Conveyor speed control system

Patent metadata

Field	Value
Publication number	US-2018317709-A1
Application number	US-201815971771-A
Country	US
Kind code	A1
Filing date	May 4, 2018
Priority date	May 5, 2017
Publication date	Nov 8, 2018
Grant date	—

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.

First claim

What is claimed is:

1 . 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, wherein the controller is configured to store the sensed temperature within the housing as a function of time, wherein the controller is configured to calculate a derivative of the sensed temperature with respect to time, and wherein the controller is configured to vary the conveyor speed based on a value of the derivative.

2 . The toaster of claim 1 , further comprising a speed adjustment input device operatively coupled to the controller, wherein the speed adjustment input device is configured to provide a speed setting for the motor, and wherein the controller is configured to vary the conveyor speed based on the speed setting.

3 . The toaster of claim 1 , wherein the controller is configured to use the derivative to determine if a change in an amount of food products being heated has occurred, and wherein the controller is configured to vary the conveyor speed based on whether or not the change in the amount of food products being heated has occurred.

4 . The toaster of claim 3 , wherein the controller is configured to determine a predicted derivative of the sensed temperature based on current operating conditions of the toaster, and wherein the controller is configured to compare the derivative to the predicted derivative in order to determine whether or not the change in the amount of food products being heated has occurred.

5 . The toaster of claim 3 , wherein the controller is configured to determine whether or not the change in the amount of food products being heated has occurred by comparing the derivative to a threshold value.

6 . The toaster of claim 1 , wherein the controller is configured to determine a predicted steady state temperature within the housing, and wherein the controller is configured to vary the conveyor speed based on the predicted steady state temperature.

7 . The toaster of claim 1 , wherein the controller is configured to vary the conveyor speed based on at least one of (a) if the toaster is in a heatup operation, (b) if the toaster is in a cooldown operation, (c) a type of the food products being heated, and (d) specifications of the toaster.

8 . 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, wherein the controller is configured to store the sensed temperature within the housing as a function of time, wherein the controller is configured to calculate a derivative of the sensed temperature with respect to time, and wherein the controller is configured to vary the conveyor speed based on a value of the derivative.

9 . The control system of claim 8 , further comprising a speed adjustment input device operatively coupled to the controller, wherein the speed adjustment input device is configured to provide a speed setting for the motor, and wherein the controller is configured to vary the conveyor speed based on the speed setting.

10 . The control system of claim 8 , wherein the controller is configured to use the derivative to determine if a change in an amount of food products being heated has occurred, and wherein the controller is configured to vary the conveyor speed based on whether or not the change in the amount of food products being heated has occurred.

11 . The control system of claim 10 , wherein the controller is configured to determine a predicted derivative of the sensed temperature based on current operating conditions of the toaster, and wherein the controller is configured to compare the derivative to the predicted derivative in order to determine whether or not the change in the amount of food products being heated has occurred.

12 . The control system of claim 10 , wherein the controller is configured to determine whether or not the change in the amount of food products being heated has occurred by comparing the derivative to a threshold value.

13 . The control system of claim 8 , wherein the controller is configured to determine a predicted steady state temperature within the housing, and wherein the controller is configured to vary the conveyor speed based on the predicted steady state temperature.

14 . The control system of claim 8 , wherein the controller is configured to vary the conveyor speed based on at least one of (a) if the toaster is in a heatup operation, (b) if the toaster is in a cooldown operation, (c) a type of the food products being heated, and (d) specifications of the toaster.

15 . A method of controlling a speed at which a motor drives a conveyor to move food products through a toaster, comprising:
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; determining an output speed of the motor based on a value of the derivative; and controlling the speed of the motor to operate at the output speed.

16 . The method of claim 15 , further comprising receiving a speed setting for the motor from a speed adjustment input device, wherein the output speed of the motor is determined based on the speed setting.

17 . The method of claim 15 , further comprising using the derivative to determine if a change in an amount of food products being heated has occurred, wherein the output speed of the motor is determined based on whether or not the change in the amount of food products being heated has occurred.

18 . The method of claim 17 , further comprising determining a predicted derivative of the sensed temperature based on current operating conditions of the toaster, wherein the derivative is compared to the predicted derivative when using the derivative to determine if the change in the amount of food products being heated products has occurred.

19 . The method of claim 17 , wherein the derivative is compared to a threshold value when using the derivative to determine if the change in the amount of food products being heated has occurred.

20 . The method of claim 15 , further comprising:
determining a predicted steady state temperature within the toaster; and varying the output speed based on the predicted steady state temperature.

Assignees

• Hatco Corp

Inventors

• Leach Jefferson

Classifications

• A47J37/0835 Primary

  with thermal timers · CPC title

• A47J37/0857

  with bread supports or heating means movable during the toasting operation · CPC title