US4316078A — Food serving system

Claim 1

Independent Claim 279 words

A mobile food serving system for rethermalizing food and maintaining food temperature after rethermalization, said system comprising; mobile housing means having at least one tray supporting rack, an electrical energy source carried by and movable with the housing means, a tray removably supported on the rack and having a supporting surface for food containers, at least one food heater associated with the supporting surface and in thermal contact with a surface of the tray for good heat transfer thereto, selectable means in series with said heater for enabling coupling of energy source power to the heater, and control means coupled from the energy source for controlling food heating and temperature, said control means including manual mode control switch means having opposite mutually-exclusive single positions including a normal position associated with a normal heating period of the food, and a rethermalization position associated with a rethermalization period, means responsive to the normal operation position for coupling operating power to the food heater at a continuous rate with the switch means set at and maintained at said single normal position throughout said normal operation position, and first means responsive to the rethermalization position and including first timing means for coupling operating power to the food at a continuous rate for a predetermined interval of sufficient length to rethermalize the food at a first temperature range and second means responsive to termination of the predetermined interval for thereafter operating the heater at a lower power level to maintain the food heated to a second temperature range lower than the first temperature range, said switch means being set at and maintained at said single rethermalization position throughout both portions of said rethermalization period.

Claim 2

Dependent Claim 279 words

A mobile food serving system for rethermalizing food and maintaining food temperature after rethermalization, said system comprising; mobile housing means having at least one tray supporting rack, an electrical energy source carried by and movable with the housing means, a tray removably supported on the rack and having a supporting surface for food containers, at least one food heater associated with the supporting surface and in thermal contact with a surface of the tray for good heat transfer thereto, selectable means in series with said heater for enabling coupling of energy source power to the heater, and control means coupled from the energy source for controlling food heating and temperature, said control means including manual mode control switch means having opposite mutually-exclusive single positions including a normal position associated with a normal heating period of the food, and a rethermalization position associated with a rethermalization period, means responsive to the normal operation position for coupling operating power to the food heater at a continuous rate with the switch means set at and maintained at said single normal position throughout said normal operation position, and first means responsive to the rethermalization position and including first timing means for coupling operating power to the food at a continuous rate for a predetermined interval of sufficient length to rethermalize the food at a first temperature range and second means responsive to termination of the predetermined interval for thereafter operating the heater at a lower power level to maintain the food heated to a second temperature range lower than the first temperature range, said switch means being set at and maintained at said single rethermalization position throughout both portions of said rethermalization period.

Claim 3

Dependent Claim 21 words

A system as set forth in claim 1 wherein said housing means is in the form of a motor powered cart.

Claim 4

Dependent Claim 44 words

A system as set forth in claim 1 including a second switch substantially in parallel with the first switch and having a first power interrupting position for the purpose of loading trays and a second operate position for coupling energy to the one switch.

Claim 5

Dependent Claim 38 words

A system as set forth in claim 1 wherein said first means includes a first time delay means defining the predetermined interval and the second means includes a second time delay means defining a second predetermined time interval.

Claim 6

Dependent Claim 28 words

A system as set forth in claim 4 wherein said second means includes cyclic operating means including a repeat timer having an "on" period and an "off" period.

Claim 7

Dependent Claim 44 words

A system as set forth in claim 5 including a plurality of heaters each associated with a tray upon which the meal is disposed and separate selectable means for each heater wherein said repeat timer operates some heaters "on" while other heaters are "off".

Claim 8

Dependent Claim 37 words

A system as set forth in claim 1 wherein said source includes a rechargeable battery and further including external power receive means and means responsive to said external power for coupling said external power to said heater.

Claim 9

Dependent Claim 34 words

A system as set forth in claim 1 including a plurality of heaters each having a separate control line and separate selectable switch means including a switch means for selecting each heater for operation.

Claim 10

Dependent Claim 38 words

A system as set forth in claim 8 including a group of at least two heaters associated with a tray upon which the meal is disposed, each heater of the group having a switch means for selection thereof.

Claim 11

Dependent Claim 24 words

A system as set forth in claim 8 wherein the heaters are operated after the predetermined time interval at a fifty percent duty cycle.

Claim 12

Dependent Claim 16 words

A system as set forth in claim 10 including ready light means associated with each heater.

Claim 13

Dependent Claim 36 words

A system as set forth in claim 10 including means for operating one of the heaters of a group continuously when selected and for operating the other heater of the group first continuously and thereafter cyclically.

Claim 14

Dependent Claim 41 words

A system as set forth in claim 8 including means for sensing a tray in position to receive power when so selected and means responsive to an absence of any tray being in power receiving position for terminating the cyclic operation.

Claim 15

Independent Claim 236 words

A system for controlling a food heater comprising; means defining a source of electrical heating power, housing means having at least one tray supporting rack, a tray removably supported on the rack and having a supporting surface for food containers, a plurality of food heaters, and control means coupled from the source for controlling the heating power applied to the food heater, said control means comprising means for operating each heater at a continuous rate for a predetermined period of time to rethermalize the food and for operating said each heater cyclically on and off after the termination of said predetermined period of time to maintain the food hot, said plurality of heaters each associated with a tray upon which the meal is disposed and separate selectable means for each heater, said control means further comprising repeat cycle timer means to control the plurality of heaters so that some heaters are maintained operating while others are maintained off during a first phase of the food temperature maintenance period, and the other heaters are operated on while the said some heaters are operated off during a second phase of the food temperature maintenance period, and the other heaters are operated on while the said some heaters are operated off during a second phase of the food temperature maintenance period to thereby provide relatively uniform heat dissipation from the electrical heating source during said food temperature maintenance period.

Claim 16

Independent Claim 236 words

A system for controlling a food heater comprising; means defining a source of electrical heating power, housing means having at least one tray supporting rack, a tray removably supported on the rack and having a supporting surface for food containers, a plurality of food heaters, and control means coupled from the source for controlling the heating power applied to the food heater, said control means comprising means for operating each heater at a continuous rate for a predetermined period of time to rethermalize the food and for operating said each heater cyclically on and off after the termination of said predetermined period of time to maintain the food hot, said plurality of heaters each associated with a tray upon which the meal is disposed and separate selectable means for each heater, said control means further comprising repeat cycle timer means to control the plurality of heaters so that some heaters are maintained operating while others are maintained off during a first phase of the food temperature maintenance period, and the other heaters are operated on while the said some heaters are operated off during a second phase of the food temperature maintenance period, and the other heaters are operated on while the said some heaters are operated off during a second phase of the food temperature maintenance period to thereby provide relatively uniform heat dissipation from the electrical heating source during said food temperature maintenance period.

Claim 17

Dependent Claim 26 words

A system as set forth in claim 14 wherein said control means operates said heater at a continuous cycling rate for said predetermined period of time.

Claim 18

Dependent Claim 27 words

A system as set forth in claim 15 wherein the cycling during said predetermined period of time is at a higher duty cycle than the cycling thereafter.

Claim 19

Dependent Claim 30 words

A system as set forth in claim 14 wherein said control means comprises means for operating said heater at different power levels during and after said predetermined period of time.

Claim 20

Independent Claim 111 words

A system for controlling a food heater comprising; a mobile cart having means for receiving a plurality of trays, with each tray having at least one food heater associated therewith, means defining a source of DC power disposed aboard said mobile cart, means for receiving an input AC power signal, and control means having two states, and one state coupling DC power to the heater and the other state coupling input AC power to the heater, said AC power and DC power being applied in a mutually exclusive manner, and said control means being responsive to application of said AC power thereto to change from the first to the second state.

Claim 21

Independent Claim 111 words

A system for controlling a food heater comprising; a mobile cart having means for receiving a plurality of trays, with each tray having at least one food heater associated therewith, means defining a source of DC power disposed aboard said mobile cart, means for receiving an input AC power signal, and control means having two states, and one state coupling DC power to the heater and the other state coupling input AC power to the heater, said AC power and DC power being applied in a mutually exclusive manner, and said control means being responsive to application of said AC power thereto to change from the first to the second state.

Claim 22

Independent Claim 164 words

A system for controlling at least one food heater comprising; means defining a source of electrical heating power, housing means having at least one tray supporting rack, at least one tray removably supported on the rack and having a supporting surface for food containers, at least a pair of heaters associated with one tray, control means coupled from the source for controlling the heating power applied to the food heaters, said control means comprising first means for operating one of said heaters at a continuous rate under normal operation on a low wattage basis, and second means for operating the other heater of said pair of heaters to rethermalize the food under rethermalization operation at a continuous rate for a predetermined period of time to rethermalize the food on a higher wattage basis including means for thereafter operating said other heater at a lower wattage basis to maintain food temperature, and switch means for mutually exclusively selecting one of said first and second means.

Claim 23

Independent Claim 164 words

A system for controlling at least one food heater comprising; means defining a source of electrical heating power, housing means having at least one tray supporting rack, at least one tray removably supported on the rack and having a supporting surface for food containers, at least a pair of heaters associated with one tray, control means coupled from the source for controlling the heating power applied to the food heaters, said control means comprising first means for operating one of said heaters at a continuous rate under normal operation on a low wattage basis, and second means for operating the other heater of said pair of heaters to rethermalize the food under rethermalization operation at a continuous rate for a predetermined period of time to rethermalize the food on a higher wattage basis including means for thereafter operating said other heater at a lower wattage basis to maintain food temperature, and switch means for mutually exclusively selecting one of said first and second means.

Claim 24

Dependent Claim 37 words

A system as set forth in claim 21 wherein the current limiting means each include a resistor with the first resistor smaller than the second to provide a first heat level greater than the second heat level.

Claim 25

Independent Claim 168 words

A system for controlling at least one food heater comprising; means defining a source of electrical heating power, housing means having at least one tray supporting rack, at least one tray removably supported on the rack and having a supporting surface for food containers, at least one heater associated with the tray, a pair of current limiting means, means disposing the current limiting means parallel and coupled to the heater, and control means coupled from the source for controlling the heating power applied to the food heater, said control means comprising first timer means for coupling heating power to one of said current limiting means for a predetermined rethermalization period, said one current limiting means adapted to provide a first heating level, and second means responsive to termination of said rethermalization period for coupling heating power to the other of said pair of current limiting means, said other current limiting means adapted to provide a second heating level less than said first heating level for food temperature maintenance.

Claim 26

Independent Claim 168 words

A system for controlling at least one food heater comprising; means defining a source of electrical heating power, housing means having at least one tray supporting rack, at least one tray removably supported on the rack and having a supporting surface for food containers, at least one heater associated with the tray, a pair of current limiting means, means disposing the current limiting means parallel and coupled to the heater, and control means coupled from the source for controlling the heating power applied to the food heater, said control means comprising first timer means for coupling heating power to one of said current limiting means for a predetermined rethermalization period, said one current limiting means adapted to provide a first heating level, and second means responsive to termination of said rethermalization period for coupling heating power to the other of said pair of current limiting means, said other current limiting means adapted to provide a second heating level less than said first heating level for food temperature maintenance.

Claim 27

Independent Claim 164 words

A system for controlling at least one food heater comprising; means defining a source of electrical heating power, housing means having at least one tray supporting rack, at least one tray removably supported on the rack and having a supporting surface for food containers, at least one heater associated with the tray, means defining a first control path to the heater, means defining a second control path to the heater, means disposing the first and second paths in parallel, and control means coupled from the source for controlling the heating power applied to the food heater, said control means comprising first timer means for coupling heating power to said first path for a predetermined rethermalization period on a cycling basis and at a first duty cycle, and second means responsive to termination of said rethermalization period for coupling heating power to said second path on a cycling basis and at a second duty cycle lower than said first duty cycle for food temperature maintenance.

Claim 28

Independent Claim 164 words

A system for controlling at least one food heater comprising; means defining a source of electrical heating power, housing means having at least one tray supporting rack, at least one tray removably supported on the rack and having a supporting surface for food containers, at least one heater associated with the tray, means defining a first control path to the heater, means defining a second control path to the heater, means disposing the first and second paths in parallel, and control means coupled from the source for controlling the heating power applied to the food heater, said control means comprising first timer means for coupling heating power to said first path for a predetermined rethermalization period on a cycling basis and at a first duty cycle, and second means responsive to termination of said rethermalization period for coupling heating power to said second path on a cycling basis and at a second duty cycle lower than said first duty cycle for food temperature maintenance.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1985-02-15	1985-08-17	1986-02-16	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1989-02-15	1989-08-17	1990-02-16	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1993-02-15	1993-08-17	1994-02-16	$7700.00	Window Closed / Lapsed

Food serving system

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