WO2019129612A1

WO2019129612A1 - A transparent cooker comprising a heat resistant frame

Info

Publication number: WO2019129612A1
Application number: PCT/EP2018/086081
Authority: WO
Inventors: Murvet SARI; Samet AKAN; Bekir Ozyurt; Cumhur Ayvazoglu; Ali Levent Hasanreisoglu
Original assignee: Arcelik Anonim Sirketi
Priority date: 2017-12-26
Filing date: 2018-12-20
Publication date: 2019-07-04
Also published as: TR201721904A2

Abstract

The transparent cooker of the invention is designed to solve the assembly and maintenance problem arising from using a high number of glasses therein, and comprises a plurality of bare glasses forming a main body by being joined so as to form a quadrangular prism, positioned so as to face the external volume, a plurality of coated glasses forming a main body by being joined so as to form a quadrangular prism, positioned so as to face the internal volume, at least one vacuumed glass for providing thermal insulation, which can be used instead of a bare glass, at least one frame holding the coated glasses or the bare glasses together to form the main body, metallic adhesive to apply on two opposite edges of the coated glasses, at least one slot provided in a frame for placing a copper sheet therein, at least one catch to position a copper sheet and to shield it from contacting oxygen, at least one wire hole bored from behind or from the center of a frame, electric wires extending out of the frame by passing through the wire hole, a copper sheet acting as a bridge by transmitting electricity between the electric wires and the coated glasses, at least one heater film coating forming a coated glass by being applied on a glass surface, at least one recess provided in a frame, for placing a bare glass or a vacuumed glass, at least one metal profile enframing the main body, at least one insulation material provided between a metal profile and a bare glass, at least one corner fitting for the metal profiles to form the main body by being attached to each other, and at least one channel provided in a metal profile between a coated glass and a bare glass, containing an inert gas or dry air to provide thermal insulation and sealing.

Description

A TRANSPARENT COOKER COMPRISING A HEAT RESISTANT FRAME

Technical Field

The present invention relates to a transparent cooker designed to enable homogeneous cooking and visibility of its interior during cooking.

Prior Art

The ovens cooking food products by transferring the heat generated in a separate section in the oven to the cooking section by means of a fan are referred to as convectional ovens. In convectional ovens, elements such as tray level, preheating temperature, and the temperature of the product to be cooked (the product being freshly prepared or taken from a refrigerator) are important for ideal cooking.

However, a limited window area is left in convectional ovens to see the cooking compartment. It is a major problem to view all sides of particularly the larger food products from this window area. The capability to view the cooking food products consists a significant criterion in buying decisions of customers. However, the producers intend to keep this area limited due to technical limitations. There are transparent ovens designed for this purpose.

Cooker appliances are present which have all of its surfaces transparent, in which the heat required for cooking is provided by using metal oxide based transparent film heater applied on all surfaces. In general, the heating system in such appliances are described as follows: Metal oxide based, electrically conductive material with optical properties which is also capable of acting as a resistor, is applied to a surface of a glass by means of PVD (Physical Vapor Deposition) or similar coating methods. Heat dissipates by the coating on the glass surface exhibiting its electrical resistor characteristics, after applying said coating on a transparent surface and coupling its electrical connections.

The steps executed in coupling said metal oxide based film heater with electrical connections is as follows: conductive adhesive with silver content is spread on the edge of the glass surface being coated, and copper sheet is placed on said adhesive.

When electricity is connected by wire to any region of the copper sheet, electricity flows onto the coating from the copper sheet. The material for the sheet acting as a bridge between the electricity wires and the coating, is opted as copper due to its good electrical conductivity. Heat dissipates on the glass surface as the coating exhibits resistance against electricity. The obtained electrical power values vary according to the thickness of the coating. The food products in the cooker appliance is enabled to be cooked by means of the heat obtained in this manner.

As the copper sheet and the metallic adhesive is applied along an edge of the glass, the electric wires can be coupled to anywhere on the copper sheet.

After coupling, an insulating material is applied on each edge of the glass in order to prevent arc formation between the copper sheet and the metal profiles and to provide electrical insulation. Then, this system is placed into a metal chassis. The large number of components used in such type of cooking appliance cause certain problems during assembly and maintenance and increases assembly duration.

Another technical problem experienced with appliances coated with transparent heater film is likely displacement over time of the copper sheet adhered on the coating by means of metallic adhesive. This may inhibit the contact of the heater film coating with electricity. Therefore, the system to be designed should compress well so that the copper sheet has continuous contact with the coating.

Copper sheets on transparent heater film coating have been observed to oxidize in time. This leads to a reduction of power values in an oven over time. Therefore, a copper sheet should be shielded from contacting oxygen as much as possible.

The materials to be used to resolve the above-mentioned problems are expected to be resistant to high temperatures, compatible for use with food products, dielectric, suitable for thermal insulation and to contribute to sealing.

State of the art Japanese patent document no. JP2011171198 mentions an elastic material and a frame produced to prevent oven glasses from being broken due to being subjected to tensile stresses. The elastic material described here addresses a different problem.

State of the art Chinese patent document no. CN101081144 mentions assembling an oven door glass by mounting it on a metal chassis for facilitating assembly. The assembly method described here addresses a different problem

State of the art European patent document no. EP1647775 mentions using 4 of oven door glasses to provide thermal insulation and the fittings holding said glasses. The oven glass assembly described here addresses a different problem.

State of the art United States patent document no. US2004211405 relates to adding a third glass to oven door glasses and assembling said glass obliquely to a metal chassis. The oven glass assembly described here addresses a different problem.

None of the state of the art documents include a solution similar to the one in the present invention.

Brief Description of the Invention

The aim of the present invention is to obtain a cooker which can be easily assembled and providing the advantage of ease of maintenance.

Another aim of the present invention is to provide thermal and electrical insulation by the design of a transparent cooker.

A further aim of the present invention is to prevent a copper sheet provided on a heater film coated glass, from being displaced on the glass over time.

Yet another aim of the present invention is to prevent a copper sheet provided on a heater film coated glass, from being oxidized.

Another aim of the present invention is to provide liquid sealing between a glass group.

Detailed Description of the Invention

The transparent cooker of the invention is designed to solve the assembly and maintenance problem arising from using a high number of glasses therein, and comprises

a plurality of bare glasses forming a main body by being joined so as to form a quadrangular prism, positioned so as to face the external volume,
a plurality of coated glasses forming a main body by being joined so as to form a quadrangular prism, positioned so as to face the internal volume,
at least one vacuumed glass for providing thermal insulation, which can be used instead of a bare glass (3),
at least one frame holding the coated glasses or the bare glasses together to form the main body,
metallic adhesive to apply on two opposite edges of the coated glasses,
at least one slot provided in a frame for placing a copper sheet therein,
at least one catch to position a copper sheet and to shield it from contacting oxygen,
at least one wire hole bored from behind or from the center of a frame,
electric wires extending out of the frame by passing through the wire hole,
a copper sheet acting as a bridge by transmitting electricity between the electric wires and the coated glasses,
at least one heater film coating forming a coated glass by being applied on a glass surface,
at least one recess provided in a frame, for placing a bare glass or a vacuumed glass,
at least one metal profile enframing the main body,
at least one insulation material provided between a metal profile and a bare glass,
at least one corner fitting for the metal profiles to form the main body by being attached to each other, and
at least one channel provided in a metal profile between a coated glass and a bare glass, containing an inert gas or dry air to provide thermal insulation and sealing.

The transparent cooker of the invention comprises a frame made of silicone or a silicone-like material resistant to high temperatures, compatible with food products, electrically non-conductive, and with good sealing characteristics and a low thermal conductivity coefficient, a coated glass applied with heater film coating, copper sheet, electric wires, bare glass or vacuumed glass without heater film coating, and a metal profile acting as a support for these components.

Of the glass surfaces forming the main body in a quadrangular prism shape, the ones facing the external volume consist of bare glasses and the ones facing the internal volume consist of coated glasses formed by being applied heater film coating. The glasses facing the internal volume are fixed to the metal profile by means of metallic adhesive.

The bare glasses and the coated glasses being assembled to each other by means of the metal profile and the frame form a main body. The metallic adhesive is applied on two opposite edges of the glass whose one surface is coated with metal oxide based heater film coating, and said glass is placed in the recesses disposed in the silicone frame. Slots are provided in the frame to enable the copper sheet to be placed. The copper sheet to which the wires are connected, is placed in said slot by opening the catch provided in front of a slot and enabling the copper sheet to be positioned and to be shielded from contacting oxygen.

The heater film coating is coated on the glass surface of the cooker and dissipates heat by exhibiting resistance against electric currents when a current passed through the electric wires. The electric wires extend out of the frame through the wire hole bored from behind or the center of the frame. Said wire hole is of a size identical to the diameter of the electric wires. Sealing problems likely to occur due to a hole here, are avoided by leveling the sizes of the hole and the diameter of the electric wires.

A recess is provided in the silicone frame for the bare glass to be placed parallel to the coated glass.

In a preferred embodiment of the invention, vacuumed glass may be used instead of the bare glass to provide thermal insulation. The structure formed by placing the coated glasses and the vacuumed glasses into the recesses and by enframing these components by the frame, is referred to as the silicone kit. Then, said kit is placed between the silicone channels in the metal profile of the transparent cooker, and is fixed by the metal profiles being coupled by the corner fitting.

Conductive adhesive with silver content is spread on the edges of the coated glass (2) formed by said metal oxide based heater film coating, and the copper sheet is placed on said adhesive.

When electricity is connected by the electric wires to any region of the copper sheet, electricity flows onto the coating from the copper sheet. The material for the sheet acting as a bridge between the electricity wires and the coating, is opted as copper due to its good electrical conductivity. Heat dissipates on the glass surface as the coating exhibits resistance against electricity. The obtained electrical power values may vary according to the thickness of the applied coating. The food product in the cooker appliance is enabled to be cooked by means of the heat obtained in this manner.

The copper sheet is fixed in the slot provided in the silicone frame. The height of the channel in the metal profile, in which the silicone frame is to be placed, is less than the height of the silicone frame. Therefore, when the silicone frame is placed in the channel, it compresses the copper sheet thanks to the elastic characteristics of silicone, thereby enhancing the contact between the copper sheet and the heater film coated glass.

Recesses are provided on the silicone frame. Glasses coated with metal oxide based heater film are placed in the recesses disposed on the side facing the internal volume. Slots are provided on the sections of the recesses where the copper sheets are to be placed. Bare glasses are placed in the recesses disposed on the side facing the external volume.

The main function of the recesses is to facilitate assembly of the glasses on the cooker appliance by enabling them to be held together. The recesses also facilitate maintenance operations to the transparent cooker in case of the glasses being damaged.

The silicone frame fixes the positions and inhibits displacement of the copper sheets used on the coated glasses, acting as a bridge in connecting the coating with electricity and enabling electricity to be distributed evenly on the coating. A copper sheet should have a god contact with the coating region in order to provide electrical homogeneity. Thanks to the elastic characteristics of silicone and the tolerance adjustments made between the silicone and the metal profile in which the silicone is placed, the silicone is enabled to continuously compress the copper sheet, enhancing the contact between the coating and the copper sheet.

The silicone frame also inhibits oxidation of the copper sheet, thereby preventing a decrease in power likely to occur over time in the transparent cooker.

The metal oxide based film coating is also inhibited from contacting oxygen by providing a good sealing by means of the silicone frame, thereby preventing damages likely to occur on the coating over time, and consequent electrical power losses.

Providing a good liquid sealing by means of the silicone frame inhibits the problems of short-circuiting, fire and protecting the useful lifetime of the cooker likely to occur due to liquid leakage from the internal volume which may also be referred to as the cooking volume, towards the coated glasses, in particular on the glass coating, copper sheet and the electric wires.

A better thermal insulation and sealing may be enabled in the system using silicone frame, by introducing an inert gas or dry air into the channel between the coated glasses and the bare glasses.

In a preferred embodiment of the invention, vacuumed glasses may be used instead of the bare glasses in the silicone frame, placed on the surfaces facing the external volume and parallel to the coated glasses. To that end, the recess in which a bare glass is placed, is designed to be slightly larger. The advantage of the vacuumed glass here is enabling a better thermal insulation.

In a preferred embodiment of the invention, the insulation material is selected amongst polymer based materials.

In a preferred embodiment of the invention, the frame is made of silicone or a silicone-like material resistant to high temperatures, compatible with food products, electrically non-conductive, and with good sealing characteristics and a low thermal conductivity coefficient.

Claims

A transparent cooker designed to solve the assembly and maintenance problem arising from using a high number of glasses therein, comprising

- a plurality of bare glasses forming a main body by being joined so as to form a quadrangular prism, positioned so as to face the external volume,

- a plurality of coated glasses forming a main body by being joined so as to form a quadrangular prism, positioned so as to face the internal volume,

- at least one frame holding the coated glasses or the bare glasses together to form the main body,

- a copper sheet acting as a bridge by transmitting electricity between the electric wires and the coated glasses,

- at least one heater film coating forming a coated glass by being applied on a glass surface,

- at least one metal profile enframing the main body, and

- at least one channel provided in a metal profile between a coated glass and a bare glass, containing an inert gas or dry air to provide thermal insulation and sealing.
A transparent cooker according to claim 1, comprising a frame produced using silicone or silicone-like materials.
A transparent cooker according to claim 1, comprising metal oxide based heater film coating.
A transparent cooker according to claim 1, comprising an insulation material made of polymer based materials.
A transparent cooker according to claim 1, wherein the wire hole through which the electric wires pass, has a diameter identical to that of the wires.
A transparent cooker according to claim 1, comprising vacuumed glasses to form a main body by being joined with coated glasses, metal profile and the frame