GB2188401A

GB2188401A - Improvements in or relating to ovens

Info

Publication number: GB2188401A
Application number: GB8607831A
Authority: GB
Inventors: Graham Howlett Goodchild
Original assignee: Thorn EMI Appliances Ltd
Current assignee: Thorn EMI Appliances Ltd
Priority date: 1986-03-27
Filing date: 1986-03-27
Publication date: 1987-09-30
Also published as: GB2188401B; GB8607831D0

Abstract

An oven chamber 1 with a cavity 2 includes metal inner walls 3 and 4, metal outer walls 5 and 6, blocks of insulating material 7 and 8, a body of ceramic insulating foam 9 between the metal panels 3 to 6, the body 9 being positioned by known injecting methods before the back panel 5 is put in place; electric wires 10 may be embedded in the insulating foam 9, for the supply of power to the oven chamber. The metal outer walls or both the outer and inner walls may be dispensed with. <IMAGE>

Description

SPECIFICATION Improvements in or relating to ovens This invention relates to ovens and in particular, though not exclusively, to electric ovens.

In oven structures of the kind known in the art, the side and back panels are all made of metal and contact each other at certain points.

These contact points produce thermal bridges which cause heat dissipation from the oven cavity to the exterior of the oven.

It is an object of the present invention to provide an improved oven in which all the thermal bridges are eliminated, thus reducing heat loss from the oven cavity to the exterior of the oven.

According to the invention there is provided an oven chamber with sides and back formed partially or wholly from ceramic foam.

According to another aspect of the invention there is provided an oven chamber with sides and back formed partially or wholly from skinning ceramic foam.

In a preferred embodiment of the invention the said chamber has metal inner back and side walls and metal outer back and side walls, said inner and outer walls sandwiching between them a layer of insulating ceramic foam which may or may not be self-skinning, said insulating ceramic foam being positioned by known injecting methods.

In an alternative preferred embodiment of the invention the said oven chamber has metal inner back and side walls which are surrounded by a layer of insulating ceramic foam, formed by mould injection. The said insulating ceramic foam in this case must either be selfskinning or alternatively receptive to a coating, which may be applied to the foam to give it a skin. The said coating may be applied by spraying the inside of the mould so that the outer surface of the foam is coated when it takes up the mould.

In yet another alternative embodiment of the invention the said oven chamber is moulded completely from insulating ceramic foam.

Again, the said insulating ceramic foam must either be self-skinning or alternatively receptive to a coating which may be applied to the foam to give it a skin. The said coating may be applied by the method described in the previous embodiment.

In a further embodiment of the invention the said oven is preferably electrically heated.

In order that the invention may be clearly understood and readily carried into effect specific embodiments of the invention will now be described by way of example with reference to the accompanying drawings, of which Figure 1 is a horizontal cross-sectional view of one embodiment of the invention.

Figure 2 is a horizontal cross-sectional view of another embodiment of the invention.

Figure 3 is a horizontal cross-sectional view of yet another embodiment of the invention.

In Fig. 1, an oven chamber 1 with a cavity 2 includes: metal inner back and side walls, 3 and 4 respectively; metal outer back and side walls 5 and 6, respectively; blocks of insulating material 7 inserted between adjacent panels 5 and 6; blocks of insulating material 8 inserted between adjacent panels 4 and 6; ceramic insulating foam 9 between the metal panels 3 and 5, and 4 and 6, said insulating foam 9 being positioned by known injecting methods before the back panel 5 is put in place; and electric wires 10 may be embedded in the insulating foam 9, for the supply of power to the oven chamber.

The oven chamber 11 shown in Fig. 2 is another embodiment of the invention. The said chamber 11 surrounds a cavity 12 and includes metal inner back and side walls, 13 and 14 respectively, surrounded by an insulating ceramic foam 15, formed by mould injection. The insulating ceramic foam 15 must either be self-skinning or alternatively receptive to a coating applied thereto, to effectively give it a skin. The said coating may be applied by spraying the inside of the mould so that the outer surface of the foam is coated when it takes up the mould. Electric wires (not shown) for the supply of power to the oven chamber may be embedded in the insulating foam 15.

A further embodiment of the invention is shown in Fig. 3. An oven chamber 16, surrounds a cavity 17 and is moulded completely from insulating ceramic foam 18. The insulating ceramic foam 18 must either be self-skinning or alternatively receptive to a coating which may be applied to give it a skin. The said coating may be applied by the method described in the previous embodiment. Electric wires (not shown) for the supply of power to the oven chamber may be embedded in the insulating foam 18.

A practical embodiment of the invention could incorporate a hob such as the moulded ceramic gas hob shown in U.K. Patent Application No. 8526068 or a combined hob/grill unit, in which case insulation would be required between the hob and grill. A particularly suitable hob/grill unit is that shown in U.K. Patent Application No. 8503354. In said invention the heating means for the hob and grill are insulated from each other by a mass of thermally insulative material which is preferably a moulded slab of ceramic fibre. The upper surface of the apparatus beneath which the cooking hobs lie is preferably of a glass ceramic material, as is the lower surface which covers the grill elements.

1. An oven comprising a chamber with a back wall and side walls, and a body of ceramic foam incorporated in the walls.

2. An oven according to Claim 1, wherein the body of ceramic foam is shaped to form a

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Improvements in or relating to ovens This invention relates to ovens and in particular, though not exclusively, to electric ovens. In oven structures of the kind known in the art, the side and back panels are all made of metal and contact each other at certain points. These contact points produce thermal bridges which cause heat dissipation from the oven cavity to the exterior of the oven. It is an object of the present invention to provide an improved oven in which all the thermal bridges are eliminated, thus reducing heat loss from the oven cavity to the exterior of the oven. According to the invention there is provided an oven chamber with sides and back formed partially or wholly from ceramic foam. According to another aspect of the invention there is provided an oven chamber with sides and back formed partially or wholly from skinning ceramic foam. In a preferred embodiment of the invention the said chamber has metal inner back and side walls and metal outer back and side walls, said inner and outer walls sandwiching between them a layer of insulating ceramic foam which may or may not be self-skinning, said insulating ceramic foam being positioned by known injecting methods. In an alternative preferred embodiment of the invention the said oven chamber has metal inner back and side walls which are surrounded by a layer of insulating ceramic foam, formed by mould injection. The said insulating ceramic foam in this case must either be selfskinning or alternatively receptive to a coating, which may be applied to the foam to give it a skin. The said coating may be applied by spraying the inside of the mould so that the outer surface of the foam is coated when it takes up the mould. In yet another alternative embodiment of the invention the said oven chamber is moulded completely from insulating ceramic foam. Again, the said insulating ceramic foam must either be self-skinning or alternatively receptive to a coating which may be applied to the foam to give it a skin. The said coating may be applied by the method described in the previous embodiment. In a further embodiment of the invention the said oven is preferably electrically heated. In order that the invention may be clearly understood and readily carried into effect specific embodiments of the invention will now be described by way of example with reference to the accompanying drawings, of which Figure 1 is a horizontal cross-sectional view of one embodiment of the invention. Figure 2 is a horizontal cross-sectional view of another embodiment of the invention. Figure 3 is a horizontal cross-sectional view of yet another embodiment of the invention. In Fig. 1, an oven chamber 1 with a cavity 2 includes: metal inner back and side walls, 3 and 4 respectively; metal outer back and side walls 5 and 6, respectively; blocks of insulating material 7 inserted between adjacent panels 5 and 6; blocks of insulating material 8 inserted between adjacent panels 4 and 6; ceramic insulating foam 9 between the metal panels 3 and 5, and 4 and 6, said insulating foam 9 being positioned by known injecting methods before the back panel 5 is put in place; and electric wires 10 may be embedded in the insulating foam 9, for the supply of power to the oven chamber. The oven chamber 11 shown in Fig. 2 is another embodiment of the invention. The said chamber 11 surrounds a cavity 12 and includes metal inner back and side walls, 13 and 14 respectively, surrounded by an insulating ceramic foam 15, formed by mould injection. The insulating ceramic foam 15 must either be self-skinning or alternatively receptive to a coating applied thereto, to effectively give it a skin. The said coating may be applied by spraying the inside of the mould so that the outer surface of the foam is coated when it takes up the mould. Electric wires (not shown) for the supply of power to the oven chamber may be embedded in the insulating foam 15. A further embodiment of the invention is shown in Fig. 3. An oven chamber 16, surrounds a cavity 17 and is moulded completely from insulating ceramic foam 18. The insulating ceramic foam 18 must either be self-skinning or alternatively receptive to a coating which may be applied to give it a skin. The said coating may be applied by the method described in the previous embodiment. Electric wires (not shown) for the supply of power to the oven chamber may be embedded in the insulating foam 18. A practical embodiment of the invention could incorporate a hob such as the moulded ceramic gas hob shown in U.K. Patent Application No. 8526068 or a combined hob/grill unit, in which case insulation would be required between the hob and grill. A particularly suitable hob/grill unit is that shown in U.K. Patent Application No. 8503354. In said invention the heating means for the hob and grill are insulated from each other by a mass of thermally insulative material which is preferably a moulded slab of ceramic fibre. The upper surface of the apparatus beneath which the cooking hobs lie is preferably of a glass ceramic material, as is the lower surface which covers the grill elements. CLAIMS

2. An oven according to Claim 1, wherein the body of ceramic foam is shaped to form a cavity.

3. An oven according to Claim 1 or Claim 2, wherein the chamber walls are formed partially from the body of ceramic foam.

4. An oven according to Claim 3, wherein the chamber has metallic inner back and side walls, and metallic outer back and side walls, said inner and outer walls sandwiching between them the body of ceramic foam.

5. An oven according to Claim 4, having blocks of insulating material between closely adjacent sections of the inner walls and the outer walls.

6. An oven according to Claim 3, wherein the chamber has metallic inner back and side walls surrounded by the body of ceramic foam.

7. An oven according to anyone of the preceding Claims, wherein the ceramic foam is self-skinning.

8. An oven according to anyone of the preceding Claims wherein the body of ceramic foam has a coating applied to the surface of the foam.

9. An oven substantially as hereinbefore described with reference to and as illustrated in Fig. 1, or Fig. 2 or Fig. 3 of the accompanying drawings.