US 12,262,718 B2Granted

Power modulator for infrared conveyor oven

AssigneeThe Middleby Corporation

InventorsWilliam S. Schjerven, Sr., James Jeffery Hanson, Ricky Joe Sullivan McIntosh

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Abstract

A system and method to control the power supplied to heating elements of a conveyor oven. The conveyor oven includes a plurality of heating elements to evenly distribute heat in an oven compartment. During peak-loads, the current draw of the heating elements may exceed available power of a power supply. Therefore, a system and method to reduce the total current draw of the plurality of heating elements is provided. The system includes a controller configured to perform the methods disclosed herein. The methods effectively lower the total current draw by rapidly cycling a plurality of relays connected to each of the plurality of heating elements to achieve even distribution of heat and reduced current draw during peak-loads.

Claims20

Dependent claims

A conveyor oven comprising:

an oven compartment;
a conveyor extending through the oven compartment;
a motor that drives the conveyor;
a first heating element,
a first relay that controls a current flow to the first heating element;
a second heating element,
a second relay that controls a current flow to the second heating element;
a third heating element,
a third relay that controls a current flow to the third heating element;
a power supply that receives external power and distributes power to the first heating element, the second heating element, and the third heating element;
and
an electronic controller electrically coupled to the power supply and to the first relay, the second relay, and the third relay, the electronic controller configured to:
execute a set of predetermined operations when a measured temperature in the oven compartment is less than a user adjustable temperature setpoint,
repeat the set of predetermined operations until the electronic controller receives a signal indicating that the measured temperature is equal to or greater than the user adjustable temperature setpoint, and
cease the set of predetermined operations upon receipt by the electronic controller of the signal indicating that the measured temperature is equal to or greater than the user adjustable temperature setpoint;
wherein the set of predetermined operations includes:
actuating the second relay and the third relay to energize the second heating element and the third heating element for a first predetermined period of time while the first heating element is de-energized during the first predetermined period of time,
actuating the second rely after the first predetermined period of time to de-energize the second heating element,
actuating the first relay after a second predetermined period of time to energize the first heating element,
actuating the third rely after a third predetermined period of time to de-energize the third heating element,
actuating the second relay after a fourth predetermined period of time to energize the second heating element,
actuating the first rely after a fifth predetermined period of time to de-energize the first heating element, and
actuating the third relay after a sixth predetermined period of time to energize the third heating element;
wherein the first predetermined period of time, the third predetermined period of time, and the fifth predetermined period of time are equal to one another and each are longer than the second predetermined period of time, the fourth predetermined period of time, and the sixth predetermined period of time, respectively, such that no more than three heating elements are energized simultaneously at any given time.

21 more elements

A system for controlling a conveyor oven, the system comprising:

an electronic controller electrically coupled to a power supply and to a first relay, a second relay, and a third relay;
wherein the electronic controller is configured to:
execute a set of predetermined operations when a measured temperature is less than a user adjustable temperature setpoint, and
repeat the predetermined set of operations until the measured temperature is equal to or greater than the user adjustable temperature setpoint,
wherein the set of predetermined operations includes:
actuating the second relay and the third relay to energize a second heating element and a third heating element for a first predetermined period of time while a first heating element is de-energized during the first predetermined period of time,
actuating the second rely after the first predetermined period of time to de-energize the second heating element,
actuating the first relay after a second predetermined period of time to energize the first heating element,
actuating the third rely after a third predetermined period of time to de-energize the third heating element,
actuating the second relay after a fourth predetermined period of time to energize the second heating element,
actuating the first rely after a fifth predetermined period of time to de-energize the first heating element, and
actuating the third relay after a sixth predetermined period of time to energize the third heating element,
wherein the first predetermined period of time, the third predetermined period of time, and the fifth predetermined period of time are equal to one another and each are longer than the second predetermined period of time, the fourth predetermined period of time, and the sixth predetermined period of time, respectively, such that no more than three heating elements are energized simultaneously at any given time.

10 more elements

A non-transitory computer-readable medium including instructions executable by an electronic controller to perform a set of functions, the set of functions comprising:

executing a set of predetermined operations when a measured temperature is less than a user adjustable temperature setpoint, and
repeating the set of predetermined operations until the measured temperature is equal to or greater than the user adjustable temperature setpoint,
wherein the set of predetermined operations includes:
actuating a second relay and a third relay to energize a second heating element and a third heating element for a first predetermined period of time while a first heating element is de-energized during the first predetermined period of time,
actuating the second rely after the first predetermined period of time to de-energize the second heating element,
actuating a first relay after a second predetermined period of time to energize the first heating element,
actuating the third rely after a third predetermined period of time to de-energize the third heating element,
actuating the second relay after a fourth predetermined period of time to energize the second heating element,
actuating the first rely after a fifth predetermined period of time to de-energize the first heating element, and
actuating the third relay after a sixth predetermined period of time to energize the third heating element,
wherein the first predetermined period of time, the third predetermined period of time, and the fifth predetermined period of time are equal to one another and each are longer than the second predetermined period of time, the fourth predetermined period of time, and the sixth predetermined period of time, respectively, such that no more than three heating elements are energized simultaneously at any given time.

8 more elements

Dependencies are inferred from the claim text.

Facts

Application: 18/455,991Filed 25 Aug 2023 · continuation
Priority: 13 May 2015
Published: US 2023/0404085 A121 Dec 2023
Granted: 1 Apr 2025
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

A21B 1/40
Bakers' ovens: characterised by the means for regulating the temperature
A21B 1/22
Ovens heated by radiators: by electric radiators
A21B 1/48
Characterised by the baking surfaces moving during the baking: with surfaces in the form of an endless band
H05B 1/0263
Of food: ovens

Family

Application14/710,841Parent of this continuation · filed 13 May 2015
Application17/190,244Parent of this continuation · filed 2 Mar 2021
US 2023/0404085 A1Pre-grant publication · published 21 Dec 2023
US 11,771,096 B2Parent of this continuation
US 2016/0330978 A1Published application
US 2021/0176997 A1Published application
US 12,262,718 B2This patent

From the US filing history. Foreign family members aren’t listed.