Food heating unit

• US 5,961,866 A
• Filed: 12/11/1998
• Issued: 10/05/1999
• Est. Priority Date: 03/27/1996
• Status: Expired due to Fees

• Current Assignee: Alto-Shaam Incorporated
• Original Assignee: Alto-Shaam Incorporated
• Inventors: Hansen, William J.
• Primary Examiner(s): Pelham, Jospeh
• Application Number:
  US09/210,193
• Time in Patent Office: 298 Days
• Field of Search: 219/403, 219/407, 219/409, 219/412, 219/413, 219/429, 219/433, 219/434, 219/436, 219/438, 219/447, 219/458, 219/459, 219/463, 219/467, 219/544, 219/448, 219/494
• US Class Current: 219/434
• CPC Class Codes: A47J 27/004 with integral electrical heating means drinking cups with integral heating means A47J36/2466
• CPC Class Codes: A47J 36/2483 with electrical heating means

Abstract

A food warming and holding receptacle lowered by a source of electrical energy comprises a well supported on a planar surface , and at least one tray containing food disposed in the well. A sheath is fixed to the well and at one-piece, flattened, looped heating element is slidably mounted in the she the and connected with the source of electrical energy for conveying heat to the food in the tray. A temperature sensor is slidably mounted in the sheath for monitoring the temperature of the heating element.

Claims

1. A burnerless heating unit for supporting food therein comprising:

a single, flattened wall defining a base of a open well;

a sheath permanently connected to said well;

a completely flattened, serpentine-shaped heating element slidably disposed for movement into and out of said sheath for maximizing heat transfer to said wall, said heating element being isolated between said wall and said sheath to superheat an air space above aid wall;

a control operably connected with said heating element for controlling the temperature thereof;

a sensor interconnected with said control and slidably mounted for movement into and out of said sheath for sensing the temperature supplied by said heating element, and a V-shaped holder slidably mounted in said sheath, said holder being engageable with said sensor.

2. The heating unit of claim 1, wherein said heating element defines a heating zone relative to said wall.

3. A food warming and holding receptacle powered by a source of electrical energy, the receptacle comprising:

a well supported on a planar surface;

at least one tray containing food disposed in said well;

a sheath permanently fixed to said well;

a one-piece, completely flattened, multiple-looped heating element slidably mounted in said sheath and connected with said source of electric energy for conveying heat to the food in said tray, wherein said heating element is a continuous member having a pair of terminals connectable with said source of electrical energy;

a temperature sensor slidably mounted in said sheath between adjacent loops of said heating element and operably connected to said source of electrical energy, and a temperature sensor holder having V-shaped walls within which said temperature sensor is retained, said holder being slidably inserted in said sheath.

4. A burnerless, warming well-type food heating apparatus connected to a source of electrical energy, the apparatus comprising:

a well including a stainless steel base mounted on a planar surface, said base having an inner surface and an outer surface, said base having a plurality of spaced apart support brackets extending from said inner surface thereof;

a series of trays containing food, each of said trays having a length and a width, each of said trays being suspended in said well above said inner surface by an adjacent pair of said support brackets and defining an air space bounded by said inner surface, said adjacent pair of support brackets, and a exterior surface of said tray;

a multiplicity of stainless steel sheaths, each of said sheaths lying substantially coextensive with the length and width of one of said trays and being permanently mounted to said outer surface between said adjacent pair of support brackets so as to minimize warpage of said base;

a completely flattened, serpentine-shaped, rigid heating element comprised of a cluster of nickel-chromium resistant wires and slidably mounted in each of said sheaths and lying substantially coextensive with the length and the width of each of said trays, said heating element having terminals protruding from said sheath when mounted therein and connected to a source of electrical energy for controllably superheating said air space and localizing heat transfer to the food in each of said trays;

a control operably connected with said heating element for controlling the temperature thereof;

wherein each of said heating elements is a continuous member having four runs, each adjacent pair of runs being interconnected by a bend;

each of said sheaths being surrounded by a jacket depending from said outer surface of said base and having a width and length substantially coextensive with said tray; and

a layer of insulation disposed between said sheath and said jacket,

said heating element comprised of nickel-chromium resistant wires being isolated in said sheath below said base and lying coextensive with said length and width of said tray to provide indirect heat to said base and then to said air space thereby individually controlling a heating zone around and beneath said tray to more efficiently maintain the desired warmth of food in said tray,

an elongated V-shaped sensor holder slidably mounted between adjacent runs of said heating element, a portion of said holder being disposed between said base and said heating element; and

an elongated temperature sensor slidably mounted in an apex of said V-shaped holder for a feedback of temperature to said control.

5. A method of supplying a burnerless heating unit for supporting food therein, said method comprising the steps of:

providing a single, flattened wall defining the base of an open well;

permanently connecting a sheath to said wall;

disposing a completely flattened, serpentine-shaped heating element having multiple loops for slidable movement into and cut of said sheath for maximizing heat transfer to said wall, said heating element being isolated between said wall and said sheath to enable superheating of an air space above said wall;

sliding a V-shaped holder between adjacent loops of said heating element and between said base and said sheath; and

sliding a temperature sensor into said holder.