Multi-zone food holding bin

Abstract

A multi-zone food holding bin has a continuous food supporting surface with multiple food holding zones. Each food holding zone is independently controllable so that different food temperatures may be maintained in adjacent food holding zones.

Description

BACKGROUND

Often the success of a restaurant depends, at least in part, on how quickly customers can be served with ordered food items and also on the quality of the food items when served. If the rate of food preparation equals the rate at which the food is ordered and sold, a restaurant can theoretically have freshly-prepared foods ready to serve for customers as they arrive. Since it is not always possible to match food production with customer ordering rates, and since certain fast food restaurant customers expect to receive their ordered food items quickly, many fast food restaurants prepare various food items in advance and keep them ready for sale until a customer arrives and purchases a pre-cooked food item.

To facilitate the food holding process, holding bins or holding ovens are often used to keep the food warm. Known holding bins can allow a cooked food item to be inserted from one side and taken from the opposite side whereby food preparers add food to the holding bin on one side and food servers on the opposite side take food from the holding bin. Food holding bins in which the cooked food item is inserted and removed from the same side are also known. The food items in the holding bins are kept warm by heating elements. However, food holding time in known holding bins or ovens is somewhat limited, generally less than 15 or 20 minutes before the food item must be discarded. As a result, restaurants can only keep a limited amount of pre-cooked food items on hand and often a significant amount of the pre-cooked food items must be discarded before they are sold, resulting in additional costs.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a multi-zone food holding bin;

FIG. 2 is a front elevational view of the multi-zone food holding bin of FIG. 1;

FIG. 3 is a rear elevational view of the multi-zone food holding bin of FIG. 1;

FIG. 4A is a partially cut-away top perspective view of an alternate embodiment of a multi-zone food holding bin, and FIG. 4B is a close up of a shelf portion of the multi-zone food holding bin from circle 4B in FIG. 4A;

FIG. 5 is a partially cut-away bottom perspective view of the food holding bin of FIG. 4; and

FIG. 6 is a partially cutaway top perspective view of yet another alternate embodiment of a multi-zone food holding bin.

DETAILED DESCRIPTION

Turning now to FIGS. 1-3, a multi-zone food holding bin 10 includes two separate food holding compartments 50. Additional food holding compartments 50 may also be included as explained in further detail below. Each separate food holding compartment 50 includes two or more separate food holding zones, for example, as illustrated in FIGS. 1-3, a first food holding zone 57a and a second food holding zone 57b. Each food holding zone 57a, 57b may include two food holding bays. For example, the first food holding zone 57a may include a first food holding bay 51a and a second food holding bay 51b. The second food holding zone 57b may include a third food holding bay 51c and a fourth food holding bay 51d. Each food holding bay 51a, 51b, 51c, 51d is capable of receiving a single food holding tray 27 and/or a single lid 21, as illustrated in the third food holding bay 51c in FIG. 2. The food holding bays 51a, 51b, 51c, and 51d are illustrated as being separated from one another by a dashed line in FIGS. 1-3. The dashed lines are for illustration only. The food holding bays need not have their boundaries identified with any sort of line or other indicia in food holding compartment 50. Each food holding zone 57a, 57b can be configured to maintain a different food holding temperature, advantageously allowing the operator to hold different food products with different heating requirements in the same food holding compartment 50, thereby permitting increased energy efficiencies to be realized and potentially reducing the space requirements for holding different foods. For example, a first food product can be held in the first food holding bay 51a of the first

food holding zone 57a and a second food product, which may be the same as the first food product or different from the first food product as long as both food products have substantially the same temperature requirements, can be held in the second food holding bay 51b of the first food holding zone 57a. Both the first food holding bay 51a and the second food holding bay 51b are held at a first temperature by independently controllable upper and lower heating elements.A third food product can be held in the third food holding bay 51c of the second food holding zone 57b and a fourth food product, which may be the same as the third food product or different from the third food product as long as both food products have substantially the same temperature requirements, may be held in the fourth food holding bay 51d of the second food holding zone 57b. Both the third food holding bay 51c and the fourth food holding bay 51d are held at a second temperature by independently controllable upper and lower heating elements.Because the heating elements used to heat the second food holding zone 57b are different from those used to heat the first food holding zone 57a, the second temperature of the second food holding zone 57b is capable of being independently set to be different from the first temperature of the first food holding zone 57a. Suitable heating elements are illustrated with respect to the embodiment shown in FIGS. 4A, 4B, and 5. This can be particularly useful for restaurants during lower demand times (as fewer food holding bins are needed to hold larger numbers of different food items than previously) and also for smaller restaurants and retail operations (as space constraints can be met more easily).

In one embodiment of the bin 10, all of the compartments 50 are heated. In another embodiment, some compartments 50 may be refrigerated while other compartments 50 are heated. In yet another embodiment, one or more compartments 50 can be selectively heated or refrigerated.

The bin 10 includes a chassis 15. As illustrated, the chassis 15 includes a top panel 20, a bottom panel 25, a left-side panel 30, a right side panel 35, an open front face 40 and an open rear face 45. When the rear face 45 is open and uncovered, food items can be inserted by a first operator responsible for initial food preparation into one of the faces 40, 45 and passed through to and removed from the other of the faces 40, 45 by a second operator responsible for final food preparation, for example, a second operator responsible for packaging and customization of a food product for serving to the ultimate customer. In another embodiment, the rear face 45 may be “closed” and provided by a rear panel such that access into the bin 10 is only provided by the open front face 40. The panels may be insulated to reduce heat transfer between the interior of the bin 10 and the atmosphere surrounding the bin 10.

The bin 10 illustrated in FIG. 1 is sized, shaped and arranged to have two compartments 50, however, the bin 10 can have any number of compartments 50, including a single compartment 50. For clarity, the two compartments 50 depicted in FIGS. 1-3 are denominated using the letters A and B. The “A” compartment is the top or uppermost compartment 50 and the “B” compartment is the bottom or lower-most compartment 50.

In the embodiment illustrated in FIG. 1, the top or “A” compartment is defined by the left and right sidewalls 30 and 35, the chassis top panel 20 and a first or upper-most shelf 52.

Compartment “B” is defined by the two sidewalls 30 and 35, the first or upper-most shelf 52, and the chassis bottom panel 25. In bin embodiments having only one compartment 50, the single compartment is defined by opposing, left and right sidewalls 30 and 35, a chassis top panel 20 and a chassis bottom panel 25. For brevity, bin construction and operation is described with regard to a bin 10 having two compartments 50 in FIGS. 1-3. However, other embodiments may have more than two compartments 50 or less than two compartments 50. For example, the embodiments illustrated in FIGS. 4A, 4B, 5, and 6 have four compartments 50. Again, other configurations are also possible.

The shelf 52, which partially defines the compartments 50, is planar or at least substantially planar and supported in the chassis 15 at opposing side ends by the two chassis side walls 30 and 35. The shelf 52 includes a planar and continuous top surface, which forms a planar and continuous bottom surface 53 of the upper compartment 50. The planar and continuous bottom surface 53 of the upper compartment 50 is configured to support food items (as used herein, the term “food item” includes but is not limited to containers or trays containing food products such as cooked protein patties, fried foods, and the like). In the illustrated embodiment, food items can be placed onto the planar and continuous bottom surface 53 and removed from the planar and continuous bottom surface 53 through the open front face 40 or through the open rear face 45. Because the bottom surface 53 is planar and continuous and substantially free of any dividing walls or other structure between the holding zones 57a, 57b, and more particularly between the food holding bays 51a, 51b, 51c, and 51d, cleaning of the bottom surface 53 can be easily accomplished.

A face plate or bezel 92 is generally attached to the front of the chassis 15. For example, the bezel can be attached to the sidewalls 30 and 35 of the chassis 15 so as to be disposed underneath a top surface of the shelf 52. In bin embodiments having only one compartment 50, the bezel 92 may be attached to either of the chassis top or bottom panels 20, 25 of the bin 10. In the illustrated embodiment of FIGS. 1-3, the bezel 92 is set forward from the shelf 52 by a space 55. The space 52 forms a slot in which one or more latches 23 translate and/or rotate from a locked/default position to an unlocked position so as to release lids held in lid holding ledges 31 as will be discussed further below.

The bezels 92 may include information displays and/or controls, which are collectively identified by reference numeral 93. Although the chassis 15 can include panels concealing the heat generating devices located within a shelf, the bezel 92 also can conceal heating elements, which are located within the shelf 52, such that a separate panel is not present.

Each food holding bay 51a, 51b, 51c, 51d may include a dedicated display and/or control 93a, 93b, 93c, 93d, respectively. While each dedicated display and/or control 93a, 93b, 93c, 93d may display and/or control the temperature within individual food holding bays 51a, 51b, 51c, 51d, the food holding bays within a particular food holding zone (51a and 51b within 57a; 51c and 51d within 57b) have the same temperature setting. The dedicated display and/or controls 93a, 93b, 93c, 93d, may also display additional information about the food item stored in the food holding bay 51a, 51b, 51c, 51d. For example, while the temperature in the first food holding bay 51a and the second food holding bay 51b is the same (because both food holding bays 51a, 51b are located within a single food holding zone 57a), the display and/or control 93a, 93b may indicate that the first food holding bay 51a has a first food item (such as sausage) while the second food holding bay 51b has a second food item (such as eggs). In the embodiment illustrated in FIGS. 1-3, the display and control 93a, 93b, 93c, and 93d can display the particular food item, the temperature setpoint of a respective food holding bay 51a, 51b, 51c, 51d, along with other information about the food item stored in the food holding bay 51a, 51b, 51c, 51d, such as the food holding bay is ready to receive food items, the food items in the food holding bay should be discarded, the food items in the food holding bay are older and should be used first relative to the same food items contained in another food holding bay, the food items in the food holding bay are newer relative to the same food items contained in another food holding bay such that the food items contained in the other food holding bay should be used first, it is time to cook more food product. Moreover, the heating elements for each food holding zone 57a, 57b can be controlled by the displays and/or controls 93a, 93b, 93c, 93d to maintain the temperature setpoint of the respective food holding zones 57a, 57b. The displays and/or controls 93a, 93b, 93c, 93d may be grouped together (i.e., arranged horizontally beneath the respective food holding bay 51a, 51b, 51c, 51d) in the bezel 92 for a corresponding compartment 50. In the embodiment illustrated in FIGS. 1-3, a single bezel 92 is used to provide the display and/or control elements for two vertically adjacent compartments 50, but of course discrete bezels can also be used. The displays and/or controls 93a, 93b, 93c, 93d thus can provide a user graphical interface to one or more controllers (not shown) for the bin. A temperature control interface panel 95 may also be provided to control the temperatures of the food holding zones 57a, 57b.

Each food holding bay 51a, 51b, 51c, 51d may be sized to receive an individual food holding tray 27 and lid 21 (see FIG. 2 where the tray 27 is illustrated in broken lines). In order to conveniently store the lid 21, each food holding bay 51a, 51b, 51c, 51d may also include a dedicated lid holding shelf 31 that is sized to receive and store the lid 21 when the lid 21 is desired for use in combination with a food holding tray 27, such as when protein patties are contained within the tray 27. Generally, a top surface 27a of a food holding tray 27, when received in the lid holding shelf 31, is substantially flush with a top surface of the lid holding shelf 31 such that when the tray 27 is disposed in the food holding bay 51c, the tray 27 can be in contact with and engaged by the lid 21 in the lid holding shelf 31 so as to retain moisture within the tray 27-lid 21 assembly. In some embodiments, the lid holding shelf 31 may be provided by formed sheet metal. In other embodiments, the lid holding shelf 31 may be provided by a wire form. Other structures are also possible.

Adjacent to each lid holding shelf 31 is one or more latches 23 having an open center portion. In the embodiment illustrated in FIGS. 1-3, each food holding zone 57a, 57b includes a single dedicated latch 23 that selectively secures lids 21 in the food holding shelves 31 in each food holding bay 51a, 51b, 51c, 51d. In the illustrated embodiment, the latches 23 have a round or curved body 29 that is rotatable and/or translatable (because of the open center) about a retaining element such as a pin or screw (not shown). In other embodiments, the latches 23 may have straight or angled outer surfaces that form other shapes, such as a square, a pentagon, a hexagon, or any other polygonal shape. The latches 23 may be disposed adjacent an opening into the food holding compartment 50 above the lid holding shelf 31. In one example, the latches 23 may be captured on a cylindrical retaining element between the chassis 15 and a top of the food holding compartment 50 above the lid holding shelf 31. In other embodiments, one or more washers (not shown), such as metal, nylon, or plastic washers, may be disposed on the cylindrical retaining element to space the latches 23 apart from the bezel 92 and the shelf 52 to prevent metal galling and/or to reduce friction between the latches 23 and the bezel 92 or shelf 52 to ease actuation of the latches 23.

The round body 29 may be oriented substantially parallel to a front face of the chassis 15 or the bezel 92 in a locked or default position, as illustrated by reference numeral 23a, which prevents inadvertent removal of a lid 21 from the lid holding shelf 31 when a tray 27 is withdrawn. The latch 23 is in its default or locked position simply because of gravity, thus re-positioning the latch to an unlocked state advantageously requires simply overcoming the weight of the latch 23 by translational and/or rotational movement. The round body 29 may be rotated and/or translated upwards relative to the bezel 92 or lid holding shelf 31 from the locked or default position to an unlocked position, as illustrated by the dotted lines referencing latch 23 between food holding bay 51a and food holding bay 51b in FIG. 1; this rotational and/or translational movement of the latch 23 about the retaining element allows facile insertion or removal of a lid 21 to/from the lid holding shelf 31. The round body 29 may be mounted on a retaining element such as a pin or a screw (not shown), which retains the round body 29 and allows the round body 29 to translate along the open center portion and/or to at least partially rotate about the pin when the round body 29 translates. The lid holding shelf 31 also allows the food holding compartment 50 to have the planar and continuous bottom surface 52 by storing the lids 27a in an elevated position, with the lid holding shelf 31 being suspended above the

continuous bottom surface 52, typically by fixedly attaching a base of the shelf to a top surface of the food holding compartment 50 at one or more positions. Such continuous planar and continuous bottom surfaces 52 are much easier to clean than compartmentalized or divided heating chambers. Furthermore, the round body 29 of the latch 23 and the translation/rotation movement of the latch allow easy removal of the lids 27 from the lid holding tray 31 with one hand while positioning the latch 23 to the unlocked position with another hand.

From a purely functional standpoint, a preferred latch 23 might simply include a locking portion that is able to prevent inadvertent displacement of the lid 21 when the tray 27 is purposefully removed. Thus, a number of different configurations and shapes can be used for the latch 23. The latch 23 illustrated here with the round body 29, on the other hand, has an alternative, ornamental arrangement for the round body 29 in which the edges of the round body 29 include an arc-shaped, curved surface. This illustrated arrangement may add to the cost of manufacture, so the illustrated latch does not provide all of the possible economic advantages that might be derived from the invention. On the other hand, this arrangement is believed to be aesthetically pleasing and is likely to be recognized and relied upon by purchasers to identify the source of the food holding bin.

FIGS. 4A, 4B, and 5 are perspective views of an alternate embodiment of a multi-zone food holding bin 10, the embodiment of FIGS. 4A, 4B, and 5 including four separate food holding compartments 50. The embodiment of FIGS. 4A, 4B, and 5 is substantially identical to the embodiment of FIGS. 1-3 with the exception that the embodiment of FIGS. 4A, 4B, and 5 includes four food holding compartments 50 instead of two, each food holding compartment 50 including two food holding zones 57a, 57b, and each food holding zone 57a, 57b including a single food holding bay 51a, 51b, respectively. Thus, reference numbers identifying identical elements are the same in FIGS. 1-3 and in FIGS. 4A, 4B, and 5. Moreover, elements not illustrated in one of the embodiments are understood to be present in the other embodiment. For example, the embodiment illustrated in FIGS. 4A, 4B, and 5 includes cut-away views showing internal components that are not visible in FIGS. 1-3. Nevertheless, these internal components are understood to be present in the embodiment illustrated in FIGS. 1-3 as well.

Similar to the embodiment of FIGS. 1-3, each separate food holding compartment 50 in the food holding bin 10 of FIGS. 4A, 4B, and 5 includes at least two separate food holding zones, a first food holding zone 57a and a second food holding zone 57b. Each food holding zone 57a, 57b is configured to maintain a different temperature. Of course, it is not necessary for the food holding zones 57a, 57b to be operated at different temperatures in practice.

The bin 10 illustrated in FIG. 4A is sized, shaped and arranged to have four compartments 50, however, bins in accordance with the disclosure can have any number of compartments, including a single compartment.

In FIG. 4, the first or top compartment is defined by the left and right sidewalls 30 and 35, the chassis top panel 20 and the first or upper-most shelf 52. The second compartment is defined by the two sidewalls 30 and 35, the shelf 52 for the first compartment and the second shelf 52. The third compartment is defined by the two sidewalls 30, 35, the second shelf 52 and the third shelf 52. The fourth compartment is defined by the two sidewalls 30 and 35, the third shelf and the chassis bottom 25.

The shelves 52, which partially define the compartments 50, are planar or at least substantially planar and supported in the chassis 15 at their opposing side ends by the two chassis side walls 30 and 35. Each shelf 52 forms a planar and continuous top surface, which defines a planar and continuous bottom surface 53 of the compartment 50. The planar and continuous bottom surface 53 of the compartment is configured to support food items (as mentioned above, the term “food item” includes but is not limited to containers or trays containing food products such as cooked protein patties, fried foods, and the like). Food items can be placed onto the planar bottom surface 53 and removed from the planar bottom surface 53 through the open front face 40 or through the open rear face 45.

Each food holding bay 51a, 51b may include a dedicated display and/or control 93a, 93b, respectively. Each display and/or control 93a, 93b may display the temperature setpoint of a respective food holding bay 51a, 51b, and in the embodiment illustrated in FIGS. 4A, 4B, and 5, the temperature of a respective food holding zone 57a, 57b. Moreover, each display and/or control 93a, 93b may control the respective heating elements that maintain the temperature setpoint of the respective food holding zones 57a, 57b. The displays and/or controls 93a, 93b may be grouped together (i.e., arranged horizontally beneath the respective food holding bay 51a, 51b) in the bezel 92 for a corresponding compartment 50. In the embodiment illustrated in FIGS. 4A, 4B, and 5, a single bezel 92 is used to provide the display and/or control elements for a single compartment 50. The displays and/or controls 93a, 93b can provide a graphical user interface to one or more controllers (not shown) for the bin 10.

Bin 10 control and control of the food holding zone 51 temperature is effectuated in part by using one or more microcontrollers or microprocessors 97 in combination with temperature sensors 99. US 2011-0114624 A1 entitled “Food Holding Cabinet Power Supplies with Downloadable Software,” the entirety of which is hereby incorporated by reference herein, discloses among other things, apparatuses and methods by which compartments of a food holding bin can be controlled using microprocessors having downloadable software.

Compartment temperature control is preferably effectuated using a semiconductor temperature sensor, thermally coupled to each food holding zone 51 and electrically connected to a processor, such as those disclosed in US 2011-0114624 A1.

A semiconductor apparatus and method for measuring temperature of a plate or shelf in a food holding bin is disclosed in U.S. Pat. No. 8,247,745, which is entitled “Temperature Sensor for a Food Holding Cabinet” the entirety of which is hereby incorporated by reference herein.

The shelf 52 includes a lower heating element 67 for the first food holding zone 57a in a first or top food holding compartment 50, and an upper heating element 65 for a second food holding zone 57b in a second or lower food holding compartment 50, directly below the first food holding compartment 50. While the first heating element 67 is illustrated as providing heat to the upper first food holding zone 57a (from below) and the second heating element 65 is illustrated as providing heat to the lower first food holding zone 57a (from above), heating elements that are not shown include at least a heating element that provides heat to the upper first food holding zone 57a from above and another heating element that provides heat to the lower first food holding zone 57a from below. Additionally, the second food holding zones 57b, which are adjacent to the first food holding zones 57a, are heated in the same way as the first food holding zones 57a, but with independent heating elements. The heating elements of the second food holding zones 57b are independently controllable from the heating elements of the first food holding zones 57a. Referring to the inset FIG. 4B, the shelf 52 includes an upper thermally conductive plate, which forms the continuous planar bottom surface 53 of the first (or upper) food holding compartment 50 and a lower thermally conductive plate, which forms a continuous planar upper surface 54 of the second (or lower) food holding compartment 50. The planar bottom surface 53 and the planar upper surface 54 are spaced apart from each other by a distance sufficient to accommodate the inclusion of at least two heating elements, which are illustrated in the figures as the separate first heating element 67 and the separate second heating element 65, respectively. Again, the temperature of each food holding zone is controlled by independently controllable heating elements. Insulative materials may be provided between the first heating element 67 and the second heating element 65 to provide better thermal control over the food holding zones 57a, 57b. The first heating element 67 is a lower heating element for the upper food holding compartment 50 and the second heating element 65 is an upper heating element for the lower food holding compartment 50.

The continuous planar bottom surface 53 of the top food holding compartment 50 and the continuous planar upper surface 54 of the bottom food holding compartment are preferably made of aluminum, between about one-eighth and about one-quarter inch-thick. Alternate embodiments of the shelf 52 may use a thermally-conductive panel made of glass-ceramic or an ultra-low expansion glass for one or both of the lower surface 53 and the upper surface 54.

Glass-ceramics and ultra-low expansion glass are considered herein to be “good” thermal conductors in that their conduction of heat energy is localized. Such materials also make excellent shelves for a heated, multi-zone food holding bin because they permit localized areas of a shelf to be heated to a first temperature, without having the entire shelf reach the same temperature.

The first heating element 67 is disposed between the planar bottom surface 53 and the planar upper surface 54 and the first heating element 67 is in thermal communication with the planar bottom surface 53. The first heating element 67 may be mechanically attached to the planar bottom surface 53 by a thermally-conductive adhesive, in one embodiment. The first heating element 67 may also be attached to the planar bottom surface 53 by brackets or clamps.

The second heating element 65 is disposed between the planar bottom surface 53 and the planar upper surface 54 and the second heating element 65 is in thermal communication with the planar upper surface 54. The second heating element 65 may be mechanically attached to the planar upper surface 54 by a thermally-conductive adhesive, in one embodiment. The second heating element 65 may also be attached to the planar upper surface 54 by brackets or clamps.

In the embodiment illustrated in FIGS. 4A, 4B, and 5, the first heating element 67 can be located above the second heating element 65 but in thermal communication with the planar bottom surface 53 such that when the temperature of the first heating element 67 rises, it provides heat energy into the planar bottom surface 53 in a region around the first heating element 67, and more specifically, within the first food holding zone 57a of the first or top food holding compartment 50. Thermally insulating the first heating element 67 from the planar upper surface 54 and thermally insulating the second heating element 65 from the planar bottom surface 53, enables the first heating element 67 to provide a first amount of heat energy into the planar bottom surface 53 (and thus into the first food holding zone 57a of the upper food holding compartment 50), while the second heating element 65 provides a second amount of heat energy into the planar upper surface 54 (and thus into the first food holding zone 57b of the lower food holding compartment 50). In this manner, each food holding zone 57a, 57b may be configured to have an independent and unique temperature profile from top to bottom of the food holding zone 57a, 57b. For example, one food holding zone 57a, 57b may have a temperature profile that generally decreases from top to bottom (i.e., the top of the food holding zone 57a, 57b is hotter than the bottom of the food holding zone 57a, 57b).

In some embodiments, the second heating element 65 may comprise a radiant heating source that projects radiant heat through the planar upper surface 54 and into the first food holding zone 57a of the lower food holding compartment 50. In other words, in one embodiment, the first heating element 67 provides heat energy into the first food holding zone 57a of the upper food holding compartment 50 through conduction, while the second heating element 65 provides heat energy into the first food holding zone 57a of the lower food holding compartment through radiation. Similarly, a radiant heating element may be provided at a top interior surface of the first or top food holding compartment 50 beneath the chassis top panel 20. In this manner, the top and bottom of a food product placed into the first food holding zone 57a may absorb different amounts of heat energy, customized depending on the type of food product. Thus, the heat profile in the first food holding zone 57a may be customized vertically as well as differentiated from the heat profile in the second food holding zone 57b. As a result, a single food holding compartment 50 (e.g., the upper compartment in FIGS. 4A and 5) may be customized to store different types of food products in the first food holding zone 57a and the second food holding zone 57b, each food holding zone 57a, 57b having a different temperature profile. As a result, the disclosed food holding bin 10 is flexible in that it can keep multiple different types of food products at their ideal holding temperatures in a single food holding compartment, thus increasing efficiency and adaptability to different food demands.

Because of this flexibility, it has been found that a food holding bin constructed in accordance with the disclosure can extend the palatability time of a food item by a factor of two or more.

An alternate embodiment, as illustrated in FIG. 6, may use the thermoelectric effect provided by one or more Peltier devices 80 to heat one or more of the compartments 50.

The thermoelectric effect is a direct conversion of a temperature difference into an electric voltage and vice versa. When a voltage is applied to a thermoelectric device, a temperature difference is created across the two sides of the device. The temperature difference created in response to an applied voltage is known as the Peltier effect. Devices that produce temperature differences in response to an applied voltage are considered herein to be Peltier devices. A Peltier device 80 is therefore considered herein to be a heat source or heating element.

Peltier devices have a “cold” side and a “hot” side. The cold side absorbs heat whereas the hot side emits heat. Heat emitted from the hot side includes at least some of the heat absorbed from the cold side. A Peltier device 80 is therefore considered herein to be a solid-state heat pump or heat-sinking device.

FIG. 6 is a cutaway view of another embodiment of a point-of-use holding bin using Peltier devices to heat the food holding compartments 50. In one embodiment, one or more Peltier devices 80 are “sandwiched” between, and in thermal communication with the bottom planar surface 53 and the upper planar surface 54 described above. Electrical energy is provided to the Peltier devices 80 through wires 85, under the control of a controller.

“Sandwiching” the Peltier devices in a shelf 52 as shown in FIG. 6 provides a shelf 52 cold on one side and hot on the other. Such a shelf 52 structure thus enables a dual-mode food holding bin 10 having a “first” food holding compartment 50 that is warm and a vertically adjacent “second” food holding compartment 50 that is cold.

Temperature control of a thermoelectric, Peltier device 80 may be accomplished by controlling the electric energy provided to the device. Temperature control of one side of the Peltier device 80 can also be effectuated by controlling heat transferred into or out of the opposite side of the device, as described in US 2010-0307168 A1, entitled “Thermo Electric Cooler,” the disclosure of which is incorporated herein by reference in its entirety.

In another embodiment of a multi-zone food holding bin 10, multiple Peltier devices 80 are mounted between the bottom surface 53 and the upper surface 54 but have only their hot sides thermally coupled to the bottom surface 53 and to the upper surface 54. Air is then moved through the inter-plate space to heat the cool sides of the Peltier devices therein.

Peltier devices as disclosed herein and similar heat transfer devices are thermally coupled to the shelf 52, preferably by way of mechanical attachment to at least one of the plates that form the lower planar surface 53 and the upper planar surface 54. Mechanical attachment and the resultant thermal coupling is preferably accomplished by a thermally-conductive adhesive, however, clamps that are attached to a plate by screws driven into a plate can also be used.

The shelves are mechanically coupled to the side panels 30 and 35. The side panels are also preferably made from thermally-conductive material such as aluminum. Thermally coupling a heat transfer device to one or more plates that comprise a shelf therefore also thermally couples the heat transfer device to the side walls and thus to the compartment. Heat transfer devices coupled to a shelf are therefore also thermally coupled to the corresponding compartment.

While the temperature of a Peltier device can be controlled by controlling the heat dissipated from the hot side and/or the heat absorbed into the cold side, bin embodiments

disclosed herein preferably control compartment temperature using one or more semiconductor temperature sensors, thermally coupled to one or more of the thermally-conductive structures that comprise a compartment. Bin embodiments disclosed herein preferably use a semiconductor temperature sensor that is directly coupled and therefore thermally coupled to the heated surfaces 53 and/or 54 provided by the shelves 52.

Semiconductor temperature sensors used in preferred embodiments disclosed herein are disclosed in U.S. Pat. No. 8,247,745, which is entitled “Temperature Sensor for a Food Holding Cabinet” the entirety of which is hereby incorporated by reference herein, especially the teachings of the structure and use of a semiconductor temperature sensor.

Thus, suitable heating elements for use in accordance with the disclosure include electrically-resistive heating elements, such as heated coils, radiant heating elements that provide heat energy via radiation, and devices and ancillary equipment that provide heat to a working fluid. As described above, Peltier devices may also be used as heating elements in accordance with the disclosure.

The foregoing description is for purposes of illustration only and not for purposes of limitation. The true scope of the invention is set forth by the appended claims.

Claims

1. A method of maintaining different temperatures within a multi-zone food holding bin, the multi-zone food holding bin comprising a chassis having a top panel, a first side panel, a second side panel, a bottom panel, and a font face, the multi-zone food holding bin having a first food holding compartment within the chassis and comprising a first food holding zone and a second food holding zone, the first food holding compartment being defined by the first side panel, the second side panel, the top panel that provides a first top surface, and a first substantially planar bottom surface of a thermally conductive material being substantially unobstructed between the first side panel and the second side panel and a first opening through the front face configured to allow a tray for food items to be passed through the first opening into the first food holding compartment and onto the first substantially planar surface and a second food holding compartment within the chassis and comprising a third food holding zone and a fourth food holding zone, the second food holding compartment being defined by the first side panel, the second side panel, the bottom panel that provides a second substantially planar bottom surface of a thermally conductive material, and a second top surface, the second substantially planar bottom surface being substantially unobstructed between the first side panel and the second side panel and a second opening into the second food holding compartment and onto the second substantially planar surface, the method comprising: operating the first food holding zone to a first temperature setpoint by independently operating a first heating element in the first food holding zone and thermally coupled to the first top surface and independently operating a second heating element in the first food holding zone and thermally coupled to the first substantially planar surface;operating the second food holding zone to a second temperature setpoint by independently operating a third heating element in the second food holding zone and thermally coupled to the first top surface and independently operating a fourth heating element in the second food holding zone and thermally coupled to the first substantially planar surface;operating the third food holding zone to a third temperature setpoint by independently operating a fifth heating element in the third food holding zone and thermally coupled to the second top surface and independently operating a sixth heating element in the third food holding zone and thermally coupled to the second substantially planar surface; andoperating the fourth food holding zone to a fourth temperature setpoint by independently operating a seventh heating element in the fourth food holding zone and thermally coupled to the second top surface and independently operating an eighth heating element in the fourth food holding zone and thermally coupled to the second substantially planar surface;wherein the first temperature, second temperature, third temperature, and fourth temperature are independent from each other.

2. The method of claim 1, wherein the multi-zone food holding bin further comprises a shelf disposed between the first side panel and the second side panel, wherein a top surface of the shelf provides the first substantially planar bottom surface and a bottom surface of the shelf provides the second top surface.

3. The method of claim 1, wherein the multi-zone food holding bin further comprises a third food holding compartment within the chassis between the first food holding compartment and the second food holding compartment, the third food holding compartment comprising a fifth food holding zone and a sixth food holding zone, the third food holding compartment being defined by the first side panel, the second side panel, a third top surface, and a third substantially planar bottom surface of a thermally conductive material being substantially unobstructed between the first side panel and the second side panel and a third opening through the front face configured to allow a tray for food items to be passed through the third opening into the third food holding compartment and onto the third substantially planar surface, the method further comprising: operating the fifth food holding zone to a fifth temperature setpoint by independently operating a ninth heating element in the fifth food holding zone and thermally coupled to the third top surface and independently operating a tenth heating element in the fifth food holding zone and thermally coupled to the third substantially planar surface; andoperating the sixth food holding zone to a sixth temperature setpoint by independently operating an eleventh heating element in the sixth food holding zone and thermally coupled to the third top surface and independently operating a twelfth heating element in the sixth food holding zone and thermally coupled to the third substantially planar surface.

4. The method of claim 3, wherein the multi-zone food holding bin comprises a first shelf disposed between the first side panel and the second side panel and between the first compartment and the second compartment, wherein a first top surface of the first shelf provides the first substantially planar bottom surface and a first bottom surface of the first shelf provides the third top surface, and the multi-zone food holding bin further comprises a second shelf disposed between the first side panel and the second side panel and between the third compartment and the second compartment, wherein a second top surface of the second shelf provides the third substantially planar bottom surface and a second bottom surface of the second shelf provides the second top surface.

5. The method of claim 1, further comprising: receiving a first tray of a first food product through the first opening into the first food holding zone;receiving a second tray of a second food product through the first opening into the second food holding zone;receiving a third tray of a third food product through the second opening into the third food holding zone; andreceiving a fourth tray of a fourth food product through the second opening into the fourth food holding zone.

6. The method of claim 5 wherein the multi-zone food holding bin comprises a rear face and the method further comprises: providing a third opening through the rear face configured to allow the first or second tray to be passed through the third opening into the first food holding compartment and onto the first substantially planar surface; andproviding a fourth opening through the rear face configured to allow the third or fourth tray to be passed through the fourth opening into the second food holding compartment and onto the second substantially planar surface.

7. The method of claim 6, further comprising: receiving a tray of the first, second, third, and fourth trays, when said tray is filled with freshly cooked food product, through the respective third or fourth opening; andreceiving the tray of the first, second, third, and fourth trays, when food product has been removed from said tray, through the respective first or second opening.

8. The method of claim 1, wherein the multi-zone food holding bin comprises a plurality of bays, the plurality of bays comprising a first bay and a second bay within the first food heating zone, a third bay and a fourth bay within the second food heating zone, a fifth bay and a sixth bay within the third food heating zone, and a seventh bay and an eighth bay within the fourth food heating zone, wherein each bay of the plurality of bays is configured to receive a tray of food product.

9. The method of claim 8, further comprising plurality of lid holding shelves, a lid holding shelf of the plurality of lid holding shelves associated with each bay of the plurality of bays, wherein each lid holding shelf is configured to receive a lid thereon.

10. The method of claim 9, further comprising: receiving a first lid through the first opening into the first bay of the first food holding zone; andretaining the first lid within the first bay on the lid holding shelf associated with the first bay.

11. The method of claim 10, further comprising: receiving a first tray of a first food product through the first opening into the first bay of the first food holding zone onto the first substantially planar bottom surface below the first lid;receiving a second tray of a second food product through the first opening into the second bay of the first food holding zone onto the first substantially planar bottom surface; andmaintaining, with the first lid, an increased moisture within the first tray compared to a moisture within the second tray, while operating the first bay and the second bay of the first food holding zone to the first temperature setpoint by independently operating the first heating element and the second heating element.

12. The method of claim 9, wherein at least some of the lid holding shelves of the plurality of lid holding shelves downwardly depend from the first top surface towards the first substantially planar bottom surface, leaving the first substantially planar bottom surface substantially unobstructed between the first side panel and the second side panel.

13. The method of claim 12, further comprising providing a latch associated with at least one of the lid holding shelves, the latch movably secured to the front face.

14. The method of claim 13, further comprising biasing the latch into a position that retains a lid on the associated lid holding shelf with gravity.

15. The method of claim 14, further comprising providing a bezel set forward of the front face to form a gap between the front face and the bezel, wherein the latch moves within the gap.

16. The method of claim 1, further comprising receiving a user input of the first temperature setpoint.

17. The method of claim 16, wherein the user input is a user selection of a food item for the first food holding zone, wherein the user selection of the food item is associated with independent operation and control of the first heating element and the second heating element.

18. The method of claim 17, further comprising operating the first heating element to output more heat than the second heating element.

19. The method of claim 17, further comprising operating the second heating element to output more heat than the first heating element.

20. The method of claim 16, further comprising: providing a bezel set forward of the front face, the bezel comprising a user interface; andoperating the user interface to receive the user input.