John M Thorn Deceased7370 Maple Ave, Saint Louis, MO 63143

6393918, May 28, 2002

Jul 2, 2001

09/897840

Alan P. French - Florissant MO
John S. Thorn - Florissant MO

Emerson Electric Co. - St. Louis MO

G01M 1300

73660, 68 231

The present invention concerns a method and device for detecting an imbalance condition in a rotating washing machine tub. An indication of a power level required to maintain a given washing machine rotation speed is compared to a predefined standard power level associated with the given rotation speed, and a tub imbalance condition is detected in response to the comparison. The predefined standard power level may be stored in a memory device accessible by a processor that is programmed to calculate the power level required to achieve the given washing machine rotation speed and compare the required power level to the predefined standard power level to detect the tub imbalance condition.

5447414, Sep 5, 1995

May 27, 1994

8/250296

Craig Nordby - Chesterfield MO
John S. Thorn - Florissant MO
James Skinner - Florissant MO

Emerson Electric Co. - St. Louis MO

F04B 4906

417 20

Air handling apparatus (10) for delivering a volume of air at a generally constant flow rate regardless of changes in the operating conditions of a system with which the apparatus is used. A blower (12) pushes air from one point to another. The blower is operated by a blower motor (14). A switch (16) controls application of power to the motor. Sensors (20) are used to sense the voltage supplied to the motor, the current drawn by the motor, and the motor's operating speed. A flow controller (22) establishes a desired air flow rate to be provided by the blower. A processor (18) is responsive to the sensed voltage (V), current (I), and speed (S), an input (C) from the flow controller, and constants (K1-K4) related to performance characteristics of the blower to determine a torque required by the motor to produce a predetermined air flow rate. The torque value is determined as a function of the combined motor speed input from the sensor and an input from the flow controller. The processor is responsive to a calculated torque value for the motor.

6282965, Sep 4, 2001

Nov 20, 1998

9/197272

Alan P. French - Florissant MO
John S. Thorn - Florissant MO

Emerson Electric Co. - St. Louis MO

G01M 1300

73660

A method and system for detecting an imbalance condition in a rotating washing machine tub includes receiving an indication of the actual tub rotation speed, comparing the actual tub rotation speed to a predetermined desired rotation speed to calculate a speed error, and determining maximum and minimum speed errors. The difference between the maximum and minimum speed error is calculated, and a tub imbalance condition is detected based at least in part on the calculated difference. In one embodiment, the speed error is input to a controller that produces an output used to minimize the absolute speed error. The difference between the minimum and maximum controller output is then used to determine tub imbalance. In another aspect of the invention, the method and system include receiving an indication of a power level required to achieve a given washing machine rotation speed and comparing the required power level to a predefined standard power level associated with the given rotation speed. A tub imbalance condition is detected in response to the comparison.