Abstract:
Disclosed herein is a laundry treating apparatus capable of sufficiently wetting laundry in a drum by spraying wash water in a tub on the laundry, without a motor. The laundry treating apparatus includes a tub configured to accommodate wash water, a drum rotatably disposed in the tub, and configured to accommodate laundry, and a lifter disposed in the drum, to tumble the laundry using rotary power of the drum, wherein the drum has a drum hole communicating with an inner space of the lifter, and the lifter has a lifter hole through which the wash water, introduced into the inner space from the tub through the drum hole, is sprayed on the laundry at a predetermined position to which the drum rotates.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the priority benefit of Korean Patent Application No. 10-2015-0125747, filed on Sep. 4, 2015 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a laundry treating apparatus, and more particularly to a laundry treating apparatus which performs washing by tumbling laundry. 
         [0004]    2. Description of the Related Art 
         [0005]    In general, washing machines are classified into a top-loading washing machine, which performs washing using the rotational stream of wash water, and a drum washing machine which performs washing by tumbling laundry. 
         [0006]    That is, the top-loading washing machine has a structure in which an inner vessel, serving as a washing vessel, is disposed so as to rotate about a direction perpendicular to the ground, and a pulsator provided on the bottom of the inner vessel rotates to generate a water stream, so as to perform washing through the friction between laundry and the water stream and by applying impacts to laundry by the pulsator. On the other hand, the drum washing machine has a structure in which an inner vessel, serving as a washing vessel, is disposed so as to rotate about a direction parallel to the ground, so as to perform washing through the friction between laundry and the inner wall surface of the inner vessel and by dropping laundry while the inner vessel rotates. 
         [0007]    The drum washing machine is equipped with a lifter for tumbling (lifting and dropping) laundry when the inner vessel, which is a drum, rotates. The lifter consists of a plurality of lifters installed inside the drum so as to be spaced apart from each other in a circumferential direction which is the direction of rotation of the drum, and the lifters rotate along with the drum. 
         [0008]    Each of the lifters protrudes inward from the drum to a predetermined height, at which the lifter does not lift laundry when the drum rotates at a low speed but lifts laundry when the drum rotates at a high speed. That is, the lifter tumbles the laundry accommodated in the drum using the rotary power of the drum only when the drum rotates at a predetermined speed. 
         [0009]    Meanwhile, the drum is rotatably disposed in a tub, serving as a reservoir. Wash water collects in the bottom of the tub up to the level at which the water may flow into the bottom of the drum, in order to wet the laundry accommodated in the drum. 
         [0010]    However, when a large amount of laundry is in the drum, only a portion of the laundry, namely that portion which is near the bottom of the drum, is wet. Accordingly, in order to sufficiently wet all of the laundry accommodated in the drum, the drum washing machine must be equipped with a motor for lifting the wash water, which collects in the tub, in the upward direction of the drum to spray the water on laundry. 
       SUMMARY OF THE INVENTION 
       [0011]    Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a laundry treating apparatus capable of sufficiently wetting laundry in a drum by spraying wash water in a tub on the laundry. 
         [0012]    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. 
         [0013]    In accordance with an aspect of the present invention, the above and other objects can be accomplished by the provision of a laundry treating apparatus including a tub configured to accommodate wash water, a drum rotatably disposed in the tub, and configured to accommodate laundry, and a lifter disposed in the drum, to tumble the laundry using rotary power of the drum, wherein the drum has a drum hole communicating with an inner space of the lifter, and the lifter has a lifter hole through which the wash water, introduced into the inner space from the tub through the drum hole, is sprayed on the laundry at a predetermined position to which the drum rotates. 
         [0014]    The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
           [0016]      FIG. 1  is a perspective view illustrating a laundry treating apparatus according to a first embodiment of the present invention; 
           [0017]      FIG. 2  is a cross-sectional view of a drum, lifters, and a tub illustrated in  FIG. 1 ; 
           [0018]      FIG. 3  is a view of the outside of the drum and the lifters illustrated in  FIG. 1 ; 
           [0019]      FIG. 4  is a front perspective view of one of the lifters illustrated in  FIG. 1 ; 
           [0020]      FIG. 5  is a cross-sectional view of the lifter illustrated in  FIG. 4 ; 
           [0021]      FIG. 6  is a back perspective view of one of the lifters illustrated in  FIG. 1 ; 
           [0022]      FIG. 7  is a view illustrating a lifter of a laundry treating apparatus according to a second embodiment of the present invention; 
           [0023]      FIG. 8  is a view illustrating a lifter of a laundry treating apparatus according to a third embodiment of the present invention; 
           [0024]      FIG. 9  is a front perspective view illustrating a lifter of a laundry treating apparatus according to a fourth embodiment of the present invention; 
           [0025]      FIG. 10  is a back perspective view illustrating the lifter of the laundry treating apparatus according to the fourth embodiment of the present invention; and 
           [0026]      FIG. 11  is a back view illustrating the lifter of the laundry treating apparatus according to the fourth embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0027]    Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings. The present invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art. Throughout the disclosure, like reference numerals refer to like parts throughout the various figures and embodiments of the present invention. 
         [0028]    Hereinafter, a laundry treating apparatus according to exemplary embodiments of the present invention will be described in more detail with reference to the accompanying drawings. 
         [0029]    The laundry treating apparatus according to exemplary embodiments of the present invention includes all apparatuses for treating laundry. Specifically, the laundry treating apparatus includes washing machines that remove contaminants from laundry using wash water, and washing machines that perform both washing and drying. 
         [0030]      FIG. 1  is a perspective view illustrating a laundry treating apparatus according to a first embodiment of the present invention. 
         [0031]    Referring to  FIG. 1 , the laundry treating apparatus according to the first embodiment of the present invention may include a cabinet  2  and a control panel  4  installed on the cabinet  2 . 
         [0032]    The cabinet  2  may be a case that defines the external appearance of the laundry treating apparatus. The cabinet  2  may have a laundry entry port  3  for the insertion and removal of laundry into and from the cabinet  2 . A tub  30  (see  FIG. 2 ) for accommodating wash water may be installed in the cabinet  2 . 
         [0033]    A drum  40  for accommodating laundry may be rotatably installed in the tub. A motor (not shown) for rotating the drum  40  may be installed in the cabinet  2 . 
         [0034]    The cabinet  2  may be configured by bending a single member many times, or may be configured by coupling a large number of members to each other. The cabinet  2  may include a base fan (not shown), a cabinet body  8 , which is installed at the base fan and has a space for accommodating the tub, a cabinet cover  10 , which is disposed in front of the cabinet body  8  and has the laundry entry port  3  formed thereon, and a top cover  12  disposed at the upper portion of the cabinet body  8 . 
         [0035]    The cabinet body  8  may be configured of a single member or a plurality of members. The cabinet body  8  may include a left cover disposed at the left upper portion of the base fan, a right cover disposed at the right upper portion of the base fan, and a rear cover disposed at the rear upper portion of the base fan. Of course, the cabinet  2  may be configured as a combination of a plurality of members, and may be changed in various forms. 
         [0036]    The cabinet  2  may be equipped with a door  14  for opening and closing the laundry entry port  3 . The door  14  may be rotatably or slidably connected to the cabinet  2  so as to open and close the laundry entry port  3 . The door  14  may be connected to the cabinet  2  by a hinge mechanism in order to open and close the laundry entry port  3  while rotating about the hinge mechanism. 
         [0037]    The control panel  4  may include an operation unit for operating the laundry treating apparatus. The control panel  4  may include a display unit for displaying information about the laundry treating apparatus. The control panel  4  may include the operation unit and the display unit together. The control panel  4  may be installed on the cabinet  2 . The control panel  4  may be disposed on the upper portion of the cabinet cover  10 . The control panel  4  may be located on the front upper portion of the cabinet  2 , and may define a portion of the external appearance of the laundry treating apparatus. 
         [0038]    The control panel  4  may include a control panel body  20 . The control panel body  20  may define the external appearance of the control panel  4 . The control panel body  20  may be located above the cabinet cover  10 , and may be provided with the operation unit which is operated by a user, and the display unit which displays various types of information about the laundry treating apparatus to the outside. 
         [0039]    The control panel  4  may include a rotary knob  50  which is gripped and operated by the user&#39;s hand. The rotary knob  50  may be installed to select various courses of the laundry treating apparatus, and the user may grip and turn the rotary knob  50  in order to select various courses of the laundry treating apparatus. The control panel body  20  may have an opening  22  which is larger than the rotary knob  50 . The rotary knob  50  may be disposed such that the front portion thereof is located in front of the opening  22 . 
         [0040]    The control panel  4  may include a knob decoration  56  located around the rotary knob  50 . The knob decoration  56  may be located between the outer circumference of the rotary knob  50  and the opening  22 . The knob decoration  56  may realize a high-quality external appearance around the rotary knob  50 , and may have the same color as the outer surface of the control panel body  20 . 
         [0041]    The control panel  4  may further include a window  82  which is disposed to surround the outer circumference of the rotary knob  50 . The laundry treating apparatus may further include a light source which irradiates the window with light. Light incident on the window  82  may penetrate the window  82 , and the user may recognize various types of information about the laundry treating apparatus by checking the shape or location of light radiated to the window  82 . A portion of the window  82  may be exposed outward between the knob decoration  56  and the opening  22 , and light may be radiated through the exposed portion of the window  82 . 
         [0042]    A lifter  45  may be installed in the drum  40 . The lifter  45  may consist of a plurality of lifters which are installed so as to be spaced apart from each other at regular intervals along the inner peripheral surface of the drum  40 . The lifters  45  may rotate along with the drum  40  when the drum  40  rotates. The lifters  45  may tumble the laundry accommodated in the drum  40  using the rotary power of the drum  40 , thereby enabling the laundry to be washed. The lifters  45  may not lift the laundry accommodated in the drum  40  when the drum  40  rotates at a low speed, but may lift and drop the laundry accommodated in the drum  40  when the drum  40  rotates at a high speed. 
         [0043]      FIG. 2  is a cross-sectional view of the drum, the lifters, and the tub illustrated in  FIG. 1 .  FIG. 3  is a view of the outside of the drum and the lifters illustrated in  FIG. 1 . 
         [0044]    Referring to  FIGS. 2 and 3 , the drum  40  may have a drum hole  41 , through which the wash water accommodated in the tub  30  is guided to the inner space in each of the lifters  45 . The drum hole  41  may consist of three drum holes which are spaced apart from each other at regular intervals in the direction of axial rotation of the drum  40  (hereinafter, referred to as an “axial direction”). The drum holes  41  preferably communicate with the inner spaces of the lifters  45  such that the wash water accommodated in the tub  30  may flow into the inner spaces of the lifters  45  through the drum holes  41 . The number of drum holes  41  is not limited to three, but one or more drum holes may be formed at positions corresponding to the inner spaces of the lifters  45 . 
         [0045]    The drum  40  may further have a scoop  42  which is formed at one side of each of the drum holes  41 . The scoop  42  may have a shape that is concave at the outside of the drum  40  and is convex at the inside thereof. The scoop  42  is preferably formed at one side of the drum hole  41  such that the wash water in the tub  30  may be guided to the drum hole  41  only when the drum  40  rotates in one direction. Here, the one direction in which the drum  40  rotates is a clockwise direction. When the drum  40  rotates clockwise, the scoop  42  is preferably disposed in front of the drum hole  41  in the clockwise direction. That is, only when the drum  40  rotates clockwise, the scoop  42  guides the wash water in the tub  30  to the drum hole  41  so that the wash water may flow into the inner space in each of the lifters  45  through the associated drum hole  41 . 
         [0046]    The lifter  45  has a lifter hole  45   a  through which the wash water introduced into the inner space from the tub  30  through the drum hole  41  is sprayed on laundry at a predetermined position to which the drum  40  rotates. That is, the wash water, which is introduced into the inner space of the lifter  45  through the drum hole  41  at position A, illustrated in  FIG. 2 , is sprayed on laundry through the lifter hole  45   a  at position B, illustrated in  FIG. 2 . In order to spray the wash water, which is introduced into the inner space of the lifter  45 , on laundry, the lifter hole  45   a  is formed in a direction perpendicular to the tangent line of the drum  40 . Position A, illustrated in  FIG. 2 , is the position at which the lifter  45  passes the bottom of the tub  30  and at which wash water collects in the tub  30 . 
         [0047]    The lifter  45  may consist of three lifters which are circumferentially arranged at a distance of 120° on the inner peripheral surface of the drum  40 . That is, the distance between position A and position B, illustrated in  FIG. 2 , is a distance of 120°. In the embodiment, the wash water introduced into the inner space of the lifter  45  through the drum hole  41  at position A may be sprayed on laundry through the lifter hole  45   a  at position B to which the drum  40  rotates at an angle of 120°. Of course, the number of lifters  45  is not limited to three. 
         [0048]      FIG. 4  is a front perspective view of one of the lifters illustrated in  FIG. 1 .  FIG. 5  is a cross-sectional view of the lifter illustrated in  FIG. 4 . 
         [0049]    Referring to  FIGS. 4 and 5 , the lifter  45  is axially elongated. The lifter  45  includes a round surface  46  which protrudes maximally inward from the drum  40 , a first inclined surface  47  which is disposed at one side of the round surface  46  in one direction of rotation (in the clockwise direction) of the drum  40 , a second inclined surface  48  which is disposed at the other side of the round surface  46  in the other direction of rotation of the drum  40 , a front surface  49  which extends from the front ends of the round surface  46 , the first inclined surface  47 , and the second inclined surface  48 , and a rear surface (not shown) which extends from the rear ends of the round surface  46 , the first inclined surface  47 , and the second inclined surface  48 . 
         [0050]    The round surface  46  is a curved surface that is convex toward the center of the drum  40 . Each of the first and second inclined surfaces  47  and  48  is inclined at a predetermined angle relative to the inner surface of the drum  40 , and generally has a flat shape. The inner angle (a) between the first inclined surface  47  and the inner surface of the drum  40  is defined as a first angle, and the inner angle (b) between the second inclined surface  48  and the inner surface of the drum  40  is defined as a second angle. In the embodiment, the first angle is an angle of 48°. 
         [0051]    One end of each of the first and second inclined surfaces  47  and  48  extends from the round surface  46 , and the other end thereof may be coupled to the drum  40 . 
         [0052]    The lifter hole  45   a  is formed in the round surface  46  and the first inclined surface  47 , but is not formed in the second inclined surface  48 . The lifter hole  45   a  may consist of a plurality of lifter holes which are spaced apart from each other at regular intervals throughout the first inclined surface  47 , and may consist of a plurality of lifter holes which are formed in a portion of the round surface  46  so as to corresponding to the lifter holes  45   a  formed in the first inclined surface  47 . The lifter holes  45   a  formed in the round surface  46  are arranged in one row, and the lifter holes  45   a  formed in the first inclined surface  47  are arranged in a plurality of rows. 
         [0053]    In the embodiment, the lifter has a hole ratio of 0.8. The hole ratio is a value obtained by dividing a sum of lengths occupied by lifter holes  45   a  by a remaining length, in a rectilinear length (L) to the tip end of the first inclined surface  47  from the center of a lifter hole  45   a  closest to the center of the drum  40 . 
         [0054]      FIG. 6  is a back perspective view of one of the lifters illustrated in  FIG. 1 . 
         [0055]    Referring to  FIGS. 2 and 6 , fastening structures for mounting the lifter  45  to the drum  40  are formed on the back surface of the lifter  45  and the drum  40 . The fastening structures includes first and second sliding holes  43   a  and  43   b  and a fastening hole  44  which are formed in the drum  40 , and a sliding protrusion  45   b  and a fastening portion  45   c  which are formed on each lifter  45 . 
         [0056]    The first and second sliding holes  43   a  and  43   b  are formed so as to be spaced apart from each of the drum holes  41  in one direction, and the fastening hole  44  is formed so as to be spaced apart from the drum hole  41  in a direction opposite to the direction. 
         [0057]    The first sliding hole  43   a  is axially elongated, and has a width perpendicular to the axial direction thereof, the width being greater than that of the second sliding hole  43   b . The second sliding hole  43   b  extends from the first sliding hole  43   a  so as to be axially elongated, and has a width perpendicular to the axial direction thereof, the width being smaller than that of the first sliding hole  43   a.    
         [0058]    The sliding protrusion  45   b  is axially elongated. The sliding protrusion  45   b  is formed on one side in the lifter  45 , and in more detail, is formed on the first inclined surface  47 . The fastening portion  45   c  is formed on the other side in the lifter  45 , and in more detail, is formed on the second inclined surface  48 . 
         [0059]    After the sliding protrusion  45   b  is inserted into the first sliding hole  43   a  formed in the drum  40 , the lifter  45  is coupled to the drum  40  by the sliding of the sliding protrusion  45   b  from the first sliding hole  43   a  to the second sliding hole  43   b . When the sliding protrusion  45   b  is located in the second sliding hole  43   b  and the lifter  45  is coupled to the drum  40 , the first sliding hole  43   a  communicates with the inner space of the lifter  45 . Accordingly, when the drum  40  rotates in one direction, the wash water in the tub  30  may flow into the inner space of the lifter  45  through the drum hole  41 , and may also flow into the inner space of the lifter  45  through the first sliding hole  43   a.    
         [0060]    The sliding protrusion  45   b  preferably has a length and a width corresponding to those of the second sliding hole  43   b  such that it may be pressed against the second sliding hole  43   b  and the lifter  45  may be coupled to the drum  40 . 
         [0061]    The lifter  45  is coupled to the drum  40  by inserting a screw, serving as a fastening member, into the fastening portion  45   c . That is, the screw is inserted and coupled into the fastening portion  45   c  through the fastening hole in the outside of the drum  40 , thereby allowing the other side of the lifter  45  to be coupled to the drum  40 . 
         [0062]    As described above, only one side of the lifter  45 , which is in one direction of rotation of the drum  40 , slides and is coupled to the drum  40  through the sliding protrusion  45   b , and the other side thereof is coupled to the drum  40  through the fastening portion  45   c . Thus, when the drum  40  rotates in one direction, the wash water in the tub  30  flows into the inner space of the lifter  45  through the drum hole  41  and the first sliding hole  43   a , and the wash water introduced into the inner space is not discharged through the other side of the lifter  45 . Therefore, the wash water introduced into the lifter  45  may be sprayed on laundry through the lifter hole  45   a  at a predetermined position to which the drum  40  rotates. 
         [0063]    After one side of the lifter  45  is first coupled to the drum  40  by coupling the sliding protrusion  45   b  to the second sliding hole  43   b , the other side of the lifter  45  is coupled to the drum  40  by inserting the screw into the fastening hole  44  and the fastening portion  45   c . Consequently, the process in which the lifter  45  is mounted to the drum  40  may be completed. 
         [0064]    The lifter  45  has an open surface which comes into contact with the inner surface of the drum  40 . The lifter  45  has a plurality of partition walls  45   d  for partitioning the inner space into a plurality of regions. Each of the partition walls  45   d  may be formed so as to extend from the round surface  46  and the first and second inclined surfaces  47  and  48 . The partition wall  45   d  has a recessed portion  45   e  formed by depressing a portion of the partition wall  45   d  toward the inner surface of the drum  40 . The recessed portion  45   e  is disposed at a position corresponding to the drum hole  41  and the scoop  42  formed in the drum  40 . The wash water introduced into the inner space of the lifter  45  through the drum hole  41  may axially flow through the recessed portion  45   e  in the lifter  45 . A portion of the partition wall  45   d , which extends from the second inclined surface  48 , may extend from the fastening portion  45   c.    
         [0065]      FIG. 7  is a view illustrating a lifter of a laundry treating apparatus according to a second embodiment of the present invention. In the second embodiment, like reference numerals refer to the same components as those of the first embodiment, and a detailed description thereof will be omitted. Moreover, only differences from the first embodiment will be described. 
         [0066]    Referring to  FIG. 7 , it can be seen that the lifter, which is designated by reference numeral  145 , of the laundry treating apparatus according to the second embodiment of the present invention differs from the lifter  45  of the first embodiment. That is, in the first embodiment, the lifter holes  45   a  are formed so as to be spaced apart from each other at regular intervals throughout the first inclined surface  47 , and the lifter holes  45   a  are formed in a portion of the round surface  46  so as to correspond to the lifter holes  45   a  formed in the first inclined surface  47 . However, the second embodiment is identical to the first embodiment in that a plurality of lifter holes  45   a  is formed so as to be spaced apart from each other at regular intervals throughout a first inclined surface  47 , but the second embodiment differs from the first embodiment in that a plurality of lifter holes  45   a  is formed so as to be spaced apart from each other at regular intervals throughout a round surface  46 . In the second embodiment, the lifter holes  45   a  formed in the round surface  46  are arranged in three rows. 
         [0067]      FIG. 8  is a view illustrating a lifter of a laundry treating apparatus according to a third embodiment of the present invention. In the third embodiment, like reference numerals refer to the same components as those of the first embodiment, and a detailed description thereof will be omitted. Moreover, only differences from the first embodiment will be described. 
         [0068]    Referring to  FIG. 8 , it can be seen that the lifter, which is designated by reference numeral  245 , of the laundry treating apparatus according to the third embodiment of the present invention differs from the lifter  45  of the first embodiment. That is, in the first embodiment, the lifter holes  45   a  are formed so as to be spaced apart from each other at regular intervals throughout the first inclined surface  47 , and the lifter holes  45   a  are formed in a portion of the round surface  46  so as to correspond to the lifter holes  45   a  formed in the first inclined surface  47 . However, the third embodiment is identical to the first embodiment in that a plurality of lifter holes  45   a  is formed so as to be spaced apart from each other at regular intervals throughout a first inclined surface  47 , but the third embodiment differs from the first embodiment in that no lifter holes are formed in a round surface  46 . 
         [0069]    In addition, in the lifter  245  of the third embodiment, the first inclined surface  47  formed with the lifter holes  45   a  has an axially asymmetrical shape. Accordingly, when the drum  40  rotates in one direction, the lifter  245  may move to a predetermined position in the state in which wash water collects in the inner space of the lifter  245 . 
         [0070]      FIG. 9  is a front perspective view illustrating a lifter of a laundry treating apparatus according to a fourth embodiment of the present invention.  FIG. 10  is a back perspective view illustrating the lifter of the laundry treating apparatus according to the fourth embodiment of the present invention.  FIG. 11  is a back view illustrating the lifter of the laundry treating apparatus according to the fourth embodiment of the present invention. In the fourth embodiment, like reference numerals refer to the same components as those of the first embodiment, and a detailed description thereof will be omitted. Moreover, only differences from the first embodiment will be described. 
         [0071]    Referring to  FIGS. 9 to 11 , it can be seen that the lifter, which is designated by reference numeral  345 , of the laundry treating apparatus according to the fourth embodiment of the present invention differs from the lifter  45  of the first embodiment. That is, in the lifter of the first embodiment, the lifter holes  45   a  are formed in the round surface  46  and the first inclined surface  47 . However, in the lifter  345  of the fourth embodiment, a plurality of lifter holes  45   a  is formed only in a round surface  46 . The lifter holes  45   a  formed in the lifter  345  of the fourth embodiment are arranged in one row in the round surface  46 . 
         [0072]    In addition, in the drum  40  of the first embodiment, the first and second sliding holes  43   a  and  43   b  are formed so as to be spaced apart from the drum hole  41  in one direction, and the fastening hole  44  is formed so as to be spaced apart from the drum hole  41  in a direction opposite to the direction. However, the fourth embodiment is identical to the first embodiment in that first and second sliding holes  43   a  and  43   b  are formed so as to be spaced apart from the drum hole  41  in one direction in the drum  40 , but the fourth embodiment differs from the first embodiment in that third and fourth sliding holes  44   a  and  44   b  are formed so as to be spaced apart from the drum hole in a direction opposite to the direction. Here, the third sliding hole  44   a  has the same structure and function as the first sliding hole  43   a , and the fourth sliding hole  44   b  has the same structure and function as the second sliding hole  43   b.    
         [0073]    In the lifter  45  of the first embodiment, the sliding protrusion  45   b  is formed only on the first inclined surface  47 , and the fastening portion  45   c  is formed on the second inclined surface  48 . However, in the fourth embodiment, sliding protrusions  45   b  and  45   f  are formed on both first and second inclined surfaces  47  and  48 . That is, the sliding protrusions  45   b  and  45   f  include a first sliding protrusion  45   b  which is coupled by sliding to the second sliding hole  43   b  from the first sliding hole  43   a , and a second sliding protrusion  45   f  which is coupled by sliding to the fourth sliding hole  44   b  from the third sliding hole  44   a.    
         [0074]    When the first sliding protrusion  45   b  is located in the second sliding hole  43   b , the first sliding hole  43   a  is opened. Thus, when the drum  40  rotates in one direction, the wash water in the tub  30  may be introduced into the inner space of the lifter  345  through the drum hole  41  and the first sliding hole  43   a.    
         [0075]    Meanwhile, the second sliding protrusion  45   f  further has a shield wall  45   g  formed at one side thereof. The shield wall  45   g  shields the third sliding hole  44   a  when the second sliding protrusion  45   f  is located in the fourth sliding hole  44   b . Therefore, when the drum  40  rotates in one direction, it is possible to prevent the wash water accommodated in the inner space of the lifter  345  from flowing out through the third sliding hole  44   a.    
         [0076]    In addition, the drum  40  of the fourth embodiment may further have fastening holes  44  which are formed as components corresponding to the fastening hole  44  of the first embodiment. One of the fastening holes  44  may be formed in a portion corresponding to the front portion of the lifter  345 , and the remaining one may be formed in a portion corresponding to the rear portion of the lifter  345 . 
         [0077]    The lifter  345  may have a fastening portion  45   c  which is formed as a component corresponding to the fastening portion  45   c  of the first embodiment. Similar to the first embodiment, the lifter  345  may be coupled to the drum  40  by inserting a screw, serving as a fastening member, into the fastening portion  45   c . That is, the screw is inserted and coupled into the fastening portion  45   c  through the fastening hole  44  in the outside of the drum  40 , thereby allowing the lifter  345  to be securely coupled to the drum  40 . 
         [0078]    As described above, in the laundry treating apparatus according to the embodiments of the present invention, the wash water in the tub  30  is introduced into the inner space of the lifter  45 ,  145 ,  245 , or  345  through the drum hole  41 , and is then sprayed on laundry through the lifter holes  45   a  at a predetermined position to which the drum  40  rotates. Therefore, the laundry treating apparatus can eliminate a motor for lifting the wash water in the tub  30  in the upward direction of the drum  40 , whereby it can reduce costs, weight, and noise and save electricity. 
         [0079]    As is apparent from the above description, a laundry treating apparatus according to exemplary embodiments of the present invention has effects of reducing costs, weight, and noise and saving electricity since it can eliminate a motor for lifting the wash water in a tub in the upward direction of a drum. 
         [0080]    The present invention is not limited to the foregoing effects, and other effects thereof will be clearly understood by those skilled in the art from the above description and the following claims. 
         [0081]    Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and applications may be devised by those skilled in the art that will fall within the intrinsic aspects of the embodiments. More particularly, various variations and modifications are possible in concrete constituent elements of the embodiments. In addition, it is to be understood that differences relevant to the variations and modifications fall within the spirit and scope of the present disclosure defined in the appended claims.