Washing machine with a variable pulsator

A washing machine with a variable pulsator, comprising:

• a stationary tub for receiving washing water during a washing operation;
• a rotating shaft disposed at a center of a bottom of the stationary tub, the rotating shaft being a double shaft composed of a pulsator-rotating shaft and a washing tub-rotating shaft, the rotating shaft having first axial grooves;
• a washing tub installed in the stationary tub under a rotatable condition with the washing tub-rotating shaft, the washing tub having a plurality of washing water communication holes, and the washing tub having a spiral guide groove formed on its lower inner surface;
• a pulsator installed at a lower part of the pulsator-rotating shaft in the washing tub under a rotatable condition with the pulsator-rotating shaft,
• the pulsator having a main body of a round plate shape having an opening formed at its center, a plurality of communication holes through which washing fluid flows freely, and a plurality of ribs formed on an upper surface of the main body,
• the pulsator having guide projections formed on an outer-circumferential face of the main body of round plate shape at a corresponding position to the spiral guide groove formed at a lower inner surface of the washing tub, and
• the pulsator having second axial grooves which are to be spline-engaged with the first axial grooves and which are formed on an inner-circumferential face of its main body, so that while the pulsator is rotated by the pulsator-rotating shaft, the pulsator is movable up or down along the pulsator-rotating shaft depending on the rotating direction;
• a variable pulsator disposed at an upper part of the pulsator on the pulsator-rotating shaft under a rotatable condition with the pulsator-rotating shaft, a width of the variable pulsator becoming wider or narrower depending on an upward or a downward movement of the pulsator in rotation of the pulsator-rotating shaft,
• the variable pulsator having a hollow body of which plane cross section has a star shape, the variable pulsator having a bottom part with an opening formed at its center, inner-circumferential face of which is provided with third axial grooves which are spline-engaged with the first axial grooves, and
• the variable pulsator having a spring therein through which the pulsator-rotating shaft is inserted, so that the bottom of the variable pulsator is tightly contacted with a top part of the pulsator by its elasticity,
• so that, in rotation of the pulsator-rotating shaft, when the pulsator is moved upwardly with rotation of the pulsator, the bottom part of the variable pulsator contacted on the pulsator is moved upwardly and thereby a width of the variable pulsator becomes wider and when the pulsator is moved downwardly, the bottom part of the variable pulsator contacted on the pulsator is moved downwardly and thereby the width of the variable pulsator becomes narrower, and
• a driving part for rotating only the pulsator-rotating shaft or for rotating both the pulsator-rotating shaft and the washing tub-rotating shaft depending on a washing mode in order to operate the washing tub, the pulsator, and the variable pulsator.