Background Art Generally, mops are implements to clean a floor. The mops are designed such that various kinds of cloths are coupled to an end of a long bar, thus allowing a user to clean the floor while standing upright. The mops have been developed to overcome the inconvenience of cleaning in an uncomfortable posture.

The mops are typically classified into a domestic floor mop to clean a floor of a house, and a string mop to clean a floor of an office, a classroom, etc. The conventional domestic floor mop is constructed as follows.

The domestic floor mop includes a long bar with a handle. A cloth support pad is rotatably coupled to a lower end of the long bar. A cloth is supported on the cloth support pad using a plurality of clamps provided on the cloth support

pad.

Since the cloth support pad of the domestic floor mop has a planar shape, the entire cloth simultaneously gets dirty during a cleaning operation. Thus, the conventional domestic floor mop has a problem in that the cloth must be frequently replaced with a new one and washed. In order to replace the dirty cloth with the new one, the plurality of clamps must be unfastened to remove the dirty cloth from the cloth support pad, and then fastened to support the new cloth while the user bends down. Thus, the conventional domestic floor mop has another problem in that it is very complicated to replace the dirty cloth with the new one.

When the user desires to clean a small space, for example a space between articles or a space under an article, it is difficult to clean the small space because the cloth support pad is wide. Thus, the conventional domestic floor mop has a further problem in that the user must bend down to clean the small space, thus causing inconvenience to the user.

In order to solve the above problems, there have been proposed roller-type mops which were disclosed in Korean U. M. Laid-Open Publication No. 2000-0002238 and Korean U. M.

Registration No. 20-0201758 by the same applicant.

The roller-type mops are designed so that a cloth unit thereof is easily rotated. Thus, when a cloth of the cloth unit gets dirty, the cloth unit is rotated to change

a dirty part to a clean part of the cloth, thus allowing a user to efficiently clean a space. Further, the cloth need not be frequently replaced with a new one to be washed.

Furthermore, the roller-type mops are advantageous in that it is easy to removably couple the cloth to a bar, in addition to allowing the user to easily clean a small space.

FIG. 1 is an exploded perspective view of important elements of a conventional roller-type mop disclosed by the same applicant. As shown in FIG. 1, the roller-type mop includes a bar 10 which has, at an upper end thereof, a handle. A mop drive unit 20 is mounted to a lower end of the bar 10. A pair of cloth units 30 is separately mounted to the mop drive unit 20.

The mop drive unit 20 includes a drive bevel gear 22 which is placed to be parallel to a surface to be cleaned by the cloth units 30. A support unit 24 supports, at an upper part thereof, the drive bevel gear 22 to allow the drive bevel gear 22 to be rotated by a rotation of the bar 10. A rotating shaft 26 horizontally passes through a central portion of a lower part of the support unit 24.

FIG. 2a is an exploded perspective view of the mop drive unit 20 of the conventional roller-type mop. As shown in FIG. 2a, the upper part of the support unit 24 has a rod shape to be inserted into a coupling pipe 22a of the drive bevel gear 22. Further, a slot 24a and a step 24b are

integrally provided on an upper end of the support unit 24.

In this case, the slot 24a provides elasticity to allow the drive bevel gear 22 to be easily fitted over the support unit 24. The step 24b prevents the drive bevel gear 22 from being removed from the support unit 24. The coupling pipe 22a is provided at a central portion of the cylindrical drive bevel gear 22, and a plurality of teeth 22b are provided on an outer circumference of a lower end of the drive bevel gear 22.

A pair of rotating cylinders 28 are, respectively, fitted over both sides of the rotating shaft 26 and operated in conjunction with the drive bevel gear 22 to transmit a rotating force to the cloth units 30 (see, FIG.

1). A driven bevel gear 25, 25'is provided on a first end of each of the rotating cylinders 28 to engage with the drive bevel gear 22. Further, holding recesses 28d are formed on diametrically opposite positions of a step 28c which is provided at a position adjacent to each driven bevel gear 25, 25'to prevent the cloth unit 30 from being removed from the associated rotating cylinder 28. Further, slots 28a are provided at a second end of each rotating cylinder 28 to allow each cloth unit 30 to be easily mounted to the associated rotating cylinder 28. Each rotating cylinder 28 also has, on the second end thereof, locking projections 28b to prevent each cloth unit 30 from being removed from the associated rotating cylinder 28.

As shown in FIG. 2b, each cloth unit 30 includes a cylindrical screw body 32 and a cloth 34. The screw body 32 has a mount hole 32a to be fitted over the associated rotating cylinder 28 of the mop drive unit 20. The cloth 34 is wound around the screw body 32.

A plurality of first annular ribs 32b are provided on each screw body 32 at regular intervals, and a second annular rib 32d having a smaller diameter than each of the first annular ribs 32b is concentrically arranged between the first annular ribs 32b. Further, a groove 32c is formed on a side of each of the first and second annular ribs 32b and 32d, so that the long cloth 34 is helically wound around the screw body 32 while passing over the channels between the first and second annular ribs 32b and 32d, in the same manner as a conventional screw.

When the long cloth 34 is helically wound around each screw body 32 to be attached to the screw body 32, the second annular ribs 32d prevent the cloth 34 from being deeply inserted between the first annular ribs 32b, thus preventing a surface area of the cloth 34 contacting a surface to be cleaned from being reduced.

In order to prevent each cloth unit 30 from being undesirably moved relative to the associated rotating cylinder 28 after the cloth unit 30 is fitted over the rotating cylinder 28 of FIG. 1, locking holes (not shown) are provided in the mount hole 32a to receive the locking

projections 28b of each rotating cylinder 28. Further, projecting parts 32e are provided at an end of each screw body 32 to engage with the corresponding holding recesses 28d of the step 28c of each rotating cylinder 28.

However, the conventional roller-type mop is problematic as follows. When the drive bevel gear 22 and the driven bevel gear 25, 25'operating in conjunction with the drive bevel gear 22 rotate, a part of the cloth 34 adjacent to the driven bevel gear 25, 25'may be involved between the teeth 22b of the drive bevel gear 22 or teeth 25a of the driven bevel gear 25, 25'.

Further, the support unit 24 is coupled to the drive bevel gear 22 by means of the slot 24a and the step 24b provided on the upper part of the support unit 24. However, when the conventional roller-type mop is in use, force continuously acts on the upper part of the support unit 24.

At this time, a gap between the slots 24a becomes narrower, and a restoring force of the slot 24a is reduced. Thus, the drive bevel gear 22, supported by the step 24b, may be removed from the support unit 24.

Meanwhile, the string mop is designed so that a cloth produced by tangling long strings is held on a bar by the clamps provided at a lower end of the bar. The string mop is soaked to clean a dirty place. In case of cleaning the dirty place using the string mop, the entire cloth becomes dirty simultaneously. Thereby, it is difficult to

efficiently clean a dirty place. Further, because the string mop is widely used to clean a floor of an office, the string mop becomes dirty rapidly. Further, the cloth of the string mop is large, so that additional implements are required to wash and wring the string mop.

In the conventional roller-type mop, the bar 10 is firmly fitted into a fitting hole which is provided between an outer part of the drive bevel gear 22 and the coupling pipe 22a of the drive bevel gear 22 into which the rod- shaped upper part of the support unit 24 is inserted.

Because the conventional roller-type mop is marketed, used, and stored while the bar 10 is firmly fitted into the fitting hole of the drive bevel gear 22, it is difficult to replace elements of the mop drive unit 20 with new ones when the elements of the mop drive unit 20, such as the support unit 24, are damaged or broken. Further, the conventional roller-type mop is large in volume, so that it is inconvenient to handle.

Furthermore, each rotating cylinder 28 fitted over the rotating shaft 26 is frequently rotated during a use of the conventional roller-type mop, so that a coupling force between the rotating cylinder 28 and the associated driven bevel gear 25, 25'may be weakened. In this case, the cloth unit 30 fitted over each rotating cylinder 28 may be undesirably moved without being fixed in a predetermined position.

Disclosure of the Invention Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a roller-type mop capable of preventing a cloth from being involved between teeth of a drive bevel gear or teeth of a driven bevel gear when a cloth unit rolls.

Another object of the present invention is to provide a roller-type mop capable of increasing a coupling force between several elements of the mop, such as a coupling force between a support unit and a drive bevel gear and a coupling force between a rotating shaft and rotating cylinders.

A further object of the present invention is to provide a roller-type mop which is usable in place of a string mop and needs not a wringing unit.

Yet another object of the present invention is to provide a roller-type mop which is designed so that elements of a mop drive unit are easily replaced with new ones, and the mop drive unit is easily stored and carried with, while maintaining a coupling force between the mop drive unit and a bar.

In order to accomplish the above object, the present invention provides a roller-type mop, including a

cylindrical bar, a mop drive unit mounted to a lower end of the bar, and a cloth unit removably mounted to the mop drive unit and rotated by the mop drive unit. The mop drive unit includes a cylindrical drive bevel gear placed to be parallel to a surface to be cleaned by the cloth unit, a support unit to support, at an upper part thereof, the' drive bevel gear to allow the drive bevel gear to be rotated by a rotation of the cylindrical bar, a rotating shaft to horizontally pass through a central portion of a lower part of the support unit, and a pair of rotating cylinders fitted over both sides of the rotating shaft, respectively. Each of the rotating cylinders has, at a first end thereof, a driven bevel gear which engages with the drive bevel gear to be operated in conjunction with the drive bevel gear, and has, at a second end thereof, a slot.

The cloth unit includes a cylindrical screw body mounted to an outer circumference of each of the rotating cylinders, with a mount hole being provided along a center of the screw body, and a cloth attached to an outer circumference of the screw body. The drive bevel gear includes a plurality of teeth, with upper surfaces of the teeth being connected to each other to prevent the cloth from being involved between the teeth.

Such a construction prevents the cloth from being involved between the teeth of the drive bevel gear when the drive bevel gear rotates.

In a roller-type mop according to an embodiment of the present invention, the screw body includes a plurality of annular ribs which have grooves, respectively, and are arranged on the outer circumference of the screw body at regular intervals, with the long cloth being helically wound around the screw body to be attached to the screw body. The support unit includes, at a center of an upper end thereof, a fastening hole. A locking screw is fastened to the fastening hole after the cylindrical drive bevel gear is fitted over the upper part of the support unit and a washer is placed on an upper end of the drive bevel gear, so that the drive bevel gear is rotatably fastened to the support unit.

Such a construction provides a coupling force between the drive bevel gear and the support unit, thus preventing the drive bevel gear from being removed from the support unit while the roller-type mop is in use.

In a roller-type mop according to another embodiment of the present invention, the drive bevel gear includes an upper end which is tapered in a direction from a lower portion to an upper portion thereof, with a plurality of slots being provided on the upper end of the drive bevel gear. An external threaded part is provided on an outer circumference of the drive bevel gear under the plurality of slots, with the cylindrical bar being inserted into a center of the drive bevel gear and assembled with the drive

bevel gear using a cylindrical fastening unit which has, on an inner circumference thereof, an internal threaded part to correspond to the external threaded part.

The above construction provides a coupling force between the drive bevel gear and the bar. Further, the roller-type mop has a separable structure, so that it is easy to replace elements of the mop drive unit with new ones, and it is easy to store and move to another place.

Brief Description of the Drawings 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: FIG. 1 is an exploded perspective view of a part of a conventional roller-type mop; FIG. 2a is an exploded perspective view of a part of a mop drive unit included in the roller-type mop of FIG. 1 ; FIG. 2b is an exploded perspective view of a part of a cloth unit included in the roller-type mop of FIG. 1 ; FIG. 3a is an exploded perspective view of a part of a mop drive unit included in a roller-type mop, according to a first embodiment of the present invention ; FIG. 3b is a perspective view of a screw body of a cloth unit included in the roller-type mop of FIG. 3a ;

FIG. 3c is a sectional view to show a cloth fastened to a cloth holding hole of the screw body of FIG. 3b; FIG. 4 is an exploded perspective view of a part of a roller-type mop, according to a second embodiment of the present invention ; FIG. 5 is an exploded perspective view of a part of a roller-type mop, according to a third embodiment of the present invention; FIG. 6 is an exploded perspective view of a mop drive unit included in the roller-type mop of FIG. 5 ; and FIG. 7 is a sectional view of important elements of the roller-type mop of FIG. 5.

Best Mode for Carrying Out the Invention Reference should now be made to the drawings, in which the same reference numerals are used throughout the different drawings to designate the same or similar components.

As shown in FIGS. 3a through 3c, a roller-type mop according to a first embodiment of the present invention includes a bar 100 having at an upper end thereof a handle, a mop drive unit 120 mounted to a lower end of the bar 100, and cloth units 130 removably mounted to the mop drive unit 120.

The mop drive unit 120 includes a drive bevel gear

122 which is placed to be parallel to a surface to be cleaned by the cloth units 130. A support unit 124 supports, at an upper part thereof, the drive bevel gear 122 to allow the drive bevel gear 122 to be rotated by a rotation of the bar 100. A rotating shaft 126 horizontally passes through a central portion of a lower part of the support unit 124.

As shown in FIG. 3a, in the roller-type mop of the present invention, the drive bevel gear 122 has a cylindrical shape. A coupling pipe 122a is provided at a central portion of the drive bevel gear 122, and a plurality of teeth 122b are provided on an outer circumference of a lower end of the drive bevel gear 122.

In the present invention, the drive bevel gear 122 is constructed so that upper surfaces 122c of the teeth 122b are connected to each other, differently from a conventional drive bevel gear. Such a construction prevents a part of a cloth 134 around the drive bevel gear 122 from being involved between the teeth 122b of the drive bevel gear 122 when the drive bevel gear 122 rotates.

Further, the drive bevel gear 122 is fastened to the support unit 124 using a locking screw. In a detailed description, a fastening hole 124a is provided at a center of an upper end of the support unit 124, and the rod-shaped upper part of the support unit 124 is inserted into the coupling pipe 122a of the cylindrical bevel gear 122.

Thereafter, a washer 123a is placed on an upper end of the drive bevel gear 122, and a bolt 123b is tightened into the fastening hole 124a, so that the drive bevel gear 122 is fastened to the support unit 124 to be rotated around a rotating axis of the drive bevel gear 122. When the bolt 123b is tightened into the fastening hole 124a, a spring 323c (see, FIG. 6) may be interposed between the bolt 123b and the washer 123a. Such a construction provides a coupling force between the drive bevel gear 122 and the support unit 124, thus preventing the drive bevel gear 122 from being removed from the support unit 124 when the roller-type mop is in use, therefore preventing the bar 100 from being unexpectedly rotated.

Further, a pair of rotating cylinders 128 is fitted over both sides of the rotating shaft 126, respectively, to transmit rotating force to the cloth units 130 in conjunction with the drive bevel gear 122. A driven bevel gear 125, 125'is provided on a first end of each rotating cylinder 128 to engage with the drive bevel gear 122.

A step 128c is provided at a position adjacent to each driven bevel gear 125, 125', and has holding recesses 128d at diametrically opposite positions of the step 128c, thus preventing each cloth unit 130 from being undesirably removed from the associated rotating cylinder 128. Two locking lugs 128e are provided on each step 128c at positions spaced apart from the holding recesses 128d at

right angles. Further, a pair of slots 128a and locking projections 128b are provided on a second end of each rotating cylinder 128. The slots 128a allow each cloth unit 130 to be easily fitted over the associated rotating cylinder 128, and the locking projections 128b prevent each cloth unit 130 from being removed from the associated rotating cylinder 128.

According to the present invention, a seat is provided on an inside end of each slot 128a of each rotating cylinder 128, and a part of each of both ends of the rotating shaft 126 made of a metal material is cut to form a cut part 126a. The cut part 126a is bent by use of a press to be seated in the seat. Such a construction allows the rotating cylinders 128 to be more firmly supported on the rotating shaft 126.

As shown in FIGS. 3b and 3c, each cloth unit 130 includes a cylindrical screw body 132 and a cloth 134, similarly to a conventional cloth unit. In this case, a plurality of first and second annular ribs 132b and 132d are arranged on an outer circumference of the screw body 132 at regular intervals. The cloth 134 is helically wound around the screw body 132 to be attached to the screw body 132.

According to the present invention, projecting parts 132e are provided on an inner wall of a mount hole 132a of the screw body 132 to respectively engage with the

corresponding holding recesses 128d which are provided on the diametrically opposite positions of the step 128c of each rotating cylinder 128.

The above construction allows the driven bevel gear 125, 125'to be disposed in an end of each screw body 132 while maintaining a coupling force between each rotating cylinder 128 and the associated screw body 132, differently from a case where projecting parts are outwardly projected from each screw body. Thereby, a part of the cloth 134 around each driven bevel gear 125, 125'is prevented from being involved between teeth 125a of the driven bevel gear 125, 125'and an interval between both cloth units 130 is reduced, thus allowing a user to efficiently clean a space.

According to the present invention, locking depressions 132f are provided on an end of an inner portion of each screw body 132 to receive the locking lugs 128e provided on the step 128c of each rotating cylinder 128.

Such a construction increases the coupling force between the rotating cylinders 128 and the corresponding cloth units 130.

A pair of cloth holding holes 132g is respectively provided on opposite ends of each screw body 132. A locking bolt 136 is tightened into each cloth holding hole 132g to hold each cloth 134 to the associated screw body 132. The reference numeral 135 denotes a packing which allows the cloth 134 to be in surface contact with the screw body 132,

thus increasing a locking force between the cloth 134 and the screw body 132.

The operation of the roller-type mop according to the present invention will be described in the following with reference to FIGS. 3a through 3c. The cloth 134 having a shape of a strip is helically wound around each cylindrical screw body 132 while passing over the channels between the first and second ribs 132b and 132d. At this time, as shown in FIG. 3c, the cloth 134 is fastened to the screw body 132 by the locking bolt 136 after an end of the cloth 134 is placed on each cloth holding hole 132g of the screw body 132. When the locking bolt 136 is tightened into the cloth holding hole 132g after being fitted into the packing 135, the screw body 132, the cloth 134, and the packing 135 are in surface contact with each other, thus increasing the locking force therebetween and thereby preventing each cloth 134 from being removed from the associated screw body 132.

Next, each cloth unit 130 is fitted over the associated rotating cylinder 128 of the mop drive unit 120.

In this case, when each cloth unit 130 is fitted over the associated rotating cylinder 128, gaps between the slots 128a provided on the second end of each rotating cylinder 128 become narrower, and the cloth unit 130 is easily fitted over the rotating cylinder 128. After the insertion of the cloth unit 130 is completed, the slots 128a are

restored to original shapes, and the locking projections 128b, the holding recesses 128d, and the locking lugs 128e of each rotating cylinder 128 engage with locking holes (not shown), the projecting parts 132e, and the locking depressions 132f, respectively. Thus, each cloth unit 130 is supported on the associated rotating cylinder 128.

In such a state, a user cleans a dirty floor while contacting the cloth 134 with the dirty floor, in a same manner as a conventional mop. During such a cleaning operation, a bottom of the cloth 134 gets dirty while a remaining part of the cloth 134 is kept clean. When the bottom of each cloth 134 gets dirty, the bar 100 is turned in a longitudinal axis thereof to rotate the cloth units 130. Thereby, a clean part of each cloth 134 is in contact with the dirty floor to be cleaned, thus allowing the user to continuously clean the dirty floor without the necessity of replacing the cloth 134 with a new one.

Each cloth unit 130 is rotated as follows. When the bar 100 is turned around the longitudinal axis thereof, the drive bevel gear 122 of the mop drive unit 120 which is mounted to the lower end of the bar 100 is rotated in the same direction. At this time, the driven bevel gears 125 and 125'engaging with the drive bevel gear 122 are rotated around rotating axes thereof in conjunction with the drive bevel gear 122. Meanwhile, since the driven bevel gears 125 and 125'are integrally provided at the first ends of the

corresponding rotating cylinders 128, respectively, the rotating cylinders 128 and the rotating shaft 126 are simultaneously rotated around the rotating axes'when the driven bevel gears 125 and 125'rotate, as described above.

Therefore, the cloth units 130 fitted over the rotating cylinders 128 rotate.

When the cleaning operation is performed, the teeth 122b of the drive bevel gear 122 constructed as described above and the projecting parts 132e provided on an inner wall of each screw body 132 engaging with the holding recesses 128d, prevent each cloth 134 from being involved between the teeth 122b of the drive bevel gear 122 or the teeth 125a of the driven bevel gear 125, 125'. Further, the locking projections 128b, the locking lugs 128e, and the holding recesses 128d of the rotating cylinders 128, and the locking holes, the locking depressions 132f, and the projecting parts 132e of each screw body 132 increase a coupling force between several elements, thus preventing the elements from being removed from original positions thereof during the cleaning operation.

When the entire cloth 134 becomes dirty, each cloth unit 130 is removed from the associated rotating cylinder 128 to be washed. Each cloth unit 130 having the washed cloth 134 is fitted over the associated rotating cylinder 128 to be used again. Further, the roller-type mop according to the present invention allows the user to

easily and efficiently clean a small space or floor. The roller-type mop according to the first embodiment may be used as a wet mop or a dry mop at home.

A roller-type mop according to a second embodiment is designed so that a cloth unit is fixed to a mop drive unit to be used in place of a string mop. The second embodiment will be described hereinafter with reference to FIG. 4. In this case, the difference between the first and second embodiments will be explained. Those elements common to the first and second embodiments will carry the same reference numerals.

According to the second embodiment, a rotating shaft 226 is longer than a total length of the rotating cylinders 128, so that the rotating shaft 226 extends at both ends thereof to an outside of the rotating cylinders 128. The rotating shaft 226 is cut, at opposite sides of each of both ends of the rotating shaft 226, to form cut parts 226a. Further, fastening depressions 232g are provided on an end of a screw body 232 to correspond to the cut parts 226a.

When the length of the rotating shaft 226 and the length of each screw body 232 are regulated, and then each cloth unit 230 is fitted over the associated rotating cylinder 128 of the mop drive unit 120, each of both ends of the rotating shaft 226 corresponds to an outside end of each screw body 232. Thereafter, the cut parts 226a of the

rotating shaft 226 are bent, using a press, to be seated in the fastening depressions 232g of the associated screw body 232. Such a construction allows each cloth unit 230 to be firmly coupled to both the rotating shaft 226 and the associated rotating cylinder 128.

As shown in FIG. 4, the groove formed between the annular ribs provided on both ends 232b, 232c of each screw body 232 may be deeper than the grooves formed between the annular ribs provided on a remaining part of the screw body 232. That is, when a cloth 234 made of relatively long strings is helically wound around each screw body 232 to be used in place of the string mop, the cloth 234 is deeply inserted in both ends of the screw body 232. Thus, although the cloth 234 is long like the string mop, the cloth 234 is prevented from being involved in the drive bevel gear 122 or the driven bevel gear 125, 125'and is prevented from being loosened.

Each screw body 232 of the second embodiment may have a larger diameter than the screw body 132 of the first embodiment. Such a construction allows a surface area of the cloth unit 230 to be increased, thus being suitable for cleaning a large space, for example, an office. The reference numeral 232f denotes locking depressions to receive the locking lug 128e of each step 128c, so as to increase a coupling force between each rotating cylinder 128 and the associated cloth unit 230.

When the roller-type mop having the long string according to the second embodiment is used in place of the string mop, only a part of each cloth 234 contacting with a floor to be cleaned gets dirty. At this time, the cloth unit 230 is rotated to change the dirty part to a clean part of the cloth 234 in a same manner as the first embodiment, thus allowing the user to continuously clean the floor.

Further, the roller-type mop of the second embodiment prevents each cloth 234 from being involved in the drive bevel gear 122 or the driven bevel gear 125,125'. In addition, the roller-type mop of the second embodiment is easily wringed without using any implements, differently from the conventional string mop. In a detailed description, the roller-type mop of the second embodiment is constructed to rotate the cloth units 230 while pressing the cloth units 230 by the user's feet, thus allowing each cloth 234 to be easily wringed by a weight of the user.

FIGS. 5 through 7 show a roller-type mop according to a third embodiment of the present invention. In the roller- type mop according to the third embodiment shown in FIGS. 5 through 7, the upper part of a drive bevel gear 322 has a shape of a longer cylinder than those of the first and second embodiments. An upper end of the upper part of the drive bevel gear 322 is tapered in a direction from a lower portion to an upper portion thereof, with a plurality of

slots 322e being provided on the upper end of the drive bevel gear 322. Further, an external threaded part 322f is provided on an outer circumference of the drive bevel gear 322 under the plurality of slots 322e. A fastening unit 340, which has, on an inner circumference thereof, an internal threaded part (not shown) to engage with the external threaded part 322f of the drive bevel gear 322, is fastened to the upper part of the drive bevel gear 322.

A lower end of a bar 400 is fitted into a fitting hole 322d provided between a coupling pipe 322a and an outermost portion of the drive bevel gear 322. In this case, the upper end of the drive bevel gear 322 is tapered in the direction from the lower portion to the upper portion thereof, and is provided with the plurality of slots 322e, thus allowing the bar 400 to be easily fitted into the drive bevel gear 322 by the elasticity of the slots 322e while preventing the bar-400 from being unexpectedly removed from the drive bevel gear 322.

Further, the fastening unit 340 is fastened to the upper part of the drive bevel gear 322, thus increasing a coupling force between the bar 400 and the drive bevel gear 322.

Since the roller-type mop of the third embodiment is constructed so that the bar 400 is easily separated from the drive bevel gear 322 when necessary, differently from the roller-type mops of the first and second embodiments,

elements of the roller-type mop are easily replaced with new ones when the elements of the mop drive unit 320, including the support unit 324 and the rotating cylinders 328, may be damaged or broken. Further, the roller-type mop is marketed, moved to another place, and stored after the bar 400 is separated from the mop drive unit 320, so that it is easy to handle.

In the roller-type mop of the third embodiment, when one desires to fit the rotating cylinders 328 over the rotating shaft 326, the driven bevel gears 325 are fitted over both sides of the rotating shaft 326. Next, a spring 329 is interposed between each rotating cylinder 328 and the associated driven bevel gear 325 before the rotating cylinder 328 is fitted over the rotating shaft 326. Cut parts 326a of the rotating shaft 326 are bent, using a press, to be seated in seats provided on inside ends of slots 328a of each rotating cylinder 328. Such a construction prevents the coupling force between the rotating shaft 326 and the rotating cylinders 328 from being weakened when the roller-type mop has been used for a lengthy period of time, thus preventing the cloth units 330 from being moved relative to the corresponding rotating cylinders 328.

Industrial Applicability

As described above, the present invention provides a roller-type mop which includes a drive bevel gear and screw bodies improved in design, thus preventing a cloth from being involved between teeth of the drive bevel gear or teeth of driven bevel gears.

A roller-type mop according to the present invention increases a coupling force between a support unit and a drive bevel gear, between a rotating shaft and rotating cylinders, and between the rotating cylinders and cloth units.

The present invention provides a roller-type mop which is used in place of a string mop without using additional wringing units.

This invention provides a roller-type mop which includes a drive bevel gear of an improved shape, and additionally includes a fastening unit, thus increasing a coupling force between a mop drive unit and a bar. Further, the roller-type mop is designed such that the bar is easily separated from the mop drive unit when necessary.

Therefore, when elements of the mop drive unit, such as the support unit and the rotating cylinders, are damaged or broken, it is possible to replace the broken elements with new ones. Further, the roller-type mop is easy to be moved to another place, be stored, and handled.

When the drive bevel gear is fastened to the support unit in a screw-type fastening method and the rotating

cylinders are fitted over the rotating shaft, springs are interposed between the drive bevel gear and the support unit and between the rotating cylinders and the associated driven bevel gears, respectively, thus increasing coupling forces between the above-mentioned elements.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.