Conveyor speed control system
AssigneeHatco Corporation
InventorJefferson Leach
Life of this patent
Estimating the term…
Abstract
A toaster includes a housing, a conveyor configured to support food products, a motor configured to drive the conveyor to move the food products through the housing, a heating element disposed adjacent the conveyor and configured to emit thermal energy toward the food products as the food products are moved through the housing, a temperature sensor configured to sense a temperature within the housing, and a controller operatively coupled to the temperature sensor and configured to control the motor to drive the conveyor at a conveyor speed. The controller is configured to store the sensed temperature within the housing as a function of time and calculate a derivative of the sensed temperature with respect to time. The controller is configured to vary the conveyor speed based on a value of the derivative.
Claims20
A toaster, comprising:
- a housing;
- a conveyor configured to support food products;
- a motor configured to drive the conveyor to move the food products through the housing;
- a heating element disposed adjacent the conveyor and configured to emit thermal energy toward the food products as the food products are moved through the housing;
- a temperature sensor configured to sense a temperature within the housing;
- and
- a controller operatively coupled to the temperature sensor and configured to:
- control the motor to drive the conveyor at a conveyor speed;
- store the sensed temperature within the housing as a function of time;
- calculate a derivative of the sensed temperature with respect to time;
- vary the conveyor speed according to a first motor speed compensation formula;
- determine a predicted derivative of the sensed temperature based on current operating conditions of the toaster;
- determine that a change in an amount of food products being heated has occurred in response to comparing the derivative to the predicted derivative;
- and
- vary the conveyor speed according to a second motor speed compensation formula in response to a determination that the amount of food products being heated has changed.
A control system for a toaster including a motor configured to drive a conveyor to move food products past a heating element, comprising:
- a temperature sensor configured to sense a temperature within a housing of the toaster;
- and
- a controller operatively coupled to the temperature sensor and configured to:
- control the motor to drive the conveyor at a conveyor speed;
- store the sensed temperature within the housing as a function of time;
- calculate a derivative of the sensed temperature with respect to time;
- vary the conveyor speed according to a first motor speed compensation formula;
- determine a range of predicted derivatives of the sensed temperature based on current operating conditions of the toaster:
- determine that a change in an amount of food products being heated has occurred in response to the derivative being outside of the range of predicted derivatives;
- and
- vary the conveyor speed according to a second motor speed compensation formula in response to a determination that the amount of food products being heated has changed.
A method of controlling a speed at which a motor drives a conveyor to move food products through a toaster, comprising:
- determining a first output speed of the motor according to a first motor speed compensation formula;
- controlling the speed of the motor to operate at the first output speed;
- sensing a temperature within the toaster at multiple points in time;
- storing the sensed temperature as a function of time;
- calculating a derivative of the sensed temperature with respect to time;
- calculating a predicted derivative of the sensed temperature based on current operating conditions of the toaster;
- determining that a change in an amount of food products being heated has occurred by comparing the derivative to the predicted derivative;
- determining a second output speed of the motor according to a second motor speed compensation formula in response to a determination that the amount of food products being heated has changed;
- and
- controlling the speed of the motor to operate at the second output speed.
Dependencies are inferred from the claim text.