Abstract:
A washer and method of forming a drum thereof are disclosed. The present invention includes a body, a tub provided within the body to accommodate water therein, a drum provided within the tub to have at least one lifter built in one body of the drum, and a motor for rotating the drum. Accordingly, the lift and drum are built in one body to perform a role of the lifter sufficiently and a volume of the drum can be maximized by maintaining an exterior size of the drum as it is.

Description:
[0001]     This application claims the benefit of the Korean Patent Application No. 10-2006-0053810, filed on Jun. 15, 2006, which is hereby incorporated by reference as if fully set forth herein.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to a washer, and more particularly, to a washer and method of forming a drum thereof. Although the present invention is suitable for a wide scope of applications, it is particularly suitable for increasing a volume of a drum by forming a lifter in one body of the drum.  
         [0004]     2. Discussion of the Related Art  
         [0005]     Generally, a drum type washer is a device that washes a laundry by rotating a drum by a drive force of a motor while a detergent, water and laundry are put in the drum. The drum type washer is advantageous in causing little damage to the laundry, preventing the laundry from being raveled and bringing washing effects of beating and rubbing.  
         [0006]      FIG. 1  is a schematic cross-sectional diagram of a drum type washer according to a related art.  
         [0007]     Referring to  FIG. 1 , a drum type washer according to a related art consists of a body  1 , a tub  10  provided within the body  1  to accommodate water therein, a drum rotatably provided within the tub  1 , and a motor for rotating the drum  20 .  
         [0008]     In particular, the body  1  configures an exterior of the drum type washer and a laundry entrance  111  is provided to a front side of the body  1 .  
         [0009]     In this case, a door  140  for opening/closing the laundry entrance  111  is provided to a portion of the body  1  provided with the laundry entrance  111 . And, a gasket  112  is loaded on an inner circumference of the laundry entrance  111  to achieve airtightness between the door  140  and the laundry entrance  111 .  
         [0010]     Moreover, the tub  10  is provided as supported within the body  1 .  
         [0011]     A drain passage (not shown in the drawing) is connected to a lower end of the tub  10  to drain the water.  
         [0012]     The drum  20 , which is rotatably provided within the tub  10 , is installed in a manner that an opening of the drum  20  is placed toward the laundry entrance  111  of the body  110 .  
         [0013]     In particular, a multitude of perforated holes  21  are formed on a circumference of the drum  20  to enable water and steam supplied to the tub  10  to be introduced into the drum  20 .  
         [0014]     And, a plurality of lifters  60  are provided to an inner surface of the drum  20  to extend in an axial direction corresponding to an axial length of the drum  20 .  
         [0015]     In the above-configured related art drum type washer, once the drum  20  is rotated by a driving force transferred by the activated motor  30 , the loaded laundry and water are lifted up to a prescribed height by the lifter  60  rotated according to the rotation of the drum  20  and then fall down. This process is repeated to generate friction between the laundry, the lifter  20 , and the inner surface of the drum  20 . Hence, washing can be achieved by both of the friction and the detergent effect.  
         [0016]     Meanwhile, the lifter  60 , as shown in  FIG. 2 , is installed within the drum  20  by the locking of a plurality of hooks  61 . And, the lifter  60  consists of 3 or 4 pieces.  
         [0017]     The pieces of the lifter  60  are formed by injection molding in a manner that a melted material is injected into a mold. And, the 3 or 4 injection-molded pieces are assembled to complete the lifter  60 .  
         [0018]     However, the related art drum type washer has the following problems.  
         [0019]     First of all, since each of the related art lifters  60  is manufactured by assembling a plurality of injection-molded pieces, a plurality of manufacturing steps are necessary. Moreover, the respective lifters  60  can be transformed by hot water supplied into the drum  20 .  
         [0020]     Secondly, the respective lifters  60  are formed separate from the drum  20  and then attached to the inner surface of the drum  20  by the hook locking. So, the laundry is stuck between the lifter  60  and the drum  20 , which may break the corresponding lifter  60 .  
         [0021]     Thirdly, each of the lifters  60  has a considerably large size to reduce an overall volume of the drum.  
       SUMMARY OF THE INVENTION  
       [0022]     Accordingly, the present invention is directed to a washer and method of forming a drum thereof that substantially obviate one or more problems due to limitations and disadvantages of the related art.  
         [0023]     An object of the present invention is to provide a washer having a lifter built-in drum and method of forming a drum thereof, by which a lifter provided within the drum can be prevented from being transformed by hot water.  
         [0024]     Another object of the present invention is to provide a washer having a lifter built-in drum and method of forming a drum thereof, by which a laundry is prevented from being stuck between a lifter and a drum and by which the lifter can be prevented from being broken.  
         [0025]     A further object of the present invention is to provide a washer having a lifter built-in drum and method of forming a drum thereof, by which a volume of a drum is increased by decreasing a volume of a lifter.  
         [0026]     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 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.  
         [0027]     To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a washer according to the present invention includes a body, a tub provided within the body to accommodate water therein, a drum provided within the tub to have at least one lifter built in one body of the drum, and a motor for rotating the drum.  
         [0028]     Preferably, the drum includes a drum center configuring a circumference wall of the drum and the at least one lifter is built in one body of the circumference wall by a drawing processing.  
         [0029]     More preferably, the at least one lifter is configured to be spaced apart from each of both ends of the drum center.  
         [0030]     Preferably, the at least one lifter includes at least four lifters.  
         [0031]     More preferably, each of the at least four lifters is provided with an embossed part.  
         [0032]     In this case, each of the at least four lifters is provided with a multitude of perforated holes.  
         [0033]     And, the embossed part includes a concave portion and a convex portion configured in a length direction of each of the at least four lifters.  
         [0034]     Moreover, a multitude of the perforated holes are provided to the concave portion of the embossed part.  
         [0035]     Besides, each of the at least four lifters is configured to have at least one or more step differences.  
         [0036]     And, the at least one or more step differences are configured to gradually increase toward a rear side of the drum.  
         [0037]     In another aspect of the present invention, a lifter built-in drum includes a circumference wall and at least one lifter built in one body of the circumference wall by a drawing processing.  
         [0038]     In a further aspect of the present invention, a method of forming a drum includes the steps of providing a lifter to a drum center by a drawing processing, seaming the drum center provided with the lifter into a cylindrical shape, and assembling a drum front and a drum back to front and rear sides of the drum center by seaming, respectively.  
         [0039]     It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0040]     The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:  
         [0041]      FIG. 1  is a schematic cross-sectional diagram of a drum type washer according to a related art;  
         [0042]      FIG. 2  is an exploded perspective diagram of a drum and a lifter assembled to the drum according to a related art;  
         [0043]      FIG. 3  is a schematic cross-sectional diagram of a drum type washer according to an embodiment of the present invention;  
         [0044]      FIG. 4  is an exploded perspective diagram of a lifter built-in drum according to an embodiment of the present invention;  
         [0045]      FIG. 5  is a detailed perspective diagram of a lifter built-in drum according to another embodiment of the present invention; and  
         [0046]      FIG. 6  is a detailed perspective diagram of a lifter built-in drum according to a further embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0047]     Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.  
         [0048]      FIG. 3  is a schematic cross-sectional diagram of a drum type washer according to an embodiment of the present invention, and  FIG. 4  is an exploded perspective diagram of a lifter built-in drum according to an embodiment of the present invention.  
         [0049]     Referring to  FIG. 3 , a washer according to an embodiment of the present invention includes a body  1 , a tub  10 , and a drum  300  formed in one body of at least one lifter  310 . And, the washer includes a drum type washer for example.  
         [0050]     In particular, the body  1  configures an exterior of the drum type washer and a laundry entrance  111  is provided to a front side of the body  1 .  
         [0051]     In this case, a door  140  for opening/closing the laundry entrance  111  is provided to a portion of the body  1  provided with the laundry entrance  111 . And, a gasket  112  is loaded on an inner circumference of the laundry entrance  111  to achieve airtightness between the door  140  and the laundry entrance  111 .  
         [0052]     Moreover, the tub  10  is provided as supported within the body  1 .  
         [0053]     A drain passage (not shown in the drawing) is connected to a lower end of the tub  10  to drain the water.  
         [0054]     The drum  20 , which is rotatably provided within the tub  10 , is installed in a manner that an opening of the drum  20  is placed toward the laundry entrance  111  of the body  110 .  
         [0055]     In particular, a multitude of perforated holes  21  are formed on a circumference of the drum  20  to enable water and steam supplied to the tub  10  to be introduced into the drum  20 .  
         [0056]     A lifter built-in drum according to an embodiment of the present invention is explained with reference to  FIG. 4  as follows.  
         [0057]     Referring to  FIG. 4 , the drum  300  according to an embodiment of the present invention includes a drum center  302  formed of a steel based material to configure a circumference wall of the drum  300 , a drum front  305  having a laundry loading hole  304  to be assembled to a front end of the drum center  302 , a drum back  307  blocking a backside of the drum center  302 , and at least one lifter  310  formed in one body of the drum center  302 .  
         [0058]     In particular, the at least one lifter  310  is formed in one body of the circumference wall  302  of the drum center  302  by a drawing processing. Preferably, the at least one lifter  310  is configured to be spaced apart from both ends of the drum center  302 .  
         [0059]     As the drum front  30  and the drum back  307  are assembled to the front and rear sides of the drum center  302  by seaming, respectively, the at least one lifter  310  is configured for the at least one lifter  310  not to interfere with the drum front  305  and the drum back  307 .  
         [0060]     Preferably, the present invention is provided with at least four lifters  310 .  
         [0061]     More preferably, the number of the lifters  310  formed built in one body of the drum  300  is set greater than that of the related art lifters. And, a volume of each of the lifters  310  is set smaller than that of the related art lifter.  
         [0062]     If so, the at least one lifter  310  can sufficiently perform its role in a washing or rinsing cycle. And, a volume of the drum  300  can be substantially increased to correspond to the reduced volume of each of the lifters  310 .  
         [0063]     Preferably, perforated holes  311  are provided to each of the lifters  310  to enable water to go in and out of the drum  300 .  
         [0064]     In particular, if the drum  300  is rotated to place the corresponding lifter  310  in an upper part of the tub  10  in the course of the washing or rinsing cycle, the water held in the corresponding lifter  310  falls down on a lower internal part of the drum  300  via the perforated holes  311 .  
         [0065]     So, washing performance can be further enhanced in a manner that the water falling down on the lower internal part of the drum  300  comes into soaking the laundry and that a frictional force is applied to the laundry by the water falling with prescribed potential energy on the lower side of the drum  300  from the upper side of the drum  300 .  
         [0066]     A lifter built-in drum according to another embodiment of the present invention is explained with reference to  FIG. 5  as follows.  
         [0067]      FIG. 5  is a detailed perspective diagram of a lifter built-in drum according to another embodiment of the present invention.  
         [0068]     Referring to  FIG. 5 , at least one lifter  310  is built in one body of a drum  300 . And, an embossed part  400  is provided to the at least one lifter  310 .  
         [0069]     In particular, the embossed part  400  includes a concave portion  410  and a convex portion  430  in a length direction of the at least one lifter  310  to increase a frictional force between the at least one lifter  310  and a laundry, thereby playing a role in enhancing a washing power.  
         [0070]     Preferably, a multitude of perforated holes  311  are provided to the at least one lifter  310 . More preferably, a multitude of the perforated holes  311  are provided to the concave portion  410  of the embossed part  400 .  
         [0071]     In this case, the perforated holes  311  are provided to the concave portion  410  of the embossed part  400 . This is to prevent the laundry from being damaged by the perforated holes  410 . In particular, since the drum  20  is rotated at high speed in the course of a dewatering cycle, it is advantageous that the laundry is prevented from being damaged by the perforated holes  311 .  
         [0072]     Besides, even if the perforated holes  311  are processed coarse, it is able to minimize a damage caused to the laundry.  
         [0073]     A lifter built-in drum according to a further embodiment of the present invention is explained with reference to  FIG. 6  as follows.  
         [0074]      FIG. 6  is a detailed perspective diagram of a lifter built-in drum according to a further embodiment of the present invention.  
         [0075]     Referring to  FIG. 6 , a plurality of step differences  500  are provided to each of a plurality of lifters  310 .  
         [0076]     Preferably, a plurality of the step differences  500  are configured to gradually increase toward a rear side of a drum  300 .  
         [0077]     In this case, each of the lifters  310  are configured to have the step differences  500  each of which increases toward the rear side of the drum  300 . In case that a laundry within the drum  399  inclines toward a drum back  307  by a centrifugal force in the course of a washing or dewatering cycle, the step difference  500  in the vicinity of the drum back  307  is greater than the rest of the step differences provided to the corresponding lifter  310 , a plurality of the lifters  310  are rotated to facilitate the distribution of a large quantity of the laundry in the vicinity of the drum back  307 .  
         [0078]     A method of forming a lifter built-in drum according to the present invention is explained as follows.  
         [0079]     First of all, at least one or more lifters  310  are formed in a drum center  302  by a drawing processing. In this case, it is preferable that an embossed part  400  and a plurality of perforated holes  311  are formed together in the course of processing the at least one or more lifters  310 .  
         [0080]     Subsequently, the drum center  302  provided with the at least one or more lifters  310  is processed into a cylindrical shape by a seaming processing.  
         [0081]     A drum front  305  and a drum back  307  are then assembled to front and rear sides of the drum center  302  by a seaming processing, respectively. Hence, a lifter built-in drum is manufactured by a series of the above steps.  
         [0082]     An operation of the above-configured drum type washer having the lift built-in drum according to the present invention is explained as follows.  
         [0083]     First of all, a laundry is loaded in the drum  300  to execute a washing cycle. The washer is then activated.  
         [0084]     If so, water is supplied to the washer. After completion of the water supply, a power is applied to the motor to rotate. The drum  300  is then rotated in forward and reverse directions by the driven motor.  
         [0085]     In doing so, the drum  300  is rotated to enable the water and laundry to be lifted to a prescribed height and fall down by each of the lifters  310 . This process is repeated to bring about active friction between the embossed part  400  provided to each of the lifters  310  and the laundry. Hence, washing and rinsing of the laundry can be surely carried out.  
         [0086]     While the drum  300  is rotated, the water is introduced into the lower lifter  310  immersed in the water among a plurality of the lifters  310  provided to the inner surface of the drum  300 , and simultaneously, the water held by the upper lifter  310  falls down on the lower inside of the drum  300  via the perforated holes  311  to apply friction to the laundry within the drum  300 . Hence, washing or rinsing performance of the laundry can be further enhanced.  
         [0087]     Accordingly, the present invention provides the following effects or advantages.  
         [0088]     First of all, in manufacturing a drum, a lifter is built in one body of the drum. Hence, the present invention reduces the number of assembly steps and the time taken for the assembly.  
         [0089]     Secondly, as a drum and a lift are formed in one body, a connecting gap between the drum and the lifter can be eliminated. Hence, a laundry is prevented from being stuck in the gap and the lifter is prevented from being broken by a shock of the laundry.  
         [0090]     Thirdly, a lifter is formed of a same material, e.g., steel of a drum, the present invention prevents the lifter from being transformed by high temperature within the drum and increases rigidity of a drum center to prevent the drum from being transformed in the course of high-speed dewatering.  
         [0091]     Fourthly, a volume of a lifter is formed small and the number of lifters is raised, in the course of building a drum and a lifter in one body. Hence, the lifters of the present invention can maintain the same role of the related art lifters and a drum volume can be maximized.  
         [0092]     Fifthly, an embossed part is provided to a lifter to increase friction between the lifter and a laundry. Hence, the present invention enhances washing performance.  
         [0093]     It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.