GB2505870A

GB2505870A - Microwave oven liner

Info

Publication number: GB2505870A
Application number: GB201212753A
Authority: GB
Inventors: Patrick Leon Bray
Original assignee: REGALE MICROWAVE OVENS Ltd
Current assignee: REGALE MICROWAVE OVENS Ltd
Priority date: 2012-07-17
Filing date: 2012-07-17
Publication date: 2014-03-19
Anticipated expiration: 2032-07-17
Also published as: GB201212753D0; GB2505870B

Abstract

A microwave oven liner has a roof 12, a floor (14), a back (15) and two sides 16. It also includes a shelf 2 , attachable to upwardly angled runners along the sides of the liner. The shelf has downturned lips 27 on its sides to connect to the runners. The liner may be made from an injection moulded plastics material which may be transparent or translucent, and which is microwave safe, dishwasher safe, food safe and has a high flashpoint. The roof, sides and floor may be angled outwards from the back to ease removal from the mould. The roof may be shorter 17 at the front than the floor to allow air circulation. A lip 19 may be provided across the front of the floor to retain any spilt liquid.

Description

Intellectual Property Office Appliealinn Nc,. (lB 1212753.6 RTN'II Dale:9 January 2014 The following terms are registered trade marks and should he rcad as such wherever they occur in this document: Mitsui Chemicals Inc. Inlelleclual Property Office is an operaling name of the Pateni Office www.ipo.gov.uk

OVEN LINER

The present invention relates to an oven liner, particularly a liner for a microwave oven.

In commercial microwave ovens, which are more heavily used than domestic microwave ovens, spits of food can become deposited around the oven, particularly on the inside walls of the oven. Unless these deposits are carefully cleaned very regularly, they can buildup to the extent that they desiccate, potentially causing arcing and/or other damage. Subsequent repairs can be expensive.

In my earlier patent, EP 1547446 I proposed a microwave oven liner comprising a roof, a floor, a back and two sides, of food grade plastics material and of sufficient rigidity for automatic washing. While this was satisfactory, difficulties in *: * 15 manufacturing the liner were found.

SSe*** * The object of the present invention is to provide an improved oven liner. * * * *.*

*:. According to the invention there is provided a microwave oven liner comprising * *.* a roof, a floor, a back and two sides *: * wherein the liner further incorporates at least one shelf positionable substantially parallel to the floor and roof, the shelf attachable to upwardly angled runners along the side, the shelf provided with turned-down lips on its sides, to connect to the runners.

Preferably the roof; back and sides slope in towards the back at an angle of at least 1.5°, to ease removal from a forming mould. Typically the liner will be made by injection moulding.

Conveniently the plastics material of the liner is transparent or translucent. It can be of any material which is microwave safe, dishwasher safe, food safe and has a high flash point. Preferably the material includes a fire retardant. Typically the material will be a polymethylpentane.

Preferably the roof is shorter at the front, which is open, than the floor, to allow air to circulate for steam withdrawal from the oven.

s Normally the roof will be apertured for withdrawal of circulated air.

Preferably the shelf will also be apertured for increased circulation of air.

Additionally, the liner will be provided with an upstanding lip across the front of the floor, to retain spilt liquid. Furthermore, the floor may be provided with a series of ridges. Preferably these will extend from front to back. Alternatively the ridges may be concentric broken circles, or radial. The effect of these ridges is to raise the vessel containing food to be heated off the floor, to allow air to circulate beneath. This helps to reduce "hot spots". In addition the shelf may be provided with ridging. These can also be front to back ridges, concentric broken circles or radial.

* is The apertures in the shelf may be in the ridges or in depressions.

* To help understanding of the invention, a specific embodiment thereof will now be described by way of example and with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a convention microwave oven; Figure 2 is a perspective view of an oven liner according to the invention, . .. with the shelf removed; Figure 3 is a perspective view ofthe oven liner of Figure 2, with shelf; Figure 4 is a front view of the oven liner; and Figure 5 is a close up view of the connection between the shelf and the side of the liner.

Referring to the Figures, a conventional microwaveoven has a glass panelled door 2 (shown open) with a cavity 3 lined with steel side and back walls 4, a ceramic floor and a thin plastics moulding roof 6. A gap 7 is provided at the front between the door and the roof, whilst a further aperture 8 is provided in the roof. Thcse are for air circulation by a non-shown fan. A silicon seal 9 seals the floor to the side walls. Non-shown microwave emitters are provided above the roof and below the floor. Different microwave ovens have different sizes of cavity and different arrangements for air circulation. Liners are generally designed to fit specific ovens.

A liner 10 according to the invention, for the microwave oven described above, is an injection moulding of approximately 5mm thick including a roof 12, a floor 14, a back 15 and two sides 16.

The moulding is of a food grade, microwave safe, dishwasher safe, and high flash point plastics material, and will generally be transparent or translucent. The material may also include afire retardant. I prefer to use polymethylpentane, sold under the name TPX (R), available from Mitsui Chemicals America Inc. I use Grade No. 18. This is a transparent plastics material with a melting temperature. As a result heated moulds are required for injection moulding. However, I have found that this material is more resistant to warping, cracking and degrading on constant use in a conmiercial microwave oven than other materials Ihave tried. However, other * materials, particularly newly developed materials can be used. * S

To ease cleaning and enhance appearance, the surfaces of the liner can be *:. provided with a minor finish by moulding in a highly polished mould tool.

In order to ease the removal of the liner from the mould, not shown, the roof; slides and floor are angled outwards from the back with respect to the internal space of the liner. Thus the open front of the liner is larger than the back wall. I have found that an angle of 1.50 eases the removal of the liner from its mould, without significantly reducing the inside space of the liner, or giving the appearance of a sloping roof However, any angle between 0.5° and 100 can be used.

The roof is shorter 17 at the front than the floor, to allow air circulation. Tn addition, the roof is apertured, also for air circulation, with a series of small approximately 4mm bores 18 registering with the roof apertureS. In different models of microwave, air-circulating fans will be provided in different positions.

Apertures can advantageously be provided to align with therewith, or can be provided anywhere for general use.

A lip 19 is provided across the front of the floor to retain any spilt liquid. As shown in the drawings, the external corners 20 are chamfered to clear the silicone seal 9 for instance, and to avoid sharp edges.

The floor has a radial pattern of regularly pitched, 2mm high ridges 21 extending from the centre. The ridges allow circulation of air beneath a container of food being heating in the oven having a liner. However, any other pattern of ridges, in particular running from front to back, or concentric circles can be provided.

According to the invention, the liner is provided with a removable shelf 25, approximately halfway between the floor and the roof. The shelf 25 allows two containers, or plates, of food to be heated simultaneously in the oven, without piling one on top of the other.

*". : The shelf 25 is a sheet of plastics moulding, generally of the same material as * the rest of the liner, and is also injection moulded. The shelf is sized to fit within the * liner, and its two ends, corresponding with the sides of the liner, are turned down 27.

The sides 16 of the liner are provided with formations or runners 28 to support the shelf 25. These comprise upwardly angled projections 29. The ends 27 of the shelf fit onto the runners 28 of the sides, holding the shelf in place. In use in a microwave a...

oven, the liner, including the shelf, will soften slightly, which may result in slight sagging of the shelf The connection between the shelf 25 and the runners 28 prevents the shelf slipping away from the sides.

The shelf is also provided with ridges 30, also substantially 2mm high, to allow air circulation beneath a container of food being heated on the shelf. As shown the ridges run from front to back. Alternatively, the ridges form a series of broken, concentric circles, or could be radial, as with the floor. Tn addition, the shelf 25 is provided with a series of apertures, 31 again for air circulation within the liner. These can be provided in three columns extending from the front of the shelf. Alternatively the apertures could be in the spaces between the ridges.

The shelf is removable, allowing for a single larger container to be heated in a liner without a shelf, or two smaller containers in a liner with a shelf The removability of the shelf if also advantages for washing of the liner and shelf.

The invention is not intended to be restricted to the details of the above-described embodiment. For example, a liner can be provided with two or more shelves, parallel to the first and to the base. Usually microwave ovens are not sufficiently large for more than one shelf to be advantageous, however in larger ovens this could be useful. * . . * .* * * * S S. * . * **. *Se S... * . **.. ** S S S*

Claims

CLAIMS: 1. A microwave oven liner comprising: a roof, a floor, a back and two sides; wherein the liner further incorporates at least one shelf positionable S substantially parallel to.the floor and roof, the shelf attachable to upwardlly angled runners along the sides, the shelf provided with turned-down lips on its sides, to connect to the runners.
2. A microwave oven liner as claimed in claim 1, wherein the roof, back and sides slope in towards the back.
3. A microwave oven liner as claimed in claim 2, wherein the slope is at an angle of at least 1.5°.
4. A microwave oven liner as claimed in claim I, claim 2 or claim 3, wherein the liner is made by injection moulding.
5. A microwave oven liner as claimed in any preceding claim, wherein the liner is madeofaplasticsmaterial.

* ..
6. A microwave oven liner as claimed in claim 5, wherein the plastics material of the liner is transparent or translucent.
7. A microwave oven liner as claimed in claim 5 or claim 6, wherein the material is microwave safe, dishwasher safe, food safe and has a high flash poilit.

*: : 20
8. A microwave oven liner as claimed in claim 7, wherein the material includes a fire * retardant.
9. A microwave oven liner as claimed in any preceding claim, wherein the roof is shorter at the front, which is open, than the floor, to allow air to circulate for steam withdrawal from the oven.
10. A microwave oven liner as claimed in any preceding claim, wherein the roof is apertured for withdrawal of circulated air.
11. A microwave oven liner as claimed in any preceding claim, wherein the shelf is apertured for increased circulation of air.
12. A microwave oven liner as claimed in any preceding claim, wherein the liner is provided with an upstanding lip across the front of the floor, to retain spilt liquid.
13. A microwave oven liner as claimed in any preceding claim, wherein the floor is* provided with a series of ridges.
14. A microwave oven as claimed in claim 13, wherein the ridges extend from front to back, are concentric broken circles, or radial.
15. A microwave oven as claimed in any preceding claim, wherein the shelf is provided with ridges.
16. A microwave oven as claimed in claim 15, wherein the ridges extend from front to back, are concentric broken circles or radial. ** * * . * .****** * * ** * , * .** * * * ** * * **