Cooking Device with Two Zones in the Cooking Cavity

This patent application is a U.S. National Stage Patent Application of International Patent Application No. PCT/EP2022/061698, filed May 2, 2022, which is incorporated herein by reference in its entirety.

The present disclosure relates to a cooking device, in particular a steam oven, comprising a cooking cavity and a heating cavity.

The air within a cooking cavity of a cooking device, in particular a steam oven, is heated by heating elements. Typically, the cooking device comprises one or more fans, wherein each fan is enclosed by a ring heater to heat the air that is circulated by the fans. The heating elements and the fans are arranged in a heating cavity, e.g. at the back side of the cooking cavity. The cooking cavity and the heating cavity are separated by a separating wall arranged between the cooking cavity and the heating cavity. Ventilation openings are located at the separating wall.

Cooking devices are known with one cooking cavity divided into two cooking zones. The two cooking zones are arranged on top of each other and separated by a baking tray or another horizontal physical wall inside the cooking cavity. The cooking cavity can be heated such that the air temperature in the first cooking zone is different to the air temperature in the second cooking zone. Two different foods can be cooked in the two cooking zones.

The exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings. Elements, features and components that are identical, functionally identical and have the same effect are—insofar as is not stated otherwise—respectively provided with the same reference character.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the present disclosure. However, it will be apparent to those skilled in the art that the embodiments, including structures, systems, and methods, may be practiced without these specific details. The description and representation herein are the common means used by those experienced or skilled in the art to most effectively convey the substance of their work to others skilled in the art. In other instances, well-known methods, procedures, components, and circuitry have not been described in detail to avoid unnecessarily obscuring embodiments of the disclosure. The connections shown in the figures between functional units or other elements can also be implemented as indirect connections, wherein a connection can be wireless or wired. Functional units can be implemented as hardware, software or a combination of hardware and software.

An object of the present disclosure is to provide an improved cooking device that creates different temperatures within the cooking cavity of the cooking device.

The disclosure relates to a cooking device, in particular a steam oven, which may comprise:

The first fan may be positioned and configured to collect air from the cooking cavity and to generate a first airflow interacting with the heating unit and being conveyed back into a first part of the cooking cavity and the second fan may be positioned and configured to collect air from the cooking cavity and to generate a second airflow interacting with the heating unit and being conveyed back into a second part of the cooking cavity. The first airflow and the second airflow are two separate airflows.

“Interacting” is understood as the airflow entering into a heat exchange with the given heating element.

The cooking device may further comprise a control unit (controller) configured to operate the first fan and the second fan independently from each other. For example, the control unit may increase the power of one fan while keeping the power of the other fan constant or decreasing, or vice versa.

This allows to feed a first airflow and a second airflow with two different flow rates from the heating cavity back into the cooking cavity. For example, if the first airflow has a higher flow rate compared to the second airflow, the first airflow will occupy a higher volume in the cooking cavity compared to the second airflow. This increases the size of the first part of the cooking cavity and decreases the size of the second part of the cooking cavity. On the other hand, if both, the first airflow and the second airflow, have the same flow rate, the first part and the second part of the cooking cavity will have the same size.

If the first airflow and the second airflow are heated on different temperatures, the foodstuff arranged in the first part of the cooking cavity and foodstuff arranged in the second part of the cooking cavity are cooked with different temperatures. If the first airflow has a higher flow rate and a higher temperature compared to the second flow rate, more volume of the cooking cavity is tempered on the higher temperature than on the lower temperature because the first part of the cooking cavity with the higher temperature has a larger volume than the second part of the cooking cavity with the lower temperature.

With other words, the described cooking device may comprise a cooking cavity divided into two different parts. Different food can be cooked on different temperatures in these two parts. The size of the two parts can be varied such that smaller or lager foodstuff can be arranged side by side in the cooking cavity and be cooked on different temperatures. For example, if a larger foodstuff is cooked in the first part and a smaller foodstuff is cooked in the second part, the power of the first fan is set higher than the power of the second fan. The volume of the first part is larger than the volume of the second part in the cooking cavity.

An advantageous embodiment of the present disclosure refers to a cooking device that is operated as a steam oven. In that case, the device may comprise a steam generator. In such an embodiment, all parts and processes are advantageously designed to be used in a highly humid environment. In particular, the fan, the first and second heating element, as well as any deflector, if present, may be of materials resistant against humidity, e.g. at least some of these parts may be formed (at least at their surfaces) from stainless steel.

Advantageously, the heating unit may comprise a first heating element and a second heating element, which both may be positioned and configured such that the first airflow interacts with the first heating element and that the second airflow interacts with the second heating element. In particular, the heating elements can be arranged around the fans and/or the first heating element and the second heating element can be part of one single heating element.

In particular, the control unit may be configured to operate the first heating element and the second heating element independently from each other, i.e. the heating elements can be operated with different power. This allows to keep the first part and the second part of the cooking cavity on different temperatures. Both the volume and the temperatures of the first part and the second part can be varied independently.

In at least one mode of operation of the device, the control unit may be configured to maintain the temperature difference between the first airflow and the second airflow, as the airflows exits the heating cavity, at at least 20° C., in particular at at least 50° C., very particular at at least 100° C. This allows to maintain a substantial temperature gradient in the heating cavity.

Advantageously, the cooking device may comprise a separating element separating the heating cavity in two parts such that the first airflow interacts only with the first heating element and the second airflow interacts only with the second heating element in the heating cavity. The separating element completely separates the first airflow and the second airflow in the heating cavity such that flow rate and temperature of the two airflows can be better controlled.

In particular, the power of the first fan and the second fan are controlled by controlling a DC motor or a dropping resistor.

Advantageously, the cooking device may comprise two or more temperature sensors arranged in the cooking cavity. In particular, a first of said temperature sensors is arranged in a left half of the cooking cavity and a second of said temperature sensors is arranged in the right half of the cooking cavity. “Right” and “left” means from the perspective of a user looking through the cooking cavity opening or through the door of the cooking device into the cooking cavity. In particular, the temperature sensors are arranged at the top wall of the cooking cavity.

Furthermore, the first and the second temperature sensors are spaced from each other not more than 400 mm, in particular not more than 200 mm. These sensors are arranged close to the center of the cooking cavity such that the temperature in the transition area between the first part and the second part can precisely be measured. It can be detected where the transition area is located, since the volume of the first part and the second part can be varied.

Furthermore, the cooking device can comprise:

The grill elements and/or the steam inlets and/or the bottom/top heating elements can be operated independently from each other.

Advantageously, the cooking device may comprise a first lighting device arranged in the first part of the cooking cavity and a second lighting device arranged in the second part of the cooking cavity. Both the first part and the second part can be illuminated independently.

In particular, if the user sets parameters, e.g. temperature or volume, of the first part, the first lighting device is active and the second lighting device is inactive. If the user sets parameters of the second part, the second lighting device is active and the first lighting device is inactive.

Advantageously, a first part of the ventilation openings is arranged in the first part of the cooking cavity. The first airflow flows only through the first part of the ventilation openings. A second part of the ventilation openings is arranged in the second part of the cooking cavity. The second airflow flows only through the second part of the ventilation openings. The arrangement of ventilation openings in both parts of the cooking cavity allows to guide both airflows separate from each other in the first and second part of the cooking cavity.

In particular the ventilation openings arranged in the first part of the cooking cavity are arranged only in the outer half of the first part of the cooking cavity and the ventilation openings arranged in the second part of the cooking cavity are arranged only in the outer half of the second part of the cooking cavity. The arrangement of the ventilation openings in the cooking cavity allows a clear separation of the first airflow and of the second airflow in the cooking cavity.

Advantageously, the cooking device may be configured such that the cooking temperature in the first part and in the second part can be set separately, i.e. individually, in particular by the user. The user can define different temperatures for the first part and the second part and cooking different foodstuff inside one single cooking cavity in different atmospheres.

In particular, the cooking device may be configured such that power of the first fan and the power of the second fan can be set separately, i.e. individually, in particular by defining the size of the first part and the second part, and/or by the user. For example, the user can define that the first part has a volume of two-thirds of the whole cooking cavity volume and the second part has a volume of one-third of the whole cooking cavity volume, or vice versa. Alternatively, the user can define that the first part and the second part have equal volume, i.e. the transition area between the first part and the second part is located in the center of the cooking cavity.

In particular, the first part and the second part of the cooking cavity are arranged horizontally side by side. For example, the first part is located on the left side and the second part is located on the right side of the cooking cavity. Advantageously, the cooking cavity consists only of the first part and the second part of the cooking cavity.

In a further exemplary embodiment, the first part and the second part of the cooking cavity are defined such that the border, i.e. the transition area, between the first part and the second part is a vertical plane dividing the cooking cavity in a left part and a right part, wherein the first part is the left part and the second part is the right par.

In particular, the cooking cavity does not comprise a separating physical wall separating the cooking cavity into two parts, in particular into the first part and the second part of the cooking cavity.

andshow a front view of the cooking device.shows a top view of the cooking device. The terms “left”, “right”, “behind”, “top”, “bottom” are understood from the perspective of a user with a front view as shown inor. The front of the cooking deviceis defined as the position where the doorof the cooking device is arranged.

The cooking devicemay comprise a cooking cavityand a heating cavity. The heating cavityis arranged behind the cooking cavity. A separating wallseparates the cooking cavityand the heating cavity. The separating wallmay comprise first ventilation openingsarranged in the center of the separating walland second ventilation openingsarranged close to the side walls of the cooking cavity. Airflow leaves the heating cavitythrough the second ventilation openingsinto the cooking cavityand returns through the first ventilation openingsinto the heating cavity.shows arrowsillustrating the airflow through the separating wall.

A first fanand a second fanare arranged in the heating cavitybehind the separating wall. The first fanis arranged on the left side and the second fanis arranged on the right side of the cooking device. A heating unit (heater)comprising a first heating elementand a second heating elementis arranged around the first fanand around the second fan. The heating elementsandare connected with a control unit (controller)via connecting elements.

The first fanmay be positioned and configured to collect air from the cooking cavityand to generate a first airflowinteracting with the first heating elementin the heating cavity. The second fanmay be positioned and configured to collect air from the cooking cavityand to generate a second airflowinteracting with the first heating elementin the heating cavity.

With other words, the first airflowflows from the cooking cavitythrough the first ventilation openingsarranged in the center of the separating wallinto the heating cavityand is heated by the first heating element. After being heated, the first airflowreturns into the cooking cavitythrough the ventilation openingsarranged close to the left side wall of the cooking cavity. The second airflowflows from the cooking cavitythrough the first ventilation openingsarranged in the center of the separating wallinto the heating cavityand is heated by the second heating element. After being heated, the second airflowreturns into the cooking cavitythrough the ventilation openingsarranged close to the right side wall of the cooking cavity.

Furthermore, the heating cavitymay comprise a separating elementarranged in the middle of the heating cavity. The separating elementdivides the heating cavityin a first partarranged on the left side of the cooking deviceand in a second partarranged on the right side of the cooking device. The separating elementavoids any interaction between the first airflowand the second airflowinside the heating cavity. The first airflowis only heated by the first heating elementand the second airflowis only heated by the second heating element.

The cooking devicemay comprise a control unit (controller)arranged above the cooking cavity. The control unitmay include one or more processors and/or circuitry configured to perform the function(s) of the control unit. The control unitmay be configured to control the first fanand the second fanindependently from each other. Additionally, or alternatively, the control unitmay be configured to control the first heating elementand the second heating elementindependently from each other. With other words, the first airflowcan be heated to a different temperature than the second airflowand the first airflowcan be conveyed into the cooking cavitywith a different flow rate than the second airflow.

In order to define and understand the disclosure, the cooking cavityis divided in a first partand a second partof the cooking cavity. The First partis arranged on the left side and the second partis arranged on the right side of the cooking cavity, i.e. the first partand the second partare arranged side by side. The first airflowenters through the ventilation openingsarranged close to the left side wall into the first partof the cooking cavity. The second airflowenters through the ventilation openingsclose to the right side wall into the second partof the cooking cavity. The boundaryseparating the first partand the second partis shown by a dashed line in. The boundaryis not a physical wall but a virtual, vertical plane dividing the cooking cavityin a left part and in a right part.

shows a situation where a user cooks bread in the first partand chicken in the second partof the cooking cavity. Bread is optimally cooked with a temperature of 180° C. and chicken is optimally cooked with a temperature of 220° C. In this situation, the control unitoperates the first heating elementwith less power than the second heating element. The first airflowenters the cooking cavitywith a lower temperature than the second airflow.

As shown in, bread uses more space inside the cooking cavitythan chicken. In order to provide an optimal cooking atmosphere for both bread and chicken, the control unit operates the first fanwith more power than the second fan. The first airflowenters the cooking cavitywith a higher flow rate than the second airflow. Due to the higher flow rate, the first airflow occupies more volume inside the cooking cavitythan the second airflow. This is illustrated by the virtual boundarynot arranged exactly in the middle of the cooking cavitybut displaced from the middle to the right for a certain distance. With other words, the first partof the cooking cavityrepresenting the space for the first airflowis bigger than the second partrepresenting the space for the second airflow. The different flow rates of the airflowsandare illustrated by arrowsandinside the cooking cavity.

shows a situation where a user cooks fish in the first partand carrots in the second partof the cooking cavity. Fish is optimally cooked with a temperature of 205° C. and carrots are optimally cooked with a temperature of 160° C. In this situation the control unitoperates the first heating elementwith more power than the second heating elementand the control unit operates the first fanwith less power than the second fan. This configuration provides a first airflowwith a higher temperature and a lower flow rate compared to the second airflow. The first partof the cooking cavity is smaller than the second part.

shows a situation where a user cooks bread in the first partand carrots in the second partof the cooking cavity. Bread is optimally cooked with a temperature of 180° C. and carrots are optimally cooked with a temperature of 160° C. In this situation the control unitoperates the first heating elementwith a little bit more power than the second heating elementand the control unit operates both the first fanand the second fanon the same power level. This configuration provides a first airflowwith a higher temperature compared to the second airflow. The flow rate is identical. The first partof the cooking cavity has the same size than the second part.

The user can define different settings for the cooking process. First of all, the user defines if he wants to cook with one unique atmosphere inside the cooking cavityor with two different atmospheres as described above. If the user cooks with two different atmosphere, he defines for both the first partand the second parttemperature and volume, i.e. the size of the first partand the second part. For example, the user defines to cook with a temperature of 160° C. in the first partand to cook with a temperature of 200° C. in the second part. Regarding the volume of the first partand the second part, the user can define that the foodstuff arranged in the first partoccupies more space in the cooking cavitythan the food stuff arranged in the second part. The user defines a larger size for the first partand a smaller size for the second partinside the cooking cavity. In this case, the control unitoperates the first fanwith more power than the second fan.

In order to better control the air temperature close to the boundary, the cooking cavitymay comprise three temperature sensors,,arranged at the top wall of the cooking cavityclose to the middle of the cooking cavity. The first temperature sensoris arranged in the left half of the cooking cavity, the second temperature sensoris arranged in the right half of the cooking cavityand the third temperature sensoris arranged in the middle of the cooking cavity. All of these three sensors,,are arranged close to each other. The first temperature sensoris spaced 150 mm from the second temperature sensor.

Depending on the measured temperatures, the control unitcan vary the power of the fans,and of the heating elementsand. The control unitmust ensure that in average the air in the first partand the air in the second partare on the required temperature level. On the other hand, the control unit must ensure that the boundaryis located where defined by the user. The boundaryis located where the temperature sensors measure the highest temperature gradient. The highest temperature gradient can be identified by interpolating the signals of the temperature sensors,,,.

In order to further improve the individual atmospheric parameters in the first partand the second partof the cooking cavity, individual grill elements, steam inletsand bottom/top heating elementsare provided for the first partand the second partof the cooking cavity. Grill elements, steam inletsand bottom/top heating elementcan be controlled individually by the control unit.

Furthermore, individual lighting devicesare arranged at the top wall in the left half and in the right half of the cooking cavity. If the user sets parameters for the first part, the lightning devicearranged in the left half of the cooking cavityis active and the lightning devicearranged in the right half of the cooking cavityis inactive. If the user sets parameters for the second part, the lightning devicearranged in the right half of the cooking cavityis active and the lightning devicearranged in the left half of the cooking cavityis inactive. This configuration visualizes to the user for which part the parameters are set.