Electric heating – Heating devices – Combined with container – enclosure – or support for material...
Reexamination Certificate
2001-10-05
2003-01-21
Pelham, Joseph (Department: 3742)
Electric heating
Heating devices
Combined with container, enclosure, or support for material...
C219S386000, C219S432000, C219S402000, C219S542000
Reexamination Certificate
active
06509550
ABSTRACT:
BACKGROUND OF INVENTION
1. Field of Invention
The present invention relates to cooking appliances and, more particularly, to a large capacity, roasting oven having a wrap-around type heating element for applying heat to the cooking vessel and a top heater element for browning.
Electric cooking pots for preparing and serving hot foods are well known to those skilled in the art. Such electric cooking pots typically include a heating element arranged in functional relation underneath the bottom surface of the cooking well for supplying heat. Such cooking wells are often constructed of stainless steel or enameled steel for reasons of durability and sanitation. However, it is known that both stainless steel and enameled steel have relatively low coefficients of heat conductivity as compared with other metals.
This presents a particular problem for cooking vessels of large capacity (ie. up to 26 quarts). Applying heat only to the bottom surface of such a large capacity cooking vessel, especially when constructed of stainless steel or enameled steel, can result in the upper portion of the cooking vessel being insufficiently heated. Thus, the food in the upper portion of the cooking vessel may become too cool for serving purposes due to the loss of heat in combination with the low rate of heat conductivity and the slow rate at which heat is supplied to the upper portion of the cooking vessel.
The heat distribution problem is compounded in a roasting oven of large capacity and cannot be resolved by simply increasing the power output of the heating element. This is due to the fact that the increased heater output tends to overheat and to cause malfunction of the temperature control components and electronic circuitry, which are typically contained within the oven housing. Thus, the present roasting oven with a food serving system has been developed to solve these problems and other shortcomings of the prior art.
2 Description of the Prior Art
One example of a prior art deep well cooker is disclosed in U.S. Pat. No. 4,024,377 to Henke comprising a heat sink preferably formed of aluminum or another corrosion resistant metal having a relatively high coefficient of heat conductivity, which is positioned over the deep well member from below. The heat sink member is generally U-shaped and has a bottom part parallel to and spaced from the bottom of the well member and side parts parallel to and engaging the sides of the well member in heat exchanging relation. An electric heating element is disposed in the space between the bottom of the well member and the bottom part of the U-shaped heat sink member. When the electric heater is energized, heat is supplied to the bottom of the well member by direct radiation and by radiation from the bottom part of the U-shaped member and by convection due to the air in the space occupied by the heating element. Simultaneously, however, heat also flows from the bottom part of the U-shaped member, up side parts of the U-shaped member, and into the sides of the well member. The heat supplied by conduction to the sides of the well member provides for more uniform heating of the well member while also providing for more efficient utilization of the energy supplied to the heating element. However, this device is designed for use with a deep well cooker having a capacity of approximately 8-12 quarts based on the dimensions provided in the specifications. This device necessarily becomes less efficient when applied to a larger capacity cooker having increased side wall dimensions.
Another example of a prior art cooking device having multiple heating elements is disclosed in U.S. Pat. No. 3,393,295 to Jepson et. al. comprising a pan with a lower electric heating element supported on its underside and a deep cover with an upper heating element supported within. A thermostatic control is connected to the lower heating element for energization thereof When the cover is closed, an electrical connection for energizing the upper heating element is completed. The control serves thermostatically to control the energization of either element in a repeating, alternating sequence and is capable of performing the functions of a frying pan, broiler, and oven. However, this invention is not directly applicable to deep well cookers nor does it disclose a wraparound heating element for controlling heat distribution to the upper surfaces of a deep well member within such a cooker.
Thus, the present invention has been developed to provide a solution to the problem of regulating the distribution of heat to all surfaces within a deep well cooker having a large capacity up to 26 quarts.
SUMMARY OF THE INVENTION
Accordingly, the present invention provides an roasting oven having a large capacity (i.e. up to 26 quarts) that includes a wrap-around heating element, which is disposed about the heating well for heating the sides thereof and a top heating element for browning (ie. to scorch slightly in cooking) mounted within the oven lid. The wrap-around heating element and the top heating element are interconnected by a temperature control for heat regulation and a function control switch for selectively energizing the desired heating elements individually or in combination. Both the wrap-around heating element and the top heating element are constructed of mica insulation board with die-cut notches formed along the lateral edges thereof to permit uniformly spaced winding of heater wires for even heating. In the present invention the power supply circuit board is located within a vented exterior compartment on the bottom surface of the roasting oven to avoid the high temperature environment inside the housing. The present roasting oven includes serving containers for maintaining the cooked food in ready-to-eat condition and for reheating leftover food items.
Other features and technical advantages of the present invention will become apparent from a study of the following description and the accompanying drawings.
REFERENCES:
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patent: 5526734 (1996-06-01), Harrison
patent: 5590583 (1997-01-01), Harrison
patent: 6170388 (2001-01-01), Shovick
patent: 6274847 (2001-08-01), Hlava et al.
patent: 3606800 (1987-09-01), None
Pelham Joseph
Rey Clifford E.
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