US3910254A

US3910254A - Oven door construction

Info

Publication number: US3910254A
Application number: US519157A
Authority: US
Inventors: Harold R. Morgan
Original assignee: Dearborn Glass Co
Current assignee: Dearborn Glass Co; US Department of Navy
Priority date: 1973-11-28
Filing date: 1973-11-28
Publication date: 1975-10-07
Anticipated expiration: 1992-10-07

Abstract

An aircooled smokestack. The smokestack has passages within it for air or other cooling fluid. The fluid circulates through the smokestack, cooling off the internal and external surfaces. The cooling fluid is then aspirated into the stack gases near the top of the stack, thereby film cooling the upper portion of the interior of the stack. Cooling air is also aspirated into the flowing gases at the top of the stack, thereby cooling the gases as they leave the stack.

Description

45] Oct. 7,1975

[54] OVEN DOOR CONSTRUCTION 3,659,582 5/1972 Morgan.........................126/198 3,384,072 5/1968 Davis et 126/200 [75] Inventor: Harold R. Morgan, Dolton, Ill.

[73] Assignee: Dearborn Glass Co., Bedford Park,

Primary Examiner-Carroll B. Dority, Jr.

Ill.

[22] Filed: Nov. 28, 1973 Larry I. Schwartz or F irm-Hofgren, Wegner, Allen, Stellman & McCord Assistant Examiner Attorney, Agent,

[21] Appl. No.: 419,764

52/304, 52/616 ABSTRACT [51] Int. F23M 7/00 An oven door construction having a safety shield [58] Field of Search...................... 126/200, 198; which may be mounted to the from light of the door 52/304 616 window and which is arranged to provide improved cooling of the surrounding metal door portion by a [56] References Cited UNITED STATES PATENTS relatively high velocity flow of cooling air thereover.

T877,004 8/1970 Payne........................L.. 126/200 10 Claims, 4 Drawing Figures US. Patent 0a. 7,1975

/ ROOM SIDE OVEN SIDE OVEN DOOR CONSTRUCTION BACKGROUND OF THE INVENTION Field of the Invention This invention relates to oven door constructions, and in particular to means for maintaining oven door constructions at relatively low temperatures.

Description of the Prior Art In my United States Letters Patent 3,659,582, an oven door construction is disclosed having a window portion defining a front light. A protective panel is mounted to the front light by suitable removable means to define an air flow passage rearwardly of the protective panel and forwardly of the window front light effectively maintaining the exposed front surface of the panel at a relatively low temperature notwithstanding a high temperature condition existing within the oven.

There has been a large number of different window constructions developed in connection with oven doors such as those illustrated in United States Letters Patent 3 ,362,396 of Bohdan Hurko; 2,625 ,717 of Roy W. Wampler et al.; 1,517,833 of Robert Gertler et al.; 2,877,761 of Raymond D. Schibley; 3,453,997 of Glen W. Klepzig; and French Patent 1,361,919 of Jean Marcel Weinling, as cited by the Patent Office in my above-identified United States Letters Patent.

Additional structures which are pertinent to such art are those disclosed in United States Letters Patent 1,417,976 of Malcolm Curry et al.; 2,325,773 of John F. Hennessy; 2,733,706 of A. G. Feder; 3,191,240 of Albert Slaman et al.; 3,192,575 of Milton D. Rosenau, Jr., et al.; 3,396,717 of William K. Winkler et al.; and 3,451,389 of Herbert G. Huff.

SUMMARY OF THE INVENTION The present invention is concerned with an oven door construction having an improved safety shield structure. In the present invention, the safety shield comprises a transparent panel which may be secured to the oven door window front light to be spaced forwardly thereof a distance greater than the recess depth of the window light. The panel includes a peripheral portion which extends forwardly of the front surface of the surrounding portion of the door body in which the window is provided to define a narrow flow passage means. At the bottom of the panel, the narrow flow passage means defines a relatively high velocity air flow inlet opening, and at the top of the panel, the narrow flow passage means defines a relatively high velocity air flow outlet opening. The peripheral portion of the panel further serves to guide the air in a direction generally parallel to the flat front surface of the door body, thereby tending to effectively reduce the temperature of the door body portions not only rearwardly of the periphery of the safety shield, but also laterally outwardly of the periphery of the safety shield.

In one embodiment of the invention, the safety shield is secured to suitable bosses provided on the portion of the door body surrounding the window. The means for securing the safety shield to either the window light or surrounding portion of the door body preferably includes insulating means to minimize the temperature of exposed portions of the structure.

More specifically, the invention comprehends providing in an oven door having a metallic body and a window defined by outer transparent light means spaced rearwardly of the front surface of the surrounding portion of the door body, safety shield structure including a transparent panel having a flatwise extent substantially greater than the flatwise extent of the door window, and means for mounting a the transparent panel either to the light means or to the surrounding portion of the door to extend in forwardly spaced relationship to the light means and the surrounding portion of the door body to provide a cooling air flow therebetween.

In the specific embodiment illustrated, the area of the safety shield outwardly of the window recess is less than the area of the window. The invention, however, comprehends providing such a safety shield having a substantially larger lateral extent, as desired.

The safety shield structure of the present invention is extremely simple and economical of construction while yet providing the highly desirable features discussed above.

BRIEF DESCRIPTION OF THE DRAWINGS Other features and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawing wherein:

FIG. 1 is a perspective view of a range provided with an oven door having a safety shield structure embodying the invention;

FIG. 2 is a fragmentary/ enlarged vertical section taken substantially along the line 2-2 of FIG. 1;

FIG. 3 is a fragmentary further enlarged diametric section of means fastening the safety shield to the window light; and

FIG. 4 is a diametric section of a modified form of mounting means wherein the safety shield is mounted to the peripheral portion of the oven door body.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the exemplary embodiment of the invention as disclosed in the drawing, a range generally designated 10, having an oven portion 11 and a front door 12, is provided with an improved safety shield structure 13 for effectively minimizing the temperature of a portion of the door which may be contacted by a user.

More specifically, as shown inFIG. 2, oven door 12 is provided with a window generally designated 14 which is recessed behind the front surface 15 of the door body 16 in an opening 17 extending through the mid-portion of the door. Window 14 may include a rear light 18 confronting the internal oven space 19, and an outer light 20 recessed within opening 17 somewhat rearwardly of the door front surface 15. Window 14 may be effectively sealingly mounted in the door body 16 by suitable mounting means 21, as shown in FIG. 2.

While the use of the double light window having an insulating space 22 between the

lights

18 and 20 provides a temperature drop from oven space 19 to the front light 20, it has been found that the front light may nevertheless have an excessively high temperature such as where the oven is being automatically cleaned by a high temperature self-cleaning operation. As brought out in my previous United States Letters Patent 3,659,582 discussed above, one excellent solution to this problem is to provide a protective panel mounted to the front light effectively overlying the light 20 and defining therewith a vertical chimney-like air flow passage wherein air rising effectively through the passage as a result of the high temperature of the front light 20 washes the rear surface of the protective panel and maintains it at below a preselected maximum temperature. The present invention comprehends an improved arrange ment of such a panel which provides further improved cooling effect of the front exposed surface of the door, thereby providing further safety in the use of the oven.

More specifically, the present invention comprehends providing a safety shield transparent panel 23 having a lateral extent greater than that of the opening 17 so as to define a mid-portion 24 disposed forwardly of window 14, and a peripheral portion 25 spaced forwardly of the surrounding portion 16 of door 12. Means 26 are provided for mounting the safety shield panel 23 to front window light 20 so as to provide a relatively narrow space between the peripheral portion 25 of the panel and the door portion 16 thereby effectively defining a narrow inlet opening 27 at the lower end of panel 23, and a narrow outlet opening 28 at the upper end of panel 23.

The peripheral portion 25 of safety shield panel 23 extends generally parallel to the front surface 15 of door portion 16, and, thus, directs the air leaving outlet 28 generally parallel to the surface 15. As the size of the flow passage 29 rearwardly of safety shield panel 23 is substantially less at outlet 28 as compared to the size thereof in the mid-portion 30 thereof, an increase in the velocity of the convectively flowed air is produced tending to urge the cooled air along the front surface 15 for a substantial distance after it leaves outlet 28, thereby providing enhanced cooling of the door surface 15.

A somewhat similar cooling action is produced at the inlet opening 27 and sides of the shield in that the parallel arrangement of panel portion 25 to the door front surface 15 tends to cause the incoming air to be drawn somewhat along the front surface 15 below the lower edge of the panel and laterally of the sides thereof to provide a further enhanced cooling of the exposed door surface.

In the embodiment of FIG. 2, mounting means 26 includes a spacer 31 having a reduced diameter outer end 32 and a corresponding reduced diameter inner end 33 received in openings 34 and 35 of safety shield panel 23 and window light 20, respectively. An outer screw 36 is threaded into a threaded central bore 37 of the insulative spacer and may be provided with a suitable insulating gasket 38 abutting the outer surface of panel 23. A similar securing screw 39 is threaded into the inner end of the threaded bore 37 and is provided with an insulating gasket 40 abutting the inner surface of the outer light 20. as shown in FIG. 3.

The length of spacer 31 is preselected to space the peripheral portion 25 of the safety shield panel 23 a preselected small distance forwardly of the door body portion 16, as discussed above. The use of the screw 36 permits the safety shield panel to be removed from the door structure when desired, such as for cleaning or replacement thereof. In the illustrated embodiment, the safety shield panel 23 is formed of glass with the screws 36 comprising stainless steel, truss head machine screws and the screws 39 comprising syn thetic resin screws formed of a high temperature material, such as Teflon. Spacer 31 may be formed of metal, such as stainless steel. and insulating

gaskets

38 and 40 may be formed of a yieldable, high temperature synthetic resin, such as Teflon, to further provide a cushioned securing of the safety shield panel to window light 20.

As shown in FIG. 4, safety shield panel 23 may be alternatively secured to the oven door 12 by means of a forwardly projecting boss 41 formed in the door portion 16 outwardly of the window with the safety shield panel being secured to boss 41 by suitable screws 42 threaded into an opening 43 in boss 41. A suitable flanged gasket 44 may be provided between the screw 42 and the safety shield panel 23. In the illustrated embodiment, screw 42 comprises a stainless steel, truss head sheet metal screw with the gasket being formed of a hightemperature synthetic resin, such as Teflon. A suitable plurality of such mounting structures may be provided such as one each at the four corners of the panel 23. The mounting arrangement of FIG. 4 provides the same highly desirable advantages as in the structure of FIGS. 2 and 3 in providing a relatively narrow flow passage adjacent the door portion 16 to provide the improved cooling action relative to the door surface 15, as discussed above.

In the illustrated embodiment, the spacing between safety shield panel portion 23 and surface 15 of door body portion 16 is approximately /s, it being obvious to those skilled in the art that any suitable desirable spacing may be utilized.

The foregoing disclosure of specific embodiments is illustrative of the broad inventive concepts comprehended by the invention.

I claim:

1. An oven cabinet construction comprising:

wall means defining an oven cavity having a front opening;

a door movably carried by said wall means for selectively closing said opening and having a window structure permitting viewing the oven cavity from forwardly of the door when the door is in a closed position across said opening, said window structure including a transparent light having a front surface exposed to forwardly thereof;

an auxiliary transparent light;

spacer means; and

means for securing said spacer means to said window light inwardly of the periphery thereof to extend forwardly from the front surface of said window light, and for securing said spacer means to said auxiliary light. whereby said spacer means and securing means define means for mounting said auxiliary light on said window light to be spaced forwardly of said front surface thereof and defining therewith an entrance passage at the bottom of said auxiliary light and an exit passage at the top of said auxiliary light for flow of ambient air upwardly through the space between said lights to maintain said auxiliary light at a preselected low temperature suitable to avoid injury to a person accidentally touching said auxiliary light when the oven is heated, said auxiliary light having an area substantially greater than the area of said window light to overlie a portion of the door adjacent the window structure.

2. The oven cabinet construction of claim 1 wherein said auxiliary light has a vertical extent substantially greater than the vertical extent of said window light.

3. The oven cabinet construction of claim 1 wherein said auxiliary light has a horizontal extent substantially greater than the horizontal extent of said window light.

4. The oven cabinet construction of claim 1 wherein said auxiliary light is formed of glass.

5. The oven cabinet construction of claim 1 wherein said auxiliary light is spaced forwardly of said door portion a preselected small distance to define a narrow air passage for causing relatively high flow velocity of air convectively flowing between said auxiliary light and said door portion.

6. The oven cabinet construction of claim 1 wherein a substantial portion of the door is exposed upwardly of the auxiliary light.

7. The oven cabinet construction of claim 1 wherein the auxiliary light is spaced forwardly of said door portion approximately /8.

8. The oven cabinet construction of claim 1 wherein said means for securing said spacer means to said auxiliary light comprises readily removable means.

9. The oven cabinet construction of claim 1 wherein said means for securing said spacer means to said auxiliary light comprises readily removable means permitting removal of said auxiliary light while retaining said spacer means secured to said window light.

10. The oven cabinet construction of claim 1 wherein said spacer means comprises thermally insulative means.

UNITED STATES PATENT OFFICE (IERTIFICATE OF CORRECTION Patent NO. a qnxyg Dated October 7, 1975 Page 1 of 2 InVent0 Harold R. Morgan It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the cover page the illustrated drawing should appear as shown on the attached sheet.

Enigncd and Sealed this thirteenth Day of April1976 [SEAL] A ttest:

RUTH. C. MSON C. MARSHALL DANN Alltsllng Oljl't' ('ummissiuncr of Parents and Trademarks Page 2 of 2 Patent No.

Claims

1. A smokestack comprising: converging interior and exterior walls having upper and lower portions with a layer of insulation between said walls; a first fluid flow channel adjacent the lower portion of said interior wall; a second fluid flow channel adjacent said exterior wall and the upper part of said interior wall; means for causing fluid within said channels to be aspirated into said smokestack; and a plenum chamber which directs fluid into said fluid flow channels, said plenum chamber having inlets spaced around its outer periphery.

2. A smokestack as in claim 1 wherein said inlets have doors which open inward and are biased closed.

3. A smokestack as in claim 1 further including a member which surrounds the exit of said smokestack and is spaced therefrom.

4. A smokestack as in claim 1 further including exit slots in said interior wall for said first anD second fluid flow channels, the exit slot of said first channel being located immediately upstream of the exit slot of said second fluid flow channel.

5. A smokestack as in claim 4 wherein the means for causing fluid within said channels to be aspirated into said smokestack comprises a splitter plate between said exit slots which prevents the fluid in either of said channels from entering the other of said channels and which projects into the converging flow path defined by said interior walls plus a member immediately upstream of the exit slot of said first fluid flow channel which projects into the flow path defined by said interior walls a greater distance than said splitter plate.