Penetration type washing machine, method for controlling the same, and tub cover for the same

A method for controlling a washing machine, the washing machine comprising:

• an outer tub mounted in a washing machine body, for storage of washing water;
• an inner tub rotatably mounted in the outer tub and having a plurality of washing holes in a wall thereof for discharge of the washing water to the outer tub;
• a pulsator rotatably mounted as one unit with the inner tub;
• a motor directly coupled to the inner tub and the pulsator;
• and,
• a tub cover mounted on a top of the outer tub for guiding the washing water to the inner tub when the washing water is circulated from the inner tub to the inner tub again through the outer tub by the high speed rotation of the motor,
• wherein the inner tub is rotated at a high speed over a predetermined speed in a regular or a reverse direction by the motor, the washing water penetrates through the laundry at a speed higher than a required speed by a centrifugal force generated by the high speed rotation of the inner tub and circulates to the inner tub again through a space between the inner tub and the outer tub, and the laundry is dropped by an inertia caused by a rotation direction change of the inner tub, whereby making a washing done.

A tub cover mounted on a top of an outer tub of a washing machine for preventing noise and foam overflow, the tub cover comprising:

• an upper surface portion of a substantially annular form on a top of the outer tub;
• a tight fit portion projected in up and down direction from an outer circumference of the upper surface portion for tight fit to an inside surface of the outer tub;
• a fastening portion extended from the tight fit portion in a horizontal direction for being fastened to the outer tub;
• a downward projection between the tight fit portion and the fastening portion;
• and,
• a sealing member for insertion into a space between the tight fit portion and the fastening portion.

A method for controlling a washing machine, comprising:

• (1) a laundry moving step for rotating an inner tub formed as a unit with a pulsator at a high speed over a required speed in one direction for moving laundry against a wall of the inner tub;
• (2) a washing water penetrating step for carrying out washing or rinsing as the washing water penetrates through the laundry by the high speed rotation of the inner tub;
• (3) a washing water pumping step for discharging the washing water passed through the laundry to an outer tub through washing holes formed in the inner tub, and, therefrom, moving the washing water upward;
• (4) a circulating step for circulating the pumped washing water to an inside of the inner tub by using the tub cover;
• and,
• (5) repeating the steps (1)˜(4) by rotating the motor at a high speed in a reverse direction.