EP1835787A2 - Microwave oven - Google Patents

Abstract

The microwave oven has a cooking chamber (10), and coupling units (12, 14, 16, 18, 20, 22) for coupling microwaves in the cooking chamber. A set of sections (26, 28) accommodating a cooking goods carrier (24) are provided in the cooking chamber, where one of the coupling units is arranged between two adjacent sections. The coupling units include a blade antenna and coaxial cable. The coupling units are incorporated in carrier plates, which are formed from ceramics. An independent claim is also included for a cooking goods carrier inserted into two adjacent sections.

Description

The invention relates to a microwave oven with a cooking chamber and with at least one coupling means for coupling microwaves in the cooking chamber. Furthermore, the invention relates to a food support for insertion into a rack level of a microwave oven and a system of a microwave oven and a food support.

From the US Pat. No. 6,831,259 B2 a microwave oven for heating pressed material is known, which has a plurality of coupling means for coupling microwaves in a cooking chamber. In the cooking chamber, a single insertion level is provided, and the coupling means are arranged above the rack level.

Domestic ovens with several insertion levels and with a microwave function are also known from the state of the art, wherein the microwaves are coupled into the cooking chamber via coupling means designed as waveguides, which are arranged on an upper side and on an underside of the cooking chamber.

For steam cooking in microwave ovens, it is known to portion foodstuffs in plastic bags, the portions ranging from a few 100 g to 10 kg. The plastic bags are pressure-tight and provided with a pressure relief valve and are placed on a food support or on a tray. Such trays are also referred to as "gastronomic measure". During cooking, steam is produced with slight overpressure, so that a combined microwave steam cooking is achieved. For this purpose, microwave ovens are used in commercial kitchens, each of which can accommodate only one tray. The plastic bag is only usable once.

The invention is in particular the object of a compact, multi-level microwave oven, in particular for the preparation of food, provide, which is also available for steam cooking at overpressure.

The invention proposes a generic microwave oven, in the cooking chamber a plurality of levels are provided for arranging food supports, wherein at least one of the coupling means is arranged between two adjacent planes.

The inventive solution can be achieved that at the same time several food support can be arranged on several levels in the oven and yet a uniform heating of the food is guaranteed. It can be avoided in particular that a food support shields another food support from the fed microwave radiation.

To solve the problem, a food support is further proposed for insertion into a rack level of a microwave oven, wherein the food support formed in such a way is that when inserting it comes with a arranged above the shelf level support plate to the plant, so that the support plate closes the food support pressure-tight. To avoid too high an increase in pressure during cooking, a pressure relief valve is preferably provided on the food support. In various embodiments, either a lid of the food support, which in turn is supported on a closure edge of the food support and / or can rest on the support plate from below .. Auch kann Border edge or flange abut directly on the support plate so that it closes the food support directly.

When heating the arranged in the food support Garguts then produces water vapor, which contributes to a gentle cooking process, especially if a slight overpressure of a few tenths bar arises. As a result, the generic microwave oven can be used for steam cooking. By reusable food support can be saved compared to the method described above with plastic bags cost.

To achieve the Dampfgarfunktion at several levels, the microwave oven according to the invention and the food support according to the invention act together advantageously, because on the one hand the support plate generates the contact force for pressure-tight sealing of the food support and on the other hand arranged between the levels or insertion levels Einkopplungsmittel ensure a constant over the different levels microwave energy input, so that the cooking process runs the same way in the different levels.

To achieve the synergy effect described above, a system is proposed in addition to an inventive Microwave oven also comprises at least one fermentation product carrier according to the invention.

A narrow-built coupling means, which, without taking up much space, can penetrate deep into the cooking chamber, can be achieved when the coupling means comprises a rod antenna and / or a coaxial conductor. The central conductor of the coaxial conductor can be particularly advantageous in areas in which the outer conductor of the coaxial conductor has openings for coupling out the microwave radiation act as a rod antenna. As a coaxial in this context, a device with a central conductor and an only partially closed outer shell should be referred to, which is also usable for reflecting the microwave radiation in a preferred coupling-out direction. In principle, in the case of a coupling means in the form of a coaxial conductor, it may also be particularly advantageous if only the inner conductor of such a coaxial structure extends inside the furnace or into its cooking space (eg transversely therethrough, as explained in greater detail below ), since the microwaves in this case are uniformly radiated along the coaxial structure. In this way, in particular over a frequently desired length of about 60 cm to 100 cm, an extremely homogeneous heating of things to be heated in the cooking chamber, such as primarily food or drinks, achieve. The physical reason for this is that the propagation direction of the electromagnetic waves extends in the direction of the inner conductor. The wave is thus "obstructed" in the radiation, emits initially "less", but runs evenly over the entire coaxial structure. Consequently, there is a considerably more uniform heating than if, for example, coupling-out units are provided at the coupling-in means, as is often the case with conventional ovens in the form of slots.

A uniform over the width or the depth of the cooking chamber coupling of the microwave energy can be achieved when the coupling means across the cooking chamber parallel to one of the planes for arranging the food support, in particular spaced from a rear wall of the cooking chamber.

Furthermore, it may be advantageous if the or the coupling means is or are stationary in the cooking chamber, resulting in a stable and robust arrangement of usually relatively sensitive coupling means.

In particular, at least two coupling means can be arranged at least in pairs in a plane which preferably extend transversely through the cooking chamber, so that it is possible for the microwave energy to be coupled directly into the food support and not only from a further point in the direction of the food support radiates, which can lead to a more uneven and / or slower heating.

Furthermore, it can be provided according to a preferred embodiment, that the coupling means between two opposite walls of the cooking chamber, in particular between the side walls, these connecting to each other. In this way, not only is a robust and effective arrangement of the coupling means (s) possible, but also, for example, a simple electrical contacting of the coupling means, such as by means of a plug, from the side walls of the microwave oven.

Protection of the sensitive coupling means against impacts on the one hand and functional integration on the other hand can be achieved if the coupling-in means are incorporated in a carrier plate. As a result, the support plate can be used at the same time for carrying the food support and / or the coupling means and for heating the food in the food support food by microwave radiation. A robust carrier plate which absorbs at most insignificant and tolerable portions of the microwave radiation can be achieved by forming the carrier plate from ceramic.

By incorporating the coupling means in the carrier plate creates a compact, easy to clean assembly. To expand the microwave oven, only the cooking chamber needs to be enlarged and a further carrier plate is inserted, so that the dimensioning of the microwave oven according to the invention is structurally particularly simple.

The carrier plate can take on a further function in the implementation of the Dampfgarvorgangs when the carrier plate is designed for sealing a food support.

By a connecting flange on a side wall of the cooking chamber, which is designed for feeding the microwave radiation into the coupling means, the microwave energy can be conveniently introduced from a waveguide or a magnetron in the coupling means. The connecting flange may also act as a switch, which distributes the radiation to a plurality of coupling means arranged in a plane.

A homogeneous heating in the depth of the cooking chamber can be achieved if the microwave oven has at least two, in the depth of the oven successively arranged, parallel coupling means between the two adjacent planes. The coupling means can, for example, divide the depth of the cooking space into equal parts.

In a further development of the food support according to the invention, it is proposed that this has a pressure relief valve. The food support according to the invention is advantageously formed of a material with low microwave absorption, high stability at the required temperatures of about 110 ° C and good cleaning properties. The material should also be approved for food when used in commercial kitchens. As such materials, for example, the plastics polypropylene, polyethylene terephthalate or polycarbonate are suitable.

Although the use of the terms "cooking space" and "food support" refers to the use in kitchens, the term "food" is not restricted to food, but in this context should include any goods to be microwaved. The person skilled in the art will recognize that the invention can also be used for other microwave ovens, in particular for those from industrial applications.

Further features and advantages will become apparent from the following description of the drawing based on embodiments of the invention. The figures, the description and the claims contain numerous features in combination which the skilled person will also consider individually and summarize to meaningful further combinations.

Fig. 1

einen Mikrowellenofen mit zwei Ebenen zum Anordnen eines Gargutträgers und zwischen den Ebenen angeordneten Einkopplungsmitteln;

Fig. 2

den Mikrowellenofen aus Fig. 1 mit zwei Gargutträgern in einer Schnittdarstellung;

Fig. 3

einen alternativen Mikrowellenofen, in dem Einkopplungsmittel in keramische Trägerplatten eingearbeitet sind;

Fig.4

eine schematische Darstellung des Mikrowellenofens au Fig. 3 mit einem Gargutträger; und

Fig. 5

den Mikrowellenofen aus Fig. 3 mit zwei Gargutträgern in einer Schnittdarstellung.

Showing:

Fig. 1

a microwave oven with two levels for arranging a food support and arranged between the planes coupling means;

Fig. 2

the microwave oven of Figure 1 with two food supports in a sectional view.

Fig. 3

an alternative microwave oven in which Einkopplungsmittel are incorporated in ceramic support plates;

Figure 4

a schematic representation of the microwave oven au Fig 3 with a food support. and

Fig. 5

the microwave oven of Fig. 3 with two food supports in a sectional view.

1 shows a microwave oven with a cooking chamber 10 and with a total of six coupling means 12-22 designed as a coaxial conductor for coupling microwaves into the cooking chamber 10. The coupling means 12-22 each comprise a central conductor which acts as a rod antenna and the microwaves radially afterward radiates outside. The coupling means 12-22 are fixed stationarily on the opposite side walls of the microwave oven and in the present embodiment are arranged in pairs in a plane, wherein they extend transversely through the cooking chamber 10 therethrough. A first pair of input means 12, 14 is disposed in a lower portion of the cooking chamber 10 immediately above the bottom thereof, and a second pair of input means 20, 22 is disposed in an upper portion of the cooking space 10 immediately below a ceiling thereof.

The coupling means 12-22 are tubular and extend transversely through the cooking chamber 10 parallel to one of two Layers 26, 28 for arranging a food support 24 (FIG. 2) and parallel to a door opening of the cooking chamber 10.

In the cooking chamber 10 more - in the present case two - levels 26, 28 for arranging each one Gargutträgers 24 (FIG. 2) are provided, wherein at least one pair of coupling means 16, 18 between the two adjacent planes 26, 28 is arranged. To carry the food support 24 or the trays, the side walls of the cooking chamber 10 each have two in the depth of the cooking chamber 10 extending, in the operating configuration of the microwave oven horizontally extending rails 40, 42 (Fig. 2). The width of the cooking chamber 10 and the rails are designed so that commercial trays or so-called "gastronomic dimensions" as food support 24 can be inserted horizontally into the cooking chamber 10. A door 30 shields the microwave radiation in the cooking chamber 10 to the outside.

Between the two adjacent planes 26, 28 for arranging the food supports 24, the cooking chamber 10 has the third pair of coupling means 16, 18 which emit microwave energy both up, to the upper level 28, and down to the lower level 26. As a result, the food support 24 (FIG. 2) arranged in the upper level 28 is irradiated with microwaves from the second pair of coupling-in means 20, 22, and microwaves are irradiated from below by the third pair of coupling-in means 16, 18. Accordingly, the food support 24 arranged in the lower level 26 is irradiated with microwaves from the third pair of input means 16, 18 from above and irradiated with microwaves from the first pair of input means 12, 14 from below.

The respectively one pair forming Einkopplungsmittel 12 - 22 are arranged in the depth of the cooking chamber 10 in a row and extend in a horizontal plane parallel to each other. The Einkopplurigsmittel 12 - 22 are spaced from the door level and the rear wall of the cooking chamber 10.

Each of the pairs of coupling means 12-22 is supplied with microwave radiation via two connecting flanges 50, 52 (FIG. 1), which are arranged mirror-symmetrically on both side walls of the cooking chamber 10. Such connecting flanges are referred to in waveguide technology as a beam splitter. The microwave radiation is generated by one or more magnetrons, not shown here, and transmitted via coaxial conductors to the connecting flanges 50, 52. For coupling the microwave radiation, the connecting flange flanges 50, 52 each have a coaxial interface 32.

In Figs. 3 to 5 an alternative embodiment of the invention is shown. The description is limited primarily to differences from the embodiment shown in FIGS. 1 and 2, reference being made to the description of FIGS. 1 and 2 with regard to features that remain the same. Comparable features are provided with the same reference numerals.

The alternative microwave oven comprises three ceramic support plates 34-38 (Figure 3) into each of which a pair of input means 12-22 of the type described above are incorporated (Figure 5). The support plates 34-38 delimit two stacked compartments of the microwave oven from above and below, so that in particular one of the support plates 36 between two levels 26, 28 is arranged for insertion of food supports 24. The carrier plate 36 therefore separates the cooking chamber 10 into two compartments, each assigned to one rack level.

By integrating the coupling means 12 - 22 formed as coaxial conductors into the carrier plates 34 - 38, the entire microwave conductor system is combined to form a compact, easy-to-clean assembly.

Immediately below the two upper support plates 36, 38 rails 40, 42 are formed in the side walls of the microwave oven, which extend horizontally into the depth of a cooking chamber 10 of the alternative microwave oven.

A system comprising the alternative microwave oven further comprises specially shaped food supports 24 (FIG. 4) made of a temperature and pressure-resistant plastic which is approved for food and absorbs at most a small proportion of the microwaves. The Gargutträger 24 have the dimensions of a gastronomischen Maßes, the shape of a flat, rectangular shell and have at its upper edge a flat, circumferential flange 44, the bottom rests upon insertion of the food support 24 on an upper side of the rails 40, 42. By a flexible suspension of the support plates 34 - 38 and / or the rails 40, 42, the bearing force can be generated elastically and at the same time a tolerance compensation can be made possible.

The distance between the upper side of the rails 40, 42 and the underside of each of the rails 40, 42 arranged support plate 36, 38 substantially corresponds to the thickness of the peripheral flange 44 of the food support 24 and the gastronomische dimensions. Thus, when inserting the food support 24, the top of the flange 44 with the underside of the support plate 36, 38 to rest, so that the support plate 36, 38 closes the food support 24 and the gastronomic measure pressure-tight when it is fully inserted.

4 shows schematically a food support 24 with a support plate 36 arranged below the food support 24 and a support plate 38 arranged above the product support 24, which seals the food support 24 or the gastronomic measure in a pressure-tight manner. During the cooking process, the food to be cooked 46 heats up in the food support 24 and there is steam that remains through the pressure-tight seal in the food support 24. When the pressure of the steam has reached a value of about 0.1 bar, opens a pressure relief valve 48 in the food support 24, which adjusts the pressure to the threshold. Depending on the desired pressure during steaming, the pressure relief valve 48 can be designed accordingly.

Another alternative, not explicitly shown here Gargutträger has a lid which rests against a flange of the food support. The cover and the flange of the food support together fill the gap between the rails 40, 42 and the carrier plate 36, 38 of the microwave oven arranged above each, so that the lid is pressed onto the flange by the carrier plate 36, 38. The food support is sealed pressure-tight in this way.

Figs. 1 to 5 show only embodiments of the invention. The person skilled in the art will generalize the invention in particular also to higher microwave ovens having more than two shelves, in each case coupling means according to the invention being arranged between two adjacent levels. In a further obvious generalization, more than two coupling means formed as coaxial or waveguides per plane will be provided. Furthermore, a modular design would be conceivable in which the microwave oven has a plurality of superposed, similar modules.

LIST OF REFERENCE NUMBERS

10

oven

12

Einkopplungsmittel

14

Einkopplungsmittel

16

Einkopplungsmittel

18

Einkopplungsmittel

20

Einkopplungsmittel

22

Einkopplungsmittel

24

food support

26

level

28

level

30

door

32

Coaxial interface

34

support plate

36

support plate

38

support plate

40

rail

42

rail

44

flange

46

be cooked

48

Pressure relief valve

50

connecting flange

52

connecting flange

Claims (15)

Microwave oven with a cooking chamber (10) and with at least one coupling means (12 - 22) for coupling microwaves in the cooking chamber (10), characterized in that in the cooking chamber (10) has several levels (26, 28) for arranging at least one food support (24) are provided, wherein at least one of the coupling means (12 - 22) between two adjacent planes (26, 28) is arranged. Microwave oven according to claim 1, characterized in that the coupling means (12-22) comprises a rod antenna. Microwave oven according to one of the preceding claims, characterized in that the coupling means (12-22) comprises a coaxial conductor. Microwave oven according to one of the preceding claims, characterized in that the coupling means (12-22) extends transversely through the cooking chamber (10) parallel to one of the planes (26, 28) for arranging the food support (24). Microwave oven according to one of claims 1 to 4, characterized in that the coupling means (12 - 22) is arranged stationarily in the cooking chamber (10). Microwave oven according to one of claims 1 to 5, characterized in that at least two coupling means (12 - 22) are arranged at least in pairs in a plane. Microwave oven according to one of claims 1 to 6, characterized in that the coupling means (12 - 22) between two opposite walls of the cooking chamber (10), in particular between the side walls, these connecting to each other. Microwave oven according to one of the preceding claims, characterized in that the coupling-in means (12-22) is incorporated in a carrier plate (34-38). Microwave oven according to claim 8, characterized in that the carrier plate (34 - 38) is formed of ceramic. Microwave oven according to one of claims 8 or 9, characterized in that the carrier plate (34 - 38) is designed for sealing a food support (24). Microwave oven according to one of the preceding claims, characterized by a connecting flange (50, 52) on a side wall of the cooking chamber (10), which is designed for feeding the microwave radiation in the coupling means (12 - 22). Microwave oven according to one of the preceding claims, characterized by at least two in the depth of the cooking chamber (10) arranged one behind the other, parallel input means (12-22) between the two adjacent planes (26, 28). Food support for insertion into a rack level (26, 28) of a microwave oven, wherein the food support (24) is formed such that it comes when inserted with a above the rack level (26, 28) arranged support plate (36, 38) to the plant, said the contact force closes the food support (24) pressure-resistant. Food support according to claim 13, characterized by a pressure relief valve (48) m. System consisting of a microwave oven according to one of claims 1 - 9 and at least one food support (24) according to one of claims 10 and 11.

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