GB2406259A

GB2406259A - Cookware for combination ovens

Info

Publication number: GB2406259A
Application number: GB0325295A
Authority: GB
Inventors: Stephen Graham Rutherford; James Harold Johns
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-09-29
Filing date: 2003-10-30
Publication date: 2005-03-30
Also published as: GB0322739D0; GB0325295D0

Abstract

An article of cookware for use in an oven, wherein the base or side walls of the article incorporate a plurality of apertures 22 passing therethrough. The invention also provides an article of cookware for use in a forced air / microwave combination oven, the article comprising a base on which food rests in use; wherein the upper surface of the base incorporates a plurality of ridges or protrusions 24,26 arranged to raise the food in use and thereby form air channels between the base and the food in use. Also provided is an article of cookware for use in a forced air / microwave combination oven, made of a liquid crystal polymer resin. The invention further provides a method of cooking using an oven and such an article of cookware. The article may have detachable side walls, may have a detachable tray under the base to catch food falling through the apertures, and may have a lid. The apertures may be slots.

Description

IMPROVED COOKWARE

This invention relates to cookware. It is particularly applicable, but by no means limited, to cookware for use in commercial ovens.

Background to the Invention

Forced air / microwave combination ovens are in common usage, and one popular model is the TurboChef C3 oven, supplied by TurboChef Technologies, Inc., of 10500 Metric Drive, Suite 128, Dallas, TX 75243, USA. Such ovens are typically found in petrol stations, motorway service area cafeterias and roadside restaurants, and are used for cooking or defrosting a wide range of foods such as pizzas, hot filled baguettes, lasagne, steak, fish, burgers and pies. The ovens use a combination of rapidly-moving electrically-heated hot air and microwave radiation, and will be referred to herein as forced air / microwave combination ovens. The TurboChef C3 can reach a cooking temperature of 275 C, and cooks on average at seven times the speed of a conventional oven. The microwave generator is located beneath the oven chamber, and transmits microwave radiation upwards into the oven chamber. The forced air is delivered from above, into the top of the oven chamber, and is extracted from the bottom of the chamber, beneath the platter on which the cookware rests. The microwave and hot air modes of cooking food may be used independently or together, and the oven is processor-controlled to run a range of cooking routines using the different cooking modes.

The term "cookware" used herein is intended to encompass any plate, dish, bowl, box, carton, tray or other receptacle in which food is placed when being defrosted or cooked in a combination oven.

Food is placed in the cookware, and then the cookware is placed on the platter inside the oven for cooking or defrosting. The platter is essentially a shelf located towards the bottom of the cooking chamber, above the microwave generator. The platter contains holes through which forced air passes, and is also microwave-permeable to enable microwave radiation to reach food placed on the platter.

Traditionally, cookware used in forced air / microwave combination ovens have been pressed from cardboard, and are known as Upresswaren. Cardboard is permeable to microwave radiation, and is hence suitable for this purpose. However, a number of disadvantages, shortcomings and problems have been identified with traditional cardboard pressware, as follows: 1. Desire for greater cooking efficiency using forced air Although the traditional cardboard pressware is permeable to microwave radiation, it does not promote the flow of hot air around the food. There is a desire to improve this, to enable food to cook quicker and more efficiently, using less energy.

2. Desire for reusable cleanable cookware Each item of traditional cardboard pressware is only used once, and is then discarded. It is not possible to reuse cardboard pressware after cooking, since it becomes coated with cooked food (e.g. baked on molten cheese) and cannot be cleaned (otherwise the cardboard would become soggy and unusable). Given the vast numbers of meals that are prepared every year using cardboard pressware, its use is not environmentally friendly and is far from ideal. There is a strong desire for cookware that is both reusable and readily cleanable.

Summary of the Invention

According to a first aspect of the invention there is provided an article of cookware for use in an oven, wherein the base or side walls of the article incorporate a plurality of apertures passing therethrough. The provision of apertures in the cookware advantageously enhances airflow through the cookware and over food placed on or in the cookware. This in turn expedites the cooking of the food and conserves energy.

The term aperture" as used herein should be interpreted broadly, to encompass holes, slits, slots and other types of openings. The term aperture" is intended to encompass both those apertures which are formed entirely within a surface of the article (e.g. a hole passing through the surface) and those apertures which extend out of an edge of the article (e.g. an open-ended slot).

In one embodiment, preferably the article of cookware further comprises a detachable tray adapted to locate under the base to catch matter dropped from the food through the apertures during cooking. This advantageously helps to maintain the cleanliness of the surface on which the cookware is placed whilst in the oven.

The article of cookware may further comprise one or more detachable side walls. These advantageously enable the user to adjust the food-containing capacity of the article as required.

The detachable side walls may also incorporate a plurality of apertures passing therethrough.

The article of cookware may further comprise a detachable lid, which may also incorporate a plurality of apertures passing therethrough. The provision of these apertures enhances airflow through the cookware and over the food during cooking, thereby enhancing and expediting the cooking process.

Preferably the lid comprises an upper lid member and a lower lid member, the upper and lower lid members are in spaced separation and both incorporate apertures, and at least some of the apertures in the upper and lower lid members are mutually staggered. The provision of the apertures in the lid enhances airflow through the cookware and over the food during cooking, and their staggered alignment prevents or at least impedes the ability of food matter to escape or splash up through the apertures in the lid members during cooking.

Preferably the upper and lower lid members are mutually separable. This enables them to be used separately if desired, and also facilitates their cleaning.

Particularly preferably the lower lid member further comprises handle means and the upper lid member further comprises an aperture shaped and sized to enable said handle means to pass therethrough. This configuration advantageously enables both lid members to be lifted as one, using the handle means.

Preferably the cross section of the handle means and the shape of the corresponding aperture in the upper lid member are such as to prevent mutual rotation of the upper and lower lid members. This ensures that the apertures in the upper and lower lid members are staggered as intended.

The base may further incorporate a plurality of ridges or protrusions arranged to raise the food in use and thereby form air channels between the base and the food. Hot air can flow along these channels during cooking, to enhance further the cooking of the food.

In another embodiment, preferably the apertures are in the form of slots, which are particularly preferably open-ended at an edge of the article. This facilitates injection moulding of the article.

Preferably the article of cookware further comprises one or more baffles, each baffle being adjacent to a corresponding aperture and arranged to impede the passage of food matter through said aperture in use.

The term baffle" should be interpreted broadly, to include any arrangement of fins, baffles or louvers arranged to impede the passage of food matter through the aperture in use.

Preferably the baffles are integrally formed as part of a wall of the article.

Preferably the baffles extend into the inside of the article.

Preferably a part of each baffle extends substantially parallel to the wall of the article in which the corresponding aperture is incorporated. Such an arrangement further impedes the passage of food matter through the aperture in use.

Preferably the article is of cookware is a lid or cover, to cover food during cooking.

With any of the variants mentioned above, preferably the article of cookware is for use in a forced air / microwave combination oven.

According to a second aspect of the invention there is provided an article of cookware for use in a forced air / microwave combination oven, the article comprising a base on which food rests in use; wherein the upper surface of the base incorporates a plurality of ridges or protrusions arranged to raise the food in use and thereby form air channels between the base and the food in use.

An article of cookware in accordance with either the first or second aspects of the invention may advantageously be made of a polymer material. Preferably the polymer material is a liquid crystal polymer resin reinforced with glass. Particularly preferably the article of cookware is made of DuPont (RTM) Zenite (RTM) 7130. Advantageously, such materials are easy to clean and may be soaked in water without detriment.

According to a third aspect of the invention there is provided an article of cookware for use in a forced air / microwave combination oven, made of a liquid crystal polymer resin.

Preferably the liquid crystal polymer resin is reinforced with glass.

Particularly preferably the article of cookware is made of DuPont (RTM) Zenite (RTM) 7130.

An article of cookware in accordance with any of the first, second or third aspects of the invention may be selected from a group comprising: plate, dish, bowl, box, carton, tray. The article may further comprise a handle to enable a user to lift the article into and out of an oven. This is particularly beneficial to domestic users, who may not otherwise have a suitable implement with which to move the article.

According to a fourth aspect of the invention there is provided a method of cooking using an oven and an article of cookware in accordance with any of the first, second or third aspects of the invention.

Brief Description of the Drawings

Embodiments of the invention will now be described, by way of example, and with reference to the drawings in which: Figure 1 illustrates a forced air / microwave combination oven, indicating the position of the microwave waveguide and platter in use; Figure 2a illustrates plan and side elevations of a cooking plate incorporating a plurality of 1 5 apertures; Figure 2b illustrates plan and side elevations of an alternative cooking plate (particularly suitable for cooking pizzas) incorporating a plurality of apertures; Figure 3 illustrates plan and side elevations of a tray adapted to locate beneath the plates of Figures 2a and 2b; Figure 4 illustrates plan and side elevations of an upper lid or cover for the plates of Figures 2a and 2b; Figure 5 illustrates plan and side elevations of another lid or cover for the plate of Figure 2, this lid being locatable under the lid of Figure 4 and having a handle arranged to pass through the aperture in the centre of the lid of Figure 4; Figure 6 illustrates a plan elevation from above, and side elevations, of another cover under which food may be cooked, incorporating a plurality of louvered slots; Figure 7 illustrates a plan elevation from below of the cover of Figure 6; and Figure 8 illustrates a perspective view of a variant of the cover of Figure 6.

The dimensions in Figures 2a, 2b, 3, 6 and 7 are provided by way of example only, as all the products may be made in a variety of shapes and sizes.

Detailed Description of Preferred Embodiments

to The present embodiments represent the best ways known to the applicant of putting the invention into practice. However they are not the only ways in which this can be achieved.

Although the embodiments of the invention that will now be described were originally designed for use in a forced air / microwave combination oven, they are also suitable for use in other types of ovens, including domestic, commercial and industrial ovens (including gas, electric, microwave and combination ovens). Although the embodiments are described in connection with forced air / microwave combination ovens, it should be appreciated that they have application in a wide range of oven types.

By way of background, Figure 1 shows an example of a TurboChef C3 forced air / microwave combination oven 10. The oven measures approximately 550 mm high, 740 mm wide, and 820 mm from front to back. The microwave waveguide 14 is situated at the base of the cooking chamber, and is covered by a waveguide cap 16. The platter 12 is then located on a pair of support rails 18, above the waveguide cap. The cookware is then placed on the platter 12.

The embodiments of the invention that will now be described are presently preferably made from DuPont (RTM) Zenite (RTM) 7130, a liquid crystal polymer resin reinforced with 30% glass that is able to withstand temperatures of up to 289 C, which is well in excess of the S maximum operating temperature of the TurboChef C3 oven. This material is well suited to injection moulding, thereby enabling the intricate shapes of cookware described herein to be readily formed. Highly advantageously, and in marked contrast to traditional cardboard pressware, resin cookware can easily be cleaned or soaked in water without detriment. This enables the cookware to be reused, thereby reducing continuous expenditure on cardboard pressware, and helping to conserve natural resources.

Other materials suitable for use in a forced air / microwave combination oven may be used instead of DuPont (RTM) Zenite (RTM), and the present disclosure is intended to apply to and encompass all suitable materials already in existence and those which have yet to be discovered or developed, such as advanced engineering polymers, glasses, ceramics and composite materials. For example, DuPont (RTM) Thermx (RTM), a high performance polyester, may be used as an alternative to Zenite (RTM).

Turning now to a first embodiment of the invention, Figure 2a shows a cooking plate 20 in which the base (i.e. the surface on which food is placed) incorporates a plurality of holes or apertures 22. An extensive array of apertures as shown in Figure 2a would not be possible with traditional cardboard pressware, as it would not have sufficient strength. With the use of an engineering polymer, however, such an array may be readily fommed without compromising the strength of the cookware for its intended purpose.

By providing an extensive array of apertures in the cookware, forced hot air can pass through the cookware during cooking, and this provides an improved flow of hot air around the food when compared with traditional cardboard pressware. This in turn enables food to cook quicker and more efficiently, using less energy.

An alternative plate, particularly suitable for cooking pizza, is shown in Figure 2b.

To provide strength and rigidity, the plate 20 in Figure 2a also incorporates concentric regions 24, 26, 28 of solid material, without apertures. These regions may extend up from the base as ridges or protrusions, to raise the food from the base in use and thereby provide channels under the food along which hot air can flow. This further enhances the cooking of the food.

Optionally, the plate may be provided with one or more side walls that may extend upwards l S or downwards from the base, or in both directions. The side walls may optionally incorporate further apertures to improve further the airflow around the oven and food. Upwardly- extending walls may be used to provide better containment of food such as vegetables.

Figures 2a and 2b show side walls 21 extending downwards from the base, which also incorporate apertures 23.

It will be appreciated that, during cooking, food matter (e.g. molten fat or cheese) may fall through the apertures 22 in the base of the plate of Figure 2a or 2b. To overcome this, a tray 30 as shown in Figure 3 may be located underneath the plate 20. When the tray 30 is used, the apertures 23 provided in the downwardly-extending side wall 21 of the base 20 enable air to pass through the apertures 22 in the base of the plate, without the tray 30 blocking airflow to the apertures 22. Thus, airflow passes through the apertures 23 in the side wall 21, and through the apertures 22 in the base of the plate 20.

One or more separate detachable side walls (not illustrated) may be attached above the S plate 20 of Figure 2a, thereby increasing the foodcontaining capacity of the article. These walls may also incorporate apertures for enhanced airflow around the food.

Figures 4 and 5 illustrate lids 40, 50 adapted to rest or locate on a plate (e.g. 20) or on top of side walls if used. Again, these also incorporate apertures 42, 44, 54, 56 to enhance airflow l 0 around the food. Lid 50 further incorporates a central lifting handle or knob 52.

Although lids 40 and 50 may each be used separately if required, they incorporate a particularly important design feature which enables them to be used together on an item of cookware to minimise the amount of food matter that escapes or splashes up through the plurality of apertures 42, 54 in the upper surface of each lid: Lid 40 may be placed on top of lid 50, with handle 52 of lid 50 passing through aperture 46 of lid 40. Lid 40 then rests on top of lid 50, such that lid 40 effectively becomes an upper lid and lid 50 becomes a lower lid. The handle 52 and aperture 46 are shaped and configured such that the handle 52 can pass through the aperture 46 but such that the two lid members and 50 cannot mutually rotate. The plurality of apertures 42 in lid 40 are staggered out of alignment with the plurality of apertures 54 in lid 50. By virtue of this staggering, food matter that escapes or splashes up through an aperture 54 in the lower lid 50 is hindered from escaping from the cookware altogether, since corresponding aperture 42 is out of alignment with aperture 54.

The plurality of apertures 42, 54 in each lid are kept apart by the upwardly-extending side wall 53 of lid 50, thereby allowing unrestricted airflow through both lids. The downwardly extending side wall 41 of lid 40 passes around the downwardly-extending side wall 57 of lid 50. The positions of the apertures 44 in the side wall 41 are staggered with respect to the apertures 56 in the side wall 57. This arrangement of apertures in the sides walls promotes airflow through the side walls during cooking, but again impedes the escape of food matter.

Another cover designed to promote the flow of hot air around the food, whilst impeding the escape of food matter, is shown in Figures 6, 7 and 8. This cover 60 incorporates a plurality of slots 61, 62, 63, 64, 65, 66, 67, 68, each of which extends the height of the vertical side wall of the cover. Although Figures 6 and 8 show the slots extending around into the top surface of the cover, this is optional and the slots may be made shorter than illustrated if desired. An optional carrying handle 78 may be provided on the top surface.

The incorporation of slots in the cover facilitates injection moulding of the article. The articles shown in Figures 6, 7 and 8 may be centreinjection-moulded in one piece. By incorporating slots rather than holes, the polymer flow is not required to diverge and then re converge during the moulding procedure, and hence these articles may be moulded without the formation of glassy join lines that may otherwise be formed when moulding walls that contain holes.

The side wall of the cover 60 is formed such that each slot is shielded by a vertically extending baffle (e.g. baffle 69-70 that shields slot 61). The baffles are integrally moulded in the cover. Since the baffles extend parallel to the slots in the vertical side walls of the cover, the mould design and the withdrawal of the product from the mould during injection moulding is facilitated. However, using a more complicated mould design, it is possible to provide apertures with baffles in the top surface of this cover, or indeed in the surfaces of other items of cookware.

The geometry of the baffles is designed to enhance the flow of hot air around the inside of the cover during cooking, and yet impede the passage of food matter through the apertures.

Looking in detail at the baffle provided to shield aperture 61 in Figure 7, this comprises a first part 69 which extends substantially diagonally into the interior of the article, and then a second part 70 which extends substantially parallel to the side wall 72 in which aperture 61 is situated. The diagonal part 69 helps to channel the hot air into the article during cooking.

The parallel part 70 further helps to direct the flow of hot air whilst impeding the escape of food matter though the aperture 69.

As shown in Figure 7, the diagonal parts of the baffles may extend in alternating senses.

For example, in the context of Figure 7, baffle parts 69, 72, 74 and 76 all extend in a clockwise sense, such that air that passes into the inside of the cover through apertures 61, 67, 65 and 63 flows in a clockwise direction (in the context of Figure 7). Baffle parts 71, 73, and 77 extend in an opposite (anticlockwise) sense, so that air passing through apertures 68, 66, 64 and 62 flows in an anticlockwise direction. The flow of air in these two opposing senses gives rise to turbulent airflow within the cover, which has been found to be desirable when cooking certain types of products.

In an alternative embodiment, however, all the diagonal baffle parts may extend in the same sense (e.g. all clockwise), thereby encouraging vertical (rather than turbulent) airflow within the cover. Since the speed and nature of the airflow is understood to have an effect on the surface finishing of the food during cooking, vertical airflow is desirable in the cooking of some products.

In yet further alternative embodiments, the baffles may only comprise diagonal parts (e.g. 69) without parallel parts (e.g. 70). The diagonal parts may extend further into the interior of the cover than is shown in Figure 7.

Alternatively, the baffles may have a substantially right-angled shape, i. e. firstly extending substantially perpendicular to the side wall of the cover, into the interior of the cover, and then parallel to the side wall.

The mould used to form such covers may be adjustable, so that moulds having different angles or geometries of baffles may be produced, according to customers' requirements.

The cover 60 may be circular, rectangular or another shape when viewed from above.

In accordance with the above embodiments, a variety of articles of cookware may be produced for use in an oven, including plates, dishes, bowls, boxes, cartons and trays.

An article may be provided with one or more handles arranged to enable a user to lift it safely into and out of the oven.

Test results The plate of Figure 2a was used in conjunction with an improved platter as described in our co-pending patent application entitled "Improved Platter", to cook frozen pizza in a TurboChef C3 oven. The conventional cooking time for frozen pizza with this oven is 2.5 minutes. Remarkably, using plate of Figure 2a, and without changing the cooking temperature, the cooking time was reduced to 1.5 minutes, saving 40% of the conventional cooking time. Thus, not only is the cooking process substantially expedited, but energy is also saved by virtue of the oven being operational for less time.

Claims

1. An article of cookware for use in an oven, wherein the base or side walls of the article incorporate a plurality of apertures passing therethrough.

2. An article of cookware as claimed in Claim 1, further comprising a detachable tray adapted to locate under the base to catch matter dropped from the food through the apertures during cooking.

3. An article of cookware as claimed in Claim 1 or Claim 2, further comprising one or more detachable side walls.

4. An article of cookware as claimed in Claim 3, wherein the detachable side walls incorporate a plurality of apertures passing therethrough.

5. An article of cookware as claimed in any preceding claim, further comprising a detachable lid.

6. An article of cookware as claimed in Claim 5, wherein the lid incorporates a plurality of apertures passing therethrough.

7. An article of cookware as claimed in Claim 6, wherein the lid comprises an upper lid member and a lower lid member, wherein the upper and lower lid members are in spaced separation and both incorporate apertures, and wherein at least some of the apertures in the upper and lower lid members are mutually staggered.

8. An article of cookware as claimed in Claim 7, wherein the upper and lower lid members are mutually separable.

9. An article of cookware as claimed in Claim 7 or Claim 8, wherein the lower lid member further comprises handle means and the upper lid member further comprises a corresponding aperture shaped and sized to enable said handle means to pass therethrough.

10. An article of cookware as claimed in Claim 9, wherein the cross section of the handle means and the shape of the corresponding aperture in the upper lid member are such as to prevent mutual rotation of the upper and lower lid members.

11. An article of cookware as claimed in any preceding claim, wherein the base further lS incorporates a plurality of ridges or protrusions arranged to raise the food in use and thereby form air channels between the base and the food in use.

12. An article of cookware as claimed in Claim 1, wherein the apertures are in the form of slots.

13. An article of cookware as claimed in Claim 12, wherein the slots are open-ended at an edge of the article.

14. An article of cookware as claimed in Claim 12 or Claim 13, further comprising one or more baffles, each baffle being adjacent to a corresponding aperture and arranged to impede the passage of food matter through said aperture in use.

15. An article of cookware as claimed in Claim 14, wherein the baffles are integrally formed as part of a wall of the article.

16. An article of cookware as claimed in Claim 14 or Claim 15, wherein the baffles extend into the inside of the article.

17. An article of cookware as claimed in any of Claims 14, 15 or 16, wherein a part of each baffle extends substantially parallel to the wall of the article in which the corresponding aperture is incorporated.

IS 18. An article of cookware as claimed in any of Claims 12 to 17 being a lid or cover, to cover food during cooking.

19. An article of cookware as claimed in any preceding claim, for use in a forced air / microwave combination oven.

20. An article of cookware for use in a forced air / microwave combination oven, the article comprising a base on which food rests in use; wherein the upper surface of the base incorporates a plurality of ridges or protrusions arranged to raise the food in use and thereby form air channels between the base and the food in use.

21. An article of cookware as claimed in any preceding claim, made of a polymer material.

S

22. An article of cookware as claimed in Claim 21, wherein the polymer material is a liquid crystal polymer resin reinforced with glass.

23. An article of cookware as claimed in Claim 21, made of DuPont (RTM) Zenite (RTM) 7130.

24. An article of cookware for use in a forced air / microwave combination oven, made of a liquid crystal polymer resin.

25. An article of cookware as claimed in Claim 24, wherein the liquid crystal polymer resin is reinforced with glass.

26. An article of cookware as claimed in Claim 24, made of DuPont (RTM) Zenite (RTM) 7130.

27. An article of cookware as claimed in any preceding claim, selected from a group comprising: plate, dish, bowl, box, carton, tray.

28. An article of cookware as claimed in any preceding claim, further comprising a handle to enable a user to lift the article into and out of an oven.

29. A method of cooking using an oven and an article of cookware as claimed in any of Claims 1 to 28.

30. An article of cookware for use in an oven, substantially as herein described with reference to and as illustrated in any combination of the accompanying drawings.

31. A method of cooking using cookware substantially as herein described with reference to and as illustrated in any combination of the accompanying drawings.