Abstract:
A washing machine is provided. The washing machine includes an outer tub configured to store washing water, an inner tub rotatably mounted in the outer tub, a pulsator configured to form a water circulation for washing laundry, and a motor installed under the outer tub and configured to rotate the inner tub and the pulsator. The motor is configured to vary a rotation speed of the inner tub and the pulsator, such that the laundry is washed by a combination of modes. The modes including a centrifugal force washing mode, wherein the motor rotates the inner tub and the pulsator in the same direction for a first predetermined period of time, thereby creating a centrifugal force that is varied according to a variation of the ratation speed, which pushes the laundry against a wall of the inner tub, and an agitation washing mode, wherein the motor rotates the inner tub and the pulsator in the same direction at an identical speed, and then rotates the inner tub and the pulsator in a first direction for a second predetermined period of time and than in a second, reverse direction for the second predetermined period of time.

Description:
This application is a Continuation of application Ser. No. 10/052,246, filed Jan. 23, 2002, now U.S. Pat. No. 6,668,410 which is a Divisional of application Ser. No. 09/376,375 filed Aug. 18, 1999, now U.S. Pat. No. 6,351,974 the entire disclosure of which is hereby incorporated by reference. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a full automatic washing machine, and more particularly, to a penetration type washing machine which makes washing by penetrating washing water through laundry; a method for controlling the same; and, a tub cover for the same. 
   2. Background of the Related Art 
   Being a device for peeling off contaminant by applying energies, such as impact, to the laundry, there are pulsator washing machines, drum washing machines, agitator washing machine, and the like according to types of energy application. Washing of the laundry is made by applying impacts to the laundry using pulsator or agitator, or dropping the laundry using rotation of the drum. 
     FIG. 1  illustrates a cross section of a related art pulsator type washing machine, referring to which a related art pulsator type washing machine will be explained. 
   There is an inner tub  3  having a plurality of washing holes  5  formed therein rotatably mounted inside of an outer tub  2  provided for storage of washing water, inside of which inner tub  3  there is a pulsator  4  rotatably mounted therein. There is a drain valve  9  under the outer tub  2  for draining the washing water outside of the washing machine. A rotation power from a motor  8  mounted on an underside of the outer tub  2  is transmitted to a dewatering shaft  6   a  coupled to the inner tub  3  and the washing shaft  6  coupled to the pulsator  4 , for rotating the inner tub  3  and the pulsator  4 . The washing shaft  6  and the dewatering shaft  6   a  are coupled/decoupled by a clutch  7 . 
   There is a tub cover  11  on the outer tub  2 , which will be explained with reference to  FIG. 2 . The tub cover  11 , of substantially an annular form, has an upper surface portion  11   a  disposed on top both of the outer tub  2  and the inner tub  3 , a tight fit portion  11   b  extended in an upper and a lower direction from an end of the upper surface portion  11   a  for tight fit to an inside surface of the outer tub  2 , and a fastening portion  11   c  projected from the tight fit portion  11   b  in a substantially vertical direction for being fastened to the outer tub  2  with screws  14 . The tub cover  110  is provided for prevention of noise and overflow of foam as well as prevention of infiltration of foreign matters into a space between the inner tub and the outer tub. 
   The operation of the aforementioned related art pulsator type washing machine will be explained with reference to  FIGS. 1 and 2 . 
   The washing machine is operative in a washing cycle, a rinsing cycle, and a dewatering cycle, by proceeding through each of which mode in a sequence the washing can be done. In the washing cycle, upon putting the washing machine into operation after placing the laundry in the inner tub  3 , the washing water is supplied until it fills to certain levels of the inner tub  3  and the outer tub  2 . Upon finishing the water supply, the motor  8  makes intermittent rotations in regular and reverse directions in a state the inner tub  3  is standstill, that leads the pulsator  4  to rotate in the regular and reverse directions for washing the laundry. That is, the pulsator  4  repeats the regular/reverse direction rotation, to rotate the laundry in of the inner tub  3  and to form water circulation, as well. Then, the laundry is washed by the impact from the pulsator  4 , the water circulation, friction with the inner tub  3 , and softening effect of the detergent, and the like. After proceeding the washing cycle for a preset time period, the drain valve  9  is opened, to drain contaminated washing water to outside of the washing machine. Then, clean washing water is supplied to inside of the inner tub  3 , and the pulsator  4  is rotated, to make rinsing cycles for a preset number of times. In the dewatering cycle, the inner tub  3  is rotated in a high speed together with the pulsator  4  in one direction in a state the washing shaft  6  and the dewatering shaft  6   a  are coupled. Consequently, the washing water is discharged to the outer tub  2  through the washing holes  5 , and drained to outside of the washing machine through the drain valve  9 . 
   However, the related art washing machines, making the washing mostly using mechanical energies, of such as pulsator or agitator, is required to have a rotating power of a certain speed for making an adequate washing, that causes entangle of or damage to the laundry. And, the related art washing machine is involved in an increased washing water and detergent consumed during the washing because the washing machine is operative under a state the washing water is filled in the inner tub and the outer tub, as well as an increased overall washing time period due to increased water supply and drain time periods, that are not directly related to the washing time period. 
   Accordingly, there has been researches for making washing without rubbing the laundry or applying impact to laundry, one of which is the penetration type washing machine. That is, according to what is known, if a relative flow speed of water passing through between textile fibers of the laundry is greater than a certain level, the water can make a washing, without rubbing or twisting the laundry. A washing machine employing such a principle is a penetration type washing machine. In general, as disclosed in U.S. Pat. No. 5,191,667, a related art penetration type washing machine is provided with a washing water sprayer for spraying the washing water to the laundry in an inner tub over a required speed, and a separate pump for pumping the washing water to the washing water sprayer. Therefore, the related art penetration type washing machine has problems in that a complicated system and a large sized pump for obtaining a spraying power for the washing are required. Therefore, the related art penetration type washing machine has been mostly used as a supplementary means for the pulsator type washing machine. 
   And, though JP S51-13416 discloses a washing machine which makes a penetration washing by rotating an inner tub, the washing machine has the following problems. 
   First, as the inner tub rotates only in one direction, the washing water penetrates a fixed position of the laundry, to cause a wash difference in which a washed portion and a non-washed portion are happened. 
   Second, the only use of penetration washing makes a washing efficiency poor. Because, though the penetration type washing machine can prevent damage to, and entangling of the laundry, in general, the washing efficiency is poor compared to the pulsator type washing machine. 
   Third, since the washing machine fails to provide a guide means for guiding the washing water to an inside surface of the inner tub when the washing water is pumped to an upper portion between the inner tub and the outer tub, and then, circulated into the inner tub, the washing machine has a poor pumping efficiency. 
   Use of a related art tub cover for the penetration type washing machine causes leakage of spray of the washing water. That is, as shown in  FIG. 2 , since the related art tub cover  11  is merely fastened to the outer tub  2  with screws  14 , the washing water leaks through gaps between the tight fit portion  11   b  of the tub cover  11  and the outer tub, and the fastening portion  11   c  and a top of the outer tub  2 . And, a pumped washing water splashes from an inside of the tub cover to outside of the outer tub  2 , to generate noise as the splash hits a washing water case, and to deteriorate washing and rinsing performances of the washing machine as the splash causes a loss of the washing water. Moreover, the leaked or splashed washing water to outside of the outer tub  102  wets various electric components of the washing machine, that is liable to cause malfunction or disorder of the washing machine. 
   The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background. 
   SUMMARY OF THE INVENTION 
   An object of the invention is to solve at least the above problems and/or disadvantages and to provide at least the advantages described hereinafter. 
   Accordingly, the present invention is directed a penetration type washing machine, a method for controlling the same, and a tub cover for the same that substantially obviates one or more of the problems due to limitations and disadvantages of the related art. 
   An object of the present invention is to provide a penetration type washing machine, and a method for controlling the same, which has a simple structure and can improve a washing efficiency. 
   Another object of the present invention is to provide a tub cover for use in a penetration type washing machine which can improve a pumping efficiency and a washing efficiency. 
   Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. 
   To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, the method for controlling a full automatic washing machine, includes a washing cycle, a rinsing cycle, and a dewatering cycle, wherein the washing or the rinsing cycle includes the step of rotating an inner tub at a high speed higher than a preset speed in one direction, thereby making a centrifugal force caused by high speed rotation of the inner tub, to push laundry against a wall of the inner tub, to enforce washing water in the inner tub to penetrate through the laundry at a speed higher than required to make the washing done, and to pump the washing water penetrated through the laundry and discharged into an outer tub upward, to recirculate to the inner tub. 
   In other aspect of the present invention, there is provided a tub cover mounted on a top of an outer tub of a washing machine for preventing noise and foam overflow, including an upper tub cover for being fastened to the outer tub, and a lower tub cover under the upper tub cover spaced therefrom for being fastened to the upper tub cover, thereby forming washing water passages between the upper tub cover and the lower tub cover. 
   It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. 
   Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objects and advantages of the invention may be realized and attained as particularly pointed out in the appended claims. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be described in detail with reference to the following drawings in which like reference numerals refer to like elements wherein: 
     The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention: 
     In the drawings: 
       FIG. 1  illustrates a section of a related art pulsator type washing machine; 
       FIG. 2  illustrates a section showing an enlarged view of “A” part in  FIG. 1 ; 
       FIGS. 3A˜3C  illustrate sections of a penetration type washing machine in accordance with a preferred embodiment of the present invention, wherein  FIG. 3A  illustrates a penetration washing process,  FIG. 3B  illustrates an agitation washing process, and  FIG. 3C  illustrates a restoration circulation washing process; 
       FIGS. 4˜6  illustrate sections of a tub cover in accordance with a first preferred embodiment of the present invention; 
       FIG. 7  illustrates a disassembled perspective view of a tub cover in accordance with a second preferred embodiment of the present invention; 
       FIG. 8  illustrates a perspective assembly view of the tub cover in  FIG. 7  with partial sections of the components; 
       FIG. 9  illustrates an assembled sectional view of a tub cover, a modified version from  FIG. 8 ; 
       FIG. 10  illustrates a perspective view of a tub cover in accordance with a third preferred embodiment of the present invention; 
       FIG. 11  illustrates a section showing the tub cover in  FIG. 10  fitted to a washing machine; 
       FIG. 12  illustrates an operation principle of the tub cover shown in  FIG. 10 ; 
       FIG. 13  illustrates a perspective view of a tub cover modified from one shown in  FIG. 10 ; 
       FIG. 14  illustrates a disassembled perspective view of a tub cover in accordance with a fourth preferred embodiment of the present invention; 
       FIG. 15  illustrates a section showing an assembled view of the tub cover in  FIG. 14 ; 
       FIG. 16  illustrates a section showing an enlarged part “B” in  FIG. 15 ; 
       FIG. 17  illustrates a disassembled view of the tub cover shown in  FIG. 14 ; 
       FIG. 18  illustrates a section showing a modified version of a fastening structure of the tub cover in accordance with a fourth preferred embodiment of the present invention; 
       FIGS. 19˜22  illustrates sections showing different modifications of the tub cover in  FIG. 14 ; 
       FIG. 23  illustrates a cross section showing another modification of the tub cover in  FIG. 14 ; 
       FIG. 24  illustrates a disassembled perspective view of a tub cover in accordance with a fifth preferred embodiment of the present invention; 
       FIG. 25  illustrates a partial cut away perspective view for explaining an operation of the tub cover shown in  FIG. 24 ; 
       FIG. 26  illustrates a disassembled perspective view showing a modification from the tub cover in  FIG. 24 ; 
       FIG. 27  illustrates a disassembled perspective view of a tub cover in accordance with a sixth preferred embodiment of the present invention; 
       FIG. 28  illustrates a section across line I-I in  FIG. 27 ; 
       FIG. 29  illustrates a section across line II-II in  FIG. 27 ; 
       FIG. 30  illustrates a disassembled perspective view showing a modification of the tub cover shown in  FIG. 27 ; 
       FIG. 31  illustrates a section across line III-III in  FIG. 30 ; 
       FIG. 32  illustrates a disassembled perspective view showing another modification of the tub cover shown in  FIG. 27 ; 
       FIG. 33  illustrates a section across line IV-IV in  FIG. 32 ; 
       FIG. 34  illustrates a bottom view of a tub cover in accordance with a seventh preferred embodiment of the present invention; 
       FIG. 35  illustrates a bottom perspective view of the tub cover shown in  FIG. 34 ; 
       FIG. 36  illustrates a longitudinal section view of the tub cover shown in  FIG. 34 ; 
       FIGS. 37A and 37B  illustrate bottom perspective views each showing a modification of the tub cover shown in  FIG. 34 ; 
       FIG. 38  illustrates a bottom view showing a tub cover in accordance with an eighth preferred embodiment of the present invention; 
       FIG. 39  illustrates a bottom perspective view of the tub cover shown in  FIG. 35 ; and, 
       FIGS. 40 and 41  illustrate bottom perspective views each showing a modification of the tub cover shown in  FIG. 38 . 
   

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
   Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. A penetration type washing machine, and a method for controlling the same will be explained with reference to  FIGS. 3A˜3C . 
   Referring to  FIGS. 3A˜3C , there is an inner tub  103  having a plurality of washing holes  104  rotatably mounted in an outer tub  102 , with a pulsator  105  formed as a unit with the inner tub  103 . There is a fluid balancer  108  provided on a top of the inner tub  103  for balancing the inner tub  103  during rotation. And, there is a tub cover  400  on a top of the outer tub  102  for preventing noise, suppressing foam formation, and guiding the washing. There is a motor  107  for generating a rotation power under the outer tub  102  and a drain valve  109 . The motor  107  is preferably a variable speed motor, with a rotating shaft thereof being directly coupled to a single driving shaft  106  which rotates the inner tub  103  and the pulsator  105  without introduction of additional power transmission device. The aforementioned penetration type washing machine of the present invention facilitates a penetration washing, an agitation washing, and a restoration circulation washing by varying a rotation speed of the motor  107 . 
   The operation of the aforementioned penetration type washing machine of the present invention will be explained with reference to  FIGS. 3A˜3C . 
   The penetration type washing will be explained with reference to  FIG. 3A . When the washing machine is put into operation, the motor  107  is rotated in a high speed. Then, the driving shaft  106  connected to the motor  107  is rotated, and the pulsator  105  and the inner tub  103  connected to the driving shaft is also rotated in a high speed. As has been explained in the related art, the penetration washing requires a relative flow speed of the washing water passing through the laundry to be higher than a certain level, and the flow speed should be enough to generate a centrifugal force that can force the washing water to flow from the inner tub to the outer tub and, therefrom to circulate to the inner tub again. When the pulsator  105  and the inner tub  103  is rotated at a high speed, a centrifugal force is generated, to push the laundry in the inner tub  103  to a wall of the inner tub  103 , and to push the washing water in the inner tub  103  to the outer tub  102  through the washing holes  104  in the inner tub  103 , when the washing water penetrates through between textile fabrics of the laundry, thereby making the penetration washing. And, the washing water pushed out to the outer tub  102  and the washing water present on a bottom surface of the outer tub  102  is pumped upward along a space between the inner tub  103  and the outer tub  102  by the centrifugal force, until the washing water hits the tub cover  400  where the washing water turns a flow direction to flow into the inner tub  103  again. The washing water flowed into the inner tub  103  has a substantially high pressure caused by the centrifugal force coming from the high speed rotation of the inner tub  103 . Therefore, the washing water can apply an impact to the laundry by the pressure from the centrifugal force and a gravity of the washing water, to provide a beating effect to the laundry, that improves a washing efficiency. 
   In the meantime, as has been explained in the related art, in the case when the inner tub rotates only in one direction, the wash difference is happened in which extents of wash differ depending on portions of the laundry because positions of the laundry are always fixed. Therefore, the inner tub is rotated in a reverse direction after the inner tub is rotated in a regular direction for a preset time period. Then, the laundry pushed to wall of the inner tub is gathered to a center of the inner tub when the inner tub changes its direction of rotation from regular direction to reverse direction, and the laundry is pushed onto the wall again as the inner tub is accelerated. Accordingly, as a position of the laundry through which the washing water penetrates is changed, the wash difference can be prevented. 
   In the meantime, as has been explained, the penetration type washing machine of the present invention permits, not only the penetration type washing, but also agitation type and restoration circulation washings by changing a speed and a direction of rotation of the motor.  FIG. 3B  illustrates an agitation washing process, referring to which the agitation washing process will be explained. 
   The agitation washing is available by setting the rotation speed to be below a certain level. That is, if the rotation speed of the motor is set to be comparatively low, the pulsator and the inner tub  103  also rotate at a low speed, at which the centrifugal force is dropped unable to push up the washing water between the inner tub  103  and the outer tub  102 , but to keep a certain level. And, the laundry pushed to the wall of the inner tub  103  drops down to the bottom of the inner tub  103  to be submerged in the washing water. Under this state, a water circulation caused by rotation of the inner tub  103  and the pulsator  105  facilitates an agitation washing in a principle identical to a related art pulsator type washing machine. The availability of the penetration washing as well as the agitation washing can provide an excellent washing efficiency. 
     FIG. 3C  illustrates a section showing a restoration circulation washing process, referring to which the restoration circulation process will be explained. 
   If the inner tub  103  which is rotating at a high speed in a penetration washing is stopped or has a speed dropped, the laundry pushed to the inside wall of the inner tub  103  by an inertia is gathered to a central portion of the inner tub  103  to hit one another. That is, the hitting among the laundry or with the pulsator  105  can make washing. In this instance, for conduction of the restoration circulation washing, though the rotating inner tub  103  may be stopped, the restoration circulation washing is available without a separate restriction. Because the inner tub repeats regular and reverse rotations in the penetration washing, the restoration circulation washing is automatically and continuously made whenever the direction of rotation is changed. 
   Upon completion of the penetration washing, the agitation washing, and the restoration circulation washing, a dewatering cycle is conducted. And, upon completion of the dewatering cycle, a water re-supply process is conducted to conduct a following rinsing process. Though the penetration type washing machine of the present invention may only carry out the penetration type washing, it is preferable that the penetration type washing machine carry out an appropriate combination of the penetration type washing, an agitation type washing and a restoration circulation washing depending on an extent of contamination and an amount of the laundry. And, as has been explained, one washing cycle or a rinsing cycle may be divided into small intervals for repeating the penetration washing and the agitation washing in the intervals, or different from this, it is also possible that re-water supply is made to conduct the agitation washing after completion of the penetration washing. 
   Advantages of the penetration type washing machine and a method for controlling the same of the present invention will be explained. 
   As the penetration type washing machine of the present invention makes the penetration type washing mostly, entangling of, and damage to the laundry is reduced compared to the pulsator type washing machine. The re-supply of the washing water into the inner tub in the penetration type washing facilitates consumption of less washing water, with use of less detergent, and faster washing water supply and drain, that minimizes waste of time in the supply and drain of the washing water. Moreover, the washing water in the outer tub do nothing but interferes the rotation of the inner tub  103  in the pulsator type washing machine because the washing water in the outer tub generates a friction when the inner tub is rotated even though the washing water in the inner tub act an important role as the washing water in the inner tub is brought into contact with the laundry to make washing. Therefore, in order to make a smooth rotation, it is important for the inner tub to make a less contact with the washing water in the outer tub as far as possible. By the way, the penetration type washing machine of the present invention has a small amount (approx. 50%) of washing water supplied to the inner tub and the outer tub, and the washing water is pumped into the inner tub again in conducting the washing. That is, as the outer tub has less amount of washing water, rotation of the inner tub is smoother. Different from the related art penetration type washing machine, the penetration type washing machine has a simple system as no separate pumping device are required, and facilitates a satisfactory washing efficiency while preventing entangling of, or damage to the laundry by an appropriate combination of the penetration washing, the agitation washing and the restoration circulation washing. The penetration type washing machine of the present invention has the washing water in the inner tub  103  pumped up to the top portion thereof through a space between the inner tub  103  and the outer tub  102  at a substantially high pressure, to be re-circulated into the inner tub  103 . Consequently, the high pressure of the washing water pumped upward may cause leakage if the related art tub cover is used as it was. Though this leakage may be prevented by providing gasket on a top surface of the outer tub  102 , accurate fitting of the gasket to a large diametered outer tub  102  is not practicable. Therefore, it is preferable that the tub cover structure of the penetration type washing machine is changed, appropriately. The tub cover of the present invention will be explained. 
   A first embodiment tub cover of the present invention will be explained with reference to  FIGS. 4˜6 . The first embodiment tub cover is substantially identical to the one of the related art except that a leakage prevention means is additionally provided in the first embodiment tub cover. 
   That is, similar to the related art tub cover, the first embodiment tub cover  400  includes an upper surface portion  411 , a tight fit portion  413 , and a fastening portion  412 . However, different from the related art, the fastening portion  412  has a downward projection at an approx. center thereof in parallel to the tight fit portion  413 , and there is a slot on a top portion of the outer tub  102  for insertion of the projection  415  thereto. And, there is a sealing member  417  in a space formed between the tight fit portion  413  and the projection  415  for prevention of leakage. 
   And, referring to  FIG. 5 , a length of the projection  415  may be formed shorter, for providing the sealing member  417  in a space formed below the projection  415 . 
   And, as shown in  FIG. 6 , the sealing member may be disposed on a top end of the outer tub  102 . In detail, as the sealing member  417  is fitted to the top end of the outer tub  102 , a support  102   b  is projected in an outward radial direction of the outer tub  102  from a portion below the top end portion  102   a  of the outer tub  102 . And, a horizontal portion  441  is formed at an outer circumference of the upper surface portion  411  of the tub cover  400 , with an end of the horizontal portion  441  bent downward, to form a tight fit portion  413  which fit to an inside surface of the support  102   b  in the outer tub  102 , without providing the fastening portion. And, in order to make the assembly easy, the sealing member  417  is preferably attached to the horizontal portion  441  of the tub cover with adhesive  452 . And, it is preferable that a position the support  102   b  in the outer tub  102  is projected is to be below the top end of the outer tub  102 , to provide a space between the top end  102   a  of the outer tub  102  and the support  102   b . Because if leakage of the washing water is happened despite of the sealing member  417 , the leakage of washing water may be collected in the space. The washing water collected in the space is drained using overflow hose(not shown) connected to an air vent hose. The first embodiment tub cover can prevent leakage of the washing water even if the washing water is pumped to the tub cover  400  at a high pressure by means of the sealing member  417 . And, as the fitting of the tub cover  400  to the outer tub  102  only requires insertion of the projection  415  at the tub cover to the slot in the outer tub  102 , the assembly is simple. And, as the slot serves as a guide, for accurate fitting of the tub cover  400  to the outer tub  102 , preventing vibration during operation of the washing machine. 
   In the meantime, even if the first tub cover  400  can prevent leakage of the washing water, neither spray of the washing water caused by hitting the tub cover can be prevented, nor an exact guide of the washing water into the inner tub  103  is possible. Therefore, the following second to seventh embodiments tub covers of the present invention will provide improved tub covers. The second embodiment tub cover will be explained with reference to  FIGS. 7 and 8 . 
   The second embodiment tub cover  200  includes an upper tub cover  201  fastened to the outer tub  102 , and a lower tub cover  203  mounted under the upper tub cover  201  with a space therefrom, wherein there are washing water guide passages P 1  and P 2  formed between the upper and lower tub covers. The upper tub cover  201  has a substantially annular form of an upper surface portion  211 , a tight fit portion  214  projected from an outer end of the upper surface portion  211  vertically for tight fit to an inside wall of the outer tub  102 , and a fastening portion  215  extended from the tight fit portion  214  in a horizontal direction for fastening to a top end of the outer tub, forming an “L” section, substantially. The lower tub cover  203  has an upper surface portion  221 , and a vertical portion  225  projected downward from an outer end of the upper surface portion  221 , with a plurality of reinforcing brackets  224  connected between the upper surface portion and the vertical portion. There are a plurality of height adjustment members  222  formed at fixed intervals. In order to couple the upper tub cover  201  to the lower tub cover  203 , it is preferable that the height adjustment members  222  have a female thread  223 , and the upper surface portion  221  of the upper tub cover  201  has a plurality of fastening holes  212  formed at positions corresponding to the height adjustment members  222 . 
   Referring to  FIG. 8 , a fastened state will be explained. The upper tub cover  201  and the lower tub cover  203  are fastened with screws  213 , and the upper tub cover  203  is fastened to a top end of the outer tub  102  with screws. Therefore, as shown in  FIG. 8 , the washing water pumped to the tub cover  200  is guided by the guide passage P 1  and P 2  between the upper tub cover and the lower tub cover, to guide the washing water into the inner tub  103  smoothly, which improves a pumping efficiency. And, the spray of the washing water can be prevented. And, a pressure of the washing water sprayed to the inner tub  103  from the tub cover  200  is adjustable by adjusting a space S between the upper tub cover and the lower tub cover, i.e., a height of the height adjustment member  222 . By the way, there is a possible leakage through a gap between the fastening holes in the upper tub cover  201  and the screws in  FIG. 8 . Therefore, as shown in  FIG. 9 , it is preferable that height adjustment members  222   a  are formed on the upper tub cover  201 , and pass-through holes are formed in the lower tub cover  203 . Because the washing water flowing from the tub cover  200  to the inner tub  103  advances in a tangential direction of an inside diameter of the inner tub  103  by the centrifugal force. 
   A tub cover having modified such drawback is the third embodiment tub cover, which will be explained with reference to  FIGS. 10˜11 . 
   The third embodiment tub cover  300  includes an upper surface portion  301  and a tight fit portion  303 , and there are a plurality of deflectors  302  on an underside of the upper surface portion  301  for deflecting a flow direction of the washing water. The deflector  302  is fitted in a radial direction for deflecting the washing water advancing in a tangential direction to a center direction. There are a plurality of deflectors fitted as fixed intervals to divide the flow paths. As shown in  FIG. 12 , this structure permits the washing water pumped and flowed into the tub cover  300  hits the deflectors  302 , to change a direction of flow toward, not the tangential direction, but the center direction, substantially. And, as shown in  FIG. 13 , there may be a guide rib  305  on the deflector  302  for reducing a friction of the washing water. And, a plate drop preventor  305  may preferably be fitted at a bottom of the deflector  302  for preventing drop of the washing water, flowing into the tub cover, into a space between the inner tub  103  and the outer tub  102  by gravity, but to be supplied to the inner tub  103 . Of course, the drop preventor  305  may be provided with a larger area or the lower tub cover of the second embodiment may be provided. And, the height adjustment members  222  and  222   a  in the second embodiment may be formed to have forms of the deflectors  302 , for combined use of the height adjustment members  222  and  222   a  as the deflectors. 
   Because outlets of the washing water passages P 2  are substantially horizontal in the first to third embodiments tub covers, the washing water flows out substantially in the horizontal direction. Opposite to this, the following fourth to seventh embodiment tub covers are provided with an adjustable spray angle, with a convenience of assembly. 
   The fourth embodiment tub cover will be explained with reference to  FIGS. 14˜16 . 
   Alike the second embodiment tub cover, the fourth embodiment tub cover also include an upper tub cover  501  and a lower tub cover  503  for forming a washing water passage. The upper tub cover  501  has an upper surface portion  521 , a tight fit portion  522 , and a fastening portion  523 , and the lower tub cover  503  also has an upper surface portion  512  and a vertical portion  511 , except that there are a plurality of guide members  505  fitted at fixed intervals provided between the upper tub cover and the lower tub cover for combined use as the height adjustment members and the deflectors in the aforementioned embodiments. The guide member  505  is preferably formed extended from inlet to outlet of the flow passage to cover the entire washing water passage. In this embodiment, the horizontal passage P 2  is formed to direct a lower portion of the inner tub  103 , and the upper tub cover  501  and the lower tub cover  503  are provided with downward curvatures to provide a stream lined horizontal passage P 2  for minimize a friction. The lower tub cover  503  is mounted spaced from the fluid balancer  108  by a preset distance T1, with a chamfer  507  in the fluid balancer  108  to suit to a contour of the passage P 2 . Because this configuration can prevent bumping between the fluid balancer  108  and the tub cover  500 . And, in order to prevent bumping between the fluid balancer  504  and the outer tub  102  and  502 , a second gap T2 formed between the fluid balancer  504  and the outer tub  102  and  502  may be further provided. The distance T1 is preferably identical to the gap T2 between the fluid balancer  108  and the outer tub  102 , substantially. 
   A fastening structure of the fourth embodiment tub cover of the present invention will be explained with reference to  FIG. 17 . 
   Alike the previous embodiment, if the upper tub cover, the guide member and the lower tub cover are fastened with screws, the washing water may leak. Therefore, it is preferable that the upper tub cover  501 , the guide members  505  and the lower tub cover  503  are fabricated separately and jointed them together by means of welding and the like. Of course, it is possible that either the upper tub cover  501  and the guide members  505  may be fabricated as a unit, to which the lower tub cover  503  is welded, or the lower tub cover  503  and the guide members  505  may be fabricated as a unit, to which the upper tub cover  501  is welded. In this instance, for the sake of convenience of assembly and preventing projection of the upper tub cover  501  to an outward radial direction, there is a stepped portion  532  at one side of the lower tub cover  503  for catching a bottom end of the upper tub cover  501 . As shown in  FIG. 18 , fastening with screws is also possible, particularly, fastening the lower tub cover  503  to the guide member  505  with screws  534  is effective in view of leakage prevention. Similar to the previous embodiments, this embodiment tub cover serves for a smooth guidance of the washing water, prevention of spray, and prevention of leakage. In addition to this, this embodiment tub cover can further improve a pumping performance and washing performance because the washing water passage is streamlined with a preset curvature, which minimizes a loss caused by friction to guide the washing water into a lower portion of the inner tub  103  effectively. By the way, in this embodiment, fore ends of the upper tub cover  501  and the lower tub cover  503 , i.e., a width W of an outlet of the washing water may be adjusted for adjusting the pressure of the washing water. That is, the more the width W of the outlet of the washing water is reduced, the higher the pressure of the washing water. The width W may preferably be adjusted by decreasing or increasing a fore end of the upper tub cover  501  by an angle θ toward a fore end direction of the lower tub cover  503 . And, as shown in  FIGS. 20 and 21 , the fore end of the upper tub cover  501  may be extended or shortened with respect to the fore end of the lower tub cover  503 , for adjusting an angle of spray of the washing water. That is, if the fore end of the upper tub cover is shortened by a distance H1 with respect to the fore end of the lower tub cover  503 , the washing water is sprayed upward, and extended by a distance H2, sprayed downward. In conclusion, this embodiment allows an appropriate adjustment of the spray pressure and the spray angle. And, as shown in  FIG. 23 , a radius R1 formed by the fore end of the upper tub cover  501  and a radius R2 formed by the fore end of the lower tub cover  503  may preferably be made different, to improve a washing water supply efficiency. 
   In the meantime, as the guide members  505  are not curved, the washing water is adapted to hit the guide member  505  as a right angle, to cause a friction and a consequential reduction of a pumping efficiency. And, the abrupt change of the flow direction of the washing water causes noise coming from impact. And, because the third embodiment tub cover has the deflectors fitted perpendicular to the washing water flow, a portion of the washing water hit onto the deflector turns a flow direction, not to the inner tub, but backwardly opposite to the flow direction of the washing water due to a reaction force. And, a vortex may be occurred in a space formed by an outer circumference of the deflector and the tight fit portion. Those are causes of dropping the pumping efficiency. Accordingly, the following embodiment is a modification for improving such problems. 
   The fifth embodiment tub cover is the one in which those disadvantages are improved, which will be explained with reference to  FIG. 24 . 
   The guide member  505  of this embodiment is formed to have a curvature, for guiding the washing water smoothly with a minimum friction at the guide member  505 . As the inner tub  103  rotates in regular and reverse directions, it is preferable that regular direction guide members  505   a  and reverse direction guide members  505   b  are provided, respectively. Because others are the same with the fourth embodiment, the explanation will be omitted. According to this, as shown in  FIG. 25 , since the washing water pumped by high speed rotation of the inner tub  103  is supplied to the inner tub  103  smoothly with a minimum friction, the pumping efficiency can be improved. However, as shown in  FIG. 24 , if the regular direction guide members  505   a  and the reverse direction guide members  505   b  are integrated, a fore end  505   c  has no curvature, which has a great friction. Therefore, the fore end  505  also need to have a curvature, preferably. To do this, as shown in  FIG. 26 , the regular direction guide members  505   a  and the reverse direction guide members  505   b  are preferably provided with curvatures throughout entire lengths, with the fore ends thereof connected with a curved portion  507   c . Thus, since the washing water pumped during a regular direction rotation of the inner tub  103  is guided by the regular direction guide member  507   a , with a reduced friction, and the washing water pumped during a reverse direction rotation of the inner tub  103  is guided by the reverse direction guide member  507   b , with a reduced friction, the curved members  507   a  and  507   b  can improve the pumping efficiency. 
   In the meantime, even though the aforementioned tub covers of the present invention can prevent spray of the washing water effectively, once sprayed, the sprayed washing water flows to outside of the outer tub  102 . Therefore, the following sixth embodiment tub cover is provided for an effective prevention of spray to outside of the outer tub  102 . The sixth embodiment tub cover will be explained with reference to  FIG. 27 . 
   Similar to the fourth and fifth embodiment tub covers, the sixth embodiment tub cover  700  includes an upper tub cover  701  and a lower tub cover  703  each having a curvature, and a guide members  705 . And, the upper tub cover  701  has an upper surface portion  714 , a tight fit portion  715  and a fastening portion  711 . The lower tub cover  703  also has an upper surface portion  722  and a vertical portion  721 . However, in this embodiment, the tight fit portion  715  of the upper tub cover  701  is projected upward to form a projection  715   a , to form a recess  712  between an outer circumference and the projection  715   a , to collect the sprayed washing water. Then, the washing water collected in the recess  712  is drained into the inner tub  103  by washing water drain means  720 . The washing water drain means  720  is sloped flow passages  713  recessed in the upper surface of the upper tub cover at fixed intervals, with walls  713   a  and  713   b  on both sides of the passage  713 . The sloped flow passage  713  is sloped inward downwardly. 
   In this embodiment, the guide member  705  may only be provided on the vertical flow passage  705 , because the walls  713   a  and  713   b  of the sloped flow passages  713  act as the guide members in the horizontal flow passage P 2 . Accordingly, as shown in  FIG. 28 , the washing water sprayed and collected in the recess  712  of the upper tub cover  701  flows into the inner tub  103  along the sloped flow passage  713 . And, as shown in  FIG. 29 , the pumped washing water flows to the inner tub  103  through the flow passages formed between the upper tub cover  701  and the lower tub cover  703 , when the walls  713   a  and  713   b  divide the passage. The walls  713   a  and  713   b  are formed with curvatures for guiding the washing water with a reduced friction in correspondence to the regular and reverse rotation. 
   The washing water drain means may be as shown in  FIGS. 30 and 31 . That is, a plurality of drain holes  725  are formed in the recess of the upper tub cover  701  at fixed intervals. And, guide members for guiding the washing water into the inner tub  103  from the drain holes  725  are preferably provided in the lower tub cover  703 . Because if there are no guide members, the washing water drained through the drain holes will flow the space between the inner tub  103  and the outer tub  102  again, to resist against the circulation of the washing water as the lower tub cover  703  also has a curvature. The guide member has one pair of walls  726  and  727  formed vertical to the upper surface of the lower tub cover  703  at a width slightly greater than the width of the discharge hole  725  and a sloped passage  728  connecting the walls  726  and  727  and sloped downwardly in an inner radial direction. The walls  726  and  727  also serve as the height adjustment member. And, a front portion  723  with a supply hole  724  may be provided in front of the walls  726  and  727 . 
   The operation of this embodiment tub cover will be explained. The pumped washing water is collected in the recess  712  of the upper tub cover  701 . The washing water collected in the recess  702  flows into the lower tub cover  703  through the drain holes  725 , and into the inner tub  103  along the sloped passage  728 . Thus, spray of the washing water out of the outer tub  102  can be prevented. In the meantime, as shown in  FIGS. 32 and 33 , it is, of course, possible that the upper surface of the upper tub cover  701  is provided with a slope α without the washing water drain means, for natural flow of the washing water sprayed to the upper tub cover  701  into the inner tub  103  along the upper surface of the upper tub cover  701 . In this instance, it is preferable that the guide member  705  is extended to the horizontal passage, i.e., to form a vertical portion  705   a  and a horizontal portion  705   b.    
   The second to sixth embodiment tub covers have complicated structures and high cost because the tub covers include the upper tub covers, the lower tub covers and guide members, which are comparatively many components that is difficulty in assembly. Therefore, the following seventh and eighth embodiment tub covers provide tub covers which have simple structures but have effects the same with the aforementioned embodiments. Different from the foregoing second to sixth tub covers, the following embodiment tub covers have one single tub cover(corresponding to an upper tub cover in the related art). And, different from the first embodiment tub cover, these embodiment tub covers are provided with means on a bottom surface of the tub cover for guiding the washing water into the inner tub. The pumped washing water can be guided into the inner tub only using a tub cover corresponding to an upper tub cover without using a lower tub cover owing to the following reason. The penetration washing requires fast running of the motor for pumping the washing water. That is, in the penetration washing, the washing water should be pumped upwardly to move upward to overcome a gravity of the washing water itself Therefore, as the washing water pumped toward the tub cover does not fall down even if the lower tub cover is used substantially, formation of the washing water passage is possible even if no lower tub cover is used. And, in the case of agitating washing, since the washing water is not circulated and the tub cover only serves for prevention of noise, and foam reduction, the lower tub cover may be dispensed with, too. The seventh embodiment tub cover will be explained in detail with reference to  FIGS. 34 to 36 . 
   The seventh embodiment tub cover  800  includes a tight fit portion  810  for tight fit on an inside surface of a top end of the outer tub, an upper surface portion  811  extended upwardly from the tight fit portion  810  at an angle for serving as a guide for the washing water, and a fastening portion  810   a  projected from the tight fit portion  810  in a horizontal direction for being fastened to the outer tub with screws. The upper surface portion  811  may preferably have a curvature, rather than at a right angle to the tight fit portion  810  for reducing friction with the washing water. And, there is a vertical deflector  813  formed downwardly at a fore end of the upper surface portion  811  for downward guide of the washing water to a lower portion of the inner tub, and preferably there is a vertical protector  811  a on an outer circumference of the upper surface portion  811  for protecting the spray of the washing water to outside of the outer tub. There are a plurality of main deflectors  812  formed on an underside of the upper surface portion  811  at fixed intervals, for deflecting a direction of the washing water pumped to the tub cover to a center direction of the inner tub. The main deflector  812  is formed to connect an inner and an outer diameters of the upper surface portion of the tub cover, with an angle θ 1  to a radial direction of the tub cover. And, supplementary deflectors  814  may be further provided for smoother guide of the washing water. The supplementary deflector  814  has a fore end started from the inner diameter, extended along a concentric circle with the tub cover substantially, and an aft end ended at a position of the main deflector  812 . In this instance, the fore end of the supplementary deflector is preferably spaced from the fore end of the main deflector  812  by a preset distance L2. Therefore, the tub cover  800  is divided by the main deflectors  812  by fixed intervals S, wherein a space between the intervals S has a main flow passage W 1  formed by the main deflector  812  and the supplementary deflector  814  and a supplementary passage W 2  formed by the supplementary deflector  814  and the vertical deflector  813 . 
   The operation of this embodiment will be explained. 
   The washing water pumped to the tub cover  800  is guided by the tub cover  800  into the inner tub with a minimum friction. In detail, the washing water risen upwardly is brought in contact with a bottom surface of the tub cover  800 . Then, the washing water is guided by the main deflectors  812  and the supplementary deflectors  814  to deflect a flow direction from a tangential direction to a center direction of the inner tub. And, the washing water having a direction changed by the main passage W 1  formed by the main deflector  812  and the supplementary deflector  814  hits onto the vertical deflector  813  again, to deflect a flow direction from horizontal to vertical downwardly, to supply the washing water to the inner tub lower portion. Most of the pumped washing water is guided by the main flow passages to be sprayed into the inner tub  103 , while a portion of the pumped washing water flows into the inner tub  103  directly from the supplementary flow passage W 2 . Because most of the pumped washing water is guided by the main flow passages and the outlet P of each main passage W 1  has a small width L2 and a limited number, that built up a pressure of the washing water, the washing water is intensely sprayed from the outlets, to improve the washing efficiency. In comparison to this, in the related art, since the washing water is sprayed from an entire inner diameter of the tub cover, the washing efficiency is poor because the spraying pressure is dispersed. Though the washing water flowed in a horizontal direction and hit onto the vertical deflector  813  turns its flow direction downwardly into the inner tub, a portion of the washing water is scattered by the impact of the hit. However, this embodiment tub cover can minimize scattering of the washing water, generation of noise, and foam formation because the washing water hits the supplementary deflector  814  before the washing water hits the vertical deflector  813 . And, the washing water still scattered is prevented from leaking beyond an outer wall of the outer tub  102  by the projection  811   a  on the tub cover  800 . And, as shown in  FIG. 37A , a damping member  815  may preferably be provided at the outlet P side of the main passage W 1 , so that the washing water hits the damping member  815  beforehand, for effective prevention of the scattering of the washing water occurred when the washing water hits the vertical deflectors  813 . The damping member  815  is disposed substantially perpendicular to a flow direction of the washing water, i.e., connected from a fore end of the supplementary deflector  814  to a fore end of the main deflector  812 , with a height lower than heights of the main deflector  812  and the supplementary deflector  814 . As shown in  FIG. 37B , instead of the damping member, a sloped portion  817  may be provided at an outlet P of the main flow passage. 
   The following eighth embodiment tub cover is a modification from the seventh embodiment tub cover to suit to a case of both direction, i.e., regular and reverse direction rotation of the inner tub  103 . An overall structure of the eighth embodiment tub cover will be explained with reference to  FIG. 8 . 
   Alike the seventh embodiment tub cover, the eighth embodiment tub cover  800  of the present invention also includes the main deflectors, the supplementary deflectors, and the vertical deflectors, except that first main deflectors  812  and second main deflectors  812   a  are provided in correspondence to the both direction rotation, and a structure of the supplementary deflectors  814   a  is modified. In detail, the first main deflectors  812  are formed on an underside of the upper surface portion of the tub cover  800  at fixed intervals, and the second deflectors  812   a  are formed in symmetry to the first main deflectors  812 . And, a fore end of the supplementary deflector  814   a  has a fore end started from the inner circumference and extended along a concentric circle of the tub cover, and an aft end connected to the inner circumference of the tub cover. That is, the fore end of the supplementary deflector  814   a  is positioned spaced from the fore end of the first main deflector  812 , and the aft end of the supplementary deflector  814   a  is positioned spaced from the fore end of the second main deflector  812   a . And, preferably there are a plurality of ribs  818  between the first main deflectors and the second main deflectors  812   a  for preventing distortion, and more preferably concentric to the tub cover circumference. And, a portion of an outer rib may be cut away. The ribs  818  are fitted under the following reasons. The washing water passed over the main deflectors  812  and  812   a  may cause a vortex between the first and the second main deflectors  812  and  812   a , or may flow to the outlet of the main flow passage, to interfere the washing water flow in the main flow passage. Therefore, the ribs  818  are provided to confine the washing water between the first and second deflectors  812  and  812   a  to some extent, for preventing interference to the washing water in the main flow passage. Thus, the tub cover is divided by the first main deflectors  812  and the second main deflectors  812   a  into fixed intervals S. And, a space between the intervals S has a main flow passage W 1  formed by the main deflector  812  and a just prior supplementary deflector  812   a , and a supplementary passage W 2  formed by the supplementary deflector  812   a  and the vertical deflector  813 . And, there is a space formed by the first main deflector  812  and an adjacent second main deflector  812   a . Accordingly, when the inner tub rotates in a regular direction(a counter clockwise direction on the drawing), most of the washing water pumped to the tub cover is guided by the tub cover as shown in arrows of solid lines to be sprayed into the inner tub through the regular direction outlets P 3  with a minimum friction. Opposite to this, when the inner tub rotates in a reverse direction(a clockwise direction on the drawing), most of the washing water pumped to the tub cover is guided by the tub cover as shown in arrows of dotted lines to be sprayed into the inner tub through the reverse direction outlets P 4  with a minimum friction. Therefore, the eighth embodiment tub cover can cope with all the regular and reverse direction rotation, effectively. 
   In the meantime, as shown in  FIG. 39 , a portion of the regular direction outlet P 3  and the reverse direction outlet P 4   a  may be cut away to form an opening  816 , for minimizing the scattering of the washing water caused by the washing water hitting onto the vertical deflector  813 . In the meantime, as shown in  FIGS. 40 and 41 , identical to the seventh embodiment, either the damping member  815  or the sloped portion  817  is provided for effective prevention of the washing water scattering. And, it is preferable that a sealing member is provided between the tub cover and the outer tub. 
   As has been explained, the penetration type washing machine, the method for controlling the same, and the tub cover for the same have the following advantages. 
   First, the penetration type washing machine can make washing using an appropriate combination of the penetration washing, the agitating washing, and the restoration circulation washing. Therefore, a washing efficiency can be improved while damage to, and entangling of the laundry is minimized. And, the washing can be carried out only with a small amount of washing water, consumption of water and detergent may be reduced, with consequential reduction of drain time period, to reduce an overall washing time. 
   Second, the tub cover of the present invention can improve a pumping efficiency of the washing water because leakage or scattering of the pumped washing water can be prevented and the washing water can be guided into the inner tub without friction loss. And, the noise and foam caused by the circulated washing water at the high speed rotation of the inner tub can be minimized. 
   Third, as the tub cover of the present invention facilitates spray of the pumped washing water toward a center of the inner rub, a washing efficiency can be improved. 
   It will be apparent to those skilled in the art that various modifications and variations can be made in the penetration type washing machine, the method for controlling the same, and the tub cover for the same of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. 
   The foregoing embodiments and advantages are merely exemplary and are not to be construed as limiting the present invention. The present teaching can be readily applied to other types of apparatuses. The description of the present invention is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures.