BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a washing machine, more particularly, to a washing machine having a floatage clutch that perform&#39;s the intermittence of power in cleansing and dehydrating operations by using the floatage thereof.  
           [0003]    2. Description of the Related Art  
           [0004]    Generally speaking, washing machines are used to clean, rinse, and dehydrate clothes and the like by using a mechanical operation via an electric driving motor. The washing machine includes a cleansing part for performing a cleansing work, and a driving part for driving the cleansing part. The washing machines can be classified into agitator type washing machines, drum type washing machines, and pulsator type washing machines according to a cleansing manner of the cleansing part.  
           [0005]    The cleansing part of the pulsator type washing machine as described above, as shown in FIG. 1, includes a water tub  12  installed in a case  10 , a cleansing basket  14  rotatably contained in the water tub  12 , a pulsator  16  disposed at the bottom of the cleansing basket for forming a water stream, a water tab  17 , and a drain valve  18 . The cleansing basket  14  is punched with numerous dehydration holes  14   a  in a sidewall thereof.  
           [0006]    In addition, the driving part includes a driving motor  20 , a transmission  30  and a clutch mechanism  40  for driving the pulsator  16  and the cleansing basket  14  by receiving a driving force of the driving motor  20 , a belt connection means for transferring the driving force of the driving motor  20  to the clutch mechanism  40 , and a brake means for maintaining the stable fixed state of the transmission  30 .  
           [0007]    As shown in FIG. 2, the transmission  30  includes a gear box  32 , an upper and lower pulsator shafts  33  and  34  connected each other via a gear means disposed within the gear box  32 , and a spin shaft  35  fixed to the gear box  32  (See FIG. 4). The upper pulsator shaft  33  is designed to be rotatably fitted in the spin shaft  35  and connected to the pulsator  16 . The spin shaft  35  is connected to the cleansing basket  14  and fixed to the gear box  32 . The lower pulsator shaft  34  is formed with a serration part  341  on the lower end thereof and constructed to be protruded exceeding the gear box  32  downwardly (See FIG. 3.).  
           [0008]    As shown in FIG. 3, the clutch mechanism  40  includes a spin shaft block  42  fixed to the lower end of the gear box  32 , a spring block  46  disposed on the one side of the spin shaft block  42 , which is engaged with the serration part  341  of the lower pulsator shaft  34  and fixed to a pulley  44  of the belt connection means, and an one-way spring  48  disposed to be surrounded the spin shaft block  42  and the spring block  46  (See FIG. 1). Here, a tight fastening state and a releasing state of the one-way spring  48  is controlled according to the rotating direction thereof.  
           [0009]    In addition, as shown in FIG. 4, the gear means constructed in the gear box  32  of the transmission  30  includes a pinion gear  50  attached to the lower end of the upper pulsator shaft  33 , an eccentric crank  52  formed with a rack gear portion  521  to be engaged with the pinion gear  50 , a first gear  54  disposed on the same rotating axial line to be engaged with the eccentric crank  52 , and a second gear  56  attached to the upper end of the lower pulsator shaft  34  to be engaged with the first gear  54 .  
           [0010]    The brake means includes a brake disk  60  disposed under the gear box  32 , a brake fictional portion  62  formed on the top surface of a frame  19  of suspension means, which has a corresponding shape to the brake disk  60 , and position adjustment means (not shown) for controlling the separation and contact states between the brake disk  60  and the brake frictional portion  62  by vertically adjusting the position of the gear box  32  according to the operating direction of the driving motor  20  (See FIG. 1).  
           [0011]    A washing process of the pulsator type washing machine constructed as described above includes the following steps in order: 1) a water supply step for supplying water into the cleansing basket  14  through the water tab  17 ; 2) a cleansing step for circulating the water and laundry during a desired time via the rotating operation of the pulsator  16 ; 3) a rinsing step for rinsing the laundry as much as certain times by supplying clear rising water not containing any detergents after draining the water through the drain valve  18 ; and 4) a dehydrating step for driving the cleansing basket  14  at a high speed to dehydrate the laundry.  
           [0012]    In the water supply step of the washing process, the water just entered through the water tab  17  is changed into a cleansing water containing a detergent with by passing in a detergent container. Also, in the cleansing step, a removal work of contaminants clinging to the laundry is performed under a chemical operation of detergent contained in the cleansing water as well as a physical operation of the pulsator  16 . The pulsator  16  is repeatedly rotated, that is intermittently reversed, in forward and backward by the transmission  30 , so that a both directional water stream composed of a left-and-right water stream and an up-and-down water stream can be formed to effectively perform the cleansing work of the laundry.  
           [0013]    Then, in a state that the clear rinsing water not containing the detergent is supplied during the rinsing step, the detergent clinging to the laundry is also effectively removed by using the both directional water streams formed by the rotation of the pulsator  16  in the same manner with the cleansing step. Finally, in the dehydrating step, the cleansing basket  14  is rotated in one direction at a high speed after the rinsing water is completely drained, then the water contained in the laundry can be discharged via the dehydration holes  14   a  due to centrifugal force. In this case, the laundry is tightly contacting with the inner wall of the cleansing basket  14 .  
           [0014]    In the dehydrating step, since the cleansing basket  14  and the pulsator  16  are simultaneously rotated in the same direction, it is possible to prevent the damage of the laundry from being caught to the pulsator  16 . Also, the water discharged through the dehydration holes  14   a  of the cleansing basket  14  is drained out of the washing machine as soon as the drain valve  18  is opened.  
           [0015]    Meanwhile, the rotating operation of the cleansing basket  14  and the pulsator  16  in all steps are performed by the driving part as described above. The operation of the driving part will be explained in detail as follows.  
           [0016]    First of all, in the cleansing step, the pulley  44  is rotated in clockwise direction by the driving force of the driving motor  20 , and then the spring block  46  connected with the pulley  44  and the lower pulsator shaft  34  coupled with the serration portion of the spring block  46  are rotated. At this time, the one-way spring  48  loosened, and since the brake disk  60  and the brake frictional portion  62  are in tightly contact with each other, so the gear box  32  is in a fixed state. In addition, as the lower pulsator shaft  34  is rotated, the first gear  54  engaged with the second gear  56  and the second gear  56  within the gear box  32  are rotated, and at the same time, the eccentric crank  52  disposed on the same rotating axial line of the first gear  54  is actuated.  
           [0017]    In this case, the eccentric crank  52  is linearly reciprocated about the rotating axial line due to the structural feature thereof then the upper pulsator shaft  33  can be reciprocated by the pinion gear  50  engaged with the rack gear portion  521  of the eccentric crank  52 , and consequently the pulsator  16  can be achieved in the forward and backward rotation.  
           [0018]    Additionally, in the dehydrating step, the driving motor  20  is rotated in counterclockwise direction in opposite to the cleansing step, and the spring block  46  connected with the pulley  44  and the lower pulsator shaft  34  coupled with the spring block  46  are rotated in counterclockwise direction. In this case, the one-way spring  48  is fastened so that the spring block  46  and the spin shaft block  42  can be coupled, and the brake disk  60  and the brake frictional part  62  are separated by the operation of the position adjustment mechanism. Therefore, the gear box  32  and the spin shaft  35  are rotated with the spin shaft block  42 . Since, the upper pulsator shaft  33  is rotated in the same direction, then the cleansing basket  14  and the pulsator  16  are rotated at the same time to perform a dehydrating work.  
           [0019]    According to the related pulsator type washing machine, because the pulsator  16  is rotated in forward and backward to generate the complex water stream, the effect of cleansing is relatively high. And, the conversion from the cleansing step to the dehydrating step is automatically performed due to the conversion of operating direction of the driving motor  20  and the linking structure of the transmission  30  and the clutch mechanism  40 .  
           [0020]    However, substantial problems exist in this related construction. First of all, the structures of the transmission  30  and the clutch mechanism  40  for transferring the driving force of the driving motor  20  to the pulsator  16  and the cleansing basket  14  have complex structures, which deteriorates the productivity of the washing machine. Also, since the cleansing work is performed only by the simple forward and backward rotation of the pulsator  16 , it is impossible to achieve various cleansing operations suitable for the feature of the laundry, thereby deteriorating a merchant ability of the washing machine.  
         SUMMARY OF THE INVENTION  
         [0021]    The present invention has been made to overcome the above-described problems. Accordingly, it is an object of the present invention to provide a washing machine having a floatage clutch, which can smoothly switch the power transmission in the conversion from the cleansing step to the dehydrating step by using the floatage thereof, and which can secure the stability of the switching process.  
           [0022]    To achieve the above objects, there is provided a washing machine comprises a water tub; a cleansing basket rotatably contained within the water tub; a pulsator rotatably mounted on the bottom surface of the cleansing basket, having a wing part for forming a water stream, and a hub part disposed in the center of the wing part; a motor for generating a driving force required to rotate the cleansing basket and the pulsator; a transmission for transmitting the driving force of the motor to the cleansing basket and the pulsator, having a hollow dryer shaft integrated to the cleansing basket; and a washing shaft mounted to penetrate the hollow dryer shaft, whose upper end of the transmission is fixed to the hub part of the pulsator, and whose lower end thereof is connected with the motor; and a floatage clutch for allowing the cleansing basket to selectively cooperate with the pulsator by being intermittently actuated depending on the existence and nonexistence of water, having a float engaged with the washing shaft to be capable of moving up and down due to the supply/drain of the water, and a fixed member fixed to the upper end of the hollow dryer shaft to be separated from and coupled with the float at the lower side thereof.  
           [0023]    The shielding means is shaped as a ring to be protruded at the bottom of the wing part of the pulsator exceeding the cleansing basket downwardly, and includes a water blocking part surrounding the float. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0024]    [0024]FIG. 1 is a cross sectional view illustrating the construction of a related washing machine.  
         [0025]    [0025]FIG. 2 is a perspective view illustrating the construction of a transmission of the related washing machine.  
         [0026]    [0026]FIG. 3 is an exploded perspective view illustrating the construction of a clutch mechanism of the related washing machine.  
         [0027]    [0027]FIG. 4 is a perspective view illustrating the construction of gear means applied in the transmission of the related washing machine.  
         [0028]    [0028]FIG. 5 is a perspective view illustrating the construction of essential parts of a washing machine in accordance with an embodiment of the present invention,  
         [0029]    [0029]FIG. 6 is a state view illustrating the operation of the floatage clutch applied in the embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0030]    An embodiment of the present invention will now be described in more detail with reference to FIG. 5 and FIG. 6. In the following description, same drawing reference numerals are endowed in the same parts with the related construction.  
         [0031]    First, FIG. 5 shows a washing machine in accordance with the embodiment of the present invention. The washing machine includes a water tub  12 , a cleansing basket  14  contained within the water tub  12 , a pulsator  16  rotatably mounted in the cleansing basket  14 , a transmission  70  for controlling the rotating direction of the pulsator  16  and the cleansing basket  14 ; and a floatage clutch  80  for allowing the cleansing basket  14  to selectively cooperate with the pulsator  16  by being intermittently actuated depending on the existence and nonexistence of water.  
         [0032]    Here, the pulsator  16  is rotatably mounted on the bottom surface of the cleansing basket  14 , and includes a wing part  161  for forming a water stream, and a hub part  162  disposed in the center of the wing part  161 .  
         [0033]    The transmission  70  includes a hollow dryer shaft  72  integrated to the bottom surface of the cleansing basket  14 , several bearings  76  supporting the hollow dryer shaft  72 , and a washing shaft  74  mounted to penetrate the hollow dryer shaft  72 . The upper end of the washing shaft  74  is fixed to the hub part  162  of the pulsator  16 , and the lower end of the washing shaft  74  is connected with the motor  22 .  
         [0034]    In addition, the floatage clutch  80  includes a float  82  coupled with the washing shaft  74  to be capable of moving up and down, and a fixed member  83  fixed to the upper end of the hollow dryer shaft  72 . The fixed member can be separated from and coupled with the float at the lower side of the float.  
         [0035]    The float  82  includes a hub portion  821  to be coupled with a serration portion of the washing shaft  74 , and a tube portion  822  constructed around the hub portion  821 . The hub portion  821  of the float  82  is formed with a convex-concave shape bottom surface, and the tube portion  822  is shaped as a blinded hollow tube. Also, the fixed member  83  is formed with a convex-concave shape top surface to be engaged with the bottom surface of the hub portion  821  of the float  82 .  
         [0036]    Furthermore, the washing machine in accordance with the present embodiment comprises shielding means for partially shielding the joint region between the float  82  of the floatage clutch  80  and the washing shaft  74  in order to prevent the joint region from being contact with the water. The shielding means is shaped as a ring to be protruded at the bottom of the wing part  161  of the pulsator  16  exceeding the cleansing basket  14  downwardly, and includes a water blocking part  163  surrounding the tub portion  822  of the float  82 .  
         [0037]    The washing machine constructed as described above will be operated as follow.  
         [0038]    First, if a given quantity of water is supplied into the cleansing basket  14  in the water supply step, the float  82  is floated up and separated from the fixed member  83  due to die floatage thereof as shown in FIG. 8 a . The floatage clutch  80  is reached to a power cutoff state, so the driving force of the motor  22  is transferred only to the washing shaft  74 .  
         [0039]    In this power cutoff state of the floatage clutch  80 , when the motor  22  is driven, only the pulsator  16  connected with the washing shaft  74  is rotated in the initial of the cleansing step. After that, the motor  22  is repeatedly driven in forward and backward, then the pulsator  16  also is rotated in forward and backward direction in the same manner with the motor. The motor and the pulsator is intermittently conversed in forward and backward rotation.  
         [0040]    Due to the forward and backward rotation of the pulsator  16 , a rotating water stream can be formed. Further, if the pulsator  16  is continuously rotated in one direction more than a certain time, the cleansing basket  14  is also rotated in the same direction with the pulsator by the water stream. Thus, the water can be discharged via dehydration holes  14   a  out of the cleansing basket  14  due to the centrifugal force. Furthermore, the discharged water can be again flown into the cleansing basket  14  through a fluid channel between the cleansing basket  14  and the water tub  12 . This washing manner is designated as a centrifugal washing manner (so-called waterfall current washing manner).  
         [0041]    The washing process is performed a cleansing step, a rinsing step, and a dehydrating step in order. Just before the dehydrating step, as the water used for rinsing laundry is drained, the floatage is gradually eliminated. Thus, as shown in FIG. 8 b , the float  82  begins to drop by the weight thereof, and the hub portion  821  of the float  82  and the fixed member  83  are engaged with each other, so the floatage clutch  80  is switched into a power transmission state.  
         [0042]    In this power transmission state of the floatage clutch  80 , when the washing shaft  74  is driven by the motor  22 , the float  82  engaged with the washing shaft  74  is rotated. At the same time, the fixed member  83  engaged with the hub portion  821  of the float  82  and the cleansing basket  14  coupled with the fixed member  83  also are rotated in the same direction with the washing shaft  74 .  
         [0043]    When the cleansing basket  14  is rapidly rotated in one direction and then the laundry becomes tightly contact with the inner wall of the cleansing basket  14 , the water contained in the laundry can be discharged via the dehydration holes  14   a  due to the centrifugal force. The cleansing basket  14  and the pulsator  16  are simultaneously rotated in the same direction as described above, so it is possible to prevent the laundry from being caught to the pulsator, and consequently to prevent the damage of the laundry.  
         [0044]    Meantime, in accordance with the present embodiment, a space above the float  82  to be closed by the water blocking part  163  is closed as the water is supplied during the cleansing step. Therefore, when the water invaded into the water blocking part  163 , the float  82  is moved upwardly exceeding a desired distance due to floatage. Consequently, it is possible to prevent the water from being entered inside the water blocking part  163  any more due to the inner air pressure of the water blocking part  163 .  
         [0045]    In this way, since the tip end of the washing shaft  74  exposed out of the float  82  upwardly does not contact with the water even if the water is supplied, the operating stability of the floatage clutch  80  can be improved.  
         [0046]    Since various foreign impurities fell down from the laundry are mixed in the water during the cleansing step, the various foreign impurities mixed in the water become interposed between the float  82  and the washing shaft  74  if the water invaded the washing shaft  74 . Consequently it is possible to prevent the smooth conversion of the floatage clutch  80  by blocking the motion of the float  82 .  
         [0047]    As described above, the washing machine according to the present invention can provide the following advantages. The power transmission in the conversion from the cleansing step to the dehydrating step can be easily switched due to the floatage clutch of simple structure. Also, since the operation stability of the floatage clutch is improved due to the shielding means, the merchant ability and the productivity thereof can be increased.  
         [0048]    While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
The present invention relates a washing machine of direct drive pulsator manner that is directly connected to a motor. In this washing machine, the conversion of cleansing/dehydrating processes can be smoothly achieved by a floatage clutch capable of being actuated by floatage and gravity to be induced during the supply/drain of water.