U.S. patent number 3,870,862 [Application Number 05/482,469] was granted by the patent office on 1975-03-11 for glass-ceramic cooktop construction.
This patent grant is currently assigned to Whirlpool Corporation. Invention is credited to John T. Doner.
United States Patent |
3,870,862 |
Doner |
March 11, 1975 |
GLASS-CERAMIC COOKTOP CONSTRUCTION
Abstract
A smooth cooktop construction wherein a glass-ceramic panel is
mounted in a frame and secured therein by means of a burner box
structure which further serves to secure a control panel of the
cooktop in the frame. A subassembly of electric burner elements
mounted in insulators is provided in a mounting tray which is
secured to the burner box structure with the insulators engaging
the underside of the glass-ceramic panel. The insulators are
mounted in the tray by means of sharp securing elements urged into
the sidewalls of the insulators retaining the insulators in
engagement with sidewall portions of the tray. This subassembly is
adjustably secured to the burner box structure. A control panel is
also secured to the frame by means of the burner box structure
permitting facilitated installation of the control switches and
indicator lights. Facilitated connection of the electrical wiring
is also provided. The cooktop structure is assembled in an inverted
position on a suitable assembly fixture for facilitated
assembly.
Inventors: |
Doner; John T. (Marion,
OH) |
Assignee: |
Whirlpool Corporation (Benton
Harbor, MI)
|
Family
ID: |
27021732 |
Appl.
No.: |
05/482,469 |
Filed: |
June 21, 1974 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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412328 |
Nov 2, 1973 |
3838505 |
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Current U.S.
Class: |
219/452.12 |
Current CPC
Class: |
F24C
7/067 (20130101); F24C 15/102 (20130101); F24C
15/104 (20130101); H05B 3/74 (20130101) |
Current International
Class: |
F24C
15/10 (20060101); H05B 3/68 (20060101); H05B
3/74 (20060101); H05b 003/68 () |
Field of
Search: |
;219/445,449,452,453,460,461,463,464 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Mayewsky; Volodymyr Y.
Attorney, Agent or Firm: Wegner, Stellman, McCord, Wiles
& Wood
Parent Case Text
This is a division of application Ser. No. 412,328 filed Nov. 2,
1973, now U.S. Pat. No. 3,838,505.
Claims
I claim:
1. A glass-ceramic cooktop comprising:
a glass-ceramic panel;
a frame member;
gasket means around the periphery of the glass-ceramic panel;
burner box side means mounted to said frame and securing the
glass-ceramic panel and gasket means to said frame member;
a tray having a sidewall spaced below said panel within the burner
box side means;
an insulator in said tray having an upper surface, said insulator
having sidewall means projecting above the sidewall of the
tray;
an electric heating element disposed on said upper surface of the
insulator;
means adjustably securing the tray to the burner box side means for
providing abutting relationship between the upper end of the
insulator sidewall means and the glass-ceramic surface; and
a burner box bottom member cover attached to said burner box side
means enclosing the tray.
2. The glass-ceramic cooktop of claim 1 wherein said adjustable
securing means comprises sharp elements projecting into said
insulator and means mounting the elements to said tray.
3. The glass-ceramic cooktop of claim 1 wherein said insulator
comprises a fibrous alumina silicate element.
4. The glass-ceramic cooktop of claim 1 wherein said insulator
comprises a high reflectance, vacuum formed, short fiber alumina
silica element.
5. The glass-ceramic cooktop of claim 1 wherein said burner box
side means includes a divider wall, and said cooktop further
includes a control panel secured to said frame by said burner box
side means.
6. The glass-ceramic cooktop of claim 1 wherein said heating
element and insulator comprises a subassembly and means are
provided for securing the insulator to said tray.
7. The glass-ceramic cooktop of claim 1 wherein said insulator
defines a pair of flat surfaces being in perpendicular planes and
facially engaging perpendicularly extending sidewall portions of
the tray, said insulator being secured to said tray by sharp
elements carried by the tray and projecting into said insulator
sidewall.
8. The glass-ceramic cooktop of claim 1 wherein said insulator
defines a pair of flat surfaces being in perpendicular planes and
facially engaging perpendicularly extending sidewall portions of
the tray, said insulator being secured to said tray by sharp
elements carried by the tray and projecting into said insulator
sidewall, one of said elements being provided at one of said tray
sidewall portions.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to smooth surface cooktops and in particular
to glass-ceramic cooktops and methods of forming the same.
2. Description of the Prior Art
In smooth cooktops, a glass-ceramic panel is provided as the
heating surface with the panel being heated from below by a
suitable electric coil heater carried in a suitable insulator
closely subjacent the glass-ceramic panel. In one form of such
cooktop, a control panel is disposed alongside the cooking surface
panel with the controls and indicating lights being disposed
subjacent the control panel portion. An example of a cooktop
utilizing such a heater coil construction is shown in U.S. Pat. No.
3,612,829 of Jesse L. Evans et al. In the Evans et al patent,
resilient means are provided for urging heated blocks of
refractory-fiber material in heat sealed cushion contact with the
undersurface of the cooking panel.
Another patent generally similar thereto is that of Homer W. Deaton
et al U.S. Pat. No. 3,624,352 utilizing a surface temperature
limiting device including a thermostat controlled by the
temperature of the bracket flanges.
Other heating means generally of this type are disclosed in U.S.
Pat. No. 2,637,800 of K. M. Hammell and U.S. Pat. No. 2,260,165 of
E. N. Calhoun.
SUMMARY OF THE INVENTION
The present invention comprehends an improved smooth cooktop
construction which is simple and economical of construction. The
cooktop utilizes a number of subassemblies which may be adjustably
secured into the overall construction for facilitated assembly. In
one such subassembly, the electric heating elements are installed
in a tray by means of supporting insulators. The insulators are
secured to the tray by sharp retaining elements pressed into the
sidewalls of the insulators and holding the insulators against a
plurality of surfaces of the tray sidewalls. At least one of the
sharp securing elements may be formed integrally with one of the
tray sidewalls.
The cooktop is assembled in an inverted position on a suitable
fixture. Thus, the cooking surface panel is installed on the frame
carried on the fixture. A sealing gasket may be provided about the
panel and the gasket retained in association with the frame by
means of the burner box subsequently secured to the frame.
The burner box may include a dividing wall dividing the burner box
space into two adjacent portions. A control panel may be mounted to
the frame and secured thereto also by the burner box structure. The
control switches and indicator light means may be mounted in the
burner box space below the control panel. The heating coil tray may
be secured to the dividing wall.
The electric wiring of the cooktop is facilitated by means of a
wiring harness package. An electric cable clamp may be attached to
the burner box bottom for facilitating connection of the electric
cable wires. The heating elements are provided with terminals at
the bottom thereof extending through the tray bottom for
facilitated electrical connection. The electric terminal block
providing support for the electric terminals is secured to the tray
with a single screw for facilitated installation.
Thus, the invention comprehends a cooktop construction which is
extremely simple and economical of construction while yet providing
the highly desirable advantages discussed above.
BRIEF DESCRIPTION OF THE DRAWING
Other features and advantages of the invention will be apparent
from the following description taken in connection with the
accompany drawing wherein:
FIG. 1 is a perspective view of a cooktop embodying the invention
mounted in a portion of a kitchen cabinet;
FIG. 2 is an enlarged transverse vertical section thereof;
FIG. 3 is a fore-and-aft vertical section thereof;
FIG. 4 is a top plan view of the heating coil subassembly;
FIG. 5 is a fragmentary enlarged vertical section taken
substantially along the line 5--5 of FIG. 4;
FIG. 6 is a fragmentary enlarged vertical section taken
substantially along the line 6--6 of FIG. 4;
FIG. 7 is a perspective view illustrating a first step in the
assembly of the cooktop;
FIG. 8 is a perspective view illustrating a subsequent step in the
assembly thereof;
FIG. 9 is a perspective view illustrating a further subsequent
step; and
FIG. 10 is a perspective view illustrating a still further
subsequent step in the assembly thereof.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the exemplary embodiment of the invention as disclosed in the
drawings, a smooth cooktop generally designated 10 is shown mounted
in a portion of a cabinet 11 which, illustratively, may comprise a
conventional kitchen counter cabinet. The cooktop is adapted for
selective use as a drop-in range unit, or in a set-in range, or in
a freestanding range, as desired.
As shown in FIG. 1, the cooktop comprises a smooth cooktop defined
by a cooking panel 12 illustratively comprising a glass-ceramic
panel of conventional construction. The panel is set in a frame 13
which, as shown in FIG. 1, overlies the upper surface 14 of the
counter.
The frame may include a divider strip 15 for separating the panel
12 from a control panel 16 also set into the frame. As shown, the
control panel may include a plurality of control knobs 17 for
controlling heating of preselected areas 18 of the panel 12 by
suitable heating elements 19 mounted subjacent the panel, as
illustrated in FIG. 2. Control panel 16 may be formed of a tempered
glass material and may be provided with indicating portions 20 to
be suitably illuminated for indicating the energization of the
selected burner areas 18 by corresponding manipulation of the
control knobs 17 controlling adjustable switches 21, as shown in
FIG. 2.
The invention comprehends as improved cooktop construction and
method of forming the same which is extremely simple and
economical. More specifically, the cooktop construction utilizes
subassemblies which are adjustably associated permitting
facilitated assembly of the entire unit by means of a simple
fixture. As shown in FIGS. 2 and 3, the cooktop includes burner box
means 22 including sidewalls 23, 24, 25 and 26, and a dividing wall
27 extending across the burner box space 28 defined by the
sidewalls 23-26 and dividing the space into a cooking space portion
29 and control space portion 30, as shown in FIG. 2. Divider wall
27, as shown in FIG. 8, extends between front sidewall 23 and rear
sidewall 24 and includes a pair of mounting bosses 31 aligned with
similar bosses 32 on left sidewall 25. The sidewalls may be
provided adjacent their lower edges 33 with a plurality of louvers
34 for venting the burner box space 28.
The heating elements 19 are carried in a box-like tray 35 in
cooking space 29. As shown in FIG. 2, tray 35 includes a left
sidewall 36 secured to mounting boss 32 and a right sidewall 37
secured to mounting boss 31 supporting the tray adjustably under
the panel 12 in the upper portion of cooking space 29.
As further shown in FIG. 2, the control switches 21 and indicating
lights 38 of control 39 are carried on a downwardly opening
box-like control tray 40 within control space 30.
The heating elements 19 are subassembled in tray 35 for facilitated
installation in the cooktop. As shown in FIGS. 4-6, the heating
unit assembly generally designated 41 may include four heating
elements 19, each defined by an electric heating coil 42 mounted in
an insulator 43 provided with a spiral groove 44 receiving the
heating coil 42. In the illustrated embodiment, the insulators 43
may be formed of a high reflectance, vacuum formed, short fiber
alumina silica insulation. The insulators may be cast of such
material to provide lightweight, heat resistant insulating supports
for the heating coils.
Connecting wires 45 and 46 are brought from the opposite ends 47
and 48 of the heating coil outwardly to a terminal block 49. As
shown in FIG. 5, each terminal block 49 includes a pair of
terminals 50 extending downwardly through the bottom wall 51 of the
tray 35 for facilitated electrical connection to the heating coils
in the assembly of the cooktop. Each terminal block 49 is secured
to the tray bottom wall 51 by a single screw 52 providing further
facilitated assembly of the unit.
As shown in FIG. 4, each insulator 43 includes a pair of flat
surfaces 53 and 54 facially engaging the right angularly extending
sidewalls of the tray 35 at the corners 55 thereof, and more
specifically, engaging portions 56 and 57 spaced from the corner
edge 58. The insulators carrying the heating coils are fixedly
secured in the tray corners by means of sharp retaining elements 59
and 60. Retaining elements 59 may comprise inturned tabs formed in
the sidewall portions 57 of the tray sidewall and projecting into
the insulating material of the insulator 43, as shown in FIG. 6.
Retaining elements 60 may comprise turned portions of a retaining
clip 61 secured to the tray bottom 51 by suitable means such as
screw 62. Retaining elements 60 engage a portion of the insulator
43 generally oppositely of the surfaces 53 and 54 and cooperate
with the retaining element 59 in locking the insulating elements
firmly in the corner portion as illustrated in FIG. 4.
As further shown in FIG. 4, the bottom wall 51 of tray 35 may be
provided with a radiating embossment 63 reinforcing the bottom
wall.
As shown in FIGS. 5 and 6, the upper edge 64 of the outer wall 65
of each insulator 43 projects above the top edge 66 of the
sidewalls of the tray 35. Thus, when the tray is mounted to the
bosses 31 and 32, the upper edge 66 of the tray is spaced slightly
below panel 12 when the upper edge 64 of the insulator engages the
undersurface 67 of panel 12. Vertical adjustment of the tray is
permitted by provision of elongated slot-type openings 68 in the
bosses 31 and 32, as shown in FIG. 3, permitting the tray to be
secured to the burner box walls 25 and 27 by suitable screws 31a
and 32a with the heater assembly 41 disposed as shown in FIGS. 2
and 3.
The assembly of the cooktop is readily effected in a novel and
simple manner, as shown in FIGS. 7-10, wherein frame 13 is firstly
set on a suitable fixture 69 with the exposed trim portion 70
lowermost and with a turned flange portion 71 thereof projecting
upwardly. As shown in FIG. 7, the frame includes the divider strip
15. The divider strip 15 similarly includes a trim portion 72 and a
mounting flange portion 73. The glass-ceramic panel 12 is provided
with a peripheral gasket 74 and the control panel 16 is similarly
provided with a peripheral gasket 75 and then placed in the frame
to rest on the trim portions 70 and 72.
In the next step, as seen in FIG. 8, the sidewalls 23, 24, 25 and
26 of the burner box are installed on the frame inwardly of the
flange portion 71 to rest on the inturned trim portions 70. The
dividing wall 27 is mounted to the divider strip 15 and each of the
sidewalls and divider wall is secured to the frame by suitable
screws 76 to define a burner box assembly 77, as shown in FIG.
8.
Sidewalls 23 and 24 may be suitably slotted to pass the opposite
ends of the divider strip 15 in assembling the burner box structure
77, as shown.
Heating unit assembly 41 is then installed in an inverted position
in the burner box space 29 to the left of divider wall 27, as shown
in FIG. 9.
As discussed above, the burner box assembly is secured in position
with the projecting edge 66 of the insulators engaging the
underside 67 of panel 12 and secured in place by suitable screws
31a and 32a extended through the slotted openings 68 of the bosses
31 and 32. Similarly, the control assembly 40 is installed in an
inverted position in the control space 30 to the right of divider
wall 27 and suitably secured to the burner box by suitable screws
78 to be disposed subjacent the control panel 16 as shown in FIG.
2.
Wiring 79 between the heating element terminals 50, the indicator
lights 38 and control switches 21 is then completed by means of a
suitable color coded wiring harness package (not shown). The wires
80 may be brought out through a conventional electric cable clamp
81 in a bottom wall 82 which may be secured across the lower ends
of the burner box assembly 77 by suitable screws 83 as shown in
FIG. 10.
Mounting of the side walls 23, 24, 25 and 26 and divider wall 27 of
the frame further serves to secure the panels 12 and 16 and the
peripheral gaskets 74 and 75 thereof to the frame as illustrated in
FIGS. 3 and 4. Thus, each of the sidewalls and divider wall may be
provided with a turned flange 84 engaging the gasket to provide a
cushioned mounting of the burner box and panels.
Upon completion of the subassembly of the cooktop as shown in FIG.
10, the cooktop may be removed from the fixture 69 and turned top
uppermost permitting the control knobs 17 to be installed on the
switch shafts 85 to complete the assembly of the cooktop.
In installations such as freestanding ranges, the bottom wall 82 of
the burner box may be omitted. Thus, the cooktop is adapted for use
not only as a drop-in unit, but also as a set-in or freestanding
range unit.
The assembly of cooktops 10 is facilitated by utilization of the
burner box walls as the means for retaining the gasketed panels 12
and 16 in place on the frame. Adjustability in the mounting of the
heating unit assembly 41 to the burner box walls further simplifies
and facilitates assembly of the cooktop. Facilitated mounting of
the heating unit insulators in the heating unit tray further
simplifies the assembly while yet providing accurate positioning of
the heating elements relative to the underside of the heating panel
12 in the completed cooktop.
As the heating wall terminals 50 are brought out through the bottom
wall 51 of the heating unit, facilitated electrical connection is
provided. The adjustability of the mounting of the tray permits for
a lower cost construction in obviating the need for high tolerances
in the dimensions of the heating unit element while yet a positive
firm engagement between the heating unit insulators and the cooking
panel is assured.
The foregoing disclosure of specific embodiments is illustrative of
the broad inventive concepts comprehended by the invention.
* * * * *