Patent Description:
An example of an application for the invention is a domestic kitchen multifunctional steam oven having an active air inlet for pressure and/or humidity regulation.

Some modern domestic kitchens include various kinds of ovens such as, for example, conventional ovens, microwave ovens, convection ovens, and steam ovens. With steam ovens increasing in popularity in recent years, and with limited space in many kitchens, combination ovens that are multifunctional are very useful. A multifunctional steam oven and conventional oven (or steam oven and some other type of oven) can provide versatility in a compact space. <CIT> and <CIT> are examples of such multifunctional steam ovens.

Applicants recognized a problem that can exist with some multifunctional steam ovens in that proper venting of the oven cavity after a steam mode can be difficult and/or time consuming. Applicants also recognized that proper venting can greatly increase cooking performance.

Applicants solved this problem with embodiments of the invention.

The invention achieves the benefit of providing a combination steam oven while also addressing the venting problem mentioned above. Embodiments of the invention provide an active inlet that is controlled such that it is closed during a steam mode and open during a conventional cooking mode.

Embodiments of the invention are based on the inventors' recognition that an active inlet that can be closed and opened depending on the cooking mode provides great benefits with regard to humidity control.

Particular embodiments of the invention are directed to a domestic home cooking appliance that uses steam to heat a food item. The appliance includes a cooking chamber configured to receive the food item; a steam generator configured to generate the steam to heat the food item; a heating element configured to generate heat to heat the food item; an exhaust outlet that fluidly connects the cooking chamber to a first external environment outside of the cooking chamber; and an active inlet that fluidly connects the cooking chamber to a second external environment outside of the cooking chamber. The active inlet has a blocking member that prevents a fluid from the second external environment from entering the cooking chamber though the active inlet, and an actuator that moves the blocking member between a closed position in which the blocking member prevents the fluid from entering the cooking chamber through the active inlet, and an open position in which the blocking member allows the fluid to enter the cooking chamber through the active inlet.

In some embodiments the controller includes programming that controls the steam generator to generate steam to heat the food item during a first heating mode, the generated steam being the only source of heat that heats the food item during the first heating mode, and the controller includes programming that controls the heating element to generate heat to heat the food item during a second heating mode, the generated heat being the only source of heat that heats the food item during the second heating mode.

Other embodiments of the invention are directed to a method of controlling humidity in a domestic home cooking appliance. The method includes providing a cooking chamber that receives the food item; providing a steam generator that generates the steam to heat the food item; providing a heating element that generates heat to heat the food item; providing an exhaust outlet that fluidly connects the cooking chamber to a first external environment outside of the cooking chamber; providing an active inlet that fluidly connects the cooking chamber to a second external environment outside of the cooking chamber, the active inlet having a blocking member and an actuator that moves the blocking member between an open position and a closed position; preventing a fluid from the second external environment from entering the cooking chamber through the active inlet by moving the blocking member to the closed position; and allowing the fluid to enter the cooking chamber through the active inlet by moving the blocking member to the open position.

Some embodiments further include generating steam with the steam generator to heat the food item during a first heating mode, the generated steam being the only source of heat that heats the food item during the first heating mode, and generating heat with the heating element to heat the food item during a second heating mode, the generated heat being the only source of heat that heats the food item during the second heating mode.

The following figures form part of the present specification and are included to further demonstrate certain aspects of the disclosed features and functions, and should not be used to limit or define the disclosed features and functions. Consequently, a more complete understanding of the exemplary embodiments and further features and advantages thereof may be acquired by referring to the following description taken in conjunction with the accompanying drawings, wherein:.

The invention is described herein with reference to the accompanying drawings in which exemplary embodiments of the invention are shown. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

As explained above, embodiments of the invention provide a solution to the problems associated with multifunctional steam ovens that have a steam mode and another cooking mode, such as, for example, a conventional heating mode, a convection heating mode, or a microwave mode.

<FIG> shows an example of a multifunctional oven <NUM> that can operate as a steam oven and a conventional oven. Oven <NUM> has a main body <NUM> and a door <NUM> that provides access to a cooking chamber <NUM> (<FIG>). Door <NUM> has, in this example, a handle <NUM> by which a user can open door <NUM>. In this example, oven <NUM> has a control panel <NUM> that includes user operable controls for, among other things, mode selection, cooking duration, cooking temperature, and power level. A display <NUM> is provided to supply information to the user such as, for example, mode, temperature, time remaining, and other information. Display <NUM> can also include touchscreen or other types of controls. Also shown in <FIG> is an inlet hole <NUM> that provides access to air outside of oven <NUM>.

<FIG> shows oven <NUM> with door <NUM> removed for clarity. Inlet hole <NUM> is fluidly connected to an active inlet <NUM> by a tube or other conduit <NUM>. Although not shown in <FIG>, conduit <NUM> can include a fan or other air mover to induce air flow from outside oven <NUM>, into inlet hole <NUM>, through conduit <NUM>, out of active inlet <NUM>, and into cooking chamber <NUM>. The function and purpose of active inlet <NUM> will be described in more detail below. In this example, cooking chamber <NUM> has two side walls <NUM>, a bottom surface <NUM>, a top surface <NUM>, and a back wall <NUM>. Cooking chamber <NUM> has a vent <NUM> located, in this example, in top surface <NUM>. Vent <NUM> can be an exhaust vent or a two directional vent that also allows air from outside cooking chamber <NUM> to enter or exit cooking chamber <NUM>. Vent <NUM> can be attached to a conduit (not shown) to connect vent <NUM> to a space inside main body <NUM> and/or to the environment outside of main body <NUM>. Similarly, active inlet <NUM> can be connected to a space inside main body <NUM> and/or to the environment outside of main body <NUM> by conduit <NUM> or some other conduit.

Multifunction ovens in accordance with embodiments of the invention have a steam generator and some other type of cooking apparatus such as, for example, a conventional heating element, a convection system, a microwave system, an induction heating system, or some other type of cooking system. In the example shown in <FIG>, multifunctional oven <NUM> has a steam generator <NUM> and two conventional heating elements <NUM>, <NUM>. Steam generator <NUM> and conventional heating elements <NUM>, <NUM> are shown schematically and the exemplary locations and number are not limiting. The term "heating element" as used in this specification and claims is understood to include any type of non-steam generating heating or cooking device including, but not limited to, a conventional heating element, a convection system, a microwave system, and/or an induction heating system.

Embodiments of the invention include a steam oven which operates in what is referred to as "full steam" mode, which is understood to mean <NUM>% relative humidity with little or no over pressure (pressure inside the cooking chamber that is above atmospheric pressure outside of the cooking chamber. Steam oven in accordance with embodiments of the invention also operate in steam assist or partial steam modes where steam is added to normal cooking modes (those that do not include steam). Cooking chambers that operate in full steam mode are sealed to prevent electrical and other components from damage resulting from exposure to moisture. These ovens can be multifunctional ovens which also have normal heating modes like, for example, bake and convection. As a result of this sealed cavity it can be difficult to develop normal heating modes (those that do not include steam). It can be difficult to properly vent the moisture that needs to be removed from the cooking chamber, even if an active exhaust vent is provided. The term "active" when used with an exhaust, inlet, or other vent is understood to mean an opening that can be closed or opened. The closing or opening can be achieved automatically or manually by a user, a spring or other mechanism, or a control system of the oven. For example, an active exhaust or inlet can be opened or closed by an electric actuator that is controlled by an electronic controller in the oven as a result of the current operational mode.

Some embodiments of the invention contain an active inlet in the appliance which opens and closes actively or even automatically, depending on the pressure inside the cooking chamber. A purpose of the active inlet is to reduce the humidity during normal heating modes by introducing fresh air into the cooking chamber. An exhaust outlet can be, for example, connected to the under-pressure side of a convection fan and can create constant under pressure. The under-pressure can cause outside air to be drawn into the cooking chamber through the open active inlet and out of the exhaust vent, thereby reducing the humidity level in the cooking chamber.

A further advantage of an active inlet is that the moisture can be removed at a specific point of time if, for example, a user wants a crust on a baking good at the end of an automatic program or heating mode. Another advantage of an active inlet is that it facilitates drying the cooking chamber with heat by allowing necessary fresh air into cooking chamber. By having an active inlet, embodiments of the invention provide flexibility to multifunctional steam ovens that is not present in multifunctional steam ovens without an active inlet. The active inlet in conjunction with an exhaust vent (either active or not) provides control over the humidity level in the cooking chamber of a multifunctional steam oven that is not currently known in the art.

<FIG> show an example of an active inlet <NUM> in accordance with embodiments of the invention. Active inlet <NUM> has a blocking member <NUM> that can be moved between a closed position where it blocks an opening in a wall (for example, side wall <NUM>) of cooking chamber <NUM> and an open position where it allows air or some other fluid to pass through the opening. <FIG> shows active inlet <NUM> in an open position where blocking member <NUM> is separated from side wall <NUM> so that air A can pass through side wall <NUM> and into cooking chamber <NUM>. In this example, an actuator <NUM> moves a shaft <NUM> to move blocking member <NUM> left and right in the figure between the open and closed positions. A spring <NUM> is provided to maintain blocking member <NUM> in a default position (either opened or closed) when actuator <NUM> is not activated. In some embodiments, the default position is the closed position to prevent outside air from entering cooking chamber <NUM> during, for example, steam mode. In other embodiments, the default position is the open position to provide access to outside air through active inlet <NUM>. <FIG> shows active inlet <NUM> in the closed position. In this position, blocking member <NUM> is in contact with side wall <NUM> of cooking chamber <NUM> to close active inlet <NUM>. In this example, actuator <NUM> is controlled by a controller <NUM>. In some embodiments, controller <NUM> is an electronic controller that provides instructions to actuator <NUM> depending on the desired mode of oven <NUM>.

While the example of active inlet <NUM> shown in <FIG> opens inwardly into cooking chamber <NUM>, <FIG> show an example not encompassed by the wording of the claims of an active inlet <NUM> that opens outwardly away from cooking chamber <NUM>.

Active inlet <NUM> shown in <FIG> has a blocking member <NUM> that can be moved between a closed position where it blocks an opening in a wall (for example, side wall <NUM>) of cooking chamber <NUM> and an open position where it allows air or some other fluid to pass through the opening. <FIG> shows active inlet <NUM> in an open position where blocking member <NUM> is separated from side wall <NUM> so that air A can pass through side wall <NUM> and into cooking chamber <NUM>. In this example, an actuator <NUM> moves a shaft <NUM> to move blocking member <NUM> left and right in the figure between the open and closed positions. A spring <NUM> is provided to maintain blocking member <NUM> in a default position (either opened or closed) when actuator <NUM> is not activated. In some embodiments, the default position is the closed position to prevent outside air from entering cooking chamber <NUM> during, for example, steam mode. In other embodiments, the default position is the open position to provide access to outside air through active inlet <NUM>. <FIG> shows active inlet <NUM> in the closed position. In this position, a seal <NUM> mounted to blocking member <NUM> is in contact with side wall <NUM> of cooking chamber <NUM> to close active inlet <NUM>. In this example, actuator <NUM> is controlled by controller <NUM>. In some embodiments, controller <NUM> is an electronic controller that provides instructions to actuator <NUM> depending on the desired mode of oven <NUM>.

While the example shown in <FIG> does not include a seal and the example shown in <FIG> includes a seal, it is noted that either configuration can be provided with or without a seal.

<FIG> shows a front view (from the right in <FIG>) of blocking member <NUM>. <FIG> shows a rear view (from the left in <FIG> of blocking member <NUM> and seal <NUM>.

<FIG> shows an example of a method in accordance with embodiments of the invention. In <FIG>, step <NUM> provides a cooking chamber that receives a food item. Step <NUM> provides a steam generator that generates steam to heat the food item. Step <NUM> provides a heating element that generates heat to heat the food item. It is noted, as explained above, that the term "heating element" includes any type of non-steam generating heating or cooking device including, but not limited to, a conventional heating element, a convection system, a microwave system, and/or an induction heating system. Step <NUM> provides an exhaust outlet that fluidly connects the cooking chamber to a first external environment outside of the cooking chamber. Step <NUM> provides an active inlet that fluidly connects the cooking chamber to a second external environment outside of the cooking chamber, the active inlet having a blocking member and an actuator that moves the blocking member between an open position and a closed position. Step <NUM> prevents a fluid from the second external environment from entering the cooking chamber through the active inlet by moving the blocking member to the closed position. Step <NUM> generates steam with the steam generator to heat the food item during a first heating mode, the generated steam being the only source of heat that heats the food item during the first heating mode. Step <NUM> allows the fluid to enter the cooking chamber through the active inlet by moving the blocking member to the open position. Step <NUM> generates heat with the heating element to heat the food item during a second heating mode, the generated heat being the only source of heat that heats the food item during the second heating mode.

<FIG> is just one example of a method in accordance with embodiments of the invention. Other methods are also within the scope of the invention.

Claim 1:
A domestic home cooking appliance (<NUM>) that uses steam to heat a food item, the appliance (<NUM>) comprising:
- a cooking chamber (<NUM>) configured to receive the food item;
- a steam generator (<NUM>) configured to generate the steam to heat the food item;
- a heating element (<NUM>, <NUM>) configured to generate heat to heat the food item;
- an exhaust outlet (<NUM>) that fluidly connects the cooking chamber (<NUM>) to a first external environment outside of the cooking chamber (<NUM>); and
- an active inlet (<NUM>) that fluidly connects the cooking chamber (<NUM>) to a second external environment outside of the cooking chamber, the active inlet (<NUM>) having a blocking member (<NUM>) that prevents a fluid (A) from the second external environment from entering the cooking chamber (<NUM>) though the active inlet (<NUM>),
- an actuator (<NUM>) that moves the blocking member (<NUM>) between a closed position in which the blocking member (<NUM>) prevents the fluid (A) from entering the cooking chamber (<NUM>) through the active inlet (<NUM>), and an open position in which the blocking member (<NUM>) allows the fluid (A) to enter the cooking chamber (<NUM>) through the active inlet (<NUM>),
- a controller (<NUM>) that sends instructions to the actuator (<NUM>) to move the actuator (<NUM>) between the closed position and the open position; and
characterized in that the appliance comprises
- a spring (<NUM>) provided to maintain the blocking member (<NUM>) in a default position when the actuator (<NUM>) is not activated,
- wherein the blocking member (<NUM>) is positioned in the cooking chamber (<NUM>) and, in its closed position, blocks an opening in a wall (<NUM>) of the cooking chamber (<NUM>) from the cooking chamber (<NUM>).