WINDOWED DOORS FOR SELF-CLEANING OVENS

• US 3,692,015 A
• Filed: 06/01/1971
• Issued: 09/19/1972
• Est. Priority Date: 06/01/1971
• Status: Expired due to Term

• Current Assignee: Harold E. Mckelvey, Joseph E. Jendrisak, William B. Chase
• Original Assignee: Harold E. Mckelvey, Joseph E. Jendrisak, William B. Chase
• Inventors: Jendrisak, Joseph E., McKelvey, Harold E., Chase, William B.
• Primary Examiner(s): Dority, Jr., Carroll B.
• Application Number:
  US05/148,616
• Time in Patent Office: 476 Days
• Field of Search: 126/200 52/304,398,616
• US Class Current: 126/200
• CPC Class Codes: F24C 14/02 pyrolytic type
• CPC Class Codes: F24C 15/04 with transparent panels

Abstract

Windowed doors for self-cleaning household ovens where the window assembly has a series of spaced parallel glass window panels secured in alignment with two of such panels near the oven cavity enclosing a dead-air insulating space, and a third of such glass window panels being separated from the oven cavity by two dead-air space enclosing glass panels, with the space between the third panel and the two dead-air enclosing panels being ventilated for replacement of heated air therein by natural circulation of cooler air, and a thin grid-like foraminous reflective coating on at least one of the glass panels disposed in the ventilated air space to reflect a relatively large proportion of radiant oven heat and to be cooled by the air wash during such ventilation.

Claims

1. A hinged oven door for closing a door opening in a household oven, said door comprising:

a hollow sheet metal frame having a central opening and a window closing said opening, the rear of said hollow frame which is adapted to close an oven cavity being covered with insulation surrounding and in abutting relationship with said window unit;

said window comprising four transparent panels mounted in predetermined spaced parallel relation in said central opening including an inner glass panel, a first intermediate glass panel near and spaced from said inner panel, a second intermediate glass panel outwardly of said first intermediate panel and spaced therefrom, and an outer transparent panel spaced from said second panel, said first intermediate panel being located between said inner panel and said second intermediate panel, said second panel being located between said first panel and said outer panel;

means essentially sealing the space between said inner panel and said first intermediate panel to provide an insulating dead-air space between said panels and near the inner side of the oven door;

a gridlike foraminous reflective coating located on said second intermediate panel, the foramens of said coating having an average area no greater than 0.02 square inch, said coating having a thickness no greater than about 1,500 Angstroms and being formed of a substantially non-chemically-reactive metal having a thermal conductivity in excess of about 40 BTU/ (ft.2hr. *F/in.) at 212*F. and a surface emissivity less than about 0.50 throughout a temperature range between 750* and 950*F. and selected from the group consisting of gold, platinum and alloys thereoff;

a cool air inlet means in the lower part of said door communicating with the spaces on both sides of the panel provided with said reflective coating, and a warm air outlet means in the upper part of said door communicating with said air inlet means, so that, when heat escapes through said deadair space, substantial amounts of the escaping heat impinge upon said gridlike foraminous reflective coating, portions of which are reflected back toward the inner panel and other portions of which are absorbed by said coating, said coating being cooled by the flow of air across it from said air inlet means to said outlet means to maintain the outermost exposed surface of the outer transparent panel at a temperature below 230*F. when the door is exposed to an oven temperature of 950*F., said air inlet and air outlet means providing a natural upward circulation of air over the inner and outer faces of said second panel, the ratio of the total reflective surface area of said gridlike foraminous coating to the total area of the foramens of said coating being between 3;

1 and 3;

2.

2. An oven door as defined in claim 1 wherein said reflective coating has a thickness of at least 1,000 Angstroms.

3. An oven door as defined in claim 1 wherein a second gridlike foraminous reflector is provided between said first intermediate panel and said outer panel, said second reflector being mounted in a predetermined position during normal use to permit viewing through the door.

4. An oven door as defined in claim 3 wherein said second foraminous reflector is mounted in a fixed position relative to the first reflector.

5. An oven door as defined in claim 4 wherein said second reflector comprises a reflective coating on one face of said second intermediate panel and said first refLective coating is located on the opposite face of said second panel.