Patent Publication Number: US-2010107357-A1

Title: Electric vacuum cleaner

Description:
RELATED APPLICATIONS 
     This application claims priority under 35 U.S.C. §119 to Japanese Patent Application No. JP2008-282714 filed on Nov. 4, 2008, the entire content of which is hereby incorporated by reference. 
     TECHNICAL FIELD 
     The present invention relates to an electric vacuum cleaner having a suction port portion and a handle portion. 
     BACKGROUND ART 
     In an existing electric vacuum cleaner, dust collecting performance using a sweeping-up rotary brush is good in regards to a floor surface and particularly a carpet surface. However, since the electric vacuum cleaner is equipped with a motor for driving the rotary brush, it is disadvantageous in that the suction port portion easily becomes heavy and the cleaning operation is wearisome. In order to solve the disadvantage, for example, Japanese Patent Unexamined Publication No. 2-7923 discloses a technology in which a suction port portion is provided with a self-propelling roller or a rotary brush itself is actively brought into contact with a floor surface so as to have a self-propelling property. 
     However, in the above-described technology, it is possible to reduce the effort upon operating the suction port portion forward or backward, but it is necessary to change a direction of the suction port portion by twisting a wrist upon changing the direction in the left and right direction. For this reason, it is not possible to reduce the effort involved. Particularly, in an upright cleaner having a heavy suction port portion, it takes a good deal of effort to change the direction of the suction port portion. Since the direction of the suction port portion is frequently changed during an actual cleaning operation, particularly at this time, a large burden is applied to the wrist. As a result, the wrist feels fatigued after a long-time cleaning operation. 
     SUMMARY OF THE INVENTION 
     An object of the invention is to provide an electric vacuum cleaner capable of changing a direction of a suction port portion to a desired changing direction and reducing the burden applied to a user&#39;s wrist. 
     According to an aspect of the invention, there is provided an electric vacuum cleaner including: a cleaner body portion which has an electric blower for generating a suction wind; a suction port portion which sucks dust together with the suction wind; a handle portion which moves the suction port portion; a rotary brush unit which is disposed inside the suction port portion and in which two rotary shaft bodies each having a brush are disposed in series; a rotary brush unit driving portion which separately rotates each of the rotary shaft bodies; and a rotation speed difference generating mechanism which generates a difference in the rotation speed between two rotary shaft bodies. 
     According to the invention, the rotary brush unit includes two rotary shaft bodies, and the rotation speed difference generating mechanism generates a difference in the rotation speed between two rotary shaft bodies. For this reason, it is possible to easily change the direction of the suction port portion to the desired changing direction. Accordingly, since it is possible to remarkably reduce a burden during a cleaning operation, it is possible to more comfortably perform the cleaning operation which is a comparatively heavy labor in the housework. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an entire perspective view showing a cleaner body portion of an electric vacuum cleaner according to a first embodiment of the invention. 
         FIG. 2  is a partially sectional view showing a suction port portion according to the embodiment. 
         FIG. 3  is a block diagram showing a configuration of an electric controller according to the embodiment. 
         FIG. 4  is an entire perspective view showing the cleaner body portion of the electric vacuum cleaner according to a second embodiment of the invention. 
         FIG. 5  is a plan view showing a rotary brush unit of the electric vacuum cleaner according to a third embodiment of the invention. 
         FIG. 6  is a plan view showing the rotary brush unit of the electric vacuum cleaner according to a fourth embodiment of the invention. 
         FIG. 7  is a plan view showing the rotary brush unit of the electric vacuum cleaner according to a fifth embodiment of the invention. 
         FIG. 8  is a plan view showing the rotary brush unit of the electric vacuum cleaner according to a sixth embodiment of the invention. 
         FIG. 9  is a plan view showing the rotary brush unit of the electric vacuum cleaner according to a seventh embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter, exemplary embodiments of the invention will be described with reference to the accompanying drawings. In addition, the invention is not limited to the embodiments. 
     First Embodiment 
       FIG. 1  is an entire perspective view showing a cleaner body portion of an electric vacuum cleaner according to a first embodiment of the invention.  FIG. 2  is a partially sectional view showing a suction port portion according to the embodiment when seen from the bottom of the suction port portion. 
     As shown in  FIG. 1 , an electric vacuum cleaner according to this embodiment includes suction port portion  1  which sucks dust, handle portion  11  which moves suction port portion  1 , and cleaner body portion  12  of which a lower portion is provided with suction port portion  1  and an upper portion is provided with handle portion  11 . Cleaner body portion  12  includes an electric blower for generating a suction wind. Suction port portion  1  sucks dust together with the suction wind generated by the electric blower. Switch lever portion  10  is attached onto handle portion  11 . Switch lever portion  10  is attached to a position where switch lever portion  10  is operable by a finger when gripping handle portion  11  using a hand. When switch lever portion  10  is pushed down in the left and right direction, as depicted by the arrow, suction port portion  1  is controlled so that the direction thereof is changed to the direction in which switch lever portion  10  is pushed down. 
     As shown in  FIG. 2 , rotary brush unit  2  is disposed inside suction port portion  1 . Rotary brush unit  2  includes two rotary shaft bodies  2 A and  2 B. Brush  3  is disposed in surfaces of rotary shaft bodies  2 A and  2 B. 
     In  FIG. 2 , brush  3  is formed as a so-called bristle transplant brush in which bristles are tied and transplanted inside a hole, but may be formed as a brush in which a narrow raised fabric is inserted and fixed into an undercut groove or a bonded brush. 
     Each of the rotary shaft bodies  2 A and  2 B is provided with driving motor  4  and decelerating gear  5 . Driving motor  4  is connected to decelerating gear  5  to thereby form a rotary brush unit driving portion. An output shaft of decelerating gear  5  is fixed to each of rotary shaft bodies  2 A and  2 B. With such a configuration, when driving motors  4  are driven, rotary shaft bodies  2 A and  2 B located in the peripheries thereof rotate. 
     Likewise, a rotary mechanism is constituted by only rotary brush unit  2  in such a manner that driving motor  4  and decelerating gear  5  are disposed inside each of rotary shaft bodies  2 A and  2 B. Accordingly, it is not necessary to dispose a large component such as a driving motor in the inside of suction port portion  1 . For this reason, it is possible to decrease the size of suction port portion  1 . That is, it is possible to realize suction port portion  1  which can move and turn slightly and has good operability or cleaner body portion  12  which is small in size and low in weight. 
     The length of brush  3  is set to a length at which brush  3  slightly comes into contact with a floor surface. For this reason, when rotary shaft bodies  2 A and  2 B rotate in a direction (positive direction) in which suction port portion  1  is pushed forward, suction port portion  1  propels itself, thereby improving the operability of cleaner body portion  12 . That is, when driving motors  4  inside rotary shaft bodies  2 A and  2 B rotate at the same speed (including substantially the same speed) in the same direction (positive direction), suction port portion  1  propels itself forward. 
     In addition, each of rotary shaft bodies  2 A and  2 B is driven by a separate driving motor  4 . For this reason, it is possible to independently change the rotation speeds thereof. When the right driving motor on the user side rotates faster than the left driving motor or only the right driving motor rotates, a direction of suction port portion  1  is changed to the left direction. On the other hand, when the left driving motor rotates faster than the right driving motor or only the left driving motor rotates, the direction of suction port portion  1  is changed to the right direction. 
     In addition, when the driving motor located in the desired rotation direction rotates in the reverse direction and the opposite driving motor rotates in the positive direction, it is possible to further strongly change the direction of suction port portion  1 . 
     Switch lever portion  10  controls driving motors  4  inside rotary shaft bodies  2 A and  2 B through the electric controller shown in  FIG. 3 .  FIG. 3  is a block diagram showing a circuit of the electric vacuum cleaner according to this embodiment. In  FIG. 3 , motor  35  for driving the electric blower generating the suction wind is connected in parallel to AC power source  36 . Power switch portion  37  controlling an on-off state of motor  35  is disposed close to handle portion  11  of cleaner body portion  12  (not shown in  FIG. 1 ). Driving motor  38 A (one driving motor  4  shown in  FIG. 2 ) for driving rotary shaft body  2 A is connected in series to rotary shaft body switch portion  39 A for controlling the on-off state of driving motor  38 A. In the same manner, driving motor  38 B (the other driving motor  4  shown in  FIG. 2 ) for driving rotary shaft body  2 B is connected in series to rotary shaft body switch portion  39 B for controlling an on-off state of driving motor  38 B. The two serial connection portions are connected in parallel to motor  35 . Rotary shaft body switch portions  39 A and  39 B are operated in an interlocking manner as depicted by the dotted line by switch lever portion  10 . 
     In the normal state where no operation is performed, switch lever portion  10  turns on rotary shaft body switch portions  39 A and  39 B, and rotates driving motors  38 A and  38 B at the same speed in the same direction (positive direction). Accordingly, suction port portion  1  propels itself forward. When switch lever portion  10  is pushed down in the left and right direction, as described above, switch lever portion  10  controls driving motors  38 A and  38 B inside rotary shaft bodies  2 A and  2 B so that the direction of suction port portion  1  is changed to the direction in which switch lever portion  10  is pushed down. 
     That is, when switch lever portion  10  is pushed down in the right direction, only left driving motor  38 B on the user side rotates in the positive direction. For this reason, it is possible to easily change the direction of suction port portion  1  to the right direction. At this time, when switch portion  39 A of rotary shaft body  2 A and switch portion  39 B of rotary shaft body  2 B are interlocked with each other so that right driving motor  38 A on the user side rotates in a direction opposite to the rotation direction of driving motor  38 B, it is possible to more easily change the direction of suction port portion  1  to the right direction. In the same manner, when switch portion  39 A of rotary shaft body  2 A and switch portion  39 B of rotary shaft body  2 B are interlocked with each other so that right driving motor  38 A on the user side rotates slower than driving motor  38 B, it is possible to more easily change the direction of suction port portion to the right direction. In any case, there is a difference in the rotation speed between rotary shaft bodies  2 A and  2 B. 
     On the contrary, in order to further change the direction of suction port portion  1  to the left direction, switch portion  39 A of rotary shaft body  2 A and switch portion  39 B of rotary shaft body  2 B are interlocked with each other as below. Switch portion  39 A of rotary shaft body  2 A and switch portion  39 B of rotary shaft body  2 B are interlocked with each other so that only right driving motor  38 A on the user side rotates in the positive direction, left driving motor  38 B on the user side rotates in a direction opposite to the rotation direction of driving motor  38 A, or left driving motor  38 B on the user side rotates more slowly than driving motor  38 A when switch lever portion  10  is pushed down in the left direction. 
     That is, in this embodiment, rotation speed difference generating mechanisms are separately disposed in each of rotary shaft bodies  2 A and  2 B, and include separately rotating driving motors  38 A and  38 B, rotary shaft body switch portions  39 A and  39 B, and switch lever portion  10 . 
     As described above, in this embodiment, the direction of suction port portion  1  can be changed by generating a difference in the rotation speed between two rotary shaft bodies  2 A and  2 B. For this reason, it is possible to reduce a burden applied to an arm or wrist upon changing the direction of suction port portion  1  in the left and right direction. 
     In this embodiment, suction port portion  1  propels itself in accordance with the rotation of rotary shaft bodies  2 A and  2 B. For this reason, since suction port portion  1  propels itself forward or backward during a cleaning operation, it is possible to reduce the burden during the cleaning operation. 
     In this embodiment, suction port portion  1  propels itself in accordance with the rotation of rotary shaft bodies  2 A and  2 B. For this reason, since there is a difference in the rotation speed between two rotary shaft bodies  2 A and  2 B, it is possible to reduce the burden applied to the arm or wrist upon changing the direction of suction port portion  1 . 
     In this embodiment, driving motor  4  is disposed inside each of rotary shaft bodies  2 A and  2 B. For this reason, it is possible to decrease the size of suction port portion  1  and to easily handle suction port portion  1  in a narrow space. In addition, it is possible to dispose rotary brush unit  2  in substantially the entire width of suction port portion  1 , and to improve a cleaning performance for cleaning a side wall. 
     In this embodiment, handle portion  11  includes switch lever portion  10  which is operable in the left and right direction, and the rotation of two rotary shaft bodies  2 A and  2 B of rotary brush unit  2  is controlled so that the direction of suction port portion  1  is changed to the direction in which switch lever portion  10  is operated. For this reason, it is possible to change the direction of suction port portion  1  just by using a finger tip without performing a large action in which handle portion  11  is twisted or pushed down. 
     Second Embodiment 
       FIG. 4  is an entire perspective view showing the electric vacuum cleaner according to a second embodiment of the invention. This embodiment is different from the first embodiment in that switch lever portion  10  is not provided. Instead of switch lever portion  10 , handle portion  11  which is twistable in the left and right direction is provided. The rotation speed of two rotary shaft bodies  2 A and  2 B disposed in rotary brush unit  2  inside suction port portion  1  is controlled through the electric controller (not shown) so that the direction of suction port portion  1  is changed to the twisting direction of handle portion  11 . When the twisting amount becomes large, the difference in the rotation speed between rotary shaft bodies  2 A and  2 B becomes large, and the turning amount becomes large. In the case where handle portion  11  is not twisted, suction port portion rotates forward. Since the other configurations are same as those of the first embodiment, detailed description thereof will be omitted. 
     As described above, in this embodiment, handle portion  11  is twistable in the left and right direction. When handle portion  11  is twisted in the left and right direction, the rotation of two rotary shaft bodies  2 A and  2 B of rotary brush unit  2  is controlled so that the direction of suction port portion  1  is changed to the twisting direction of handle portion  11 . Accordingly, it is possible to change the self-propelling direction of the suction port portion while having the same feeling of operation as with a general cleaner having an oscillation mechanism. 
     Third Embodiment 
       FIG. 5  is a plan view showing rotary brush unit  2  inside suction port portion  1  of the electric vacuum cleaner according to a third embodiment of the invention. Rotary shaft bodies  2 A and  2 B constituting rotary brush unit  2  are rotatably connected to each other through connection portion  30 . Connection portion  30  is formed as a simple bearing, and a difference in the rotation speed between rotary shaft bodies  2 A and  2 B is absorbed by connection portion  30 . Brush  3  is attached to surfaces of rotary shaft bodies  2 A and  2 B. 
     Stiff brushes  3 A depicted by the solid line are attached to predetermined ranges  101  of rotary brush unit  2 . Soft brush  3 B depicted by the dotted line is attached to predetermined ranges  102  at the center of rotary brush unit  2 . Since the other configurations are the same as those of the first embodiment, detailed description thereof will be omitted. 
     With such a configuration, since a large self-propelling force is generated at a position far from the turning center, it is possible to more efficiently turn suction port portion  1 . 
     In this embodiment, the direction of the suction port portion is changed by generating a difference in the rotation speed between the driving motors using switch lever portion  10  of the first embodiment or handle portion  11 B, which is twistable, of the second embodiment. At this time, in this embodiment, since the brush  3  includes stiff brushes  3 A in the vicinity of both ends of rotary brush unit  2  and soft brushes  3 B in the vicinity of the center thereof, it is possible to more efficiently turn suction port portion  1 . 
     As described above, in this embodiment, the stiffness of each of the brushes  3  in the vicinity of both ends of rotary brush unit  2  is set to be larger than that in the vicinity of the center thereof. Accordingly, since it is possible to improve the direction changing force of suction port portion  1 , it is possible to change the self-propelling direction even on a floor surface having a high resistance such as a deep carpet. 
     Fourth Embodiment 
       FIG. 6  is a plan view showing rotary brush unit  2  inside suction port portion  1  of the electric vacuum cleaner according to a fourth embodiment of the invention. In rotary shaft bodies  2 A and  2 B constituting rotary brush unit  2 , the outer diameter of range  110  in the vicinity of the center of rotary brush unit  2  is small, and the outer diameter becomes large toward both ends. The length of brush  3  attached to rotary shaft bodies  2 A and  2 B becomes shorter as the outer diameters of rotary shaft bodies  2 A and  2 B become larger. That is, in each of rotary shaft bodies  2 A and  2 B, brush  3  includes brushes  3 C and  3 D of which the lengths becomes short in a direction from the center to both ends. Accordingly, as depicted by one-dot dashed line P 1 , the outer diameter of brush  3  up to the end of the bristle is substantially uniform throughout the entire width of the rotary brush unit  2 . Since the other configurations are same as those of the first embodiment, detailed description thereof will be omitted. 
     With such a configuration, since the brush is hardly pushed down due to the short length of the brush, it is possible to improve the self-propelling force at both ends of rotary brush unit  2  even in the case of using a brush formed of the same material. That is, it is possible to more efficiently turn suction port portion  1 . 
     In this embodiment, the direction of the suction port portion is changed by generating a difference in the rotation speed between the driving motors using switch lever portion  10  of the first embodiment or handle portion  11 B, which is twistable, of the second embodiment. At this time, in this embodiment, since brush  3  includes brushes  3 C and  3 D of which the lengths become short in a direction from the center of rotary brush unit  2  to both ends thereof, it is possible to more efficiently turn suction port portion  1 . 
     As described above, in this embodiment, the outer diameter of each of rotary shaft bodies  2 A and  2 B in the vicinity of both ends of rotary brush unit  2  is set to be larger than that in the vicinity of the center thereof. In addition, the length of each of brushes  3  in the vicinity of both ends of rotary brush unit  2  is set to be shorter than that in the vicinity of the center thereof, and the outer diameter of each of brushes  3  up to the end of the bristle in the vicinity of both ends of rotary brush unit  2  is set to be same as that in the vicinity of the center thereof. Accordingly, it is possible to improve the direction changing force of suction port portion  1 , and to change the self-propelling direction even on a floor surface having a large sliding resistance such as a deep carpet. Further, since the outer diameter of each of brushes  3  up to the end of the bristle is set to be uniform, it is possible to have uniform contact with a floor surface. Accordingly, it is possible to obtain a uniform suction function and a uniform self-propelling function throughout the entire width of rotary brush unit  2 . 
     Fifth Embodiment 
       FIG. 7  is a plan view showing rotary brush unit  2  inside suction port portion  1  of the electric vacuum cleaner according to a fifth embodiment of the invention. In brush  3  attached to the surfaces of rotary shaft bodies  2 A and  2 B constituting rotary brush unit  2 , the length of brush  3  is short in range  110  in the vicinity of the center of rotary brush unit  2 , and becomes longer toward both ends. The outer diameter of brush  3  up to the end of the bristle is depicted by one-dot chain line P 2 . That is, brush  3  includes brushes  3 E and  3 F which are respectively disposed in rotary shaft bodies  2 A and  2 B so that the lengths thereof become longer in a direction from the center of rotary brush unit  2  to both ends thereof. Since the other configurations are same as those of the first embodiment, detailed description thereof will be omitted. 
     With such a configuration, brush  3  at both ends of rotary brush unit  2  strongly comes into contact with the floor surface to thereby generate a large self-propelling force. As a result, it is possible to more efficiently turn suction port portion  1 . 
     In this embodiment, the direction of the suction port portion can be changed by generating a difference in the rotation speed between the driving motors using switch lever portion  10  of the first embodiment or handle portion  11 B, which is twistable, of the second embodiment. At this time, in this embodiment, since brush  3  includes brushes  3 E and  3 F of which the lengths become longer in a direction from the center of rotary brush unit  2  to both ends thereof, it is possible to more efficiently turn suction port portion  1 . 
     As described above, in this embodiment, the length of each of brushes  3  in the vicinity of both ends of rotary brush unit  2  is set to be longer than that in the vicinity of the center thereof. Accordingly, since it is possible to improve the direction changing force of suction port portion  1 , it is possible to change the self-propelling direction even on a floor surface having a large resistance such as a deep carpet. Further, since the distance from the center of the attachment portion of brush  3  is uniform, it is possible to easily perform a transplanting operation using an automatic machine. 
     Sixth Embodiment 
       FIG. 8  is a plan view showing rotary brush unit  2  inside suction port portion  1  of the electric vacuum cleaner according to a sixth embodiment of the invention. In the same manner as the above-described embodiments, brush  3  is attached to the surfaces of rotary shaft bodies  2 A and  2 B constituting rotary brush unit  2 . The pitch between brushes  3  attached to predetermined ranges  120  of both ends of rotary brush unit  2  is narrow. The pitch at predetermined range  121  in the vicinity of the center of rotary brush unit  2  is wide. That is, brush  3  includes high-density brush  3 G attached to both ends of rotary brush unit  2  and low-density brush  3 H attached to the vicinity of the center thereof. Since the other configurations are same as those of the first embodiment, detailed description thereof will be omitted. 
     Accordingly, it is possible to generate a large self-propelling force at both ends of rotary brush unit  2 . For this reason, it is possible to more efficiently turn suction port portion  1 . 
     In this embodiment, the direction of the suction port portion is changed by generating a difference in the rotation speed between the driving motors using switch lever portion  10  of the first embodiment or handle portion  11 B, which is twistable, of the second embodiment. At this time, in this embodiment, since brush  3  includes high-density brush  3 G attached to both ends of rotary brush unit  2  and low-density brush  3 H attached to the vicinity of the center thereof, it is possible to more efficiently turn suction port portion  1 . 
     As described above, in this embodiment, the density of each of brushes  3  in the vicinity of both ends of rotary brush unit  2  is set to be higher than that in the vicinity of the center thereof. Particularly, brush  3  of each of rotary shaft bodies  2 A and  2 B is formed with a comb tooth shape, and the pitch of the comb tooth shape of each of brushes  3  in the vicinity of both ends of rotary brush unit  2  is set to be denser than that of each of brushes  3  in the vicinity of the center thereof. Accordingly, since it is possible to improve the direction changing force of suction port portion  1 , it is possible to change the self-propelling direction even on a floor surface having a high resistance such as a deep carpet. In addition, since it is possible to make the type, stiffness, and length of the bristles of brush  3  uniform throughout the entire width of brush unit  2 , it is possible to improve the productivity. 
     Seventh Embodiment 
       FIG. 9  is a plan view showing rotary brush unit  2  inside suction port portion  1  of the electric vacuum cleaner according to a seventh embodiment of the invention. In the same manner as the above-described embodiments, brush  3  is attached to the surfaces of rotary shaft bodies  2 A and  2 B constituting rotary brush unit  2 . In brushes  3 , four lines of brushes  3 I are respectively attached to predetermined ranges  130  of both ends of rotary brush unit  2 . Two lines of brushes  3 J are attached to range  131  in the vicinity of the center of rotary brush unit  2 . Since the other configurations are same as those of the first embodiment, detailed description thereof will be omitted. 
     Accordingly, it is possible to generate a large self-propelling force at both ends of rotary brush unit  2 . For this reason, it is possible to more efficiently turn suction port portion  1 . 
     In this embodiment, the direction of the suction port portion is changed by generating a difference in the rotation speed between the driving motors using switch lever portion  10  of the first embodiment or handle portion  11 B, which is twistable, of the second embodiment. At this time, in this embodiment, since brush  3  includes four lines of brushes  3 I in both ends of rotary brush unit  2  and two lines of brushes  3 J in the vicinity of the center thereof, it is possible to more efficiently turn suction port portion  1 . 
     As described above, brushes  3  of rotary shaft bodies  2 A and  2 B are formed in a stripe shape, and the number of lines of brushes  3  in the vicinity of both ends of rotary brush unit  2  is larger than that of brushes  3  in the vicinity of the center thereof. Accordingly, since it is possible to improve the direction changing force of suction port portion  1 , it is possible to change the self-propelling direction even on a floor surface having a high resistance such as a deep carpet. In addition, since it is possible to make the type, stiffness, length, and transplanting pitch of the bristles of brush  3  uniform throughout the entire width of brush unit  2 , it is possible to improve the productivity. 
     As described above, the electric vacuum cleaner according to the invention includes the cleaner body portion which has the electric blower for generating a suction wind; the suction port portion which sucks dust together with the suction wind; the handle portion which moves the suction port portion; the rotary brush unit which is disposed inside the suction port portion and in which two rotary shaft bodies each having a brush are disposed in series; the rotary brush unit driving portion which separately rotates each of the rotary shaft bodies; and the rotation speed difference generating mechanism which generates a difference in the rotation speed between two rotary shaft bodies. 
     With such a configuration, it is possible to reduce the burden applied to the arm or wrist upon changing the direction of suction port portion in the left and right direction. 
     In the invention, the suction port portion propels itself in accordance with the rotation of the rotary shaft bodies. With such a configuration, since the suction port portion propels itself forward or backward during the cleaning operation, it is possible to reduce the burden applied to the arm or wrist. 
     In the invention, the rotary brush unit driving portion is configured as the driving motor disposed inside each of the rotary shaft bodies. With such a configuration, it is possible to decrease the size of the suction port portion and to easily handle the suction port portion in a narrow space. In addition, it is possible to dispose the rotary brush unit in substantially the entire width of the suction port portion, and to improve the cleaning performance for cleaning a side wall. 
     In the invention, the handle portion includes the switch lever portion which is operable in the left and right direction, and controls the rotation of two rotary shaft bodies of the rotary brush unit so that the direction of the suction port portion is changed to the operation direction of the switch lever portion. With such a configuration, it is possible to change the direction of the suction port portion just by using a finger tip without performing a large action in which the handle portion is twisted or pushed down. 
     In the invention, the handle portion is twistable in the left and right direction. When the handle portion is twisted in the left and right direction, the rotation of two rotary shaft bodies of the rotary brush unit is controlled so that the direction of the suction port portion is changed to the twisting direction of the handle portion. With such a configuration, it is possible to change the self-propelling direction of the suction port portion while having the same feeling of operation as with a general cleaner having an oscillation mechanism. 
     In the invention, the stiffness of each of the brushes in the vicinity of both ends of the rotary brush unit is set to be larger than that in the vicinity of the center thereof. With such a configuration, since it is possible to improve the direction changing force of the suction port portion, it is possible to change the self-propelling direction even on a floor surface having a high resistance such as a deep carpet. 
     In the invention, the outer diameter of each of the rotary shaft bodies in the vicinity of both ends of the rotary brush unit is set to be larger than that in the vicinity of the center thereof. In addition, the length of each of the brushes in the vicinity of both ends of the rotary brush unit is set to be shorter than that in the vicinity of the center thereof, and the outer diameter of each of the brushes up to the end of the bristle in the vicinity of both ends of the rotary brush unit is set to be same as that in the vicinity of the center thereof 
     With such a configuration, it is possible to improve the direction changing force of the suction port portion, and to change the self-propelling direction even on a floor surface having a large sliding resistance such as a deep carpet. Further, since the outer diameter of the brush up to the end of the bristle is set to be uniform, it is possible to have uniform contact with a floor surface. Accordingly, it is possible to obtain a uniform suction function and a uniform self-propelling function throughout the entire width of the rotary brush unit. 
     In the invention, the length of each of the brushes in the vicinity of both ends of the rotary brush unit is set to be longer than that in the vicinity of the center thereof With such a configuration, since it is possible to improve the direction changing force of the suction port portion, it is possible to change the self-propelling direction even on a floor surface having a large resistance such as a deep carpet. Further, since the distance from the center of the attachment portion of the brush is uniform, it is possible to easily perform a transplanting operation using an automatic machine. 
     In the invention, the density of each of the brushes in the vicinity of both ends of the rotary brush unit is set to be higher than that in the vicinity of the center thereof With such a configuration, since it is possible to improve the direction changing force of the suction port portion, it is possible to change the self-propelling direction even on a floor surface having a high resistance such as a deep carpet. In addition, since it is possible to make the type, stiffness, and length of the bristles of the brush uniform throughout the entire width of the brush unit, it is possible to improve the productivity. 
     In the invention, the brushes of each of the rotary shaft bodies are formed with a comb tooth shape, and the pitch of the comb tooth shape of each of the brushes in the vicinity of both ends of the rotary brush unit is set to be denser than that in the vicinity of the center thereof. 
     With such a configuration, since it is possible to improve the direction changing force of the suction port portion, it is possible to change the self-propelling direction even on a floor surface having a high resistance such as a deep carpet. In addition, since it is possible to make the type, stiffness, and length of the bristles of the brush uniform throughout the entire width of the brush unit, it is possible to improve the productivity. 
     In the invention, the brush of the rotary shaft body is formed in a stripe shape, and the number of lines of the brushes in the vicinity of both ends of the rotary brush unit is set to be larger than that in the vicinity of the center thereof. 
     With such a configuration, since it is possible to improve the direction changing force of the suction port portion, it is possible to change the self-propelling direction even on a floor surface having a high resistance such as a deep carpet. In addition, since it is possible to make the type, stiffness, and length of the bristles of the brush uniform throughout the entire width of the brush unit, it is possible to improve the productivity. 
     As described above, the advantage of the invention is particularly apparent in a heavy electric vacuum cleaner such as an upright cleaner. For this reason, it is possible for even an old person, a woman, or a child to perform a cleaning operation using the electric vacuum cleaner, and to suppress fatigue even during a lengthy cleaning operation. In addition, regardless of age, sex or whether used at home or the office, it is possible to reduce the effort involved during a cleaning operation.