US3870862A

US3870862A - Glass-ceramic cooktop construction

Info

Publication number: US3870862A
Application number: US482469A
Authority: US
Inventors: John T Doner
Original assignee: Whirlpool Corp
Current assignee: Whirlpool Corp
Priority date: 1973-11-02
Filing date: 1974-06-21
Publication date: 1975-03-11
Anticipated expiration: 1992-03-11

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.

Description

Ir V i United States tet 1 [11] 3,870,862 Doner Mar. 11, 1975 GLASS-CERAMIC COOKTOP CONSTRUCTION Primary Examiner-Yolodymyr Y. Mayewsky [75] Inventor: John T. Doner, Marion, Ohio s fg gffigg'g 0r Flrm wegner Stenman Mccord [73] Assignee: Whirlpool Corporation, Benton Harbor, Mich. ABSTRACT [22] Flled: June 1974 A smooth cooktop construction wherein a glass- [21] Appl. No.: 482,469 ceramic panel is mounted in a frame and secured Related U S Application Data therein by means of a burner box structure which further serves to secure a control panel of the cooktop in [62} g g'g g gg S 1973 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 [52] US. Cl 219/464, 219/460, 221194746613, insulators engaging the underside of the glass ceramic I 51 I t Cl Hosb 3/68 panel. The insulators are mounted in the tray by i 452 453 means of sharp securing elements urged into the side- 1 le 0 earc 219/460 walls of the insulators retaining the insulators in engagement with sidewall portions of the tray. This subassembly is adjustably secured to the burner box struc- [56] References Cited ture. A control panel is also secured to the frame by UNITED STATES PATENTS means of the burner box structure permitting facili- 3,6'12,826 10/1971 Deaton 219/453 tated installation of the control switches and indicator 3,612,828 0/1971 Siegla 219/ lights. Facilitated connection of the electrical wiring is 391L829 10/1971 Evans A 4 219/464 also provided. The cooktop structure is assembled in 3624'352 11/1971 Demo" et 219/449 an inverted position on a suitable assembly fixture for 3,627,986 12/1971 Anderson 219/460 facilitated assembl 3.632.983 1/1972 Dills 219/464 3,636,309 H1972 Deaton et a1. 219/452 8 Claims 10 Drawing Figures 3,679,870 7/1972 Opp 219/445 lllllli 41 e l a,.,...,...lllll llllllllll 24 /23 12 74 7516 38 13 37* a4 57 &2 19 6 I 4 ,-i -a2a 49 51 M gg 71; a5 39 a f o 53 L/ PATENTED HARI 1 I975 SHEET 2 0F 4 PATENTED 3 870 862 sum 3 pg 9 This is a division of application Ser. No. 412,328 filed Nov. 2, 1973, now U.S. Pat. No. 3,838,505.

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 glassceramic 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 urgingheated 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 I 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 US. 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 atray 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. I 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 subassemy;

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 forseparating 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'adividing 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 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 resistantinsulating 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. Asshown ,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 assem bly of the cooktop. Each terminal block 49 is secured to the tray bottom wall 51 bya single screw 52 providing furtherfacilitated 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 porti0n73. The glassceramic 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 con- .trol 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 maybe secured across the lower ends of the burner box assembly 77 by suitable screws 83 as shown in FIG. 10. i I

Mounting of the

side walls

23, 24, 25 and 26 and di vider 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 is facilitated by utilization of the burner box walls as the means for retaining the gasketed panelsl2 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.

I claim:

1. A glass-ceramic cooktop comprising:

a glass-ceramic panel;

a frame member;

gasket means around the periphery of the glassceramic 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 fiat 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.

Claims

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.