MULTI-FUNCTIONAL OVEN WITH AIR FRYER CAPABILITY

A multi-functional oven includes: a housing having a floor, a rear wall, a ceiling, and first and second side walls; a door that serves as a front wall of the housing; an internal side wall that divides the housing into a cooking cavity and an control cavity; a removable cooking rack that defines a cooking surface; a lower heating element positioned in a lower region of the cooking cavity beneath the cooking surface; an upper heating element positioned in an upper region of the cooking cavity above the cooking surface; and a fan residing in a recirculation duct in the control cavity configured to draw air from the cooking cavity through lower vents located in a lower area of the internal side wall, thereby creating an airstream above and below the cooking surface that flows into the lower vents, and to force air from the control cavity through upper vents into the cooking cavity.

FIELD OF THE INVENTION

The present invention is directed generally to cooking appliances, and more specifically to multi-functional oven cooking appliances.

BACKGROUND

Various toaster-ovens exist for heating and cooking a variety of food items. For example, existing toaster ovens are used for toasting bagels, heating sandwiches, baking desserts, broiling meats and reheating leftovers. Heating and cooking these food items is often accomplished by the operation of upper and lower heating elements within the toaster oven, and temperature control and time control over these heating elements through a user interface or control panel.

In addition, air fryers are a relatively new innovation in home cooking. Traditionally, deep fat fryers have been used to cook French fries and numerous other food products (e.g., chicken, fish, onion rings). These food products can be prepared from frozen, refrigerated, ambient, or above ambient temperature conditions. Some consumers place a high value on healthier foods that are prepared using less oils or fats, and the replacement of the deep fat frying process with air frying eliminates a significant amount of oil and fat absorption into the food product. But, while consumers desire healthier foods prepared with less fat and oil, they still desire the taste, texture and mouth feel associated with the deep fat frying process.

It may be desirable to provide a single appliance that is capable of both typical toaster-oven and air fryer functionality and in doing so provide the crispness and texture typically associated with each cooking method.

SUMMARY

As a first aspect, embodiments of the invention are directed to a multi-functional oven, and in particular a multi-functional oven with conventional toasting/cooking and air frying modes. The oven comprises: a housing having a floor, a rear wall, a ceiling, and first and second side walls; a door that serves as a front wall of the housing; an internal side wall that divides the housing into a cooking cavity and an control cavity; a removable cooking rack that defines a cooking surface; a lower heating element positioned in a lower region of the cooking cavity beneath the cooking surface; an upper heating element positioned in an upper region of the cooking cavity above the cooking surface; and a fan residing in a recirculation duct in the control cavity. The fan is configured to draw air from the cooking cavity through one or more lower vents located in a lower area of the internal side wall, thereby creating an airstream below the cooking surface that flows into the lower vents, and to force air from the control cavity through upper vents into the cooking cavity.

As a second aspect, embodiments of the invention are directed to a multi-functional oven, comprising: a housing having a floor, a rear wall, a ceiling, and first and second side walls; a door that serves as a front wall of the housing; an internal side wall that divides the housing into a cooking cavity and an control cavity; a removable cooking rack that defines a cooking surface; a lower heating element positioned in a lower region of the cooking cavity beneath the cooking surface; an upper heating element positioned in an upper region of the cooking cavity above the cooking surface; and a fan residing in a recirculation duct in the control cavity. The fan is configured to draw air from the cooking cavity into the control cavity through one or more vents in the internal side wall, and to exhaust air from the control cavity into the cooking cavity. The oven further includes a vent located in the control cavity configured to open at a predetermined pressure and to exhaust a portion of the air drawn into the control cavity prior to the exhausting of air into the cooking cavity.

As a third aspect, embodiments of the invention are directed to a multi-functional oven comprising: a housing having a floor, a rear wall, a ceiling, and first and second side walls; a door that serves as a front wall of the housing; an internal side wall that divides the housing into a cooking cavity and an control cavity; a removable cooking rack that defines a cooking surface; a lower heating element positioned in a lower region of the cooking cavity beneath the cooking surface; an upper heating element positioned in an upper region of the cooking cavity above the cooking surface; a supplemental heating element; a fan residing in a recirculation duct in the control cavity, the fan configured to draw air from the cooking cavity into the control cavity through one or more vents in the internal side wall, and to exhaust air from the control cavity into the cooking cavity; and a controller operatively associated with the lower, upper and supplemental heating elements, the controller configured to activate only the lower and upper heating elements in a first cooking mode, and to activate the lower, upper and supplemental heating elements in a second cooking mode.

As a fourth aspect, embodiments of the invention are directed to a cooking rack comprising: a frame having longitudinal runners; a pan mounted to the frame; and heat shields mounted to the longitudinal runners and configured and positioned to prevent drippings from the pan to reach heating elements located beneath the heat shields.

DETAILED DESCRIPTION

In the figures, certain layers, components or features may be exaggerated for clarity, and broken lines illustrate optional features or operations unless specified otherwise. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

Referring now to the drawings, a multi-functional toaster-oven, designated broadly at10, is shown inFIG. 1. The toaster-oven10is generally box-shaped and includes a floor12, side walls13,14, a rear wall16, and a ceiling18. The front of the toaster-oven10includes a panel20that covers a portion of the front of the device, and which has control dials22mounted thereon that are connected with a controller200(depicted inFIG. 7). The remainder of the front of the toaster-oven10is covered with a door24(shown as transparent inFIG. 1) that is pivotally attached to the floor12. A handle26is mounted to the upper portion of the door24to facilitate opening and closing of the door24.

As can be seen inFIGS. 2-5, an internal side wall28is present inboard of the side wall14and extends from the inboard edge of the panel20to the rear wall16. The floor12, the side wall13, the rear wall16, the ceiling18, the door24and the internal side wall28define a cooking cavity30. The internal wall28, the floor12, the side wall14, the rear wall16, the ceiling18and the panel20define a control cavity32. Typically, the cooking cavity30has a width dimension (between the side wall13and the internal wall28) of about 10 to 14 inches, a depth dimension (from the door20to the rear wall16) of about 10 to 14 inches, and a height (from the floor12to the ceiling18of about 6 to 9 inches. As is conventional in toaster-ovens, the width and/or depth of the cooking cavity30are greater than the height.

Within the cooking cavity30, the toaster-oven10may have one or more cooking racks. More specifically, a grill-style lower rack34extends between the side wall13and the internal side wall28. The lower rack34is supported within a slot36in the side wall13and a set of three discontinuous slots38in the internal side wall28(seeFIG. 6). The front member of the rack34is captured by two hooks40that are also attached to the door24, such that opening of the door24draws the lower rack34forwardly as it slides within the slots36,38. The hooks40also enable the lower rack34to be removed entirely.

As seen inFIGS. 6, 8 and 8A, a frying rack40is illustrated therein. The frying rack40may be employed in place of the lower rack34described above. The frying rack40includes a wire frame42that has lowered ends43that are configured to fit within the slots36,38described above. A generally rectangular pan44is mounted to the upper surface of the wire frame42. Two runners46are mounted to the lower surface of the pan44and extend lengthwise beneath it. An arcuate heat shield48(typically formed of painted or plated steel) is mounted to each of the runners46. A grill50(seeFIG. 8A) is positioned within the pan44and above the bottom surface of the pan44to create a gap52.

In some embodiments, the frying rack40may include notches, recesses, protrusions, projections, latches or other features (see, e.g.,FIGS. 14, 15, 15A and 15B) that mate with complementary features in the wall(s)13,14to ensure that the frying rack40is positioned within the cooking cavity30at the proper height and location. Proper location of the frying rack40(and, in turn, food resting thereon) can provide more consistent cooking results and prevent food from falling or dripping from the rack40onto the underlying heating elements100(discussed below).

Referring now toFIGS. 6 and 7, the heating elements of the toaster-oven10are shown therein. More specifically, two elongate heating elements100are located in the lower region of the cooking cavity30below the rack40. Two elongate heating elements102are located in the upper region of the cooking cavity30. These heating elements100,102are electrically connected so that they are all activated when the toaster-oven is used for toasting or heating. In addition, two elongate supplementary heating elements104are also positioned in the upper region of the cooking cavity30(e.g., between the heating elements102), and another supplementary heating element106is positioned elsewhere in the cooking cavity30(for example, mounted to the internal side wall28) or in the control cavity32as discussed below. The supplementary heating elements104,106are electrically connected to the heating elements100,102(e.g., via switches110,112shown schematically inFIG. 7) so that they are activated when the toaster-oven10is used in an air frying mode (e.g., both switches110,112are closed), but are not activated when the toaster-oven10is used in a toasting or heating mode (the different modes of cooking are discussed below).

Referring now toFIGS. 2-4, within the control cavity32, the toaster-oven10includes a recirculation duct61within which is mounted a fan60. The fan60is illustrated herein as a centrifugal impeller fan which is oriented such that it rotates about an axis A that is generally parallel with the internal side wall28(i.e., the axis A extends through the hub of the impeller from the front of the toaster-oven10to the rear). The recirculation duct61also includes a shroud62that covers the fan60. The fan60and shroud62are configured such that impellers or other air-directing members of the fan60draw air from the cooking cavity30through one or more relatively large inlet vents66positioned in a lower area of the internal wall28into the shroud60(seeFIG. 5). In some embodiments, the lower inlet vents66are positioned below the elevation of the cooking surface of the grill50of the frying rack40, which can encourage a desirable air flow pattern as described herein. The shroud62leads to an outlet64that delivers air back into the cooking cavity30through upper outlet vents68that are positioned in an upper area of the internal wall28. Any or all of the vents66,68may be covered by screens or filters to prevent food crumbs or particles from reaching the fan60or shroud62.

The positioning and orientation of recirculation duct61, and in particular the fan60and the vents66,68, results in a general air flow pattern illustrated inFIGS. 6, 6A and 10. More specifically, operation of the fan60causes the impeller to rotate in a counterclockwise direction from the vantage point ofFIGS. 6 and 10. Such rotation draws air into the shroud62through the lower vents66and forces air out through the upper vents68. This flow pattern has the overall general effect of air being drawn into the lower vents66from a lower region of the cooking cavity30beneath the grill50of the frying rack40(shown by the right-pointing arrows L inFIGS. 6 and 10), around the fan60and upwardly through the shroud62(seeFIG. 10), and forced out of the upper vents68, across the upper region of the cooking cavity30(shown by the left-pointing arrows U inFIGS. 6 and 10), and downward within the cooking cavity30. In some instances, there may also be a beneficial “downdraft” effect that occurs within the cooking cavity30. Referring toFIG. 6A, food resting on the grill50of the frying rack40is typically cooler than the ambient air surrounding it. This is particularly true for frozen foods, such as frozen French fries. The cooler temperature of the food can create a natural downdraft of air (shown by the arrows D inFIG. 6A), which can enhance the tendency of the air to follow the flow path described, and in doing so pass evenly over food on the cooking surface. (It should be understood that additional, centrally-located vents, which also serve as outlets for the shroud62into the cooking cavity30, may be desirable for larger toaster-ovens, as their larger cooking cavities are capable of cooking a wider array of food sizes and varieties.)

Generally speaking, conventional toaster-ovens occupy a relatively large footprint, and have a relatively short (in height) cooking cavity. In contrast, air fryers tend to have taller cooking cavities with smaller footprints. Air fryers are also typically designed to provide an air flow that is sufficient in temperature, humidity, volume and velocity to absorb and expel moisture from the food surfaces. Such air flow, when created with the correct balance of dehydration and heat, can produce food with a desirable crisp finish/texture. The air flow pattern described above, driven by the fan60and directed by the shroud62, can create an environment in which the airflow (which may be 15-25 cfm, in some cases about 20 cfm) produces cooking conditions that enable satisfactory frying. The orientation of the fan60, with its axis of rotation A being generally parallel with the internal wall28(i.e., with the front-to-back direction of the toaster-oven10) can facilitate the creation of a relatively large, relatively low velocity airstream into and through the food on the cooking surface.

One characteristic that can improve air flow, and in turn frying quality, is to position the food low in the cooking cavity30. Such positioning can tend to even air flow across the food and/or to create a low velocity airstream around the food, while positioning the food far from the higher velocity airstream exiting the vents68. The suction zone of the fan60is non-jetted, and therefore forms a large, evenly-dispersed, low pressure flow field. As the distance from the food to the jetted outlet increases, the more likely the air is to evenly disperse across the food for even heating. As such, the food heats and releases moisture relatively evenly on all surfaces. Moreover, because the lower vents66are relatively large, and the intake duct of the shroud62is similarly large, the velocity of the airstream L is relatively low (particularly compared to the upper vents68, which typically have a lower total open area than the lower vents66), which can provide desirable cooking (i.e., air-frying) conditions.

In addition, the motor coil (not specifically shown) of the fan60is mounted relatively low in the control cavity32, which can provide cooling advantages.

Referring now toFIGS. 9 and 10, vents70are present in the upper surface of the outlet64of the shroud62. The vents70are covered with a flapper plate72that is mounted to the outlet64via a hinge74. In some embodiments, a baffle76is located within the outlet64just downstream from the vents70and is configured to redirect some of the air traveling in the outlet64through the vents70. The flapper plate72and hinge74may be configured so that the flapper plate72is biased toward the closed position (i.e., covering the vents70), with movement to the open position requiring a predetermined magnitude of positive pressure through the vents70(e.g., 5 psi). Such biasing may be achieved via the weight of the flapper plate72itself, a spring-loaded hinge, or another mechanism.

Referring now toFIG. 11, the inner surface of the side wall13may have mounted on it one or more baffles80. These baffles80are positioned so that air traveling down the inner surface of the side wall13may be slowed and redirected somewhat. The baffles80may be employed to assist with the creation of the air flow pattern described above. In addition, the lower of the baffles80may be positioned so that some of the air flowing down the side wall13may be deflected into the gap52between the pan44and the grill50(seeFIG. 8A).

To operate the toaster-oven10in a conventional toasting or cooking mode, the user places food on the rack34and manipulates one or more of the dials22to the proper cooking/toasting setting. The dials22signal the controller200(which is typically located in the control cavity32) to activate the heating elements100,102to the desired time/temperature. In some embodiments, the heating elements100,102may be 350 W heating elements, so that at full power the toaster-oven10produces 1,400 W of heat to toast or cook. Notably, at full power, the heating elements100,102tend to “glow”, which can enhance the crispness of a toasted surface of food. The toaster-oven10continues to toast/cook in conventional fashion until the food is done.

To operate the toaster-oven10in an air-frying mode, the user removes the rack34, places the frying rack40within the cooking cavity30, and places the food to be fried on the frying rack40. The user then manipulates one or more of the dials22to the proper setting for air frying. The dials22signal the controller200to activate the heating elements100,102as well as the supplementary heating elements104,106. However, in the illustrated embodiment, the heating elements100,102are not fully activated; for example, if 350 W heating elements are used for the heating elements100,102, they may be activated only to 250 W, a level at which they do not “glow” as described above. The supplementary heating elements104,106provide additional heat; for example, the supplementary heating elements104may be 250 W heating elements, and the supplementary heating element108may be a 185-200 W heating element. Thus, when the heating elements100,102are partially activated to 250 W, and the supplementary heating elements104,106are at full power, the total wattage of the toaster-oven is about 1700 W, which is a typical heat load for an air fryer. However, because none of the heating elements100,102,104,106is sufficiently heated to reach a “glowing” state, they do not toast the food; instead, the food gradually and consistently loses moisture and heats up in the manner of traditional frying. Of course, in other embodiments the overall power level may vary (for example, the total wattage may be between 1,100 and 1,300 W).

Also notable is the presence of the heat shields48on the frying rack40. When the frying rack40is in place, each of the heat shields48is positioned directly above a respective heating element100, such that heat from the heating elements100is deflected from directly reaching the food. As a result, the portions of food nearest the heating elements100are not “cooked” directly by the heating elements100, but instead the heat from the heating elements100flows into the airstream L.

Further, when the toaster-oven10operates in the air-frying mode, the controller200activates the fan60, which creates the air flow pattern discussed above. In operation, the air stream generated by the fan60creates sufficient pressure that it causes the flapper plate72to pivot upwardly from the upper surface of the shroud62, thereby opening the vents70and allowing a portion of the airstream to exit through the vents70. In some embodiments, between about 15 and 30 percent of the overall airstream may escape through the vents70(as an example, if the airstream has a flow rate of 20 cfm, the portion that escapes through the vents70may be 3 to 6 cfm). As the vented portion of the airstream escapes the vents70, it carries with it moisture that has been drawn from the food as it cooks. Thus, the vents70serve to reduce the humidity in the cooking cavity30. The reduction in humidity can help to produce a crisp finish/texture to the food. (This venting of a portion of the airstream can cause some loss of heat from the airstream. In some instances, it may be desirable to include additional thermal insulation in the walls of the toaster-oven and/or to employ materials, such as potassium ion-coated LowE glass, in the door to reduce heat loss).

Those of skill in this art will appreciate that the toaster-oven10may take other forms. For example, larger toaster-oven designs (e.g., those with cooking cavities of between about 1 and 1.4 cubic feet, such as 1.2 cubic feet), may include additional features. As one example,FIG. 12illustrates an alternative fan shroud62′ as part of the recirculation duct61The shroud62′ includes an outlet duct64′ with two separate outlets: a lower outlet65′ and an upper outlet66′. Each of the outlets65′,66′ leads to appropriately positioned vents (not shown herein) in the internal wall28that open into the cooking cavity30. A shroud of this configuration may be well-suited for a larger toaster-oven that, for example, may receive a second frying rack.

As another example of a variation in the toaster-oven10,FIG. 13illustrates a recirculation duct161in which a fan shroud162feeds directly into a duct300that extends above the cooking cavity (and in some embodiments across the entire cooking cavity) and discharges air downwardly into the cooking cavity. The duct300includes vent holes302in its lower surface that open into the cooking cavity30. The duct300may also have louvres or baffles304within its interior to assist with the direction of air toward and through the vent holes302.

As a further example of a variation that may be suitable for a larger toaster-oven model,FIG. 14illustrates part of the frame of a relatively deep fry basket320. A wire tab324is present on an upper wire rim322on the basket320. An actuator rod326is pivotally mounted to a pivoting crank328. The crank328is fixed to a cam330that is pivotally mounted to the internal wall28′ of the toaster-oven10′. When the fry basket320is slid into place within a slot332in the internal wall28′, the tab324engages the cam330and forces it to pivot. This action rotates the crank328, which in turn extends the actuator rod326upwardly. The upward movement of the actuator rod326opens a pivoting flap valve336(shown in an open position inFIG. 14) that typically covers a humidity-reducing vent334in the duct300. Opening of the flap valve336can enable additional humidity/moisture to be removed from the cooking cavity during cooking. In this manner, the vent334remains closed unless and until the fry basket320is inserted into the slot332, ensuring both that the vent334remains closed when the fry basket320is note being used (presumably for toasting and conventional cooking) and that the vent334is open for air frying.

Those skilled in this art will also appreciate that the wire tab324or a similar protrusion, projection, recess, notch, latch or the like may also serve other functions. For example, as illustrated inFIGS. 15, 15A and 15B, in some embodiments an electrical switch340may be present on the internal wall28′ of the toaster-oven10, and positioned such that sliding the fry basket320into the proper slot activates the switch340. Activation of the switch340(which is typically operatively connected with the controller200) may enable the air-fry mode to operate (and, conversely, the air fry mode may not operate unless the switch340is activated). Thus, the combination of the tab324and the switch340may provide a mechanism that prevents the toaster-oven from operating in the air fry mode if the fry basket320is inserted into the wrong slot.

Similarly, if a fry basket (e.g.,40or320) is formed as a separate component from the heat shields (such that the heat shields348are mounted as a unit360on their own separate frame342—seeFIG. 16), the heat shield frame348may have one or more protrusions that can interact with a switch350that in turn activates the air-fry mode. Such a mechanism may ensure that both (a) the heat shields348are in place for the air fry mode and (b) they are oriented correctly (i.e., they are not upside down). Those skilled in this art will appreciate that other, non-electrical protrusions and features may be present on the fry basket320and/or heat shield frame348to ensure proper orientation thereof when installed.

Referring now toFIGS. 17 and 18, a separate heat shield assembly360′ may also be free-standing. The heat shield assembly360′ includes a wire frame361with two lower lateral runners362that are well below the elevation of the heat shields348′. As can be seen inFIG. 18, the heat shield assembly360′ rests on the floor12of the toaster-oven10rather than being mounted in slots on the walls13,28.

Referring now toFIG. 19, another embodiment of a pan, designated broadly at400, is shown therein. The pan400, which may be suitable for foods that are typically cooked in a solid pan like a skillet (e.g., steaks, burgers, chicken, etc.), is designed to have a somewhat modified air flow pattern. The pan400has a bottom surface402, a front wall403, side walls404,405and a rear wall406. A lip407extends outwardly from the upper edges of the walls403-406. A grill410is positioned over and spaced from bottom surface402. Each of the walls403-406includes a plurality of small windows408located below the elevation of the grill410. The vents408provide exits for air that is directed downwardly from the ceiling of the toaster-oven onto food residing on the grill410; the air descends from the ceiling, flows over and around the food, exits the vents408, continues toward the floor of the toaster-oven, and is drawn therefrom into the vents in the internal wall28of the toaster-oven into the fan for recirculation. Thus, this arrangement further encourages the “downdraft” caused by colder food discussed above.

Another variation of the pan400is shown inFIG. 20and designated at500. The pan500is similar to the pan400, with a bottom surface502and walls503-506, but the pan500lacks the vents in the walls as described above. Instead, the front wall503is shorter than the remaining walls504-506, such that the grill510rests above the upper edge of the front wall503. Air directed from above flows over and around the food, but in particular flows beneath the food and out of the pan500through the gap512formed by the front wall503and the grill510.

Referring now toFIG. 21, it can also be seen that the grill510may include projections or “stand-offs”514,516that extend both above and below the cooking surface of the grill510. Notably, the stand-offs514are shorter than the stand-offs516, which can enable the grill510to be spaced at different heights relative to the bottom surface502of the pan500. The different heights may be desired for the cooking of different foods.

As a further example of alternative embodiments of the invention, a portion of a toaster-oven having a control cavity632is shown inFIGS. 22-24. The control cavity632employs a recirculation duct661that includes an outer shroud662with a floor662abelow the lower vents666, a vertical wall662b, and a ceiling662cabove the upper vents668. Side walls663(only one side wall663is shown herein) meet the front and rear edges of the shroud662to form an enclosure with the internal wall628. A centrifugal fan660is mounted within the enclosure. A partition669is mounted above the fan660to divide the space within the shroud662into lower and upper chambers672,674. The partition669includes an opening671that serves as an outlet for the fan660. A supplemental heating element706is mounted in the upper chamber674(and, notably, in this embodiment the supplemental heating elements104within the cooking cavity described above may be omitted). A duct676(seeFIG. 24) is mounted to the rear surface of the rear side wall663covering a window675in the rear side wall663and serves as a pathway between the upper chamber674and the atmosphere outside of the toaster-oven. Vanes678are present on the internal wall628to direct air through upper vents668, and in some instances deflect the air sufficiently to reduce its exit velocity.

As can be seen inFIG. 23, when the toaster-oven is operating in the air frying mode, rotation of the fan660(counterclockwise from the vantage point ofFIGS. 22 and 23) draws air from the cooking cavity630through the lower vents666and into the lower chamber672. The fan660draws in this air and expels it through the opening671in the partition669into the upper chamber674. From there much of the air exits back into the cooking cavity630through the upper vents668. To reduce humidity in the airstream as described above, some of the air in the upper chamber674exits the toaster-oven through the duct676. Also, the air in the upper chamber674is heated by the supplemental heater706prior to exiting the upper vents668. In this embodiment, the total wattage of the toaster-oven in the air fry mode may be about 1,200 W (e.g., each of the 350 W heating elements100,102may be heated to 250 W to avoid “glowing”, and the supplemental heating element706may provide an additional 185-200 W of heat).