EP0517694A1

EP0517694A1 - Cooking kit for microwave oven

Info

Publication number: EP0517694A1
Application number: EP90904534A
Authority: EP
Inventors: Melvin L. Levinson
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-02-28
Filing date: 1990-02-28
Publication date: 1992-12-16
Also published as: EP0517694A4; NO923352D0; CA2075913A1; JPH05503433A; WO1991013529A1; NO923352L

Abstract

Un jeu d'éléments de cuisson pour four à micro-ondes comprend un premier élément de cuisson (10) absorbant les micro-ondes, renversable, et ayant une première surface de cuisson (20) adaptée à la cuisson d'un aliment; un second élément de cuisson (12) ayant une seconde surface de cuisson adaptée à la cuisson d'un aliment. Le premier et le second élément de cuisson (10, 12) peuvent être rassemblés pour former, une fois rassemblés, une chambre de cuisson renfermant la vapeur (40). Dans certaines applications, le premier élément (10) est l'élément inférieur; dans d'autres applications, le premier élément (10) est l'élément supérieur. Le poids des deux éléments de cuisson (10, 12) peut être utilisé pour reproduire les effets d'une cocotte-minute à basse pression. Le second élément (12) peut soit transmettre, soit réfléchir les micro-ondes. Deux accessoires-bacs facultatifs renversables et réfléchissant les micro-ondes (44, 46), dont l'un est perforé (46) et l'autre non perforé (44), peuvent être utilisés en différentes combinaisons avec les premier et second éléments (10, 12).A set of cooking elements for a microwave oven comprises a first cooking element (10) absorbable by microwaves, reversible, and having a first cooking surface (20) suitable for cooking a food; a second cooking element (12) having a second cooking surface suitable for cooking a food. The first and second cooking elements (10, 12) can be combined to form, once assembled, a cooking chamber containing the steam (40). In some applications, the first element (10) is the lower element; in other applications, the first element (10) is the upper element. The weight of the two cooking elements (10, 12) can be used to reproduce the effects of a pressure cooker at low pressure. The second element (12) can either transmit or reflect the microwaves. Two optional reversible and microwave-reflective accessories-trays (44, 46), one of which is perforated (46) and the other non-perforated (44), can be used in different combinations with the first and second elements ( 10, 12).

Description

Cooking Kit for Microwave Oven

BACKGROUND OF THE INVENTION

Field of the Invention - The present invention concerns a cooking kit for use in a microwave oven. The kit has

invertible cooking members and optional invertible accessory pan members.

The members may be employed in a variety of combinations. The invention for cooking various foodstuffs via microwave energy, e.g., baking, boiling, broiling, crusting, frying, pressure cooking, searing, steaming and toasting.

Description of the Prior Art - U.S. Patents 3,701,872 and

3,777,099 describe preheating metal plates by means of a microwave-absorptive heating member for use in microwave cooking. U.S. Patents 3,731,037 and 3,881,027 describe cooking food in a container which is in a preheated, heat insulated microwave chamber. U.S. Patent 3,985,990 describes the use of a microwave shielded chamber, perforated on its food receiving surface, to permit recovery of by-products of cooking and to utilize the latent heat of vaporization which is normally dissipated in microwave cooking techniques. U.S. Patents

3, 854, 023 and 3,985,991 describe methods and apparatus for microwave cooking in metal containers. U.S. Patent 4,027,132 describes microwave cooking a frozen pizza pie. U.S. Patent 4,306,133 describes microwave cooking a fruit pie having a double crust. U.S. Patent 4,280,032 describes microwave soft cooking eggs. U.S. Patent 4,390,555 describes melting and defrosting food. U.S. Patent 3,914,967 describes microwave heating grill constructions. U.S. Patent 2,622,187 describes a microwave oven pressure cooker.

Microwave Cooking

Microwave cooking is conducted in microwave ovens that have appropriate boundary walls to confine microwaves therein. In a microwave oven most foods and certain microwave absorptive materials become heated when exposed to microwave energy. Many cooking utensils are available that are specially designed for use in a microwave oven cooking chamber. There are steak makers, steamers, browning dishes, egg cookers, pizza pie cookers, bacon cookers, et cetera. Each of these special purpose devices employs its own unique operating sequence to cook a particular food product.

A principal object of this invention is to provide a kit of multi-purpose members that can be employed for practically all of the familiar cooking requirements such as baking, boiling, broiling, crusting, frying, pressure cooking, searing,

steaming, toasting.

It is another object of this invention to provide a kit which can be used in a microwave oven for cooking materials such as soft cooked eggs and fried eggs; meats and vegetables; frozen foods including TV dinners, souffles, pizza pies, meat pies and fruit pies, both one-crust and two-crust; baking cakes,

cookies, rolls, fruit turnovers, biscuits, breads; heating and popping popcorn; cooking deep fried pre-prepared frozen fried foods such as fried chicken, fried shrimp and the like.

STATEMENT OF THE PRESENT INVENTION

According to the present invention, a cooking kit for use in a microwave oven, consists of engageable, invertible, cooking members. The kit, in its simplest embodiment, includes an invertible, microwave-absorptive, first cooking member, with a first surface fabricated to cook a food thereon; an invertible, second cooking member with a second surface fabricated to cook a food thereon; a steam-confining, cooking chamber defined by said first and second members; and means to retain said first and second members in engagement (a) when said first member is the top member, (b) when said second member is the top member and (c) when said first and second cooking members are inverted together. The weight of the first and second cooking members can be chosen to duplicate low-pressure, pressure-cooker results. Optional accessory pan members Include a perforated microwave-reflective, invertible, accessory pan member and an imperforate, microwave-reflective, invertible accessory pan member.

The microwave-absorptive first cooking member includes a homogeneous, microwave-lossy material, e.g., it may be a compound member, for example, a metal grill having microwave- absorptive coating mounted in a microwave-transmissive bowl.

The second member may be either microwave-reflective, partially microwave-transparent or microwave-transparent. The second member may consist of two distinct cooking containers, one microwave-transmissive and one microwave-reflective, which can be employed together or individually.

In one embodiment, the second cooking member is a microwave transmissive bowl made from glass, ceramic, glass-ceramic, or heat resistant plastic. The bowl has a rim which is engageable with the first cooking member to define a steam confining chamber. Microwave energy passes through the microwave

transmissive cooking member to heat food within the steam confining chamber by direct absorption of the microwave energy. In an alternative embodiment, the second cooking member is a microwave reflective bowl or pan member formed from metal such as steel or aluminum alloy. The microwave reflective second cooking member has a rim which engages the first cooking member tit define a steam confining chamber. Food which is prepared in the alternative embodiment will receive all of its heat from the first cooking member because the steam-confining chamber of the second embodiment is entirely surrounded by microwave reflective metal. All of the microwave energy is absorbed by the microwave-lossy substance of the first cooking member which supplies all of the cooking heat for the food. The food may be in direct contact with the cooking surface of the first cooking member or the first cooking member may be on top of and

supported by the second cooking member. In this embodiment the food on the cooking surface of the second cooking member will be heated by radiant energy emanating from the heating surface of the first cooking member.

In a further embodiment, both the microwave-transmissive second cooking member and the microwave-reflective second cooking member may be combined to provide two steam confining chambers, if the alternative microwave-reflective second cooking member will fit within the microwave-transmissive second cooking member.

The first and second invertible cooking members may be employed in various combinations. Optional accessory members may be employed individually with one or the other of said first and second members as well as with both of said first and second invertible cooking members in various combinations. In some applications, the first member is the bottom member; in other applications, the first member is the top member. Similarly, in some applications, the second member is the bottom member arid, in other applications, the second member is the top member.

DESCRIPTION OF THE DRAWINGS

The advantages and benefits resulting from the described elements will become apparent from the following detailed description by reference to the accompanying drawings in which:

FIGURE 1 is a cross-sect ion illustration of a first member, a heat generating element.

FIGURE 2 is a cross-section illustration of a second member, a chamber-for ming element. FIGURE 3 is a cross-section illustration of a third member, a collector element, including, as shown, three

components.

FIGURE 4 is a cross-section illustration of an optional fourth member, a pan element.

FIGURE 5 is a cross-section illustration of an assembly of the first and second elements.

FIGURE 6 is a cross-section illustration of an alternative, i.e., inverted, assembly of the first and second elements.

FIGURE 7 is a cross-section illustration of an assembly of the second and third elements.

FIGURE 8 is a cross-section illustration of an assembly of the first, and third elements.

FIGURE 9 is a cross-section illustration of an assembly of the first element and an optional pan element.

FIGURE 10 is a cross-section illustration of an assembly of the first, second and third elements.

FIGURE 11 is a cross-section illustration of an assembly of the first and second elements and an optional pan

element.

FIGURE 12 is a cross-section illustration of an assembly of the first and second elements.

FIGURE 13 is a cross-section illustration of an assembly of the first and second elements, similar to Figure 5 including a cross-section view of a two-crust pie and pie pan.

FIGURE 14 is a cross-section illustration of an assembly of the first, second and fourth elements including a cross- section of a pizza pie. FIGURE 15 is a cross-section illustration of an assembly of the first and second elements similar to Figure 5 including a cross-section view of a pizza pie.

FIGURE 16 is a cross-section illustration of an alternative

construction of the fourth element for cake baking.

FIGURE 17 is a cross-section illustration of an assembly of the first, second and fourth elements wherein the fourth element corresponds to that illustrated in Figure 16.

FIGURE 18 is a cross-section illustration of the fourth element similar to that of Figure 16 containing a baked cake.

FIGURE 19 is a cross-section illustration of an assembly of the first and fourth elements with a baked cake in the fourth element.

FIGURE 20 is a cross-section of the first and fourth elements with a frozen food illustrated in cross-section on the fourth element.

FIGURE 21 is a cross-section illustration of an assembly of the first and second elements and fourth elements showing a frozen food, in its tray, contained on the first element.

FIGURE 22 is a cross-section illustration of the first element with an inverted, two-crust pie and pie pan illustrated in cross-section.

FIGURE 23 is a cross-section illustration of the first, second and fourth elements wherein the fourth element is a pie pan and the pie pan contains a two-crust pie, shown in cross-section.

FIGURE 24 is a cross-section illustration of an assembly of the first and second elements including a conical frustum sleeve for heating popcorn. FIGURE 25 is a cross-section illustration of an assembly of the first, second and fourth elements to provide a baking chamber for biscuits, breads, rolls, etc.

FIGURE 26 is a cross-section illustration of a nested kit of elements for shipping or storage.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will be described in several different and useful, embodiments.

A heat-generating member, first cooking member 10 is

illustrated in Figure 1. A microwave-transmissive, second cooking member 12 is illustrated in Figure 2. A collector assembly 14 is illustrated in Figure 3. An optional pan element 16 is illustrated in Figure 4.

All of the elements 10, 12, 14, 16 are intended to be of such shape that they can be employed in various combinations as will be more fully set forth.

The heat generating, first cooking member 10 may be constructed of a homogeneous, microwave-lossy material, for example,

Carbofrax, a silicon carbide compound manufactured by General Refractories Company, or may be a compound member, as a metal grill having a microwave-absorptive coating mounted in a microwave-transmissive vessel. The following preferred

embodiiiien ts will describe the compound member.

The heat generating, first cooking member 10, as shown in

Figure 1, comprises a microwave transmissive vessel 18, a metal grilling plate 20, a microwave absorptive substance 22 in contact a surface of the metal grilling plate 20, a perimeter sealing ring 24 and an interior chamber 26 preferably filled with a microwave-non-absorptive heat insulator 28 which can be a particulate thermal insulating substance such as vermiculite. The heat generating, first cooking member 10 also has

appropriate handle elements 30 which are fabricated from microwave transparent, heat-insulating materials. Preferably the metal grilling plate 20 is flat but in some embodiments, the grilling plate 20 may be dished, i.e., concave, to

facilitate frying eggs, infra or baking cakes, in fra .

Preferably the microwave transmissive vessel 18 is fabricated from a substance such as heat resistant glass or glass ceramic or high temperature resistant plastic. The metal grilling plate 20 is preferably formed from aluminum alloys although steel, copper or other metals and metal alloys may be employed. The metal grilling plate 20 must transmit heat energy quickly and provide a rugged, reusable, cieanable cooking surface.

The microwave absorptive substance 22 preferably is a

dispersion of ferrite particles in an appropriate carrier such as a silicone rubber or other temperature resistant carriers. Tn a preferred embodiment, a silicone rubber coating

composition is filled with ferrite particles and applied as a relatively thick coating (up to about 5 millimeters) to the inner surface of the metal grilling plate 20. The size of the metal grilling plate 20 establishes the size of the other elements in the kit. Typically the metal grilling plate 20 has a diameter from 6 to 15 inches, preferably about 8 to 12 inches.

The microwave-transmissive, second cooking member 12, as shown in Fi gure 2 , i s imperf orate and has an essentially fiat base 32, tapering sidewalis 34, handle members 36, and a peripheral coplanar rim 38. The peripheral rim 38 preferably is adapted to engage the perimeter sealing ring 24 of the heat generating, first cooking member 10 thereby, as illustrated in Figure 5, to establish a perimeter seal for a chamber 40 that is bounded by the mi crowave-transmissive, second cooking member 12 and the heat generating, first cooking member 10. The rim 38 of the microwave- tr ansmissive, second cooking member 12 may engage the metal grilling plate 20.

Tt is an important feature of this invention that the

microwave-transmissive, second cooking member 12 have a

substantial mass, preferably from about 1.5 to 3 pounds whereby a reliable sealing engagement between the rim 38 and the perimeter sealing ring 24 can be established, sufficient to permit development of superatmospheric pressure in the chamber 40. The sealing engagement may be developed between the rim 38 of the microwave-transmissive, second cooking member 12 and the surface of the metal grilling plate 20. The microwave

transmissive, second cooking member 12 preferably is

transparent to light. The microwave transmissive, second cooking member 12 can be formed from heat resistant glass, glass-ceramic or temperature resistant plastic.

An optional accessory metal pot 44 is analogous to a frying pan having a base 58, tapering sidewalls 60 and an outwardly extending upper rim flange 62 that rests upon the shoulder 54 of a microwave transmissive pot 42. A perforated metal pan 46 has a perforated base 66 and tapering sidewalls 68 that permit engagement with the inner surface of the tapering sidewalls 60 of the metal pot 44. The metal pot 44 is preferably fabricated from aluminum or aluminum alloy and has a thickness of about 1.5 millimeters. The perforated pan 46 is preferably

fabricated from aluminum or aluminum alloy and has a thickness of about 1.5 millimeters. The perforations of the perforated pan 47 must be small enough to block passage of microwave energy arid large enough to permit free passage of steam and rendered by-product. The perforations are distributed over the base 66 in a preferred embodiment. Alternatively the

perforations are provided solely in the perimeter region of thebase 66, in which case, some by-products will remain in contact with food on the pan. The perforation area is about 6 to 65 sq. millimeter. The total area of ail of the perforations is from about 10 to about 50% of the total area of the base 66. Circular perforations from about 0.5 to 10 millimeters diameter are preferred.

The optional pan element 16, Figure 4, includes a base 70 and upstanding sidewalls 72, preferably outwardly tapered. The optional pan element 16 preferably is fabricated from aluminum or aluminum alloy. The optional pan element 16 functions to prevent spread of liquids and cooking juices from food products that are being heated in the present apparatus and also as a serving or eating dish. The base 70 of the optional pan element 16 preferably rests in direct heat exchange engagement with the exposed surface of the metal grilling plate 20 as shown clearly in Figures 9, 11. Optionally, the surface of the metal grilling plate 20 may be coated with a film of cooking oil or other liquid to improve the heat transfer between the metal grilling plate 20 and the optional pan element 16. A similar film of cooking oil, melted butter, or other fluid may be placed in the optional pan element 16 to cover the base 70 and improve the heat exchange from the auxiliary cooking pan 16 to its food contents.

Assembly of Elements

The elements of the present cooking assembly can be combined in a variety of novel and useful cooking utensils.

The microwave-transmissive, second cooking member 12 and the heat generating, first cooking member 10 can be combined as shown in Figures 5, 6. In each of these examples, the rim 38 of the microwave-transmissive, second cooking member 12 engages the perimeter ring 24 on the metal grilling plate 20 to provide a steam confining chamber 40. When the microwave-transmissive, second cooking member 12 is fabricated from transparent

material such as heat resistant glass and the temperature within the chamber 40 is above the steam condensation

temperature, then the inner walls of the microwave- transmissive, second cooking member 12 will be free of

condensed moisture and the contents cooking in chamber 40 will be visible through the transparent wails of the microwave- transmissive, second cooking member 12. In Figure 5, the weight of the microwave-transmissive, second cooking member 12, preferably 1.5 to 3 pounds, urges engagement of the rim 38 and sealing member 24 or metal grilling plate 20 to provide a seal to confine steam at slightly elevated pressures above

atmospheric. In Figure 6, the inverted combination of Figure 5 can be employed in a variety of food heating sequences depending upon the nature of the food and the desires of the cook the weight of the heat generating, first cooking member 10, preferably about 1.5 to 3 pounds, urges engagement to provide a seal to confine steam at slightly elevated pressures above atmospheric.

The microwave-transmissive, second cooking member 12 may be combined with the collector assembly 14 as shown in Figures 7, 10 wherein the rim 38 of the microwave-transmissive, second cooking member 12 engages the upper rim 52 of the microwave transmissive pot 42 to form a chamber 40'.

As shown in Figure 10, three of the members are combined in an assembly including the microwave-transmissive, second cooking member 12, the collector assembly 14 and the heat generating, first cooking member 10.

The heat generating, first cooking member 10 can be combined with the collector member 14 as shown in Figure 8 with a food item 74 , such as a steak, resting upon the perforated plate 46 and supporting the metal grilling plate 20.

The optional pan member 16 may be combined with the heat generating, first cooking member 10 as shown in Figures 9, 11 wherein the flat base 70 of the optional pan member 16 rests upon the metal grilling plate 20 of the heat generating, first cooking member 10. In Figure 9, the optionaJ pan member 16 functions as a frying pan, griddle plate, pizza-pie pan or cake pan. In Figure 11, the optional pan member 16 is confined within a steam retaining chamber 40 and supports food items (not shown in Figure 11) that are being cooked.

Figure 12 illustrates the heat generating, first cooking member 10 and the microwave-transmissive, second cooking member 12 as an assembly in which the heat generating, first cooking member 10 is being heated and the contents of the microwave- transmissive, second cooking member 12 (e.g., soup, frozen food, et cetera) is being heated by microwave energy. The assembly of Figure 12 suggests that two differing functions of the cooking members can be carried out concurrently in a

microwave oven chamber.

Other useful combinations of the elements are hereinafter described as they are employed in various cooking operations. I. A Frozen Two-crust Pie

A frozen two-crust pie has presented difficulties in microwave cooking because of several different heating requirements. The bottom crust and the top crust require high temperatures for baking the pastry and browning it to an aesthetically pleasing appearance without burning. The interior of the frozen pie is largely water (e.g., apple pie, cherry pie, meat pie, etc.) that requires thawing and subsequent heating to complete its cooking cycle.

The assembly of elements shown in Figure 5 has been reproduced in Figure 13 to illustrate double-crust pie cooking with the present kit.

A frozen two-crust pie, typically a fruit pie, can be baked successfully by initially heating the assembly of Figure 5 until the metal grilling plate 20 rises to 350-500 degrees F, i.e., sufficient to bake a pie crust. The pre-heated assembled unit con sisting of the microwave-transmissive, second cooking member 12 and the heat generating, first cooking member 10 is removed from the microwave oven by means of the juxtaposed handles 30, 36. A frozen fruit pie 76 is introduced, Figure 13, into the chamber 40 in its metal pie plate 78 which is placed directly upon the metal grilling plate 20. The

microwave-transmissive, second cooking member 12 is replaced and the assembly as shown in Figure 13 is returned to the microwave oven and exposed to microwave energy. The very high temperature of the metal grilling plate 20 is transmitted directly through the metal pie plate 78 into the frozen pie 76 causing defrosting and actual baking of a bottom pie crust 80. Microwave energy enters through the top pie crust 82 and bakes the top pie crust 82 and defrosts and heats the pie filling 84. The Die filling 84 is also heated by heat conducted from the metal grilling plate 20 through the metal pie plate 78 and the bottom crust 80. If the upper pie crust 82 is imperforate, it is easier for the crust 80 to rise upwardly and bake uniformly in a dome shape.

In operation, the cook considers the thermal capacity of the heat generating, first cooking member 10 and chooses the amount of time to preheat the heat generating, first cooking member 10 so that, when the pie 76 contacts the preheated metal grilling pLate 20, a suitable amount of stored heat will be available for delivery to the bottom crust 80. For some foods such as a 26 oz. frozen fruit pie, preheating the heat generating, first cooking member 10 to store heat may not be necessary. While the pie defrosts, its filling heats and its top crust browns, the heat generating, first cooking member 10 has adequate time to heat and brown the bottom crust. A small 8 oz. meat pie with a liquid filling may require more preheating or standing time on a hot. metal grilling plate 20.

Tn all cases, the pie is confined within the chamber 40 while in the baking process.

The assembly of Figure 13 may be employed to bake freshly prepared two-crust pies, i.e., pies which have not been frozen.

The apparatus of Figure 13 may be employed to cook one-crust pies (top crust) by placing the frozen one-crust pie in its metal pie plate into the chamber 40 and placing the assembly in a microwave oven for exposure to microwave energy.

II. Pizza Pies

The assembly of Figure 11, reproduced in Figure 14, may be employed to prepare a frozen pizza pie wherein the optional pan element 16 is placed on the metal grilling plate 20 and a frozen pizza pie 86 is placed on an accessory pan element 16. The assembly of Figure 11 is preheated without the pizza pie to a suitable elevated temperature, preferably from about 350-500 degrees F. The pizza pie 86 on the optional accessory pan element 16 is placed in a heat transfer relationship with the metal grilling plate 20 and the assembly is exposed to

microwave energy. Microwave energy, entering through the microwave-transmissive, second cooking member 12, heats the topping 88 of the pizza pie 86 and causes moisture from the pizza pie to form steam within the steam confining chamber 40. The steam is confined at a slight superatmospheric pressure determined by the weight of the microwave-transmissive, second cooking member 12. If the frozen pizza pie 86 has its own aluminum foil pan 90, the optional accessory pan element 16 is not required and the assembly may be used as illustrated in Figure 15. The pizza pie 84 may be applied directly to the metal grilling plate 20, on its aluminum foil pan 90. To achieve uniform heating of a pizza pie, it may be desirable to apply several drops of cooking oil to the top of the metal grilling plate 20 to achieve more uniform thermal contact between the metal grilling plate 20 and the optional accessory pan element 16 (Figure 14) or the aluminum foil pan 90 (Figure 15).

In Figure 11, a perforated pan 46 may be used in place of the pan 16 on the metal grilling plate 20. The perforations on pan 46 do not hinder the crusting and browning of a pizza pie crust.

III. Soft Cooking and Frying Eggs

The combination of the optional accessory pan member 16 and the heat generating, first cooking member 10 is illustrated in Figure 9 wherein the optional accessory pan element 16

functions as a griddle or frying pan. The combination of the two members of Figure 9 is placed into a microwave oven and heated until an appropriate temperature is achieved. The unit is then removed from the oven and its stored heat energy can be employed for frying eggs ou ts ide the microwave oven . The metal gr i l l i ng pl ate 20 may be concave for this embodiment to direct the egg toward the center of the plate.

It is known that fresh eggs are sensitive to microwave oven cooking and, if heated in a microwave oven, are frequently cooked unevenly with some parts firm and other parts

essentially raw. The unevenness can be offset in part by providing rotating tables or by frequently opening the

microwave oven and manually moving the cooking egg to different locations within the microwave oven chamber. However when eggs are cooked according to the present invention, the heated optional accessory pan member 16 in combination with the heat generating, first cooking member 10 retains appropriate heat to complete cooking of a raw egg to the desired degree of firmness outside the microwave oven.

In operation, when heat generating, first cooking member 10, the microwave-transmissive, second cooking member 12 and accessory pan 16, as shown in Figure 11, are preheated, the preheated aluminum pan 16 can become a frying pan to fry an egg therein. The heat generating, first cooking member 10 is heated to a suitable temperature and sufficient heat is stored in the assembly. A shelled egg is applied to the heated accessory pan 16 and the cooking egg is not exposed to

microwave energy which could "harden" the egg yolk.

When heat generating, first cooking member 10 and microwave- transmissive, second cooking member 12, as shown in Figure 5, are preheated for a predetermined time, the assembly is

available to soft cook (e.g. coddle) an egg placed on the metal gr i l l i ng plat e 20 or i n a metal accessory pan 16 ( Figure 9 ) . Note that (1) the time required to preheat the metal grilling plate 20 in order to soft cook an egg is a fraction of the time required to fry an egg; (2) the aluminum accessory pan 16 is not preheated empty; and (3) no oil is used to make good thermal contact. The egg is slowly soft cooked to individual taste, i.e., about five minutes, solely from the heat energy stored in the heat generating, first cooking member 10.

Other foods which may be fried or grilled can be placed on the heated combination of the heat generating, first cooking member 10 and the optional accessory pan member 16 as shown in Figure 9 and in Figure 11. The assembly of Figure 11 is preferred becaue (1) the heat collected in the chamber 40 is not lost; (2) any splatter is contained; and (3) the food is shielded from the cooling action of circulating air which is present in most microwave oven chambers; and (4) a heavy, glass,

microwave-transmissive second cooking member 12 increases in microwave lossiness as it heats.

IV. Cake Baking

Baking cakes in microwave ovens in th past has been difficult because of the unevenness of the heat application. Cakes tend to rise unevenly and to provide irregular top surfaces which are undesirable.

According to the present invention, a cake batter 92 is mixed and introduced into a lightly greased optional accessory pan member 16', preferably having generally vertical or slightly sloping sidewalls 72', corresponding to a conventional cake tin shown in Figure 16. The quantity of cake batter 92 should be sufficient so that the baked cake will rise slightly above the level of the sidewalls 72'. The combination of a heat

generating, first cooking member 10 and a microwave- transmissive, second cooking member 12 as in Figure 5, is preheated in a microwave oven before placing the cake batter 92 and the optional accessory pan member 16' therein. The

combination of heated heat generating, first cooking member 10, accessory pan member 16' with cake batter 92 and the microwave- transmissive, second cooking member 12 shown in Figure 17, is returned to the microwave oven wherein the cake bakes because of (1) exposure to the microwave energy in the microwave oven; (2) by conductive heat from the heat generating, first cooking member 10; and (3) by the superatmospheric steam in the chamber 40. After the cake rises above the level of the rim of the optional accessory pan member 16' and completes. its baking, the top surface of the cake 92, Figure 18, will be irregular and neither crusted nor browned. The assembly of Figure 17 is removed from the microwave oven and disassembled. The heated heat generating, first cooking member 10 is inverted and placed on top of the cake as shown in Figure 19. The cake 92" will be browned, crusted and flattened to a uniform top surface by direct contact with the heated metal grill plate 20.

The weight of the heat generating, first cooking member 10 does not crush the cake 92' and it results in a flat top for the cake copianer with th upper rim of the optional accessory pan member 16'.

Additional browning and crusting is possible by exposing heat generating, first cooking member 10 resting on top of pan member 16' for an additional period of time to microwave energy. During this additional period of time, microwave energy cannot reach the baked cake because it is shielded on its top by metal grilling plate 20 and on its sides and bottom by accessory pan member 16'.

V. Defrosting and Heating TV Dinners

A frozen food, conventionally packaged on an aluminum foil tray or on a high temperature resistant plastic tray or on another heat-resistant support, is placed in an assembly of the type shown in Figure 5, i.e., a heat generating, first cooking member 10 and a microwave-transmissive, second cooking member 12. The frozen food 96 can be quickly and conveniently heated. If the assembly was not preheated before the frozen food was placed therein, the microwave-transmissive, second cooking member 12 may become coated with condensed moisture on its inner surface. The condensed moisture will run down on to the surface of the metal grilling plate 20 of the heat generating, first cooking member 10, where it boils and forms steam that increases the total heat content of the assembly. At some stage, the chamber 40 is heated above the dew point of its steam contents and the condensation on the inner surface of the microwave-transmissive, second cooking member 12 disappears. Thereafter the cook can visually observe the food and decide when the food has properly heated. The experienced cook will recognize and take into account that some after-cooking of the frozen food may occur. The frozen food 96 is heated by a combination of heat conducted from the metal grilling plate 20 through frozen food container 94 and into the bottom portions of the frozen food 96.

Simultaneously microwave energy entering chamber 40 through the microwave-transmissive, second cooking member 12, penetrates into the frozen food 96 causing volatilization of moisture and heating of the frozen food 96. The amount of dehydration of the frozen food 96 is controlled because the volatilized steam is confined at slightly superatmospheric pressures within the chamber 40. Tt may be desirable to spray selective areas of the upper surface of the frozen food 96 with moisture prior to defrosting and heating in order to reduce the hydration

tendencies of peas and carrots, for example, relative to the meat portions. Adding moisture is more fully described in U.S. Patent 4,390,555.

VI Alternative Technique for Baking Pies

An alternative technique for baking pies can be described in connection with Figures 22 and 13. A frozen meat pie or other moist ingredient pie having a bottom crust which is difficult to bake satisfactorily, can be baked in a novel manner with selected members of the kit of this invention. In Figure 22, a frozen pie 98 includes a bottom crust 102, a top crust 104 and a moisture containing filling 106. The frozen pie 96 is placed on a metal pie pan 100 which may be aluminum foil or other metal. The frozen pie 98 is placed upside down with its top crust 104 against the metal grilling surface 20 of the heat generating, first cooking member 10 and covered by the

microwave-transmissive, second cooking member 12.

The assembly as shown in Figure 22 is placed in a microwave oven and exposed to microwave energy. Microwave energy cannot penetrate the metal pie pan 100 and accordingly functions to heat the microwave absorbent substance 22. That heat is conducted to the metal grilling plate 20 and thence directly to the top pin crust 104. The top pie crust 104 thaws and

partially bakes to a suitable brown coloring. Thereafter the assembly of Figure 22 is removed from the microwave oven. The frozen pie 98 has its top crust 104 partially baked and its bottom crust 102 defrosted and heated from the steam evolved during the partial baking of top crust 104. This partially baked pie is placed on the heat generating, first cooking member 10 in its normal position and the assembly is covered with a microwave-transmissive, second cooking member 12 to produce the assembly of Figure 23. The aqueous pie filling 106 remains frozen throughout the partial baking of the top crust 104. Thus the pie 98 remains essentially frozen and can be easily inverted.

The heated assembly of Figure 23 is returned to the microwave oven and baking of the pie is completed. During the final stage of the baking, the bottom crust 102 is heated primarily by conduction of heat energy from the metal grilling plate 20 through the pie pan 100. The aqueous pie filling 106 is heated primarily by microwave energy which penetrates the microwave- transmissive, second cooking member 12 and penetrates the top crust 104. The prebrowned top crust 104, now free to rise, will rise, crust and turn brown. The chamber 40 becomes filled with superatmospheric steam, which combines with the 350-500 degrees F heat that is released by the metal grill surface 20 to complete the heating and baking of the side and bottom crust 102.

Typically, in the operation described concerning Figure 22, the preferred defrosting and partial browning of the top surface of the pie occurs approximately two minutes after the time

normally required for the temperature of metal grilling plate 20 to rise to a temperature of about 350 degrees F. For example, if the metal grilling plate 20 required seven minutes to rise to 350 degrees F, then in contact with the frozen pie crust, the metal grilling plate 20 wiiL heat in about nineminutes.

VII. Popcorn

A number of processes for baking popcorn in microwave ovens are described in the literature. U.S. Patents 3,973,045; 4,292,332; 4,435,628; 4,450,180. The kit of the present invention provides an improved popcorn making facility as shown in Figure 24. The assembly of Figure 12 is provided with a frustoconical sleeve 108 which is placed with its narrow opening on the metal grilling plate 20. The sleeve 108

restricts unpopped corn to the central region of the metal grilling plate 20 which is the hottest region. A supply 110 of unpopped popcorn is placed in the bottom of the frustoconical sleeve 108. The microwave-transmissive, second cooking member 12 is placed on the heat generating, first cooking member 10 and the assembly of Figure 24 is placed in a microwave oven. Heating the supply 110 of unpopped popcorn causes popping to occur to produce popped popcorn 112 which rises in the

frustoconical sleeve 108 and overflows onto the cooler

perimeter of the heated surface of the metal grilling plate 20. After the popping is completed, the assembly of Figure 24 is removed from the microwave oven and is inverted. The

microwave-transmissive, second cooking member 12 thereafter functions as a warm serving dish for the popped popcorn 112. The frustoconical sleeve 108 is removed from the microwave- transmissive, second cooking member 12 after it is inverted to its open top position. Preferably the frustoconical sleeve 108 is formed from heat resistant glass.

VIII. Steam Cooking

Referring to Figure 7, the present kit may be assembled to produce a steamer type cooking utensil wherein a supply of water is introduced into the chamber 41 beneath the perforated accessory pan 46 and the metal pot 44. The metal pot 44 may be dispensed with or the metal pot 44 may be inverted over the perforated accessory pan 4.6. The water vaporizes and the resulting steam is contained within the chambers 40, 41. Any food positioned on top of the perforated pan 46 will be steamed and thereby cooked in the manner of a steam cooker. This technique is useful for seafoods (lobsters, shrimp, etc.), desserts (plum puddings, fig puddings, etc.), steam heating bakery goods (rolls, buns, etc.). When a perforated accessory pan 46 is employed as a shelf within the chamber 40, a food can be exposed to microwave energy on a perforated accessory pan 46 or directly in the microwave transmissive pot 42. When a perforated accessory pan 46 is used as a shelf, water can be boiled beneath the

perforated accessory pan 46, and the steam from the boiling water will be contained within the chamber 40, to steam cook contained food. Steam which contacts heated metal grilling plate 20 becomes superheated.

To steam foods, for example, to cook frozen lobster tails, the cook can first dip the frozen lobster tails in water before heating in the microwave-transmissive, second cooking member 12, in the assembly shown in Figure 6. Alternatively some water could be first boiled in the microwave-transmissive, second cooking member 12; thereafter the frozen lobster tails are placed in the boiling water and covered by heat generating , f i rs t cook i ng member 10 . The food i s then exposed to

superatmospheric steam, i.e., steam heated by the metal

grilling plate 20 and by microwave energy.

Another example of steaming is cooking a frankfurter (hot dog) in the assembly of Figure 6. The frankfurter is placed in the microwave-transmissive, second cooking member 12 and heated by microwave energy and superatmospheric steam. Steam from frankfurter juices or from moisture added to the chamber by the operator becomes superheated upon contact with the heated metal grilling plate 20. When the frankfurter is heated, the

assembly of Figure 6 is inverted to create the assembly of Figure 5. The frankfurter falls onto the hot metal grilling plate 20 and is grilled to the desired degree of browning.

Frankfurter rolls also may be placed in the microwave- transmissive, second cooking member 12 with the frankfurter for heating in the Figure 6 assembly. When the elements are inverted, the frankfurter roils are toasted on the metal grilling plate 20 while the frankfurters are being grilled. IX. Frozen Fried Foods

A novel process for heating and cooking frozen prefried foods such as fried potatoes, fried chicken employs the heat

generating, first cooking member 10 and the microwave- transmissive, second cooking member 12 assembled as shown in Figure 6. The assembly is preheated to an operating

temperature (about 500 degrees F) by exposure to microwaves in a microwave oven. The assembly is removed and a frozen fried food is placed into the chamber 40 on the base 32 of the microwave-transmissive, second cooking member 12. The

preheated assembly is returned to the microwave oven and exposed to microwave energy until the food defrosts and heats to a temperature approaching a desired serving temperature.

Thereupon the heat generating, first cooking member 10 and the microwave-transmissive, second cooking member 12 are inverted to a position shown in Figure 5 so that the warm, fried food falls by gravity onto the metal grilling plate 20 where the food bakes, browns, crusts, fries and/or sears as the case may be in surface contact with the hot metal grilling plate 20.

Deep fat frying can be simulated by applying a small quantity of cooking oil to the frozen food to replace some of the oil which may be driven off during the defrosting and heating.

When the heated food drops onto the heated metal grilling plate 20 at the moment of inversion of the assembly, there is no significant loss of temperature on the metal grilling plate 20, as happens when a frozen food contacts a heated metal grilling plate.

In either the Figure 5 or the Figure 6 configuration, the food can be stirred conveniently by removing the assembly from the microwave oven and firmly holding handles 30, 36 together and shaking the assembly to agitate its food contents.

X. Steak Broiling

Tn Figure 8, a steak 74 is shown supported on a perforated aluminum accessory pan 46 over a microwave-shielded by-product condensation chamber 41 defined by the metal pot 44 and the perforated cake pan 46. The steak 74 contacts and supports the heat generating, first cooking member 10. The weight of the heat generating, first cooking member 10 urges the metal grilling plate 20 into engagement with the top of the steak 74. The heated metal grilling plate 20 heats and grills the top surface of the steak 74. Liquid by-products of the steak process fall by gravity into the by-product collection chamber

41 from where they may be recovered for use as gravy.

Microwave energy may enter into the steak 74 directly through the sides of the steak to heat and cook the meat. Preferably any bones are removed from the steak 74 because bones might interfere with the required surface contact of the metal grilling plate 20 with the upper surface of the steak. Note that the microwave-shielded by-product condensation chamber 41 is microwave-shielded which prevents microwave energy heating of the by-products of cooking. The cooking by-products may be saved for subsequent cooking or may be discarded.

XI. Sausage Cooking

Figure 10 illustrates a microwave-transmissive, second cooking member 12 on top of a collector assembly 14. This

configuration is useful for rapid defrosting and heating food such as sausages which yield large quantities of liquid byproducts during cooking. Where the microwave transmissive pot

42 of Figure 10 is fabricated from glass or ceramic, it can rest directly on the metal grilling plate 20 whereby the heat generating, first cooking member 10 is preheated while the byproduct producing food is being precooked. After the product such as sausages is adequately precooked, via microwave energy, the collector assembly 14 is removed and the assembly of Figure 5 is reconstituted to permit the searing and final grilling of the sausage on the heated metal grilling plate 20. The

preheated sausage, for example, may complete its cooking on the metal grilling plate 20 concurrently with frying an egg on the metal grilling plate 20. The egg-cooking and final sausage cooking are preferably conducted without microwave energy --- i.e., outside the microwave oven. XII. Biscuit Baking

Biscuits may be baked with the assembly illustrated in Figure 25 including a heat generating, first cooking member 10, a microwave-transmissive, second cooking member 12 and an

inverted metal pot 44. The metal pot 44 and the metal grilling plate 20 combine to define a steam-confining baking chamber 121. In this embodiment, the inverted metal pot 44 functions as a microwave-reflective, second cooking member because it combines with the heat generating, first cooking member 10 to create the steam-confining chamber 121. Individual biscuits 120 are placed in the baking chamber 121 and are protected from exposure to microwaves because they are surrounded by a metal enclosure consisting of the inverted metal pot 44 and the metal grilling plate 20. The metal grilling plate 20 may be at room temperature when the biscuit baking commences or may be

preheated. The biscuits 120 are heated from the heated metal grilling plate 20 by conduction and rise (expand) upwardly.

After the biscuits have risen and the bottom surfaces become brown, the assembly may be removed from the microwave oven and the biscuits 120 may be inverted on the heated metal grilling plate 20 and the assembly of Figure 25 reconstructed and returned to the microwave oven to brown the other surface of the biscuits. The presence of the microwave-transmissive, second cooking member 12 prevents any significant heat loss from the system and further confines the superatmospheric pressure in the chamber 121 during the baking operation.

Nesting

In a preferred embodiment, all of the elements of the present cooking kit, namely, the heat generating, first cooking member 10, the microwave-transmissive, second cooking member 12, the collector assembly 14 and the optional pan element 16 should be nestable for shipping and storage purposes. Note that the optional pan element 16 is also a microwave-reflective second cooking member. A typical nested kit is shown in Figure 26. Preferably all of the elements in their nested condition should fit into a microwave oven for storage therein when not in use. Nesting requires appropriate design of the slopes of the side walls of the various elements and appropriate selections of depths and widths. It may be desirable to provide more than one metal pot 44, for example, to develop a larger baking chamber 121.

General Comm ents

When cooking is complete, the second cooking member 12 may be left in place on top of the heat generating, first cooking member 10 as shown in Figure 12 to keep the food warm during serving.

It may be desirable to provide additional useful accessory metal pans of different sizes and shapes. Preferably the cross-section shape of the elements of the present kit are circular. Other cross-sections are feasible and sometimes even desirable, for example, generally square, preferably with rounded corners; rectangular, preferably with rounded corners; oval; and other shapes corresponding to the shape of the anticipated food article or container.

Claims

CLAIMS :

1. A microwave-oven cooking-kit, with engageable, invertible, cooking members, which comprises: an invertible, microwave-absorptive, first cooking member, including a first surface adapted to cook a food thereon, an invertible, second cooking member including a second surface adapted to cook a food thereon, a steam-confining, cooking chamber defined by said first and second members, means to retain said first and second members in engagement (a) when said first member is the top member, (b) when said second member is the top member; and (c) when said members are inverted together.

2. The cooking kit of Claim 1 wherein said first cooking member weighs between 1.5 and 3.0 pounds.

3. The conking kit of Claim 1 wherein said second cooking

member weighs between 1.5 and 3.0 pounds.

4. The cooking kit of Claim 1 wherein said means to retain said first and second members in engagement comprises at least one handle member on said first cooking member and at least one handle member on said second cooking member, said handle members arranged in juxtaposition to permit

transport and inversion of said cooking kit as a unit.

5. The cooking kit of Claim 1 where said second cooking member is a microwave-permeable bowl member having a rim.

6. The cooking kit of Claim 5 with said second cooking member in its said rim resting on and engaged with said first surface of said first cooking member; and an accessory pan member having a base resting on said first surface in heat-transfer relationship and being entirely confined within said steam-confining chamber.

7. The cooking kit of Claim 6 where said accessory pan member is perforated to permit the passage of steam and is fabricated of a microwave reflective material.

8. The cooking kit of claim 1 where said second cooking member is a microwave reflective first pan member having a base and a sidewall with a rim; and said rim supports and engages said first cooking member.

9. The cooking kit. of claim 8 including a perforated,

accessory pan member in said steam confining chamber and having a base supported above said second surface, a byproduct collection chamber defined by said accessory pan member and by said first pan member, said by-product collection chamber being entirely confined within said steam-confining chamber.

10. The cooking kit of Claim 1 wherein said second cooking

member is a metal pan having a base and a sidewall, and the open rim of said sidewall is engageable with said first surface of said first cooking member and said base comprises the said second surface.

11. The cooking kit of Claim 5 wherein said second cooking

member is formed from heat, resistant glass, ceramic

material, glass-ceramic material or heat-resistant

plastic.

12. For use in a microwave oven, an invertible microwave cooking apparatus comprising: a heat generating member which includes a heat conductive metal grill having in contact with its reverse surface a microwave absorptive material; an imperforate, microwave transmissive bowl member having a rim engaged with said heat generating member; a steam confining chamber defined by said heat generating member and said bowl member; means to retain said heat generating member and said bowl member in engagement, while said apparatus is inverted; said bowl member being adapted in its rim-up position to confine food in contact with an inner surface thereof while said food is being heated; said inner surface within said bowl member being below but not in contact with said heat conductive metal grill; and said bowl member being further adapted in its rim-down position to confine vaporous cooking by-products from cooking food in contact with said heat conductive metal grill.

13. The cooking apparatus of Claim 12 wherein said heat

generating member weights between 1.5 and 3.0 pounds.

14. The cooking apparatus of Claim 12 with said bowl member in its rim-down position, including an auxiliary pan member having a base resting on said metal grill in heat transfer relationship and being entirely confined within said steam-confining chamber.

15. The cooking apparatus of Claim 12 wherein said bowl member has at least one handle member and said heat generating member has at. least one handle member arranged in

juxtaposition with said handle members of said bowl member to permit transport and inversion of said cooking

apparatus as a unit.

16. The cooking apparatus of Claim 12 wherein said bowl member weighs between 1.5 and 3.0 pounds.

17. The cooking apparatus of Claim 12 including an auxiliary imperforate metal pan having its base disposed within said bowl member in its rim-up position and having a perforated metal pan member positioned above said base of said imperforate metal pan member to define a microwave

shielded chamber between the two said pans, said heat generating member positioned above the open top of said bowl member to define said steam confining chamber.

18. The microwave cooking apparatus of Claim 12 wherein said bowl member is in its rim-down position including means engageable with said metal grill for restricting location of a food to a selected location on said grill, said location comprising less than the cooking surface of said metal grill.

19. The microwave cooking apparatus of Claim 18 wherein said means for restricting location of a food comprises a sleeve, open at each end and having a rim at each end, said sleeve having a first rim engaged with said cooking surface of said metal grill and having the second rim disposed above said grill.

20. The microwave cooking apparatus of Claim 12 wherein said bowl member is in its rim-down position, including an auxiliary imperforate metal pan member having a base and a rim, said rim being engaged with said metal grill within said steam confining chamber, whereby said auxiliary pan member and the cooking surface of said metal grill define a microwave shielded heating chamber.

21. The microwave heating apparatus of Claim 20 wherein said bowl member weighs between 1.5 and 3.

22. The cooking apparatus of Claim 14 wherein said base of

said auxiliary pan member which engages said grill is provided with perforations.

23. The microwave cooking apparatus of Claim 12 comprising: a collector assembly comprising a microwave transmissive pot, a metal pot engaged within said microwave

transmissive pot, and a perforated metal pan engaged within said metal pot, a rim at the open end of said microwave transmissive pot; said microwave transmissive bowl member having its rim engaged with said rim of said microwave transmissive pot to define an enclosed chamber between said microwave transmissive bowl member and said microwave transmissive pot; said microwave transmissive pot resting upon said microwave absorptive heating member.