Abstract:
A method for steam cooking in an oven having a heating device disposed in a bottom area utilizes a cooking container that can be placed in the oven and having a heat-conductive dish element for receiving a liquid supply and a steam tray disposed on the dish element for receiving a product to be cooked. Steam is produced from the liquid supply in the dish element by placing the heating device in the bottom area of the oven so that the steam flows around the product to be cooked on the steam tray to steam cook said product. To such an end, the dish element of the cooking container includes a holding device for disposing the dish element at a distance from the bottom of the oven. Preferably, the dish element divides the oven into two substantially separate spatial regions.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]     This application is a continuation, under 35 U.S.C. § 120, of copending international application No. PCT/EP03/01310, filed Feb. 10, 2003, which designated the United States; this application also claims the priority, under 35 U.S.C. § 119, of German patent application No. 102 06 690.6, filed Feb. 18, 2002; the prior applications are herewith incorporated by reference in their entirety. 
     
    
     BACKGROUND OF THE INVENTION  
     FIELD OF THE INVENTION  
       [0002]     The method relates to a steam cooker and to a method and configuration for steam cooking. European Patent Application EP 0 566 166 B1 discloses a generic steam cooker for the cooking of food in a specially constructed steam oven. The steam oven has an oven muffle, on the bottom of which a heating device is provided and which additionally possesses a water tank. For steam cooking, a steam cooker, which is configured as a closed cooking vessel and in which the food is disposed on a steam insert, is placed with its lower part, which serves as a water reservoir, onto the heating device of the oven muffle, the lower part being connected to the water tank. By the lower part of the cooking vessel being heated with the aid of the heating device, steam is generated, which, as a result of its buoyancy, rises upward and, at the same time, flows around the steamed food on the steam insert to cook the food. The steam, then, condenses partially on the colder surface of the food or on the top side of the cooking vessel, the condensate dripping back into the lower part. Because the cooking vessel is not completely leak tight, however, a large part of the steam escapes into the oven muffle. One disadvantage of this configuration of the steam cooker is that, for the steam operation, it is necessary to have a specially configured steam oven with an exposed heating device onto which the cooking vessel is placed directly for steam cooking. Furthermore, handling is complicated because the cooking vessel has to be connected manually to the water tank in the steam oven to ensure a sufficient supply of water for the cooking operation.  
         [0003]     European Patent EP 045817 B1 discloses a further steam cooker with a closed cooking vessel for the reception of food, in which the cooking vessel is pushed into a heatable oven muffle capable of being closed by an access door and the cooking vessel is, at the same time, connected to a steam generation device disposed outside the oven muffle. The oven muffle, together with the cooking vessel, is heated to a temperature of at least 100° C. in a heating phase. As a result, a condensation of the steam subsequently injected by the steam generation device for steam cooking is prevented. In such a configuration of the steam cooker, too, a special steam oven with an external steam generation device is, again, necessary, to carry out the steam generation operation.  
         [0004]     Moreover, German Utility Model GM 77 03 401 describes a steam cooker with a cooking vessel formed from a lower pot and a lid, in which, a steam insert for receiving the food is disposed, and, for steam cooking, externally generated steam is injected into at least one inlet orifice in the lid and is drawn off from at least one condensate orifice in the vessel bottom so that the steam flows positively through the food from the top downward.  
         [0005]     German Published, Non-Prosecuted Patent Application DE 37 14 324 A1 discloses, furthermore, a steam cooker for microwave ovens that has a vessel containing a water supply and in which a microwave-impermeable steam insert provided with steam passages is inserted, and has a likewise microwave-impermeable lid. During steam cooking, the water in the vessel of the steam cooker is heated with the aid of the microwaves in the microwave oven, flows through the food on the steam insert, and is, subsequently, discharged into the microwave oven through a pressure outlet lid.  
       SUMMARY OF THE INVENTION  
       [0006]     It is accordingly an object of the invention to provide a steam cooker and configuration and method for steam cooking that overcome the hereinafore-mentioned disadvantages of the heretofore-known devices and methods of this general type and that make it possible, in a conventional baking oven, to carry out a steam cooking operation that is simple to handle.  
         [0007]     With the foregoing and other objects in view, there is provided, in accordance with the invention, a steam cooker for steam cooking food in a baking oven having a bottom region, a bottom, and a heating device disposed in the bottom region, the steam cooker including a cooking vessel removably introduced into the baking oven and having a heat-conducting trough part for receiving a supply of liquid, the trough part having a holding device holding the trough part spaced apart from the bottom of the baking oven and a steam insert disposed on the trough part for receiving the food and, with the heating device, generating steam from the liquid supply that flows around the food on the steam insert.  
         [0008]     The steam cooker according to the invention for the steam cooking of food in a conventional baking oven, with a heating device in the bottom region, is distinguished by a heat-conducting trough part for receiving a liquid supply, on which is disposed a steam insert for the reception of food that, to be steam-cooked, has flowing around it steam generated from the liquid supply in the trough part. The trough part of the steam cooker is, in such a case, provided with a holding or spacing device to dispose the trough part so as to be spaced apart from the bottom of the baking oven and, consequently, from the heating device. By virtue of such a configuration, it is possible to carry out the steam cooking operation in a conventional baking oven with a standard heating device under the baking oven bottom because the configuration spaced apart from the baking oven bottom ensures that no heat accumulation occurs at the bottom of the baking oven, which accumulation would arise when the steam cooker is placed thereon directly, which could, then, lead to damage to the baking oven. It may be particularly advantageous if the steam cooker has no feet, but, instead, is held in holding devices provided on the side walls, the trough part being configured such that the baking oven is subdivided substantially into two space regions separate from one another.  
         [0009]     The configuration of the trough part for subdividing the cooking space of the baking oven into two space regions substantially separate from one another and disposed one above the other ensures, furthermore, that, during the steam cooking operation that is brought about by the heating device in the baking oven bottom, a temperature drop occurs in the oven muffle between the upper region and the lower region so that the steam that is generated in the trough part and flows around the food condenses in the upper region, in order, then, to be returned into the liquid supply in the trough part. The configuration ensures that there does not have to be any additional water tank or any steam injection in the roasting over because, due to the circulatory process, the liquid supply contained in the trough part is sufficient to conclude the cooking operation. The two space regions obviously do not, in such a case, have to be sealed off hermetically relative to one another.  
         [0010]     What has been the applies similarly to the configuration according to the invention for steam cooking with a steam cooker in the manner described above and with a baking oven having a separately switchable underheat heating device that is suitable for the use of the cooking operation according to the invention.  
         [0011]     In accordance with another feature of the invention, to achieve better heat transmission in the steam cooker, that side of the trough part that faces the baking oven bottom has a structured and/or dark construction to increase a heat-absorbing surface.  
         [0012]     In accordance with a further feature of the invention, for the simplified division of the two space regions in the baking oven, the holding device is configured as two guide rails that are disposed on opposite sides of the trough part and that can be pushed onto corresponding carrying elements formed in the baking oven sidewalls or disposed there. It is, in such a case, preferable, furthermore, that an outwardly angled edge of the trough part serves as guide rails. As a result, a holding device of simple configuration is achieved for the steam cooker. At the same time, as a result, the trough part can also be used, alternatively to the steam cooking operation, for a roasting operation in which the food is, then, disposed directly in the trough part without a liquid supply.  
         [0013]     In accordance with an added feature of the invention, the cooking vessel of the steam cooker is configured in two parts with an additional heat-insulating lid that possesses an inclined lid roof. Such a configuration ensures that the steam generated from the liquid supply in the trough part largely condenses on the heat-insulating and, therefore, colder lid, the lid inclination ensuring that the condensate is led back along the cooking vessel wall into the liquid supply quickly and reliably.  
         [0014]     In accordance with an additional feature of the invention, there is provided a depression, in which the lid is held securely, is provided peripherally in the edge region of the trough part.  
         [0015]     In accordance with yet another feature of the invention, the lid may have at least one steam outlet orifice to make the steam cooking operation in the steam cooker pressureless so that a complicated excess pressure device in the cooking vessel may be dispensed with. The introduction of a minimum quantity of water in the trough of, for example, 500 to 750 ml, is, therefore, sufficient to make it possible to carry out the steam cooking operation reliably. At the end of the steam cooking operation, unconsumed water is left behind in the trough and can be disposed of in a simple way.  
         [0016]     In such a case, preferably, orifices in the lid and/or in the trough part serve for steam outlet. The lid is, in such a case, preferably, provided with a hood-shaped lid roof disposed on four glass plates that serve as sidewalls, the glass plates being connected at the corners to battens that are shortened in relation to the height of the glass plates. Such a configuration gives rise to orifices through which steam can emerge between the trough part and the lid.  
         [0017]     In accordance with yet a further feature of the invention, the glass side wall plates have a lower edge and a sealing batten is disposed on each lower edge of the side wall plates, the sealing batten having a U-shaped receptacle slipping onto the lower edge and a sealing surface disposed opposite the U-shaped receptacle adapted to lie on the trough part.  
         [0018]     In accordance with yet an added feature of the invention, the trough part has a bottom and the steam insert has grips for handling by a user and a perforated plate with feet adapted to stand on the bottom of the trough part.  
         [0019]     In accordance with yet an additional feature of the invention, the trough part has a heat-absorbing surface and a side facing the bottom of the baking oven and the side has at least one of a structure and a heat-absorbing color increasing heat absorption of the heat-absorbing surface.  
         [0020]     With the objects of the invention in view, in a baking oven having a bottom region, a bottom, and a heating device disposed in the bottom region, there is also provided, a steam cooker for steam cooking food including a cooking vessel removably introduced into the baking oven and having a heat-conducting trough part for receiving a supply of liquid, the trough part having a holding device holding the trough part spaced apart from the bottom of the baking oven and a steam insert disposed on the trough part for receiving the food and, with the heating device, generating steam from the liquid supply that flows around the food on the steam insert.  
         [0021]     With the objects of the invention in view, there is also provided a baking oven, including a oven housing having a bottom region with a bottom and a separately switchable underheat heating device, a heating device disposed in the bottom region, and a steam cooker for steam cooking food having a cooking vessel removably introduced into the baking oven and having a heat-conducting trough part for receiving a supply of liquid, the trough part having a holding device holding the trough part spaced apart from the bottom of the baking oven and a steam insert disposed on the trough part for receiving the food and, with the heating device, generating steam from the liquid supply that flows around the food on the steam insert.  
         [0022]     According to the invention, the configuration for steam cooking is constructed such that the baking oven has a separately switchable underheat heating device in the bottom region. The use of only underheat during steam cooking ensures an optimum cooking process. Further, a baking oven control may be provided, with a “steam cooking” setting facility, in which, by an appropriate control of the underheat heating device, a desired temperature for the baking oven of 130° to 170° C., preferably, 150° C., can be set. Such a configuration ensures that a temperature of above 100° C. is reached reliably in the trough part spaced apart from the bottom of the baking oven to ensure the evaporation process. It is preferable to operate the baking oven without the steam cooker with a preheating phase of preferably 10 to 15 minutes in the region of the abovementioned desired temperature, to bring about, in the baking oven, a temperature drop in which substantially the desired temperature is established in the bottom region of the baking oven so that, when the steam cooker is pushed in, steam generation and, consequently, the cooking operation commence abruptly.  
         [0023]     With the objects of the invention in view, the steam-cooking setting includes a cooking phase with the steam cooker, the cooking phase having a duration dependent upon a food item to be cooked.  
         [0024]     In accordance with again another feature of the invention, the steam-cooking setting includes a cooking phase with the steam cooker, the cooking phase having a duration dependent upon a food item to be cooked.  
         [0025]     With the objects of the invention in view, there is also provided a method for steaming food in a baking oven having a heating device in a bottom region thereof, the method including the steps of providing a removable steam cooking vessel with a heat-conducting trough part for receiving therein a liquid supply and a steam insert for receiving food therein, the steam insert being disposed on the trough part, providing a liquid in the trough part and food to be steam cooked in the steam insert, introducing the cooking vessel in the baking oven with the trough part spaced apart from a bottom of the baking oven, and steam cooking the food by generating steam flowing around the food on the steam insert from the liquid supply in the trough part with aid of the heating device.  
         [0026]     In accordance with a concomitant feature of the invention, for a steam cooking operation, a cooking space of the baking oven is subdivided into two space regions substantially separate from one another.  
         [0027]     Other features that are considered as characteristic for the invention are set forth in the appended claims.  
         [0028]     Although the invention is illustrated and described herein as embodied in a steam cooker and configuration and method for steam cooking, it is, nevertheless, not intended to be limited to the details shown because various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.  
         [0029]     The construction and method of operation of the invention, however, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0030]      FIG. 1A  is an exploded perspective view of a steam cooker according to the invention;  
         [0031]      FIG. 1B  is a cross-sectional view through a trough part of the cooker of  FIG. 1A ;  
         [0032]      FIG. 1C  is a fragmentary, enlarged, cross-sectional view through a sealing batten slipped onto a side part of a lid of the steam cooker of  FIG. 1 ;  
         [0033]      FIG. 2A  is a front elevational view of a steam cooking configuration according to the invention with the steam cooker of the invention pushed therein; and  
         [0034]      FIG. 2B  is a cross-sectional, diagrammatic side view and a partially block circuit diagram of an embodiment of the steam cooker according to the invention  FIG. 2   b  illustrating the baking oven with the steam cooker.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0035]     Referring now to the figures of the drawings in detail and first, particularly to  FIG. 1  thereof, there is shown a steam cooker has a cooking vessel  1  with a trough part  10  and with a lid  20 . The trough part  10  serves for receiving a liquid supply, in particular, water, and, as the cross-section in  FIG. 1B  shows, has a bottom  11  that has a, preferably, waffled-shaped construction. The waffle-shape achieves an increased bottom surface and, therefore, heat-absorbing surface, thus ensuring that the trough part has improved heat absorption. Alternatively to a waffle structure, there is also the possibility of providing another type of bowed structure in the bottom of the trough part  10  to achieve such an increased heat-absorbing surface. Furthermore, the bottom  11  of the trough part  10  is, preferably, produced from a highly heat-conducting material. As a result, heat absorption is further improved. The bottom  11  of the trough part  10  is, preferably, dark and, thus, acts as a black radiator. As a result, heat absorption is increased.  
         [0036]     A peripheral edge  18  of the trough part  11  is angled on all sides perpendicularly outward, the edge  18  being configured with two steps so that a depression  19 , which serves as a support and sealing surface for the lid  20 , is formed all-around in a side facing the cavity in the trough part. The edge  18  is, preferably, configured to be widened on the two narrow sides of the substantially rectangular trough part  11  to serve as holding elements that can be placed or pushed onto corresponding carrying elements in a baking oven. As shown in the embodiment in  FIGS. 2A and 2B , these carrying elements may be push-in grooves  51  on a baking oven wall  55 . The widened edge  18  of the trough part  10  can be pushed into the grooves  51 .  
         [0037]     Instead of such push-in grooves  51 , however, carrying frames, for example, telescopic pull-outs in the baking oven  5 , may also be used for carrying the trough part  10  in its widened edge region  18 . Alternatively to the configuration of the widened edge as holding elements for the trough part  10  and, consequently, the cooking vessel  1  of the steam cooker, spacers, for example, in the form of four feet disposed on the bottom  11  of the trough part  10 , may also be provided.  
         [0038]     As shown in  FIG. 1A , furthermore, there is provided on the longitudinal sides of the edge  18  a bent portion  17  that, preferably, extends vertically downward and that serves as a handle so that the cooking vessel can be pulled out of the baking oven in a simple way at the trough part. The overall surface of the trough part  10  of the cooking vessel  1 , preferably, corresponds to the bottom surface of the baking oven  5  so that, with the cooking vessel  1  pushed in, the trough part  10  subdivides the baking oven  5  into two space regions  52 ,  53  substantially separate from one another, as shown in  FIGS. 2A  and B.  
         [0039]     A steam insert  30  spaced apart by feet  33  may be provided in the trough part  10  of the cooking vessel  1 . The steam insert  30  is, preferably, manufactured from plastic or high-grade steel and has a horizontal supporting plate  31  that is provided with a matrix-shaped configuration of passage holes  32  through which steam can pass. The food can be disposed on the supporting plate  31 . The large continuous surface of the supporting plate  31  makes it possible to cook even large items of food here. The supporting plate  32  is drawn up at its edges  34  to ensure that the food cannot slip off from the supporting plate  32  when the steam insert  30  is being taken out of or introduced into the trough part  10 . To ensure that the steam condensing on the steam insert  30  or on the food can flow back into the liquid supply in the trough part  30 , the edge  34  is perforated laterally. For the simple handling of the steam insert  30 , in particular, the insertion into and removal from the trough part  10 , furthermore, bow-shaped grips  36  are provided on the narrow sides. The height of the feet  33  on the supporting plate  31  is coordinated so as to give rise, between the supporting plate  31  and the bottom  11  and trough part  10 , to a cavity that makes it possible to receive at least one liter of liquid, this amount being sufficient for the steam cooking of even heavy and bulky food.  
         [0040]     A second cooking level can be provided on the steam insert  30  with the aid of a carrying frame  37 . The carrying frame  37 , in such a case, preferably, has a horizontal framework  38  that is formed from four tubes and that is carried by four vertical tubes  39  disposed on the framework. These tubular feet  39  can be inserted, preferably, into the steam passage holes  32  in the supporting plate  31  of the steam insert  30 . The narrow sides of the framework  38  have, provided on them laterally in each case, bow-shaped grips  40  by which the carrying frame  37  can be handled in a simple way. Furthermore, the bow grips  40  are, preferably, connected through a transverse strut  41  that is disposed above the framework and onto which an outwardly angled edge  42  of a cooking vessel  43 , which is carried with its bottom by the framework  38  of the frame  37 , can be placed. In the embodiment shown, two cooking vessels  43  can be disposed next to one another on the frame  37 , a secure hold of these cooking vessels being ensured by two humps  45  into which a clearance  44  disposed on the cooking vessel  41  can engage.  
         [0041]     The lid  20  of the cooking vessel  1  is composed of four sidewalls  21  that are, in each case, of a glass plate and on which is disposed a hood-shaped lid roof  42  descending on two sides. The sidewalls  21  of the lid, which are of glass or are, alternatively, manufactured from pressed glass or PSU-like plastic, are connected to one another by battens  23 . These battens  23 , preferably, manufactured from metal, are configured to be somewhat shorter than the sidewalls  21  so that, with the lid  20  inserted into the depression  19  on the trough part  10 , orifices are obtained, through which steam can escape from the cooking vessel  1 . These orifices serve for keeping the cooking vessel pressureless during the cooking operation. As a result, a complicated excess pressure valve device may be dispensed with. However, the steam orifices may also be disposed at any other desired point on the lid  20  or in the upper region of the trough part  10 .  
         [0042]     Furthermore, a sealing batten  24 , which leaves the corner battens  23  free, is placed in each case on the lower edge of the sidewalls  21 . A cross-section through these sealing battens  24  placed onto the sidewalls  21  of the lid  20  is shown in  FIG. 1C . The sealing batten  24  is configured such that it has a U-shaped recess  25  having substantially the width of the sidewall, for slipping onto this sidewall  21 , and a lower, preferably slightly concavely shaped plane sealing surface  26  that, with the lid  20  placed on, sits on the depression  19  on the trough part  10  and, due to the deadweight of the lid  20 , ensures reliable sealing so that steam outlet orifices remain in the corner batten region. Alternatively, there is also the possibility of manufacturing the lid as a molding, for example, from a transparent plastic, in which case the venting recesses may, then, be incorporated at any desired point.  
         [0043]     Apart from the sidewalls  21 , the hood-shaped lid roof  22  may also be manufactured from glass, thus, affording a clear view of the food during the steam operation. Alternatively, however, there is also a possibility of manufacturing the lid  20  from another material that, however, should, preferably, be heat insulating in a similar way to glass—in which case, an inspection hole for a view of the food is provided in the sidewall or in the lid, the inspection hole, preferably, being in the form of an eye to provide an increased viewing angle. Alternatively to a hood-shaped lid inclined on two sides, there is also the possibility of constructing the lid in the form of a penthouse roof or with any other desired roof shape in which the lid roof is inclined to divert the condensing steam to the sidewalls.  
         [0044]     The cooking operation with the steam cooker illustrated in  FIG. 1  is explained below with reference to  FIGS. 2A and 2B . For steam cooking, the trough part  10  of the cooking vessel  1  is filled with a liquid supply, liquid quantity amounting to between 500 and 1000 ml. For improved handling, a line marking, indicating the height of the liquid quantity introduced, may be provided on the trough part  10  for such a purpose. The steam insert  30  provided with the food is, then, inserted into the trough part  10  of the cooking vessel  1 , and, if appropriate, a second food level is formed by the frame  37  having the cooking vessels  43  that may, likewise, contain food. The lid  20  is, then, placed onto the trough part  10  to close the cooking vessel  1 . At the same time, the baking oven is preheated. The baking oven may be a conventional baking oven with a separately switchable underheat heating device  56  disposed under the bottom.  
         [0045]     The underheat heating device  56  is, then, set to a desired temperature of between 130° C. and 170° C., preferably, to 150° C., and is preheated for 10 to 15 min. so that a temperature drop is obtained in the baking space, a temperature of approximately 150° C. being obtained in the region of the lowest push-in level in which the trough part  10  is pushed in with its widened edge  18 . After the preheating phase, the steam cooker is, then, pushed into the baking oven muffle, the trough part  10  being inserted into the lowermost push-in level and dividing the baking oven into two space regions substantially separate from one another, the space region  52  with the bottom of the trough part  10  and the space region  53  with the lid  20 . What is achieved by the preheating phase is that the heat-conducting bottom  11  of the trough part  10  with the liquid supply is heated substantially immediately to 100° C., as a result, evaporation commences immediately. This steam, then, rises automatically and passes through the steam passage holes  32  of the steam insert  30  and flows around the food lying on the latter and the food disposed in the cooking vessels  44  on the second cooking level lying thereabove to steam-cook the food.  
         [0046]     The steam, then, condenses partially on the cooler surfaces of the food and drips back into the trough part  10 , and the remaining steam rises as far as the lid roof  22  and condenses, here, and is, then, returned substantially along the sidewalls  21  of the lid  20  to the trough part  10 . Furthermore, a small part of the steam escapes through the steam orifices in the lid  20  into the upper space part  53  of the baking oven muffle, the steam outlet being such that, during a cooking process with a desired temperature of 130° C. to 170° C., preferably, 150° C., a cooking operation of up to 1.5 hours is possible, without the entire liquid supply evaporating out of the steam cooker and escaping into the baking oven muffle.  
         [0047]     The cooking operation, with the steam cooker pushed in the baking oven, is shown in a front view in  FIG. 2A  and in a lateral cross-section in  FIG. 2B . In the version illustrated, an additional setting knob  58  for steam-cooking setting is provided next to the conventional setting knobs  57  for the baking oven. By such a steam-cooking setting, the type of food can, preferably, be preset so that the steam-cooking setting, then, automatically adapts the length of the cooking operation to the food. Alternatively, however, there may also be provision for setting the length of the cooking operation manually by a time clock. Furthermore, a steam-cooking monitoring device  59  may be configured such that it emits an acoustic or optical signal after the end of the preheating operation to indicate to the operator that he is, then, to introduce the steam cooker into the baking oven to initiate the cooking operation.  
         [0048]     To monitor the desired temperature, the steam-cooking monitoring device  59  is connected to a temperature sensor  60  located in the baking oven muffle and, preferably, disposed below the lowermost push-in level, to measure the temperature and to set the heating power of the underheat heating device  56  correspondingly. The end of the steam-cooking phase can, then, be indicated to the user again by an acoustic or optical signal from the steam-cooking monitoring device  59 . Furthermore, the steam-cooking monitoring device may be configured such that the underheat heating device  56  is, then, switched off automatically.  
         [0049]     Furthermore, alternatively to a steam cooking operation, the cooking vessel may also be used for a roasting operation, in which the trough part, then, does not contain a liquid supply. The food can, then, be laid directly onto the trough bottom or, else, onto the steam insert, and the roasting operation can be carried out with or without the lid.