U.S. patent number 3,877,460 [Application Number 05/438,864] was granted by the patent office on 1975-04-15 for oven door.
This patent grant is currently assigned to Whirlpool Corporation. Invention is credited to Thomas D. Ford, Larry C. Lotz.
United States Patent |
3,877,460 |
Lotz , et al. |
April 15, 1975 |
Oven door
Abstract
A hollow heat insulating door for a cooking oven and the like in
which the insulating effect is achieved by a combination of an
internal dead air space and an internal heat absorbing black body
baffle adjacent to the viewing openings through the door. The
disclosure also includes a door for a cooking oven in which aligned
inner and outer glass panes are provided for viewing the interior
of the oven with one of the panes being semi-opaque with artificial
light within the oven shining through but outer natural light being
substantially barred when the interior artificial light is
absent.
Inventors: |
Lotz; Larry C. (Marion, OH),
Ford; Thomas D. (Larue, OH) |
Assignee: |
Whirlpool Corporation (Benton
Harbor, MI)
|
Family
ID: |
23742344 |
Appl.
No.: |
05/438,864 |
Filed: |
February 1, 1974 |
Current U.S.
Class: |
126/200;
126/198 |
Current CPC
Class: |
F24C
15/04 (20130101) |
Current International
Class: |
F24C
15/04 (20060101); F24C 15/02 (20060101); F23m
007/04 () |
Field of
Search: |
;126/200,190,198,192,194
;99/341 ;52/304,616,398,399 ;220/24H,9C |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Camby; John J.
Assistant Examiner: Yuen; Henry C.
Attorney, Agent or Firm: Hofgren, Wegner, Allen, Stellman
& McCord
Claims
We claim:
1. A hollow heat insulating door for a cooking oven, comprising: a
peripheral closed frame comprising a marginal wall and spaced apart
inner and outer panels having aligned viewing openings, the opening
in said outer panel being vertically substantially larger than the
opening in the inner panel; an inner glass pane on the inner panel
spanning the inner viewing opening; an outer glass pane on the
outer panel spanning the outer viewing opening; means sealing said
inner glass pane to its said panel, said panels and panes providing
an interior insulating substantially dead air space; and a heat
absorbing baffle in said dead air space for limiting heat transfer
through the door, said baffle having an upper portion spaced
outwardly of said inner panel above said inner glass pane and
spaced inwardly of the upper portion of the outer glass pane and
defining an opening providing unimpeded viewing of the oven through
said aligned panel viewing openings.
2. The door of claim 1 wherein said outer glass pane is semi-opaque
with interior artificial light shining therethrough but outer
natural light being substantially barred.
3. The door of claim 1 wherein said heat absorbing baffle comprises
a black coated steel sheet.
4. The door of claim 3 wherein said heat absorbing baffle comprises
a black oxide coated steel sheet.
5. The door of claim 1 wherein said outer panel is of narrow width
about its opening compared to the width of said inner panel about
its opening.
6. The door of claim 5 wherein said inner glass pane is of
considerably smaller area than said outer glass pane.
7. The door of claim 1 wherein each said panel is provided with
resilient means locating each panel with respect to its glass pane
adjacent to said inner and outer openings.
8. The door of claim 1 wherein said heat absorbing baffle comprises
side portions and a top portion having inner edges substantially
coextensive with the corresponding outer edges of the sides and top
of said inner glass pane and has a projecting flange underlying and
supporting the bottom of said inner glass pane.
9. A hollow heat insulating door for a cooking oven, comprising: a
peripheral closed frame comprising a marginal wall and spaced apart
inner and outer panels having aligned viewing openings, the opening
in said outer panel being vertically substantially larger than the
opening in the inner panel; an inner glass pane on the inner panel
spanning the inner viewing opening; an outer glass pane on the
outer panel spanning the outer viewing opening, said outer pane
being substantially larger than said inner pane and being
semi-opaque with interior artificial light shining therethrough but
outer natural light being substantially barred; means sealing one
of said panes to its said panel, said panels and panes providing an
interior insulating dead air space; and a heat absorbing baffle in
said dead air space for limiting heat transfer through the door,
said heat absorbing baffle comprising a black coated steel sheet
having an upper portion spaced outwardly of said inner panel above
said inner glass pane and spaced inwardly of the upper portion of
the outer glass pane and defining an opening providing unimpeded
viewing of the oven through said aligned panel viewing
openings.
10. The door of claim 8 wherein said outer panel is of narrow width
about its opening compared to the width of said inner panel about
its opening, said inner glass pane is of considerably smaller
extent than said outer glass pane and with resilient means sealing
one of said panels to its glass pane adjacent to said inner and
outer openings.
11. The door of claim 9 wherein said heat absorbing baffle
comprises side portions and a top portion substantially coextensive
with the corresponding sides and top of said inner glass pane and a
projecting flange underlying and supporting the bottom of said
inner glass pane.
12. A hollow heat insulating door for a cooking oven, comprising: a
peripheral frame; an inner panel; an inner glass pane; an outer
glass pane; means sealing said panel and glass panes to the frame
to provide an interior insulating substantially dead air space; and
means for reducing heat flow from the inner panel to the outer pane
through said space comprising a black heat absorbing thermally
conductive baffle interposed between preselected portions of said
inner panel and said outer pane.
13. The door of claim 12 wherein said heat absorbing baffle
comprises a black coated steel sheet.
14. The door of claim 12 wherein said heat absorbing baffle
comprises a black oxide coated sheet.
15. The door of claim 12 wherein said heat absorbing baffle
comprises a black oxide coated steel sheet.
16. A hollow heat insulating door for a cooking oven, comprising: a
peripheral closed frame comprising a marginal wall and spaced apart
inner and outer panels having aligned viewing openings; an inner
glass pane on the inner panel spanning the inner viewing opening;
an outer glass pane on the outer panel spanning the outer viewing
opening; means sealing said inner glass pane to its said panel,
said panels and panes providing an interior insulating
substantially dead air space; and a black heat absorbing baffle
interposed between preselected portions of said inner panel and
said outer pane for limiting heat transfer through the door.
17. The door of claim 16 wherein said heat absorbing baffle
comprises a black coated steel sheet.
18. The door of claim 16 wherein said heat absorbing baffle
comprises a black oxide coated sheet.
19. The door of claim 16 wherein said heat absorbing baffle
comprises a black oxide coated steel sheet.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to door constructions, and in particular, to
insulating door constructions for use with heated compartments such
as ovens.
2. Description of the Prior Art
In the conventional cooking oven construction, a front door is
provided to provide selective access to the oven chamber. It is
desirable to permit inspection of the interior of the oven such as
during the cooking process, and it has been conventional to provide
transparent window means in the access door for this purpose. A
problem has arisen, however, in that relatively high temperatures
of the oven have caused a dangerous high temperature condition of
the window means, and a number of different attempts have been made
to provide improved insulation of the window means and/or cooling
thereof as by venting or selectively shielding the window
means.
In the U.S. Pat. No. of J. W. Jacobs et al 3,024,074, the door of a
domestic appliance, such as a dishwasher is provided with a
continuous venting arrangement for permitting exhaustion of steam
or vapor from the dishwashing chamber.
In U.S. Pat. No. 3,186,401 of C. M. Mayer et al, a gas range is
disclosed wherein the oven is vented at the front of the range.
In U.S. Pat. No. 3,267,930 of R. E. Casciani, an oven door is
provided wherein an area of decoration is associated with a glass
window means thereof.
In U.S. Pat. No. 3,362,396 of Bohdan Hurko, the oven door is
provided with a removable reflective shield which may be moved into
one position obstructing the view through the observation window,
or a second position recessed within the door structure.
In G. W. Klepzig U.S. Pat. No. 3,453,997, a sump is provided in a
flue-like opening, or space, between an insulation retainer and
baffle plate in an oven door to provide improved cooling of the
door.
In F. T. Astrella U.S. Pat. No. 3,489,135, an oven door window is
provided with an outer glass panel spaced from the
aperture-defining portions of the frame so that a controlled
quantity of air may pass into and through the space between the
inner and outer glass panels of the window.
In Donald L. Upp U.S. Pat. No. 3,717,138, a sliding shielded window
arrangement is provided in an oven door wherein an uninsulated,
reflective shield is movable to a blocking position adjacent an
outer glass panel to define a large air wash channel for cooling
the exposed outer glass panel, a relatively small panel, to provide
an air barrier for the door area above the outer glass panel.
SUMMARY OF THE INVENTION
This invention comprehends a hollow heat insulating door for a
heated compartment such as a cooking oven with improved simplified
means for inhibiting heat transfer through the door and also
comprehends such a compartment wherein an interior artificial light
shines through glass panes of the door for viewing the interior of
the compartment, at least one of the panes being substantially
opaque when the interior light is absent.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of a cooking oven having a door
embodying the invention.
FIG. 2 is an exploded perspective view of the parts of the
door.
FIG. 3 is an enlarged vertical sectional view through a door
embodying the invention and taken substantially along line 3--3 of
FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The door 10 embodying the invention is illustrated in conjunction
with a cooking stove 11 having four surface cooking elements 12 the
top one of which is occupied by a pan 13 and all of which are
controlled by separate controls 14 at one side of the stove as
illustrated in FIG. 1. In this illustrated embodiment the oven 15
is on the bottom of the structure and is provided with its own set
of controls all in the customary manner.
The door 10 whose parts are shown in exploded perspective view in
FIG. 2 and in assembled vertical section in FIG. 3 is heat
insulating and therefore acts as a heat barrier between the
interior of the oven 15 which is on the right-hand side of FIG. 3
and the exterior of the door which is on the opposite side of FIG.
3. As illustrated, the door comprises a peripherally closed frame
16 comprising an outer marginal wall 17 and spaced apart inner 18
and outer 19 panels with these panels having aligned viewing
openings 20 and 21, respectively.
The outer viewing opening 21 is considerably larger than the inner
opening 20 and each is provided with an inner glass pane 22 and an
outer glass pane 23 with the inner pane being correspondingly
smaller than the outer pane. Means are provided for locating each
pane with respect to its panel with the locating means for the
inner pane 22 comprising sealing means in the form of a distortable
silicone rubber gasket 24 attached to the inner panel 18 at a
flange 25 defining the viewing opening 20 and an edge distortable
foot 26 pressing against the inner surface 27 of the inner pane
22.
The outer glass pane 23 is located with respect to the outer panel
19 by a plurality of silicone rubber bumper or cushion members 28
which in this instance are of L-shaped cross section to embrace the
outer edge and the inner surface adjacent this edge as shown in
FIG. 3. The pane 23 and the bumpers 28 are held in position by four
sheet metal glass clamps 29 each located at a corner of the panel
19 and pane 23 with each clamp 29 held in position by a pair of
screws 30 engaging the panel 19 of which only one each of two
corner pairs are illustrated in FIG. 3.
The combination of the panes and panels provides an interior dead
air space that results in conduction heat insulation from the
interior of the oven 15 to the front 31 of the oven adjacent to the
outer glass pane 23 in the outer panel 19. To provide additional
heat insulation there is also provided a heat absorbing baffle 32
which is a "black body" for absorbing heat and which in this
embodiment is sheet metal having a coating on both sides of black
oxide. The baffle 32 is of generally inverted U-shape as
illustrated in FIG. 2 with spaced sides 33 that define the sides of
the inner viewing opening 20 with these spaced sides 33 being
provided with outwardly turned bottom flanges 34 that are
horizontally aligned to serve as a bottom support for the bottom
edge of the inner pane 22 as illustrated in FIG. 3.
The outer glass pane 23 is semi-opaque. The outer glass pane 23 may
advantageously have a transparent viewing area 23a, and an opaque
border area 23b covered by ceramic paint, with the viewing area 23a
having crossing opaque lines of ceramic paint applied to the glass
in a screen pattern. The viewing area 23a is capable of passing
artificial light so that an interior illumination in the oven will
shine through so that the interior can be viewed during cooking
when the interior electric light (not shown) is on but will
substantially bar exterior and particularly natural light when the
interior of the oven is not illuminated.
The bottom of the marginal wall 17 is attached to the inner panel
18 by a plurality of screws 35. The inner panel 18 at the top and
sides is attached to corresponding portions of the frame 16 by a
plurality of screws 36 that extend through the inner panel 18 and
engage a flange 37 that is integral with the frame 16.
As is shown most clearly in the exploded view of FIG. 2 the method
of assembly is as follows. The outer extruded frame 16 and outer
glass pane or panel 23 are assembled together with the corner
clamps 29, four pairs of corner screws 30 and glass edge bumpers
28. Then a customary hinge frame 38 with lower side hinge members
39 is positioned on the above frame and glass pane subassembly and
then the heat absorbing baffle 32 is positioned against the hinge
frame 38 as shown in FIG. 3. Then the inner glass pane 22 is
positioned as shown in FIG. 3 with the bottom being held by
previously described aligned flanges 34 and the vertical edges of
the pane 22 being held by the pair of side clamps 40 with these
clamps being held in position by two sets of three screws 41 that
are driven through the glass clamps 40 and the baffle sides 33 and
the hinge frame 38 where they are retained in the hinge frame
38.
The inner door panel 18 with the seal 24 in place on the flange 25
as shown in FIG. 3 is positioned over the previously assembled
parts and joined to the frame 16 by the screws 35 and 36.
As can be seen from the above description, the heat insulated door
of this invention is light in weight and inexpensive to build yet
has high heat insulating value due to the provision of the interior
dead air space, the "black body" heat insulating panel and the
outer pane 23. In addition, there are few paths of direct heat
transfer from the interior of the oven to the exterior as the inner
panel 18 is out of direct contact with the frame 16 except for
eight attaching screws 35 and 36. The door may be used in built-in
ovens, set-in ranges including glass cooktop versions and similar
heated cabinets. The door is attractive, inexpensive and is
sufficiently cool to meet the severe requirements for listing by
Underwriters' Laboratories, Inc. (UL). UL requires that the viewing
area of the door be not more than 90.degree. F. above room ambient
temperature, the frame 16 be not more than 105.degree. F. above
this ambient, and that the other external portions of the oven door
be not more than 75.degree. F. above this room ambient.
With the door of this invention there is no need for cooling air
circulation through the door as was required in many prior doors
and there are very few areas of direct heat transfer through the
door.
* * * * *