Middleby has been granted a patent for a system and method to control the power supplied to heating elements in a conveyor oven. The system includes a controller that rapidly cycles relays connected to each heating element to achieve even heat distribution and reduce current draw during peak loads. The patent also describes a set of predetermined operations executed by the controller based on the measured temperature in the oven compartment. GlobalData’s report on Middleby gives a 360-degree view of the company including its patenting strategy. Buy the report here.
Middleby's grant share as of September 2023 was 59%. Grant share is based on the ratio of number of grants to total number of patents.
Patent granted for controlling power to heating elements in oven
A recently granted patent (Publication Number: US11771096B2) describes a conveyor oven with improved temperature control and energy efficiency. The oven includes an oven compartment, a conveyor, and multiple heating elements. A motor drives the conveyor, and a power supply distributes power to the heating elements. An electronic controller is connected to the power supply and relays that control the current flow to the heating elements.
The electronic controller is programmed to perform a set of predetermined operations when the measured temperature in the oven compartment is below a user-adjustable temperature setpoint. These operations involve selectively energizing and de-energizing the heating elements in a specific sequence and for predetermined periods of time. The controller repeats these operations until it receives a signal indicating that the measured temperature is equal to or higher than the setpoint, at which point the operations cease.
The patent also mentions that the predetermined periods of time for energizing and de-energizing the heating elements are equal within certain groups, but differ between groups. Additionally, the controller is configured to limit the maximum amount of time each heating element is energized during the operations. It can selectively actuate the relays to achieve a predetermined duty cycle, such as a 70% on and 30% off cycle, to further control the current draw of the heating elements.
Furthermore, the electronic controller is designed to ensure that the total current draw of the heating elements remains below a maximum current draw available. It achieves this by limiting the current draw of each heating element during the predetermined operations. The patent suggests that the maximum current draw can be between one-half and three-fourths of continuous operation.
Overall, this patented conveyor oven offers improved temperature control and energy efficiency through its precise and controlled operation of the heating elements. By optimizing the duty cycle and current draw, the oven can maintain consistent temperatures while minimizing energy consumption.