Patent Publication Number: US-9420926-B2

Title: Vacuum cleaner

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of Korean Patent Application No. 10-2013-0067002, filed on Jun. 12, 2013 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. 
     BACKGROUND 
     1. Field 
     One or more embodiments relate to a vacuum cleaner that smoothly performs straight movement and direction change. 
     2. Description of the Related Art 
     A vacuum cleaner is a device that suctions air using suction force generated by a fan and a motor and filters foreign matter from the suctioned air to perform cleaning. 
     The vacuum cleaner includes a dust collector to filter foreign matter from the suctioned air using a predetermined filtering device. A porous filter unit to forcibly filter foreign matter from air when the air passes through a porous filter or a cyclone type dust collection unit to filter foreign matter from air during cyclonic flow of the air may be used as the filtering device. 
     The vacuum cleaner includes a main body including a dust collector to separate and collect foreign matter from air, a suction nozzle assembly to suction foreign matter, such as dust, from a floor while moving along the floor, and a connection pipe to guide the foreign matter suctioned by the suction nozzle assembly to the main body. 
     The suction nozzle assembly includes a suction head, a handle pipe, and an extension pipe connected between the handle pipe and the suction head. The suction head may suction foreign matter from a surface to be cleaned while contacting the surface. The handle pipe is connected to the suction head for user manipulation. The handle pipe and the suction head are connected to each other via the extension pipe. A user may perform cleaning while holding the handle pipe connected to the suction head. 
     The main body and the suction nozzle assembly may be connected to each other via the connection pipe. One side of the connection pipe may be connected to the suction nozzle assembly and the other side of the connection pipe may be connected to the main body. A flexible hose may be used as the connection pipe. 
     The main body includes an air suction device to generate suction force. The vacuum cleaner is provided at one side thereof with a dust collection container mounting unit, to which a dust collection container is mounted. The main body may be provided with a wheel assembly to move the main body. 
     In a conventional vacuum cleaner, traveling wheels are provided at opposite sides of the rear of the main body and a caster to change the direction of the main body is provided at the front of the bottom of the main body. In this case, although the direction of the main body is abruptly changed by a user, the traveling direction of the traveling wheels is not changed accordingly. As a result, the main body may be forcibly moved in a state in which the traveling wheels are lifted from the floor or the main body may overturn. 
     In a case in which the wheel assembly includes only a caster rotatable in all directions, on the other hand, the main body may shake even during straight movement of the main body with the result that the main body may collide with a wall or furniture in a room. In addition, when a carpet is cleaned, the main body may not easily travel on the carpet due to a long pile of the carpet. 
     SUMMARY 
     The foregoing described problems may be overcome and/or other aspects may be achieved by one or more embodiments of a vacuum cleaner configured such that a main body first may rotate independently of a wheel assembly during a change in direction of the vacuum cleaner and then the wheel assembly may rotate in a direction in which the main body is directed, thereby changing a movement direction of the main body while possibly improving straight mobility of the main body due to wheels. 
     Additional aspects and/or advantages of one or more embodiments will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of one or more embodiments of disclosure. One or more embodiments are inclusive of such additional aspects. 
     In accordance with one or more embodiments, a vacuum cleaner may include a main body including a fan motor to generate suction force, a suction unit connected to the main body to suction foreign matter from a surface to be cleaned when contacting the surface, a dust collector separatably mounted to the main body to separate and collect foreign matter from air suctioned by the suction unit, and a wheel assembly to move the main body, wherein the main body may be rotatable independently of the wheel assembly such that the main body may rotate to change a movement direction thereof and the main body may be moved in the changed direction by the wheel assembly. 
     The vacuum cleaner may further include an elastic member disposed between the wheel assembly and the main body, wherein, when the main body first rotates to change the movement direction thereof, a direction of the wheel assembly may be changed by elastic force of the elastic member. 
     The wheel assembly may include frames provided at an upper part, a lower part, and left and right sides of the main body and wheels rotatably mounted to the frames, the wheels being provided at opposite sides of the main body. 
     The frame provided at the lower part of the main body may be provided with a first rotation guide in a protruding state. 
     The main body may be provided at the bottom thereof with a receiving unit to receive the first rotation guide. 
     The receiving unit may be provided at the inside thereof with a second rotation guide in a protruding state, the second rotation guide functioning as a rotary shaft of the main body. 
     The frame provided at the lower part of the main body may be provided with a guide-receiving groove, into which the second rotation guide may be inserted. 
     The guide-receiving groove may be formed at the first rotation guide and the second rotation guide may be rotatably inserted into the guide-receiving groove. 
     The receiving unit may be formed at the bottom of the main body such that the receiving unit may extend backward and forward. 
     The frame provided at the lower part of the main body may be provided with an elastic member. 
     The main body may be provided at the bottom thereof with a pressing unit to press the elastic member. 
     The pressing unit may press the elastic member when the main body rotates to change the movement direction thereof. 
     The wheel assembly may be rotated in a direction in which the main body is directed by elastic force of the elastic member. 
     The frame provided at the lower part of the main body may be provided with an elastic member mounting unit to receive the elastic member. 
     The elastic member mounting unit may be provided at the side thereof with a hole, through which the pressing unit may press the elastic member. 
     The pressing unit may be provided in a receiving unit formed at the bottom of the main body. 
     The inside of the receiving unit may interfere with the elastic member mounting unit or a stopper provided at the frame provided at the lower part of the main body to restrict a rotational angle of the main body. 
     The vacuum cleaner may further include a handle connected to the upper side of the main body such that the handle is perpendicular to the main body, wherein the suction unit may be directly connected to one side of the main body. 
     The main body may be provided at the bottom thereof with a first rotation guide that may extend toward the left and right sides of the main body. 
     The frame provided at the lower part of the main body may be provided with a second rotation guide to guide movement of the first rotation guide. 
     When the main body rotates according to manipulation of the handle, the suction unit may rotate along with the main body. 
     When the main body rotates, the first rotation guide may move in the rotated direction along the second rotation guide. 
     When the main body rotates to change the movement direction thereof, the movement direction of the wheel assembly may be changed to move the main body. 
     The main body may be rotatable within a range of 10 to 15 degrees. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and/or other aspects will become apparent and more readily appreciated from the following description of embodiments, taken in conjunction with the accompanying drawings of which: 
         FIG. 1  is a view showing a vacuum cleaner according to one or more embodiments; 
         FIG. 2  is a view showing a state in which a dust collector is separated from a main body according to one or more embodiments; 
         FIG. 3  is a view showing a state in which a wheel assembly is separated from the main body according to one or more embodiments; 
         FIG. 4  is a view showing a wheel assembly according to one or more embodiments; 
         FIG. 5  is a view showing a lower part of the main body according to one or more embodiments; 
         FIGS. 6A to 6C  are views showing the main body according to one or more embodiments before and after rotation when viewed from below; 
         FIGS. 7A to 7C  are views showing the main body according to one or more embodiments before and after rotation when viewed from above; 
         FIG. 8  is a view showing that the main body according to one or more embodiments turns at a corner and moves; 
         FIG. 9  is a view showing a vacuum cleaner according to one or more embodiments; 
         FIG. 10  is a view showing a state in which a dust collector is separated from a main body of the vacuum cleaner according to one or more embodiments; 
         FIGS. 11 and 12  are views showing a state in which a wheel assembly is separated from the main body according to one or more embodiments; 
         FIG. 13  is a view showing a rotational direction of a handle to rotate the vacuum cleaner according to one or more embodiments; and 
         FIGS. 14A to 14C  are views showing rotation of the main body according to one or more embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to one or more embodiments, illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. In this regard, embodiments of the present invention may be embodied in many different forms and should not be construed as being limited to embodiments set forth herein, as various changes, modifications, and equivalents of the systems, apparatuses and/or methods described herein will be understood to be included in the invention by those of ordinary skill in the art after embodiments discussed herein are understood. Accordingly, embodiments are merely described below, by referring to the figures, to explain aspects of the present invention. 
       FIG. 1  is a view showing a vacuum cleaner according to one or more embodiments and  FIG. 2  is a view showing a state in which a dust collector is separated from a main body according to one or more embodiments. 
     Referring to  FIGS. 1 and 2 , a vacuum cleaner  1  according to one or more embodiments may include a main body  10 , a dust collector  40 , a suction unit  21 , and a wheel assembly  50 . The dust collector  40  and the wheel assembly  50  may be mounted to the main body  10 . The suction unit  21  may contact a surface to be cleaned to suction foreign matter from the surface. The vacuum cleaner  1  according to one or more embodiments may be a canister type vacuum cleaner. 
     The main body  10  may include a fan motor (not shown) to generate suction force. The suction unit  21  may suction air from the surface, including dust contained in the air, using suction force generated by the main body  10 . The suction unit  21  may be formed in a wide shape such that the suction unit  21  may tightly contact the surface. 
     Between the main body  10  and the suction unit  21  may be provided an extension pipe  20 , a handle pipe  30 , and a flexible hose  23 . The extension pipe  20  may be made of a resin or metal material. The extension pipe  20  may be connected between the suction unit  21  and the handle pipe  30 . 
     The handle pipe  30  may be connected between the extension pipe  20  and the flexible hose  23 . A handle  31  and a manipulator  32  may be provided at the handle pipe  30 . A user may perform cleaning while holding the handle  31 . In addition, the user may manipulate buttons of the manipulator  32  to turn the cleaner on/off or adjust a suction degree. 
     The flexible hose  23  may be connected between the handle pipe  30  and the main body  10 . The flexible hose  23  may be made of a flexible material such that the handle pipe  30  may move freely. 
     The suction unit  21 , the extension pipe  20 , the handle pipe  30 , and the flexible hose  23  may communicate with each other. Air suctioned from the suction unit  21  may be introduced into the main body  10  through the extension pipe  20 , the handle pipe  30 , and the flexible hose  23 . 
     The main body  10  may be provided with a suction port  13  to guide the suctioned air to the dust collector  40  and a discharge port  12  to discharge air purified by the dust collector  40 . The discharge port  12  may communicate with a fan motor compartment (not shown) in which the fan motor (not shown) is mounted. 
     The main body  10  may be provided with a mounting unit  11 , to which the dust collector  40  may be mounted. The dust collector  40  may be separatably mounted to the mounting unit  11 . The dust collector  40  may separate dust from the air suctioned through the suction unit  21  and may discharge purified air through the discharge port  12 . 
     The dust collector  40  may include an inlet  91 , through which air containing dust may be introduced, and an outlet  72 , through which purified air may be discharged. When the dust collector  40  is mounted to the main body  10 , the inlet  91  may communicate with the suction port  13  of the main body  10  and the outlet  72  may communicate with the discharge port  12  of the main body  10 . 
     The dust collector  40  may separate dust from air using centrifugal force generated by a swirling air current. When dust accumulates in the dust collector to some extent, the user may separate the dust collector  40  from the main body  10  and remove the dust from the dust collector  40 . 
     The main body  10  may be mounted to the wheel assembly  50 . The main body  10  may be moved on a floor by the wheel assembly  50 . The wheel assembly  50  may include a frame  51  and wheels  52 . The frame  51  may be connected to the main body  10  and the wheels  52  may be mounted to the frame  51 . The wheels  52  may be located at opposite sides of the main body  10 . 
     The main body  10  may be provided at the bottom thereof with a caster  60  and an auxiliary wheel  70 . The caster  60  may be located at the front of the main body  10  such that the caster  60  rotates in all directions to smoothly rotate the main body  10 . The main body  10  may be supported on the floor at three points by the caster  60  and the wheels  52  that may be provided at the left and right sides of the main body  10 . The caster  60  may be located at the front of the bottom of the main body  10 , at which the flexible hose  23  may be connected to the main body  10 . When a direction of the flexible hose  23  is changed by user manipulation, the front of the main body  10  may rotate in a direction in which the flexible hose  23  is directed. 
     The auxiliary wheel  70  may be provided at the rear of the bottom of the main body  10 . The auxiliary wheel  70  may assist the main body  10  in smooth movement by the wheel assembly  50 . 
     Hereinafter, structures of the main body and the wheel assembly according to one or more embodiments will be described in detail with reference to the accompanying drawings. 
       FIG. 3  is a view showing a state in which the wheel assembly is separated from the main body according to one or more embodiments,  FIG. 4  is a view showing the wheel assembly according to one or more embodiments, and  FIG. 5  is a view showing a lower part of the main body according to one or more embodiments. 
     Referring to  FIGS. 3 to 5 , the main body  10  according to one or more embodiments may be rotatably mounted to the wheel assembly  50 . The main body  10  may be moved by the wheel assembly  50 . When the direction of the flexible hose  23  is changed by user manipulation during cleaning, the main body  10  may rotate in the changed direction of the flexible hose  23  independently of the wheel assembly  50 . 
     The wheel assembly  50  may include a frame  51  and wheels  52  rotatably mounted to the frame  51 . The wheels  52  may be provided at left and right sides of the main body  10  in a movement direction of the main body  10 . The wheels  52  smoothly move the main body  10  in a movement direction of the flexible hose  23  connected to the main body  10 . 
     The frame  51  may include a first frame  511  and a second frame  512 , to which the wheels  52  provided at the left and right sides of the main body  10  may be mounted, and a third frame  510  that may be connected between the first frame  511  and second frame  512 . The third frame  510  may be located at a lower part of a base  14  that may be provided at the bottom of the main body  10 . The frame  51  may further include a fourth frame  513  that may be located at an upper part of the main body  10 . The fourth frame  513  may be connected between the first frame  511  and second frame  512 . 
     The main body  10  may rotate relative to the frame  51 . The base  14  of the main body  10  and the third frame  510  may be rotatably coupled to each other via a fastening member. The main body  10  may rotate within a range of about 10 to 15 degrees, for example. 
     A first rotation guide  514  to guide rotation of the main body  10  may be formed at the third frame  510  in a protruding state. The first rotation guide  514  may be formed in a ring shape. The first rotation guide  514  may be inserted into a receiving unit  100 , which will hereinafter be described, that may be formed at the base. 
     The first rotation guide  514  may be provided with a guide-receiving groove  515 . A second rotation guide  110 , which will hereinafter be described, formed at the base  14  may be inserted into the guide-receiving groove  515 . 
     An elastic member  53  may be provided at one side of the third frame  510 . The third frame  510  may be provided with an elastic member mounting unit  516 . The elastic member  53  may be received in the elastic member mounting unit  516 . The elastic member mounting unit  516  may protrude from the third frame  510 . The elastic member mounting unit  516  may be located outside the first rotation guide  514 . 
     The third frame  510  may be provided with a stopper. The elastic member mounting unit  516  protruding from the third frame  510  may function as the stopper. Alternatively, the stopper may be formed at the third frame  510  separately from the elastic member mounting unit  516  in a protruding state. The stopper may be provided at the other side of the third frame  510  separately from the elastic member mounting unit  516 . 
     In this case, the stopper may be provided opposite to the elastic member mounting unit  516  with respect to the center of rotation of the first rotation guide  514 . The distance from the center of rotation of the first rotation guide  514  to the elastic member mounting unit  516  may be equal to that from the first rotation guide  514  to the stopper. 
     Holes  517  may be formed at opposite sides of the elastic member mounting unit  516 . Pressing units  111 , which will hereinafter be described, may be formed at the base  14 . The pressing units  111  may press the elastic member  53  received in the elastic member mounting unit  516  through the holes  517 . 
     A receiving unit  100  may be formed at the base  14  that may be provided at the bottom of the main body  10 . The first rotation guide  514  of the third frame  510  may be rotatably received in the receiving unit  100 . The elastic member mounting unit  516  may be received in the receiving unit  100 . 
     The receiving unit  100  may include a first receiving unit  101  and a second receiving unit  102 . The first receiving unit  101  may be formed in the shape of a circle R1 that may correspond to the outer diameter of the first rotation guide  514 . The second receiving unit  102  may be located outside the first receiving unit  101 . Specifically, the second receiving unit  102  may be located at the front or the rear of the first receiving unit  101  such that the second receiving unit  102  may be connected to the first receiving unit  101 . The receiving unit  100  may extend backward and forward with respect to the movement direction of the main body  10 . 
     The second receiving unit  102  may be formed in the shape of a portion of a circle R2 corresponding to a movement route of the outside of the elastic member mounting unit  516  or the outside of the stopper during rotation of the base  14 . That is, the inside of the receiving unit  100  forming the second receiving unit  102  may be provided to correspond to a portion of the circle R2 corresponding to the movement route of the outside of the elastic member mounting unit  516  or the outside of the stopper during rotation of the base  14 , i.e. an arc of a sector having a central angle θ1. The shape of the second receiving unit formed at the pressing units  111  may correspond to that of the second receiving unit into which the stopper provided at the third frame  510  is inserted. 
     Since the second receiving unit  102  may not formed in the shape of the entirety of the circle R2 corresponding to the movement route of the outside of the elastic member mounting unit  516  or the outside of the stopper but may be formed in the shape of a portion of the circle R2, the side of the stopper or the elastic member mounting unit  516  may interfere with the inside of the receiving unit  100  forming the second receiving unit  102  with the result that a rotational angle of the main body may be restricted. 
     The second rotation guide  110  may be formed at the base  14  provided at the bottom of the main body  10  in a protruding state. The second rotation guide  110  may be a rotary shaft, about which the main body  10  may rotate. When the main body is mounted to the wheel assembly  50 , the second rotation guide  110  may be inserted into the guide-receiving groove  515  formed at the third frame  510 . The second rotation guide  110  may rotate in a state in which the second rotation guide  110  may be inserted into the guide-receiving groove  515 . 
     Hereinafter, an operation of changing a movement direction of the main body  10 , based on the structures of the wheel assembly  50  and the base  14 , will be described. 
       FIGS. 6A to 6C  are views showing the lower part of the main body according to one or more embodiments before and after rotation,  FIGS. 7A to 7C  are views showing the upper part of the main body according to one or more embodiments before and after rotation, and  FIG. 8  is a view showing that the main body according to one or more embodiments turns at a corner and moves. 
     Referring to  FIGS. 6A to 8 , when a movement direction of the main body  10  according to one or more embodiments is changed by the flexible hose  23 , etc., the main body  10  may first rotate independently of the wheel assembly as shown in  FIG. 7B . After rotation of the main body  10 , the wheel assembly  50  may rotate in a direction in which the main body  10  is directed due to the elastic member  53 . 
     As shown in  FIGS. 6A and 7A , the main body  10  may move in a state in which the main body  10  is located in a forward direction. As shown in  FIGS. 6A and 7A , the wheel assembly  50  may be located in the same direction as the main body  10 . 
     When the main body  10  turns at a corner or the movement direction of the main body  10  is changed by the flexible hose  23 , etc. as shown in  FIG. 8 , the main body  10  may first rotate in a state in which the direction of the wheel assembly  50  is not changed as shown in  FIGS. 6B and 7B . At this time, the pressing units  111  provided at the base  14  of the main body  10  may press the elastic member  53  received in the elastic member mounting unit  516  through the holes  517  formed at the elastic member mounting unit  516  of the third frame  510 . 
     When force is applied to the main body  10  in the changed movement direction of the main body  10  in a state in which the main body  10  has rotated, elastic force of the elastic member  53  may be applied to the pressing units  111  such that the pressing units  111  may return to positions before change in movement direction. As shown in  FIGS. 6C and 7C , the wheel assembly  50  may rotate in the direction in which the main body  10  is directed due to the elastic force that may be applied to the pressing units  111 . As a result, both the main body  10  and the wheel assembly  50  may rotate and thus the movement directions of the main body  10  and the wheel assembly  50  may be changed. In a state in which the main body  10  and the wheel assembly  50  are directed in the same direction, therefore, the main body  10  may move in the movement direction after rotation. 
     As described above, the main body  10  may rotate independently of the wheel assembly  50  and, after rotation of the main body  10 , the wheel assembly  50  may rotate in the direction in which the main body  10  is directed due to the elastic force of the elastic member  53 . Consequently, the direction of the main body  10  may be smoothly changed. When the main body  10  turns at a corner as shown in  FIG. 8 , the main body  10  may be prevented from being pulled or overturning and the direction of the main body  10  may be rapidly and stably changed. Consequently, straight movement of the main body  10  may be smoothly achieved by the wheel assembly  50  while rotatability of the main body  10  may be improved, thereby possibly improving user convenience and satisfaction in use. 
       FIG. 9  is a view showing a vacuum cleaner according to one or more embodiments and  FIG. 10  is a view showing a state in which a dust collector is separated from a main body of the vacuum cleaner according to one or more embodiments. 
     Referring to  FIGS. 9 and 10 , a vacuum cleaner  2  according to one or more embodiments may be an upright type vacuum cleaner. The vacuum cleaner  2  may include a main body  600 , a suction unit  610  directly connected to one side of the main body  600  to suction air and dust from a surface to be cleaned in a state of contacting the surface, a dust collector  620  mounted to the main body  600 , and a wheel assembly  630 . In the upright type vacuum cleaner  2 , the suction unit  610  may be directly connected to the main body  600  not via an additional hose. 
     A fan motor (not shown) to generate suction force may be provided in the main body  600 . A handle  640  may be provided at the upper side of the main body  600  such that the handle  640  may be approximately perpendicular to the main body  600 . The wheel assembly  630  to move the main body  600  may be provided at the lower end of the main body  600 . The suction unit  610  may be provided with a suction brush (not shown) to clean a carpet. 
     The main body  600  may be provided with a mounting unit  601 , to which the dust collector  620  may be mounted. The dust collector  620  may be separatably mounted to mounting unit  601  provided at the main body  600 . 
     When the dust collector  620  is mounted to the mounting unit  601 , an inlet  621  of the dust collector  620  may communicate with a suction port of the main body  600  and an exhaust pipe (not shown) of the dust collector  620  may communicate with a discharge port of the main body  10 . 
     Air suctioned by the suction unit  610  may be introduced into the dust collector  620  through the suction port of the main body  600  and the inlet  621  of the dust collector  620 , purified in the dust collector  620 , and discharged from the dust collector  620  through the exhaust pipe (not shown) of the dust collector  620  and the discharge port of the main body  600 . 
     The wheel assembly  630  may be provided at the rear of the main body  600 . The main body  600  may be smoothly moved on a floor by the wheel assembly  630 . The main body  600  may rotate independently of the wheel assembly  630 . 
     An auxiliary wheel unit  650  to facilitate movement of the main body  60  may be provided at the bottom of the main body  600  or the bottom of the suction unit  610 . The auxiliary wheel unit  650  may be a caster rotatable in all directions. 
     Hereinafter, construction and operation of the main body  600  and the wheel assembly  630  according to one or more embodiments will be described with reference to the accompanying drawings. 
       FIGS. 11 and 12  are views showing a state in which the wheel assembly is separated from the main body according to one or more embodiments. 
     Referring to  FIGS. 11 and 12 , the wheel assembly  630  may include frames  631 ,  632 , and  633  and wheels  635 . The wheels  635  may be mounted to the frames  632 . The wheels  635  may be located at left and right sides of the main body  600 . 
     The frames  631 ,  632 , and  633  may include a first frame  631 , second frames  632 , and a third frame  633 . The first frame  631  may be located at the lower part of the main body  600 . The second frames  632  may be provided at opposite ends of the first frame  631  such that the second frames  632  are connected to the first frame  631 . 
     In a case in which the first frame  631  is located at the lower part of the main body  600 , the second frames  632  may be located at opposite sides of the main body  600 . The wheels  635  may be rotatably mounted to the second frames  632 . As the wheels  635  may be located at the opposite sides of the main body  600 , the main body  600  may perform straight movement. 
     The third frame  633  may be connected between the second frames  632  located at the opposite sides of the main body  600 . The third frame  633  may be located at the upper part of the main body  600 . 
     As the first frame  631  may be located at the lower part of the main body  600 , the second frames  632  may be located at opposite sides of the main body  600 , and the third frame  633  may be located at the upper part of the main body  600 , the main body  600  may be located in a space defined by the frames  631 ,  632 , and  633 . The frames  631 ,  632 , and  633  may serve to hold the main body  600 , which may be rotatable. The main body  600  may be rotatably placed on the first frame  631 . 
     The main body  600  may be connected to the handle  640  such that the main body  600  may be moved along with the handle  640 . When the handle  640  is rotated to the left or to the right, the main body  600  may be rotated to the left or to the right. When the handle  640  is laid down, the main body  600  may rotate in the frames  631 ,  632 , and  633  along with the handle  640 . 
     The main body  600  may be provided at the bottom thereof with a first rotation guide  604 . The first frame  631  may be provided with a second rotation guide  634 . The first rotation guide  604  may be formed at the bottom of the main body  600  in a protruding state. The first rotation guide  604  may extend toward the left and right sides of the main body  600 . The first rotation guide  604  may be inserted into the second rotation guide  634  such that movement of the first rotation guide  604  is guided by the second rotation guide  634 . The second rotation guide  634  may correspond to the first rotation guide  604 . The second rotation guide  634  may extend toward the left and right second frames  632 . 
     When the main body  600  is rotated to the left or the right, the first rotation guide  604  formed at the bottom of the main body  600  may be moved along the second rotation guide  634  while being guided by the second rotation guide  634  formed at the first frame  631 . 
       FIG. 13  is a view showing a rotational direction of the handle to rotate the vacuum cleaner according to one or more embodiments and  FIGS. 14A to 14C  are views showing rotation of the main body according to one or more embodiments. 
     Referring to  FIGS. 13 and 14A to 14C , the main body  600  may rotate in the frames  631 ,  632 , and  633  to change a movement direction of the vacuum cleaner  2 . When the main body  600  rotates, the wheel assembly  630  may rotate along with the main body  600  to move the main body  600  in a direction after rotation. 
     When a user wishes to change the movement direction of the vacuum cleaner  2  to the left with respect to an advancing direction of the vacuum cleaner  2  during cleaning, the user may rotate the handle  640  in a counterclockwise direction. When the handle  640  rotates in the counterclockwise direction, the main body  600  connected to the handle  640  may rotate in the counterclockwise direction. 
     As the main body  600  rotates in the counterclockwise direction, the first rotation guide  604  provided at the bottom of the main body  600  may move along the second rotation guide  634  provided at the first frame  631 . 
     When the main body  600  rotates in the counterclockwise direction, the suction unit  610  may rotate along with the main body  600  in the counterclockwise direction. As a result, the suction unit  610  may be directed to the left in the movement direction before rotation. After the movement direction of the vacuum cleaner  2  is changed to the left in the movement direction before rotation as described above, the vacuum cleaner  2  may continue to move. 
     In a case in which the movement direction of the vacuum cleaner  2  is changed to the right, a procedure similar to the case in which the movement direction of the vacuum cleaner  2  is changed to the left as described above may be applied. In order to change the movement direction of the vacuum cleaner  2  to the right, the user may rotate the handle  640  in a clockwise direction. When the handle  640  rotates in the clockwise direction, the main body  600  connected to the handle  640  and the suction unit  610  connected to the main body  600  may rotate in the clockwise direction. As a result, the suction unit  610  may be directed to the right in the movement direction before rotation. After the movement direction of the vacuum cleaner  2  is changed to the right in the movement direction before rotation as described above, the vacuum cleaner  2  may continue to move. 
     Change in movement direction of the vacuum cleaner  2  may be achieved during movement of the vacuum cleaner  2  and cleaning. After movement of the vacuum cleaner  2 , the handle  640  may be rotated to change the movement direction of the vacuum cleaner  2  and then the vacuum cleaner  2  may move in the changed direction. In addition, the handle  640  may be rotated in a desired direction during straight movement of the vacuum cleaner  2  to achieve the change in movement direction of the vacuum cleaner  2 . 
     The straight movement of the upright type vacuum cleaner may be smoothly achieved and, in addition, the movement direction of the vacuum cleaner may be smoothly changed through the structure as described above. Consequently, user convenience may be improved. 
     As is apparent from the above description, the vacuum cleaner according to one or more embodiments may be configured such that the wheels may be provided at the left and right sides of the main body. Consequently, straight movement of the vacuum cleaner may be performed. In addition, the main body may first rotate independently of the wheels during a change in direction of the vacuum cleaner and then the wheels may rotate in a direction in which the main body is directed and move. Consequently, the movement direction of the vacuum cleaner may be changed. 
     While aspects of the present invention have been particularly shown and described with reference to differing embodiments thereof, it should be understood that these embodiments should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in the remaining embodiments. Suitable results may equally be achieved if the described techniques are performed in a different order and/or if components in a described system, architecture, device, or circuit are combined in a different manner and/or replaced or supplemented by other components or their equivalents. 
     Thus, although a few embodiments have been shown and described, with additional embodiments being equally available, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.