US20050252253A1 - Drum assembly for washing machine - Google Patents

Abstract

A lifter is provided on a drum for lifting and dropping laundry in the drum during a rotation of the drum. The lifter slides and moves along an inner surface of the drum after passing through the inner surface so as to be engaged to the drum. At least one slot is provided on a circumference of the drum, and at least one hook is provided on the lifter for being engaged to the slot. Further, at least one projection is provided on the drum, and at least on rib is provided on the lifter. The projection and the rib are tightly engaged with each other so as to secure the lifter to the drum when the lifter completely slides and moves laterally.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• This application claims the benefit of Korean Utility Model Application No. U2004-013533, filed on May 15, 2004, which is hereby incorporated by reference as if fully set forth herein.
BACKGROUND OF THE INVENTION
• 1. Field of the Invention
• The present invention relates to a washing machine, and more particularly, to a drum assembly with lifters therein for lifting and dropping laundry to improve washing, rinsing, and dehydrating performances.
• 2. Discussion of the Related Art
• Washing machine is a representative home appliance for washing laundry using detergent and water. The washing machine is generally classified into two types, i.e., a top loading type and a front loading type based on the location of an opening for receiving the laundry.
• The top loading type washing machine generally comprises a vertical tub for accommodating the laundry, a pulsater rotating in the tub and washing the laundry, and a lid provided on an upper surface of the washing machine for opening and closing the tub.
• The front loading type washing machine generally comprises a horizontal tub for accommodating washing water, a horizontal drum provided in the tub for accommodating the laundry, at least one lifter provided on an inner surface of the drum for lifting and dropping the laundry when the drum is rotated for washing, rinsing or dehydrating the laundry, and a door provided on a front surface of the washing machine for opening and closing the drum.
• As mentioned above, there is at least one lifter in the drum of the front loading type washing machine. And, the lifter is generally mounted on an inner surface of the drum by coupling members such as screws or bolts. Thus, there are disadvantages in the above mentioned coupling structure of the drum and the lifter that it takes long time for an assembler to fix the lifters to the drum and that the assembling process for producing the washing machine become complicated.
SUMMARY OF THE INVENTION
• Accordingly, the present invention is directed to a drum assembly for washing machine that substantially obviates one or more problems due to limitations and disadvantages of the related art.
• An object of the present invention is to improve a structure of a drum assembly of the washing machine so that an assembler can fix lifters to a drum quickly and easily.
• Another object of the present invention is to improve the structure of the drum assembly of the washing machine so that lifters are stably secured to the drum.
• 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.
• To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a drum assembly for washing machine comprises a drum accommodating laundry therein, and at least one lifter provided on an inner surface of the drum, and lifting and dropping the laundry in the drum during a rotation of the drum, wherein the lifter slides on the inner surface of the drum after passing through a circumference of the drum so as to be engaged with the drum.
• The drum may comprise a cylinder including a space accommodating the laundry therein, a back mounted on a rear of the cylinder, and a front cover mounted on a front of the cylinder and having an opening which is opened and closed by a door.
• The drum may further comprise at least one slot provided on the circumference of the drum. And, the lifter may comprise at least one hook put into the slot and moving along a longitudinal direction of the slot so as to be engaged with the slot when the lifter slides. The slot may be configured to be elongated along a longitudinal direction of the drum. The slot may be configured to hold a head of the hook after the head passes through the slot and laterally moves along the longitudinal direction of the slot.
• The hook may comprise a neck extended from the lifter, and a head formed on an end of the neck. And, the slot may comprise a wide portion allowing the head to pass through therein and a narrow portion narrower than the head and connected to the wide portion for receiving the neck when the lifter slides on the inner surface of the drum.
• The slot of the drum may further comprise at least one rounded portion provided between the wide portion and the narrow portion, and smoothly guiding the hook put into the wide portion into the narrow portion. Wherein, the rounded portion is provided on both sides of the narrow portion, or is provided on one side of the narrow portion.
• The slot may comprise a pair of slots arranged to have a predetermined distance therebetween. The pair of slots may be configured to be formed that the hook put into each slot is bent with elasticity when the lifter is secured to the drum. And, the pair of slots may be configured to be getting far away from each other along a sliding direction of the lifter. Further, each slot of the pair of slots may comprise an end accommodating each hook when the lifter is secured to the drum, wherein a distance between the each end is longer than a distance between the each hook.
• The drum may further comprise a projection extended from the drum and supporting the lifter so as to prevent the lifter from sliding backward after the lifter is secured to the drum. The lifter may be configured to go over the projection when the lifter slides on the inner surface of the drum so as to be secured to the drum. Wherein, the projection comprises a slope provided on an upper surface of the projection so that the lifter smoothly goes over the projection along on the slope when the lifter slides so as to be coupled to the drum.
• The drum may further comprise a cut away portion surrounding a portion of the projection, further wherein the projection is configured to be formed that the portion of the projection surrounding the cut away portion is bent toward an inside the drum. The projection is configured to be bent with a predetermined slope.
• The lifter may further comprise a protrusion extended from the lifter, wherein the protrusion is engaged with the projection so as to prevent the lifter from sliding backward after the lifter is secured to the drum.
• The lifter in the drum may further comprise a recess provided on a lower portion of the lifter; and a rib provided on the recess and reinforcing strength of the lifter, wherein the rib is engaged with the projection and secures the lifter to the drum when the lifter is coupled to the drum.
• The drum may further comprise at least one projection extended from the drum between the pair of slots, wherein the projection supports the lifter so as to prevent the lifter from sliding backward after the lifter is secured to the drum.
• 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
• 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 of the invention and together with the description serve to explain the principle of the invention. In the drawings;
• FIG. 1 illustrates a cross sectional view of the washing machine according to the present invention;
• FIG. 2 illustrates an exploded perspective view of the drum assembly according to the present invention;
• FIG. 3 illustrates a perspective view of the assembled drum assembly according to the present invention; and
• FIG. 4 illustrates a perspective view of the other embodiment of slots formed in the drum according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
• 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.
• With reference toFIG. 1, acase1 of the washing machine according to the present invention comprises a base plate2, awall4, atop cover6, and afront cover8. The base plate2 forms a bottom of the case2, and thewall4 is vertically mounted on the base plate2, and forms a rear wall and both side walls of the washing machine according to the present invention. A top of thewall4 is open, and a front of the wall is also open. And, thetop cover6 covers the open top of thewall4, and thefront cover8 covers the open front of thewall4. Further, there is acontrol panel12 between a top of thefront cover8 and thetop cover6 so that the user can control the washing machine using thecontrol panel12.
• There is ahorizontal tub14 in thecase1 for holding washing water therein. Thetub14 is suspended in thecase1 by a plurality ofsprings5 anddampers3. Thesprings5 are provided between an upper portion of thetub14 and thecase1, and thedampers3 are provided between a lower portion of thetub14 and thecase1. Thesprings5 and thedampers3 not only suspend thetub14 in thecase1, but also reduce the vibration of thetub14 generated during the operation of the washing machine.
• There is an opening16 on a front portion of thetub14, and there is an opening9 on thefront cover8 of thecase1. Theopenings9 and16 communicate with each other and face each other. And, adoor10 coupled to thefront cover8 of thecase1 by a hinge opens and closes theopenings9 and16. Further, there is agasket22 between the opening16 of thetub14 and thedoor10. Thegasket22 prevents a leakage of the washing water stored in thetub14.
• There is awater supply hole18 on the upper portion of thetub14 for supplying the washing water into thetub14. Thewater supply hole18 communicates with awater supply hose60 through adetergent box65. Thus, the washing water is supplied into thetub14 with detergent stored in thedetergent box65. And, there is adrain20 for draining the washing water in thetub14 on the lower portion of thetub14. Thedrain20 communicates with adrain hose70 through adrain pump75. Thus, contaminated washing water in thetub14 is drained out through thedrain20 and thedrain hose70 when thedrain pump75 is operated.
• There is a rotatable andhorizontal drum assembly40 for accommodating laundry therein in thetub14. The drum assembly is directly driven by amotor20 mounted on a rear surface of thetub14. Themotor24 comprises astator26 fixed to the rear surface of thetub14, and arotatable rotor28 surrounding thestator28. Aspider30 is mounted on a rear surface of thedrum assembly40, and ashaft33 connected to therotor28 is connected to thespider30 through thetub14.
• Thedrum assembly40 according to the present invention comprises adrum100 accommodating the laundry therein, and at least onelifter200 provided on an inner surface of thedrum100. Thelifter200 lifts and drops the laundry in thedrum100 during a rotation of thedrum100 in order to improve washing, rinsing, and dehydrating performances of the washing machine.FIGS. 2 and 3 illustrate the structure of thedrum assembly40 according to the present invention in detail. Thus, detailed structure of thedrum assembly40 will be described in the followings with reference toFIGS. 2 and 3.
• Thedrum100 comprises acylinder110, a back120, and afront cover130. Thecylinder110 forms a circumference of thedrum100 and has a space for accommodating the laundry therein. The back120 is mounted on an open rear of thecylinder110 and covers the rear of thecylinder110. Thefront cover130 is mounted on an open front of thecylinder110, and covers the front of thecylinder110.
• There are a plurality ofapertures115 on the circumference of thedrum100, i.e., thecylinder110 and the back120, as shown inFIGS. 1 and 2. Thus, the washing water in thetub14 can be introduced into the space of thedrum100 through theapertures115. In addition, there is anopening131 on thefront cover130, so the user can put the laundry into thedrum100 and can draw the laundry in thedrum100 outward through theopening131. Theopening131 is opened and closed by thedoor10. Further, thespider30 is mounted on a rear surface of the back120, as shown inFIG. 1.
• As mentioned above, in the conventional washing machine, lifters are mounted on a drum by coupling members such as screws. On the contrary, in the washing machine according to the present invention, thelifter200 is engaged with and secured to thedrum100 without any separate coupling members such as screws or bolts. More particularly, thelifter200 according to the present invention has a portion passing through the inner surface of thedrum100 and sliding along the inner surface of thedrum100 when the lifter is coupled to thedrum100. Thereby, thelifter200 can be engaged with and secured to thedrum100 without any coupling members such as screws and bolts. Such unique coupling structure of thedrum100 and thelifter200 according to the present invention will be described in the followings in detail.
• As shown inFIG. 2, there is at least oneslot150 on the circumference of thedrum100, i.e., thecylinder110. Theslot150, for example, is elongated along a longitudinal direction of thedrum100. Theslot150 has a pair of slots having a predetermined distance therebetween. Each slot of the pair of slots is arranged to be approximately parallel to each other as shown inFIG. 2. Each pair of slots is arranged to be along the longitudinal direction of thedrum100, and to be apart from one another with a predetermined distance. And, a plurality of rows of slots is provided along the circumference of thedrum100 as shown inFIGS. 2 and 3.
• Thelifter200 comprises at least onehook210, and eachhook210 is engaged to eachslot150. Thehook210 is extended from a lower portion of thelifter200, and slides and moves along a longitudinal direction of theslot150 after being put into theslot150. Thereby, thehook210 of thelifter200 is engaged to and secured to theslot150 of thedrum100. Thehook210 comprises aneck211 extended from the lower portion of thelifter200, and ahead215 formed on an end of theneck211. Wherein thehead215, for example, has a wedge shape with a sharp tip as shown inFIG. 2, and has a width wider than a width of theneck211.
• After being putting into and passing through theslot150, thehead215 moves along the longitudinal direction of theslot150 as thelifter200 slides and moves laterally so as to be coupled to thedrum100. After that, thehead215 is held by a portion of theslot150 in where thehook210 is finally accommodated, and can not be released from the portion theslot150. Thereby thelifter200 as well as thehook210 is engaged to and secured to thedrum200.
• For this, theslot150, for example, comprises awide portion151 having a wide width, and anarrow portion155 connected to thewide portion151. Thewide portion151 is wide enough to allow thehead215 to pass through therein, and thenarrow portion155 is narrower than thewide portion151. Wherein, thenarrow portion155 is wide enough to receive theneck211 of thehook210 when thelifter200 slides and moves along the longitudinal direction of theslot150, but is narrower than the width of thehead215. In other words, thenarrow portion155 is narrow enough to prevent thehead215 from passing through therein.
• There are stepped portions between thewide portion151 and thenarrow portion155. And there is at least onerounded portion160 on the stepped portion. Therounded portion160 guides thehook210, especially theneck211 in thewide portion151 into thenarrow portion155 smoothly. Therounded portion160 can be provided on each stepped portion on both sides of thenarrow portion155 as shown inFIG. 2. On the contrary, therounded portion160 also can be provided on only one stepped portion on one side of thenarrow portion155 as shown inFIG. 4.
• Meanwhile, it is preferable that thehook210 is engaged to thedrum100 with elasticity rather than that thehook210 is engaged to thedrum100 with no elasticity. Then, thelifter200 can be more stably mounted on thedrum100 without any play. Therefore, it is preferable that the pair ofslots150 is formed that eachhook210 can be bent with elasticity when thelifter200 is completely secured to thedrum200.
• For this, the pair ofslots150 arranged to have the predetermined distance therebetween is formed that the pair ofslots150 are getting far away from each other along a sliding direction of thelifter200 rather than that the pair ofslots150 are arranged to exactly parallel to each other, as shown inFIG. 4. In other words, the predetermined distance between the pair ofslots150 is getting longer along the sliding direction of thelifter200. Thus, while a distance between eachwide portion151 of the pair ofslots150 is substantially the same as a distance ‘h’ between eachhook210, a distance ‘H’ between eachnarrow portion155 of the pair ofslots150 is greater than the distance ‘h’ between eachhook210.
• In this case, eachneck211 of the pair ofhooks210 is getting more bent outward as the pair ofhooks210 slides and moves along the longitudinal direction of theslot150 after the pair ofhooks210 being put into a pair ofslots150. Therefore, the pair ofnecks211 of the pair ofhooks210 tightly grasps a portion of thedrum100 between eachslot150 of the pair ofslots150 as shown inFIG. 3. Thereby thelifter200 is stably secured to thedrum100 when thehook210 is completely inserted into thenarrow portion155 of theslot150 due to the elasticity of thehook210.
• Meanwhile, there is aprojection170 on thedrum100 for preventing thelifter200 completely secured to thedrum100 from being released from thedrum100. Theprojection170 is extended from the inner surface of thedrum100 to an inside thedrum100 as shown inFIG. 2. Theprojection170 supports thelifter200 in order to prevent thelifter200 from sliding backward after thelifter200 is completely coupled to thedrum100. Thereby, a release of thelifter200 from thedrum100 is effectively prevented. Further detailed structure of theprojection170 provided on thedrum100 will be described in the followings with reference toFIG. 3.
• As shown inFIG. 3, there is at least one cut awayportion180 on the circumference of thedrum100, wherein the cut awayportion180 surrounds a portion of thedrum100. The cut awayportion180, for example, has a U-shape, and the portion of thedrum100 surrounded by the cut awayportion180 is bent toward the inside thedrum100 with a predetermined slop. Thereby, the bent portion forms theprojection170. As mentioned above, theprojection170 is tilted and thereby theprojection170 has a slope on an upper surface thereof which is connected to the inner surface of thedrum100. Meanwhile, theprojection170, for example, is disposed between the pair ofslots150, as shown inFIGS. 2 and 3.
• There is at least one protrusion provided on thelifter200, the protrusion is engaged with theprojection170 when thelifter200 is secured to thedrum100. More particularly, the protrusion, for example, is provided on a lower surface of thelifter200, and is engaged with theprojection170 in order to secure thelifter200 to thedrum100 when thelifter200 is completely coupled to thedrum100.
• Meanwhile, there is arecess220 provided on the lower portion of thelifter200 for reducing the weight of thelifter200, and there is at least onerib230 provided on therecess220 for reinforcing the strength of thelifter200. Thus, it is preferable that therib230 is engaged with theprojection170 when thelifter200 is engaged to thedrum100 so as to play a role as the protrusion mentioned above, as shown inFIG. 2, rather than that the protrusion is provided on the lower surface of thelift200 separate from therib230 so as to be engaged to thedrum100.
• An assembling process of thedrum100 and thelifter200 will be described in the followings in detail. Above all, the assembler puts eachhook210 into eachwide portion151 of eachslot150, then thehead215 of thehook210 passes through thewide portion151 of theslot150. After that, the assembler laterally pushes thelifter200 along the longitudinal direction of theslot150, then theneck211 accommodated in thewide portion151 is transferred into thenarrow portion155 of theslot150. At this time, therounded portion160 smoothly guides theneck211 in thewide portion151 into thenarrow portion155.
• As theneck211 of thehook200 comes into thenarrow portion155, theneck211 of thehook200 is getting more bent outward with the elasticity. In addition, as thelifter200 slides and moves laterally along the longitudinal direction of theslot150, therib230 protruded from on therecess200 smoothly goes over the slope on the upper portion of the bent andtilt projection170. At this time, thebent projection170 is pushed toward the outside of thedrum100 with elasticity by therib230.
• Finally, therib230 completely passes over theprojection170 when thelifter200 is completely moved laterally. Then, theprojection170 pushed by therib230 is returned to the initial location by the elasticity, and thereby theprojection170 is tightly engaged with a side of therib230 and supports therib230. Therefore, thelifter200 can not slide backward, and thereby thelifter200 is stably secured to thedrum100 with no play.
• As mentioned above, the lifter according to the present invention is secured to the drum without any separable coupling members such as screws or bolts. Thus, the assembler can assemble the drum assembly quickly and with ease. In addition, since a pair of hook tightly grasps the portion of the drum between two slots with elasticity and the projection of the drum is tightly engaged with the rib of the lifter, the lifter is stably secured to the drum with no play.
• 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.

Claims (21)

1. A drum assembly for washing machine comprising:

a drum accommodating laundry therein; and

at least one lifter provided on an inner surface of the drum, and lifting and dropping the laundry in the drum during a rotation of the drum, wherein the lifter slides on the inner surface of the drum after passing through a circumference of the drum so as to be engaged with the drum.

2. The drum assembly as claimed inclaim 1, wherein the drum comprises

a cylinder including a space accommodating the laundry therein;

a back mounted on a rear of the cylinder; and

a front cover mounted on a front of the cylinder, and having an opening which is opened and closed by a door.

3. The drum assembly as claimed inclaim 1, wherein the drum comprises at least one slot provided on the circumference of the drum, and the lifter comprises at least one hook put into the slot and moving along a longitudinal direction of the slot so as to be engaged with the slot when the lifter slides.

4. The drum assembly as claimed inclaim 3, wherein the slot is configured to be elongated along a longitudinal direction of the drum.

5. The drum assembly as claimed inclaim 3, wherein the slot is configured to hold a head of the hook after the head passes through the slot and laterally moves along the longitudinal direction of the slot.

6. The drum assembly as claimed inclaim 1, wherein the lifter comprises a hook including a neck extended from the lifter and a head formed on an end of the neck, and the drum comprises a slot including a wide portion allowing the head to pass through therein and a narrow portion narrower than the head and connected to the wide portion for receiving the neck when the lifter slides on the inner surface of the drum.

7. The drum assembly as claimed inclaim 6, wherein the slot further comprises at least one rounded portion provided between the wide portion and the narrow portion, and smoothly guiding the hook put into the wide portion into the narrow portion.

8. The drum assembly as claimed inclaim 7, wherein the rounded portion is provided on both sides of the narrow portion.

9. The drum assembly as claimed inclaim 7, wherein the rounded portion is provided on one side of the narrow portion.

10. The drum assembly as claimed inclaim 3, wherein the slot comprises a pair of slots arranged to have a predetermined distance therebetween.

11. The drum assembly as claimed inclaim 10, wherein the pair of slots is configured to be formed that the hook put into each slot is bent with elasticity when the lifter is secured to the drum.

12. The drum assembly as claimed inclaim 10, wherein the pair of slots is configured to be getting far away from each other along a sliding direction of the lifter.

13. The drum assembly as claimed inclaim 10, wherein each slot of the pair of slots includes an end accommodating each hook when the lifter is secured to the drum, further wherein a distance between the each end is longer than a distance between the each hook.

14. The drum assembly as claimed inclaim 1, wherein the drum comprises a projection extended from the drum and supporting the lifter so as to prevent the lifter from sliding backward after the lifter is secured to the drum.

15. The drum assembly as claimed inclaim 14, wherein the lifter is configured to go over the projection when the lifter slides on the inner surface of the drum so as to be secured to the drum.

16. The drum assembly as claimed inclaim 14, wherein the projection comprises a slope provided on an upper surface of the projection so that the lifter smoothly goes over the projection along on the slope when the lifter slides so as to be coupled to the drum.

17. The drum assembly as claimed inclaim 14, wherein the drum comprises a cut away portion surrounding a portion of the projection, further wherein the projection is configured to be formed that the portion of the projection surrounding the cut away portion is bent toward an inside the drum.

18. The drum assembly as claimed inclaim 17, wherein the projection is configured to be bent with a predetermined slope.

19. The drum assembly as claimed inclaim 14, wherein the lifter comprises a protrusion extended from the lifter, wherein the protrusion is engaged with the projection so as to prevent the lifter from sliding backward after the lifter is secured to the drum.

20. The drum assembly as claimed inclaim 14, wherein the lifter comprises

a recess provided on a lower portion of the lifter; and

a rib provided on the recess and reinforcing strength of the lifter, wherein the rib is engaged with the projection and secures the lifter to the drum when the lifter is coupled to the drum.

21. The drum assembly as claimed inclaim 10, wherein the drum further comprises at least one projection extended from the drum between the pair of slots, wherein the projection supports the lifter so as to prevent the lifter from sliding backward after the lifter is secured to the drum.

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