer for cooking utensils and the like. However, in the standard gas oven this space is usually allotted to a separate broiler compartment.

As is best seen in FIGURE 2, the oven door 15 is of generally sheet metal fabricated construction having three main elements; an outer decorative door panel 26, an inner door liner 27 and a floating inner panel 28 supported from the inner door liner 27. For purposes of this invention the two inner door members, the inner door liner 2'7 and the floating inner panel 28, will be referred to as the inner door panel. The outer door panel 26 is of shallowpan shape in virtue of the fact that it has a slight, rearwardly turned peripheral flange 30. The inner door liner is also of shallow-pan shape, and it is of mating construction with the outer door panel 26 by virtue of the fact that it has a front-turned peripheral flange 31 which telescopes Within the flange of the outer door panel 26. The inner door liner 27 includes a generally rectangular, central, outward em'bossment 32 of such a size as to fit closely within the front opening of the oven liner, as is best seen in FIGURES 1 and 2.

The floating door panel 28 is likewise of shallow-pan shape having a front-turned peripheral flange 34, and it covers an area that is slightly less than the area of the outer embossments 32 of the inner door liner 27. A high temperature gasket 35 of woven fiberglass or the like is sandwiched under the periphery of the door panel 28 and fastened to the inner door liner 27 by means of several fastening means widely spaced around the periphery thereof. A more detailed explanation of this fastening means and door structure may be found in the patent of Clarence Getman No. 3,189,020 entitled Oven Door with Floating Inner Panel, which is also assigned to the Gen- 4 eral Electric Company, the assignee of the present invention. 7

The oven door 15 is supplied with a stationary door handle 38 adjacent the top portion thereof as is seen in FIGURE 1. The handle is fastened to the door by screw members (not shown) which extend through the door. Thus the screws for mounting the handle 38 also serve as part of the fastening means for holding the inner door liner 27 to the outer door panel 26. Moreover, the oven door 15 is hinged to the range body along the bottom edge of the door by means of hinge arms (not shown), as is standard in this art.

Looking at FIGURE 2, the present invention relates to a high temperature transparent window 45 formed in the oven door 15 and used by the housewife for viewing the food while it is being cooked in the oven. This window is so constructed that it is protected by means of a vertically movable shutter 46 which serves both as a radiation barrier and a visual barrier during a high temperature oven operation. The door also has an interlocking means shown at the top of FIGURE 3 for cooperation with an oven door latching system shown in FIGURE 5 so as to preclude the operation of the high temperature cycle unless the oven window is first protected by the movable shutter as will be better understood hereinafter.

A window opening is formed in each of the three door elements; namely, the outer door panel 26, the inner door liner 27, and the floating inner panel 28. Thus, there is a window opening 47 in the outer door panel 26, a window opening 48 in the inner door liner 27 and finally a matching window opening 49 in the floating inner panel 28. It is well to provide a plurality of high temperature transparent glass panes in the window openings so as to improve the thermal insulating properties of the window and retard heat transfer to the exterior of the range. Moreover, it is well to provide for the sealing of the window so as to prevent the escape of odors, vapors as well as convection currents of hot air. It is particularly important to prevent the condensation of oven vapors 0n the inner surfaces of the glass panes which would otherwise tend to soil the glass and obscure viewing into the oven cavity.

As seen in FIGURE 2, it will be recognized that there are three glass panes 51, 52 and 53. The two frontmost panes 51 and 52 are separated by a continuous spacer frame 54, and they are held together by an outer frame 55 of U-shaped transparent cross-section which fits around the periphery of the two panes to form a sealed window unit 58. A decorative trim frame 57 extends around the periphery of the front edge of the outermost glass pane 51, and is held by studs (not shown) to the outer door panel 26. This window unit sub-assembly 58 is shown as being fastened to the back side of the outer door panel 26 by means of support flanges 60 and 61 by means of screw fasteners 62.

The third glass pane 53 is shown in FIGURE 2 as being fastened over the window openings 48, 49 from the inner side thereof by means of fastening screws and clip members (not shown) along the top and bottom edges of the third pane 53. Moreover, there is a decorative trim frame 66 assembled around the peripheral edge of the glass pane 53 so as to mask the peripheral edge of the glass pane from view. This trim frame 66 telescopes into the window opening 49 of the floating inner panel 28. A suitable sealing gasket 68 is sandwiched between the glass pane 53 and the inner door liner, again to seal the glass against the escape of gases and vapors around the edges thereof.

Notice that thermal insulation 70 of fiberglass or the like substantially fills the floating inner panel 28. A second layer of insulation 71 is located between the outer door panel 26 and the inner door line-r 27, but it does not completely fill this cavity. There is a front air channel 72 formed between the inner surface of the outer door panel 26 and an insulation guard 73 which holds the insulation 71 in place. Suitable air inlet openings (not shown) are formed in the bottom edge of the door 15 to permit room air to rise through the air channel. Moreover, the top-edge of the door is provided with suitable air outlet openings (not shown). A second insulation guard 75 confines the other side of the insulation 71 so that the raised embossment 32 is substantially hollow.

The hollow raised embossment 32 includes the spacing between the second window pane 52 and the third window pane 53. The purpose of this hollow chamber is to accommodate a reflective shutter 46 which is shown in the raised position in FIGURE 3, but which is capable of being retracted into the lower portion of the door so as to be completely out of view and enable the housewife to see into the oven cavity 13. This shutter 46 is of generally rectangular configuration and may be formed of aluminum sheet metal. The shutter 46 is supported and guided on a track system comprising a pair of vertical rails 77 of generally Z-shape in transverse, cross-sectional view as it best seen in FIGURE 2. Each rail 77 is positioned inboard of the related vertical side of the shutter 46. Adjacent the upper and lower extremity of each vertical side of the shutter 46 is fastened a slide member 79 which is preferably of non-metallic material that is impregnated with graphite such as is sold under the tradename Graphitar that is sold by the US. Graphite Company of Saginaw, Michigan. Such a material has a characteristic lubricity which is not effected by high temperatures in the vicinity of 900 F. in that it does not lose its low friction characteristic. This cooperation between the four slide members 79 and the two rails 77 of the track system gives positive location of .the shutter and prevents any jamming action that might be caused by thermal expansion of the shutter 46.

The shutter 46 is a symmetrical member and as seen in FIGURE 3 the upper corners of the shutter are each provided with an outwardly extending handle 81. Looking at FIGURE 1 the side walls of the outer emboss-ments 32 are provided with a long, narrow, vertical slot 83 through which the handle 81 extends. Of course, the purpose of the handle is to enable the housewife to grasp the shutter 46 and raise or lower it as is needed.

It is necessary to provide means for supporting the shutter 46 in its raised position, and this invention contemplates the use of a gravity actuated catch member 85 as is best seen in FIGURES 3 and 4. This catch 85 is a pivotal member that is pivoted about its top end by -a pivot pin 87 that is supported in the side wall of the raised embossment 32 slightly above the top end of the slot '83 as is best seen in FIGURE 4. The lower end of the catch 85 is provided with a cam-shaped hook 88 which faces toward the front surface of the door 15. The cam surf-ace is marked 89 and the hook has a lip 90 which is adapted to engage behind the handle 81 and prevent inadvertent removal of the catch from the handle. It will be understood that the handles 81 cannot be reached unless the oven door 15 is first opened. Thus with the door 15 in either a partially open or fully open position it is clear that the hook portion 88 is located beside the slot 83. Hence when the shutter 46 is to be raised by engaging and lifting the handles 81, the handles will strike .the cam surface 89 and the catch 85 will be deflected out of the way until the handles move above the hook portion 88 at which time the catches are moved by gravity back beneath the handles and are automatically engaged thereby.

Means must be provided for releasing the catch member so that the shutter 46 may be lowered upon the completion of the self-cleaning oven cycle and after the door is opened. Such a release means is shown in FIGURE 4 as a combination of an arcuate slot 93 that is generally concentric with the pivot pin 87 of the catch, and a tab 95 formed as an integral part of the catch near its pivotal axis. The tab extends out through the slot 93 to be accessible on the inner face of the oven door 15. Thus to move the shutter 46 to its retracted position, the housewife would open the door and first lift upwardly on the 6 handles '81 and simultaneously lift the tabs of the catch members thereby pivoting the catches out of engagement with the handles so the handles can be lowered until the shutter reaches its completely retracted position in the door beneath the window.

FIGURE 5 merely shows a door latch mechanism which is adapted to be built into the range body above the front of the oven liner 14 so that the oven door may be locked and may not be opened during the high temperature heat cleaning operation. The specific door latching mechanism is fully disclosed in the patent to Clarence Getman No. 3,189,375 which is assigned to the same assignee as is the present invention. The mechanism includes a handle 102 which extends through an elongated, horizontal slot 103 in the front of the range body, for example, beneath the cooktop 11 as is best seen in FIGURE 1. A complete description of this door latch mechanism is not deemed necessary here since it does not form part of the present invention. It does, however, include a latching bolt 108 pivoted to a mounting bracket 109 by means of pin and slot connections which are shown in dotted lines therein. When the door latch handle 102 is moved from left to right for latching the door, the latching bolt 108 is caused to swing in a horizontal plane and reach out of the range body through the elongated slot 103 for engaging in a keeper slot 112 that is formed in the inner surface of the inner door liner 27 as is best seen in FIGURE 3.

As is taught in the before-mentioned Baughman et al. Patent No. 3,311,106, the oven door 15 is provided with a mechanical door latch interlocking system to insure that the door latch 100 cannot be closed unless the movable shutter 46 is first raised to its window blocking position as shown in FIGURE 3. One side of the upper edge of the shutter 46 is provided with a finger member 115 which is capable of engaging a pivoted interlocking member 116 which is normally biased by spring means 117 into a position to cover or to close the keeper slot 112 in the door. If the shutter is not raised, this interlocking member 116 fills the keeper slot and prevents the pivoted bolt member 108 of the door latching mechanism from entering the keeper slot and hence the door latch handle 102 cannot be moved to its closed position. There are suitable switch means (not shown) which must be closed by the door latching mechanism in the closed position before the heat cleaning circuit can be established, and the heat cleaning cycle initiated.

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 particular embodiments disclosed but that it is intended to cover all modifications which are within the true spirit and scope of this invention as claimed.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In an oven door having a window formed therein, said door comprising an outer door panel with a first window opening, at least one transparent pane sealed over the said first window opening, an inner door panel with a second window opening, at least one transparent pane sealed over the said second window opening, and fastening means for attaching the inner and outer door panels together, and a shutter positioned within the door and movable between a first position retracted within the door structure and a second position blocking the view through the window, the shutter having handle portions formed on opposite sides thereof, and slots formed on the inner door panel for receiving the handle portions therethrough for accessibility when the door is open, and at least one pivoted catch member positioned within the door and having a cam-shaped hook portion, said catch member being biased by gravity under an adjacent handle portion when the shutter reaches its raised blocking position for holding the shutter in place, and manual releasing means for withdrawing the catch from the shutter so the shutter may be lowered to its said first retracted position.

2. In an oven door having a window formed therein, said door comprising an outer door panel with a first window opening, at least one transparent pane sealed over the first window opening, an inner door panel with a second Window opening, at least one transparent pane sealed over the second window opening, and fastening means for attaching the inner and outer door panels together, and a shutter positioned within the door and movable between a retracted position in the lower portion of the door structure and a raised position blocking the view through the window, track means within the door on which the shutter is supported and guided in its movement, the shutter having handles at the top corners thereof, and slots formed on the inner door panel for receiving the respective handles therethrough, and at least one catch member positioned within the door and near the top of the said slot, said catch having a camshaped hook portion which is biased to move under an adjacent handle when the door is open and the shutter is manually raised to its blocking position for supporting the shutter in place, and manual release means for disengaging the catch from the shutter so the shutter may be moved to its retracted position.

3. In an oven door as recited in claim 2 wherein the catch member is a pivotal member with its pivot at one end thereof adjacent the top edge of the door, and the said cam-shaped hook portion is at the lower end of the member and facing toward the front panel of the door, and a small opening in the inner door panel, the said manual release means comprising a tab on the catch member which extends outwardly through the small opening.

4. In an oven door having a window formed therein, said door comprising an outer door panel with a first window opening, at least one transparent pane sealed over the said first window opening, an inner door panel with a second window opening, at least one transparent pane sealed over the said second window opening, and fastening means for attaching the inner and outer door panels together, and a shutter positioned within the door and movable between a first position retracted within the door structure and a second position blocking the view through the window, the shutter having handle portions formed on opposite sides thereof and accessible when the door is open, and at least one movable catch member positioned on the door and biased into handle engaging position when the shutter reaches its raised blocking position for holding the shutter in place, and manual releasing means for withdrawing the catch from the shutter so the shutter may be lowered to its said first retracted position.

References Cited UNITED STATES PATENTS 2,926,658 3/1960 Ligon 126-200 3,311,106 3/1967 Baughman et a1. l26200 3,396,717 8/1968 Winkler et al 12 6-200 KENNETH W. SPRAGUE, Primary Examiner.

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