CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims the benefit of priority under 35 U.S.C. §119(a) to Korean Patent Application No. 2005-89809, filed Sep. 27, 2005, the entire contents of which are incorporated herein by reference. This application may also be related to commonly owned U.S. patent application Ser. No. 10/991,426, filed Nov. 19, 2004, and commonly owned U.S. Pat. No. 6,918,156, the contents of each of which are incorporated herein by reference in their entireties.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to a suction brush of a vacuum cleaner.  
         [0004]     2. Description of the Related Art  
         [0005]     In general, a suction brush of a vacuum cleaner has a suction port at the bottom thereof to enable suctioning of dust or other debris (collectively, “debris”) from a surface to be cleaned, and a dust guide groove to guide the debris to the suction port.  
         [0006]     In order to improve the manipulability of the suction brush of a vacuum cleaner, it has been proposed to provide plural auxiliary wheels on the bottom of the suction brush adjacent to the dust guide groove, as described in Korean Patent Publication No. 2004-47365, or to provide rolling rollers at the rear part of the bottom of the suction brush, as described in Korean Patent Publication No. 2005-18492.  
         [0007]     The above-mentioned techniques may somewhat reduce the sticking force between the suction brush and the surface to be cleaned. However, if the object to be cleaned is a soft carpet, it is difficult to improve the manipulability of the suction brush and often the auxiliary wheels or rolling rolls do not smoothly roll.  
       SUMMARY OF THE INVENTION  
       [0008]     Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior art, and an object of the present invention is to provide an improved suction brush of a vacuum cleaner, which is superior in manipulability for moving the suction brush while contacting a surface to be cleaned. At the same time, a suction force which is directly related to the debris removing capability of the suction brush is maintained.  
         [0009]     To this end, a non-limiting aspect of the present invention provides a suction brush of a vacuum cleaner, which includes: a body configured to communicate with a dust collection device and including at least one suction port; a cover configured to cover a top of the body; and at least one rolling pin configured to be rotatably coupled at a bottom of the body.  
         [0010]     Another non-limiting aspect of the present invention provides a vacuum cleaner, including: at least one suction brush; at least one dust collector; and means for separating the at least one suction brush from a surface to be cleaned. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     The above aspects and features of the present invention will be more apparent from the description for certain embodiments of the present invention taken with reference to the accompanying drawings, in which:  
         [0012]      FIG. 1  is a perspective view showing a non-limiting example of a suction brush of a vacuum cleaner;  
         [0013]      FIG. 2  is a cross-sectional view showing a suction brush of a vacuum cleaner according to a non-limiting embodiment of the present invention;  
         [0014]      FIG. 3  is a view showing a bottom of the suction brush shown in  FIG. 2 ;  
         [0015]      FIGS. 4A  to  4 C are schematic views illustrating a non-limiting example of coupling a rolling pin shown in  FIG. 2  to the body of the suction brush;  
         [0016]      FIG. 5A  is a graph comparatively showing the dust removing capabilities of a suction brush according to a non-limiting embodiment of the present invention and a conventional suction brush in comparison; and  
         [0017]      FIG. 5B  is a graph comparatively showing the manipulation forces required for a suction brush according to a non-limiting aspect of the present invention and a conventional suction brush. 
     
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS  
       [0018]     Hereinbelow, the embodiments of the present invention are described in detail with reference to accompanying drawings. In the accompanying drawings, like numerals refer to like elements thoughout.  
         [0019]     An exemplary vacuum cleaner is illustrated in  FIG. 1 . Generally, the vacuum is turned on when the suction brush is on the surface to be cleaned. A suction motor (not shown) may be driven and debris (with air) is suctioned through the opposite ends  5   a  and  5   b  of the dust guide groove  5  when the bottom of the suction brush  1  is proximate to or contacting the surface to be cleaned (e.g., a carpet) (not shown).  
         [0020]     After the debris and air, which are caused to flow into the dust guide  5 , are suctioned into the vacuum cleaner through the suction port  7 , the debris is collected through a dust collecting unit (not shown) and the air is filtered and discharged to the outside of the vacuum cleaner.  
         [0021]     The effectiveness of a carpet type suction brush may be determined by two factors, i.e., suction force and ease of maneuvering (maneuverability). In general, if the suction force is increased, the force between the suction brush and the carpet is strong, and maneuverability reduces. If the maneuverability is improved, the suction force is generally reduced. In particular, when an object to be cleaned is lightweight (like a carpet), it is helpful to design the dust guide groove so that the suction force can be increased while the force to be exerted by a user to maneuver the suction brush can be reduced, thereby improving the maneuverability of the suction brush.  
         [0022]     As mentioned above, the dust guide groove  5  is the part into which the debris is introduced during cleaning. In particular, the carpet strongly contacts opposite ends  5   a  and  5   b  of the dust guide groove  5  and the suction port  7  due to the suction force of the vacuum cleaner. Therefore, when the user moves the suction brush  1  in any direction when the suction brush  1  is in contact with the carpet, the suction force opposes the movement of the suction brush  1 . The force caused by suctioning decreases the maneuverability of the vacuum, which increases the amount of force required by the user.  
         [0023]     In order to overcome this problem, a pair of wheels  9   a  and  9   b  may be provided at the rear parts of the opposite sides of the body  2  of the suction brush  1 . However, when the object to be cleaned is a carpet, there is still inconvenience for the user because the carpet still strongly sticks to the dust guide groove  5  and the suction port  7  of the suction brush  1 .  
         [0024]     Referring to  FIGS. 2 and 3 , the suction brush  10  may include a body  11  which may be formed with a suction port  17  and a dust guide groove  15  for guiding debris to the suction port  17 , as well as with a cover  12  which may be provided on the top of the body  11  to cover the top of the body  11 .  
         [0025]     A suction brush  10  of a vacuum cleaner according to a first non-limiting embodiment of the present invention may be in communication with a dust collection device (not shown) of the vacuum cleaner at one end thereof directly or via a flexible hose (not shown).  
         [0026]     The dust guide groove  15  may be extended between the left and right ends of the body  11  in the left and right directions of the suction port  17  and may be in communication with the suction port  17 . A pair of rolling pins  20  may be installed at or adjacent to the left and right edge portions of the dust guide groove  15 . Each of the rolling pins  20  may include a cylindrical portion  21 , which may contact a surface to be cleaned, so that a space of height H may be formed between the surface to be cleaned and the bottom of the body  11  during cleaning, and a pair of coupling projections  25   a  and  25   b  may project from opposite ends of the rolling pin  20 . At or adjacent to the left and right edge portions of the dust guide groove  15 , two pairs of coupling grooves  15   b  and  15   c  may be formed, so that each pair of coupling projections  25   a  and  25   b  may be rotatably fitted in a corresponding pair of coupling groove  15   b  and  15 c.  
         [0027]     It may be also preferable to form the dust guide groove  15  such that the width is gradually increased corresponding to a shape of the suction port  17  as viewed from inlets  15   a  to a central portion  15   d  of the dust guide groove 15 . Moreover, to improve the efficiency of suctioning debris, it may be desirable to form the dust guide groove  15  generally in a streamlined shape, so that flow resistance can be minimized.  
         [0028]     Meanwhile, the rolling pins  20  allow the body  11  to be more easily maneuvered when an adhesion force between a surface to be cleaned and the body  11  is constantly maintained. Each rolling pin  20  may include a cylindrical portion  21  configured to contact a surface to be cleaned, thereby spacing the bottom of the body  11  from the surface to be cleaned. A pair of coupling projections  25   a  and  25   b,  which may be rotatably connected to the opposite ends of the dust guide groove  15 , may also be included.  
         [0029]     Each pair of projections  25   a  and  25   b,  which may be removably fitted in the corresponding pair of coupling grooves  15   b  and  15   c,  may have a cross-sectional area smaller than that of the coupling grooves  15   b  and  15   c,  as shown in  FIGS. 4A and 4B . Consequently, spaces S may be formed between coupling grooves  15   b  and  15   c  and projections  25   a  and  25   b,  thereby forming a passage for the debris introduced from inlets  15   a  of the dust guide groove  15 .  
         [0030]     The projections  25   a  and  25   b  may have any shape in cross-section. For example, the projections  25   a  and  25   b  may have a circular shape flattened at opposite sides as shown in  FIG. 4A  or an oval shape. Preferably, projections  25   a  and  25   b  may be rotatable within the coupling grooves  15   a  and  15   b  and the cross-sectional area thereof may be smaller than that of the coupling grooves  15   b  and  15   c.    
         [0031]     Referring to  FIG. 3 , each rolling pin  20  may be formed with a spiral groove  23  extending along the periphery of the cylindrical portion  21 . Although it is exemplified in the present non-limiting embodiment that the spiral groove  23  forms five turns around the rolling pin  20 , the present invention is not limited with respect to the number of turns and/or the pitch of the spiral groove  23 . Owing to the spiral grooves  23 , even if cleaning is performed when the bottom of the body  11  of the suction brush  10  comes into close contact with a surface to be cleaned, air flows into the suction port in the directions indicated by arrows B as well as in the directions indicated by arrows A as shown in  FIG. 3 . As a result, it may be possible to prevent the surface to be cleaned from strongly adhering to the suction brush  10  and from being dragged by the suction brush  10 . Consequently, the maneuverability of the suction brush  10  can be improved.  
         [0032]     As the rolling pins  20  rotate, passage for debris can be secured through the spiral grooves  23 . Accordingly, it is possible to smoothly move the suction brush  10  in any direction when the bottom of the body  11  is in close contact with the surface to be cleaned.  
         [0033]     To maintain the space between the surface to be cleaned and the bottom of the body  11  within a range not more than approximately 0.5 mm, it is also possible to properly set the diameter of the cylindrical portions  21  and/or to adjust the mounting depth of the rolling pins  20 . It is preferable that the space be set to height H, which allows the suction force to be substantially constantly maintained at the level obtained in the state in which the rolling pins  20  are removed from the body  11 .  
         [0034]     The procedure for installing the rolling pins  20  at or near the bottom of the body  11  will now be described with reference to  FIGS. 3 and 4 A- 4 C. At first, the projections  25   a,    25   b  of the rolling pins  20  may be turned so that they are substantially in line with the width of the coupling grooves  15   b  and  15   c  as shown in  FIG. 4A , and then the projections  25   a  and  25   b  may be fitted in the coupling grooves  15   b  and  15   c  as shown in  FIG. 4B . From this state, it may be preferable that the rolling pins  20  be turned to a predetermined angle to be stably coupled at or adjacent to the left and right edge portions of the dust guide groove  15 , so that the escape of the projections  25   a  and  25   b  of the rolling pins  20  can be prevented. Because the rolling pins  20  coupled in this manner may be interposed between a surface to be cleaned and the dust guide groove  15  during the cleaning, they may be prevented from moving away from the dust guide groove  15 .  
         [0035]     The suction brush  10  of a vacuum brush according to a non-limiting embodiment of the present invention as configured above can be improved in manipulability because the rolling pins  20  may be installed and roll at or adjacent to the left and right edge portions of the dust guide groove  15 , to which the highest suction force is applied, thereby reducing the sticking force between the surface to be cleaned and the suction brush  10 . In particular, air and debris may be suctioned from the surface to be cleaned through the spiral grooves formed on the rolling pins  20 , thereby reducing the frictional force and sticking force between the surface to be cleaned and the suction brush  10 .  
         [0036]     In addition, according to the above-mentioned embodiment of the present invention, it is possible to improve the manipulability of the suction brush  10  while maintaining the suction force whether a surface to be cleaned is a hard floor or a soft carpet.  
         [0037]      FIG. 5A  is a graph comparatively showing the suction forces, which may be directly related to the dust removing capabilities of a suction brush, according to a non-limiting embodiment of the present invention and a conventional suction brush:  FIG. 5B  is a graph comparatively showing the maneuvering forces of the suction brush according to the embodiment of the present invention and the conventional suction brush. Referring to  FIG. 5A , there is no change in suction efficiency before and after mounting the rolling pins. However, referring to  FIG. 5B , it can be confirmed that the force applied by a user to move the suction brush, i.e. the maneuvering force, is substantially reduced.  
         [0038]     By way of example, the operation of the inventive suction brush configured as described above will now be described in terms of the case in which the surface to be cleaned is the surface of a carpet. At first, if the vacuum cleaner is powered on to drive the vacuum motor of the cleaner, vacuum force is transmitted to the suction brush  10 . Then, the suction brush  10  comes into close contact with a surface of the carpet. The space between the bottom of the body of suction brush  10  and the carpet may be maintained at the height H (see  FIG. 4B ) due to the rolling pins  20 . In particular, due to the height H, the force between the carpet and the suction brush  10  is reduced.  
         [0039]     Therefore, when pushing or pulling the suction brush  10  while cleaning, the user can easily manipulate the suction brush  10  because the rolling pins  20  roll. Furthermore, because the air flowing through the spiral grooves  23  formed around the cylindrical portions  21  of the rolling pins  20  functions to slightly lift the suction brush  10 , the user can more easily maneuver the suction brush  10 .  
         [0040]     The present invention has an advantage in that by providing a pair of rolling pins at the bottom of the suction brush, the sticking force between a surface to be cleaned and the suction brush can be reduced, whereby the maneuvering force for moving the suction brush can be also reduced. In addition, because air is suctioned through the spiral grooves  23  formed around the rolling pins  20 , the frictional force between the surface to be cleaned and the suction brush can be reduced, whereby the user can easily clean the surface to be cleaned even if the surface is formed of a lightweight material such as a carpet.  
         [0041]     Although representative embodiments of the present invention have been shown and described in order to exemplify the principle of the present invention, the present invention is not limited to the specific embodiments disclosed herein. It will be understood that various modifications and changes can be made by one skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, it shall be considered that such modifications, changes, and equivalents thereof are all included within the scope of the present invention.
A suction brush of a vacuum cleaner includes: a body configured to communicate with a dust collection device and including at least one suction port; a cover configured to cover a top of the body; and at least one rolling pin configured to be rotatably coupled at a bottom of the body.