Abstract: An automatic washing machine and a method for confirmation of a washing machine clutching operation which achieves the desired mode conversion between a washing mode and a dehydrating mode by ascending and descending its inner tub. The washing machine includes an outer tub, a perforated movable inner tub, a buoyancy generator for lifting the inner tub in accordance with a water level in the outer tub, a motor mounted on the outer bottom center of the outer tub, a rotator mounted on a top end of the motor shaft, and a clutching unit for selectively coupling the inner tub to either the outer tub or the rotator according to the position of the inner tub ascending and descending under the guide of the motor shaft. To confirm the clutching operation, a driving time or a driving stop time of the motor is counted and compared with a predetermined reference time.

Abstract: An automatic washing machine having a floating member for selectively engaging the inner tub with the rotator or with the outer tub. The outer tub has first teeth on its inner bottom and the inner tub has a through hole on its bottom, and the rotator has second teeth on its lower surface. The drive motor is mounted on the outer bottom center of the outer tub and its output shaft rotatably penetrates the bottom centers of the tubs. The lever having the floating member and a moving tooth on its opposed ends is hinged to a housing between bottoms of the tubs. The selective engagement of the inner tub with the rotator or with the outer tub is achieved by selective engagement of the moving tooth with the second teeth or with the first teeth in accordance with a fluctuating movement of the floating member caused by buoyancy of the washing water in the outer tub.