US 5,705,791 AGranted

Automatic toaster and a control therefor

AssigneeWhirlpool Corporation

InventorsTimothy B. Sutton, Donald E. Schnautz, Patrick L. Glotzbach, Arlene Richardson

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Abstract

An automatic countertop toaster and its control that divides the toasting cycle into three thermodynamic phases related to a change in the physical characteristics of the toaster and the item being toasted. The time of each of the three phases is adjusted according to the user inputs and current conditions to obtain the proper toasting time. The invention disclosed uses a microcomputer to interface with the user and control the toaster. The measured or estimated time since the last toasting cycle and the temperature inside the toaster are used by the microcomputer in table lookups to set the times for the three thermodynamic phases of the toasting cycle. Two of the phases are further modified by the toasting mode (normal, frozen, bagel, frozen bagel, reheat) and the toast darkness setting selected by the user. The sum of the three phases after modification is the total toasting time.

Claims21

Dependent claims

A method for determining a toasting time for an automatic toaster comprising a housing having an opening providing access to a toasting area, a heating element positioned within the toasting area for imparting heat to a toast article, and a toaster control for controlling the operation of the toaster, including the duration of the operation of the heating element, the toaster control including a microprocessor and a user input for selecting operational modes and toast darkness levels, the method comprising:

determining a first time period which represents the time it takes for the heating element to warm up and begin transferring heat to a toast article;
determining a second time period which represents the time from the beginning of the transferring of heat to the beginning of the browning of the toast article;
and
determining a third time period which represents the time from the beginning of the browning until reaching the desired darkness level of the toast article;
whereby the sum of the first, second, and third time periods is the toasting time.

2 more elements

Dependencies are inferred from the claim text.