US20090165242A1

US20090165242A1 - Upright vacuum cleaner having steering unit

Info

Publication number: US20090165242A1
Application number: US12/154,523
Authority: US
Inventors: Byung-jo Lee; See-Hyun Kim; Joung-soo Park; Jung-gyun Han; Tae-gwang Kim
Original assignee: Samsung Gwangju Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2008-01-02
Filing date: 2008-05-23
Publication date: 2009-07-02
Also published as: KR101457430B1; GB2456195A; GB0814064D0; GB2456195B; KR20090074582A

Abstract

An upright vacuum cleaner is disclosed, the upright vacuum cleaner including a cleaner body that houses a suction motor and a dust separating unit, and includes a manipulation handle at the top thereof, a suction port assembly that is connected to a lower portion of the cleaner body; and a steering unit that is disposed between the cleaner body and the suction port assembly, and elastically supports the cleaner body to shift the center of gravity of the cleaner body to the left or right, so that the direction of the cleaner body is changed.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 119 from Korean Patent Application No. 10-2008-0000409, filed on Jan. 2, 2008, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present disclosure relates to a vacuum cleaner. More particularly, the present disclosure relates to an upright vacuum cleaner that draws in dust-laden air from a surface being cleaned through a suction port assembly or an extension pipe connected to a cleaner body according to a user's selection, using a suction force generated by a motor housed in the cleaner body, and that separates the dust from the drawn-in air.
2. Description of the Related Art
Vacuum cleaners can be generally divided into upright vacuum cleaners and canister vacuum cleaners. An upright vacuum cleaner has a suction port assembly that is directly connected to a cleaner body, without requiring a separate hose of extension pipe, and provides improved cleaning efficiency, especially on carpets, using its own weight.
Unlike the upright vacuum cleaner, a canister vacuum cleaner has a suction port assembly connected to a cleaner body using a hose and an extension pipe. The canister vacuum cleaner is easier for a user to manipulate than an upright vacuum cleaner, and therefore, the canister vacuum cleaner is generally used to clean narrow places that are not accessible by an upright vacuum cleaner, such as stairs, or corners.
An upright vacuum cleaner is generally heavy, and thus it is hard for a user to change the direction of a suction port assembly. Furthermore, since the suction port assembly generally moves in a straight line, a user of an upright vacuum cleaner has to pull the vacuum cleaner towards him first, in order to move the suction port assembly to an intended location.
An example of a conventional upright vacuum cleaner is described in GB2391459, published on Feb. 11, 2004, by Dyson. The upright vacuum cleaner of GB2391459 includes a suction motor housed in a cleaner body, and a spherical rotatable member to increase maneuverability of the vacuum cleaner.
However, conventional upright vacuum cleaners have a very complicated structure, and accordingly suffer deteriorated assemblability. Furthermore, a considerable amount of cost and time is required for repair and maintenance.

SUMMARY OF THE INVENTION

An aspect of the present disclosure is to address at least the above problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the present disclosure is to provide an upright vacuum cleaner having a steering unit to adjust the direction of a suction port assembly conveniently to the left or right, according to the movement of the center of gravity of the vacuum cleaner.
In accordance with an aspect of the present disclosure, an upright vacuum cleaner includes a cleaner body that houses a suction motor and a dust separating unit, and comprises a manipulation handle at the top thereof; a suction port assembly that is connected to a lower portion of the cleaner body; and a steering unit that is disposed between the cleaner body and the suction port assembly, and that elastically supports the cleaner body in order to shift the center of gravity of the cleaner body to the left or right, so that the direction of the cleaner body is changed.
The steering unit may include a support housing that is hinged to a lower portion of the cleaner body forward and backward, and a front portion of which is contacted by the suction port assembly; first and second main wheels; and a steering portion that is formed in such a manner that the first and second main wheels are disposed at both ends thereof, and that is elastically disposed on the support housing.
The suction port assembly may be formed in such a manner that a rear portion thereof contacts the support housing about a shaft, and the center of the shaft may be disposed so as to slope downward from the front portion of the cleaner body towards a rear portion of the cleaner body.
The steering portion may be made of a metal or synthetic resin having elasticity, and if a user tilts the cleaner body, the steering portion may be twisted, and if the user moves the cleaner body vertically, the steering portion may be restored, in order to change the direction of the suction port assembly.
The steering portion may be formed in such a manner that the center is fixed to the bottom of the support housing, and is bent toward the rear portion.
The steering portion may include a first portion of which the center is fixed to the bottom center of the support housing, and that is disposed so as to slope downward toward at the rear of the support housing; a second portion that extends from the rear of the first portion, and is disposed so as to slop upward toward the rear of the support housing; and a third portion that extends from both sides of the rear of the second portion, and is rotatably connected to the first and second main wheels.
The steering portion may include a rotating portion that is rotatably connected to the bottom center of the supporting housing; first and second main rods that are formed in such a manner that one end of each is connected to a respective side of the rotating portion, and the other end of each faces the rear of the support housing, and to which the first and second main wheels are rotatably disposed; a fixing portion that is fixed to the bottom center of the support housing; and first and second sub rods that are formed in such a manner that one end of each is pivotally fixed to a respective side of the fixing portion, and the other end of each is pivotally fixed to the first and second main rods, respectively.
The steering unit may include a support housing that is hinged to the bottom of the cleaner body, and of which the suction port assembly is connected to a front portion so that the suction port assembly rotates according to the direction of the shaft; first and second main wheels; first and second supports that are formed in such a manner that one end of each is connected to a respective side of the support housing, and the opposite end of each comprises the first and second main wheels, respectively; and first and second elastic member that elastically connect the first and second supports to the support housing, respectively, and wherein one of the first and second supports is disposed so as to be closer to the cleaner body than the other of the first and second supports, and rotates at a greater angle than the other of the first and second supports.
The first and second elastic members may be formed in such a manner that one end of each is hinged to the supporting housing, and the other end of each is formed as a damper hinged to the first and second supports, respectively.
The first and second elastic members may be torsion springs.
The support housing may include a support wheel on a lower central portion thereof.
The support wheel tapers symmetrically toward the left and right sides

DESCRIPTION OF THE DRAWINGS

The above and/or other aspects of the present invention will be more apparent by describing certain exemplary embodiments of the present invention with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view illustrating an upright vacuum cleaner according to a first exemplary embodiment of the present disclosure;

FIG. 2 is a bottom perspective views of the upright vacuum cleaner according to the first exemplary embodiment of the present disclosure;

FIG. 3 is a side view illustrating the upright vacuum cleaner according to the first exemplary embodiment of the present disclosure;

FIG. 4 is a side view illustrating a steering unit of an upright vacuum cleaner according to the first exemplary embodiment of the present disclosure;

FIG. 5 is a view illustrating the upright vacuum cleaner according to the first exemplary embodiment of the present disclosure while in use;

FIG. 6 is a side view illustrating an upright vacuum cleaner according to a second exemplary embodiment of the present disclosure;

FIG. 7 is a bottom surface view illustrating the upright vacuum cleaner according to the second exemplary embodiment of the present disclosure;

FIG. 8 is an enlarged perspective view illustrating a connection portion of a sub rod of a steering unit of the upright vacuum cleaner of FIG. 7;

FIG. 9 is a view illustrating the upright vacuum cleaner according to the second exemplary embodiment of the present disclosure while in use;

FIG. 10 is a perspective view illustrating the upright vacuum cleaner according to a third exemplary embodiment of the present disclosure;

FIG. 11 is an enlarged perspective view illustrating the steering unit of FIG. 10;

FIG. 12 is a schematic view illustrating a support wheel of FIG. 10; and

FIG. 13 is a perspective view illustrating a steering unit of an upright vacuum cleaner according to a fourth exemplary embodiment of the present disclosure.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION

Hereinafter, a vacuum cleaner according to exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawing figures.
An upright vacuum cleaner according to a first exemplary embodiment of the present disclosure is described, and specifically, a steering unit 30 is described in detail with reference to FIGS. 1 to 5.
The upright vacuum cleaner according to the first exemplary embodiment of the present disclosure includes a cleaner body 10, a suction port assembly 20, and a steering unit 30.
The cleaner body 10 houses therein a suction motor (not shown) to provide the suction force, and also houses a dust separating unit (not shown) to separate and collect dust from drawn-in air. The cleaner body 10 includes a manipulation handle 11 at the top thereof, and a support housing 31 at the bottom left and right. The support housing 31 is hinged to the cleaner body 10 so as to be capable of rotating forward and backward.
Referring to FIG. 2, the suction port assembly 20 is connected to the dust separating unit (not shown) of the cleaner body 10, and includes a suction port 21 formed on a lower portion to draw in dust and air from a surface being cleaned. A drum brush 23 may be rotatably disposed within the suction port 21 of the suction port assembly 20. A pair of protection wheels 25 may be provided at both ends of the suction port 21.
The inside of the suction port assembly 20 is connected to the suction port 21, and a guide pipe 27 extends towards the rear of the suction port assembly 20. The guide pipe 27 is rotatably connected to a connection portion 31 a protruding axially towards the front of the support housing 31.
A connection surface between the guide pipe 27 and the connection portion 31 a is inclined from a normal (N) about a surface toward the support housing 31 at a predetermined angle (⊖) as shown in FIG. 3. Accordingly, the center of a rotating shaft A2 is also inclined towards the support housing 31 at the same angle as that (⊖) of the connection surface. The inclined angle (⊖) may preferably be the same as the angle at which a user tilts the cleaner body. When the center of gravity of cleaner body 10 is shifted to the left or right to change the direction of the suction port assembly 20 while the cleaner body 10 is tilted back, the rotating shaft A2 is approximately perpendicular to a shaft C of the cleaner body 10 as shown in FIG. 4, and thus the support housing 31 easily rotates about the suction port assembly 20.
The steering unit 30 is disposed between the cleaner body 10 and the suction port assembly 20, and includes the support housing 31, a steering portion 33, and first and second main wheels 41 and 42.
The support housing 31 encloses the lower portion of the cleaner body 10, and both sides thereof are hinged to the cleaner body 10. The cleaner body 10 rotates forward and backward about a hinge point (P) at a predetermined angle. The connection portion 31 a that contacts the guide pipe 27 of the suction port assembly 20 is formed on a front portion of the support housing 31. A flexible hose (not shown) is disposed inside the guide pipe 27 to deliver the dust and air drawn-in from the suction port 21 toward the dust separating unit (not shown). This prevents the interference between the guide pipe 27 and the connection portion 31 a due to rotation.
The steering portion 33 may be made of a metal or synthetic resin having high elasticity. Accordingly, if the center of gravity of the cleaner body 10 shifts to the left or right, the steering portion 33 is twisted, and if the cleaner body 10 moves vertically, the steering portion 33 is restored. A user can efficiently move the cleaner body 10 to the original position (vertical state of FIG. 3) using the elastic force of the steering unit 33.
The steering portion 33 is bent from the first portion 33 a to the second and third portions 33 b and 33 c in a stair formation, and has greater length than width. The center of the first portion 33 a is fixed to the bottom of the support housing 31 by a fixing sphere 32, and is disposed obliquely downward at the rear of the support housing 31. The second portion 33 b extends from the rear of the first portion 33 a, and is disposed obliquely upward at the rear of the support housing 31. A plurality of support ribs 34 maintain the bent formation of the first and second portions 33 a and 33 b. The third portion 33 c extends from the rear of the second portion 33 b, and includes a shaft 33 d rotatably connected to the first and second main wheels 41 and 42. The first and second portions 33 a and 33 b of the steering portion 33 are bent, and the first and second main wheels 41 and 42 are disposed at the rear of the cleaner body 10, so the steering portion 33 stably supports the suction port assembly 20 and the cleaner body 10.
The steering portion 33 may also include only the second and third portions 33 b and 33 c, without the first portion 33 a, according to the formation of the support housing 31.
The operation of an upright vacuum cleaner according to a first exemplary embodiment of the present disclosure will be explained in detail with reference to FIG. 5. FIG. 5 is a view illustrating an example in which a user rotates the upright vacuum cleaner to the right. Herein, the direction of rotation of the cleaner body 10 will be described as being towards the right from the vantage point of the user.
Referring to FIG. 5, a user grabs the manipulation handle 11 of the cleaner body 10 and cleans a surface being cleaned while tilting the cleaner body 10 towards the user about the hinge point (P) of the support housing 31 at a predetermined angle.
If the user rotates the manipulation handle 11 to the right, in order to move the suction port assembly 20 to the right, the cleaner body 10 rotates according to the direction of rotation of a rotating shaft A2 (Referring to FIG. 3), and the center of gravity of the cleaner body 10 shifts to the right.
As a result, the weight of the cleaner body 10 is transmitted to the steering portion 33 of the steering unit 30, and the steering portion 33 is twisted horizontally. The steering portion 33 causes the first and second main wheels 41 and 42 to rotate to the right in order to move the suction port assembly 20 to the right. Accordingly, a user can maneuver the suction port assembly 20 conveniently, by simply rotating the manipulation handle 11 to the right.
If the user rotates the manipulation handle 11 to the left in order to change the direction of a suction port assembly 20 horizontally, the cleaner body 10 rotates according to the direction of rotation of the rotating shaft A2, the weight of the cleaner body 10 is removed from the twisted steering portion 33, the steering portion 33 recovers its original formation, and the first and second main wheels 41 and 42 return to their original location. The elasticity of the steering portion 33 enables the user to conveniently restore the cleaner body 10 to its original position.
Although omitted herein, one will understand that the suction port assembly 40 may also be moved to the left in a similar manner.
The operation of an upright vacuum cleaner according to the second exemplary embodiment of the present disclosure will be explained in detail with reference to FIGS. 6 to 9. The second exemplary embodiment has a steering unit 130 that differs from that of the first exemplary embodiment and that is explained hereinbelow, but other elements of the second exemplary embodiment are identical to elements of the first exemplary embodiment, and detailed description thereof is omitted here.
As in the first exemplary embodiment of the present disclosure, the steering unit 130 of the second exemplary embodiment of the present disclosure is disposed between the cleaner body 10 and the suction port assembly 20, and includes a support housing 131, a steering portion 133, and first and second main wheels 41 and 42.
The support housing 131 covers the lower part of the main body 10, and is hinged to the main body 10 to the left and right.
The steering portion 133 includes a fixing portion 135, first and second main rods 136 a and 136 b, a rotating portion 137, and first and second sub rods 139 a and 139 b.
The fixing portion 135 is fixed to the bottom of the support housing 131, and protrudes from the center thereof. One end of each of the first and second main rods 136 a and 136 b is connected to a respective side of the rotating portion 137. The other end of each of the first and second main rods 136 a and 136 b faces the rear of the support housing 131, and as shown in FIG. 7 shafts 138 a and 138 b are attached thereto. The first and second main wheels 41 and 42 are rotatably connected to the shafts 138 a and 138 b. A hinge pin 138 is inserted into the center of the rotating portion 137 and the center of the fixing portion 135, so the rotating portion 137 is rotatably fixed to the fixing portion 135. The rotating portion 137 may be directly hinged on the center of the support housing 131 without using the fixing portion 135. A torsion spring (not shown) may be mounted in the center of the fixing portion 135 in which the hinge pin 138 is inserted, in order that the rotating portion 137 may elastically rotate about the fixing portion 135.
The first and second sub rods 139 a and 139 b prevent the first and second main rods 136 a and 136 b from rotating more than a predetermined angle about the rotating portion 137. One end of each of the first and second sub rods 139 a and 139 b is pivotally fixed to a respective side of the fixing portion 135, and the other end of each of the first and second sub rods 139 a and 139 b is pivotally fixed to the center of the first and second main rods 136 a and 136 b, respectively.
One end of each of the first and second sub rods 139 a and 139 b is connected by a ball bearing 143, as shown in FIG. 8. If the first and second main rods 136 a and 136 b rotate so as to be twisted in opposite directions about the rotating portion 137, as shown in FIG. 9, the other end of each of the first and second sub rods 139 a and 139 b rotates at various angles about the fixing portion 135.
The steering operation of the upright vacuum cleaner according to a second exemplary embodiment of the present disclosure, in which the user rotates the suction port assembly 20 to the right, will be explained below.
Referring to FIG. 9, if the user grabs the manipulation handle 11 and rotates it to the right in order to move the suction port assembly 20 to the right, the cleaner body 10 rotates to the right about the rotating shaft A2 (referring to FIG. 6), and the center of gravity of the cleaner body 10 thus shifts to the right.
As a result, the weight of the cleaner body 10 is transmitted to the steering portion 133 of the steering unit 130, the first and second main rods 136 a and 136 b of the steering portion 133 rotate in opposite directions about the rotating portion 137 at a predetermined angle, and the rotating portion 137 rotates to the left side. The first and second sub rods 139 a and 139 b prevent the first and second main rods 136 a and 136 b from rotating more than a predetermined angle. Accordingly, the first and second main wheels 41 and 42 rotate to the right, and a user can thus maneuver the suction port assembly 20 conveniently by simply rotating the manipulation handle 11 at a predetermined angle.
If the user rotates the manipulation handle II to the left at a predetermined angle in order to move the suction port assembly 20 to the left, the cleaner body 10 rotates to the left about the rotating shaft A2 (Referring to FIG. 6). Accordingly, the weight of the cleaner body 10 is removed from the steering portion 133, the first and second main rods 136 a and 136 b rotate in opposite directions, and thus the rotating portion 137 rotates to the right. As a result, if the first and second main rods 136 a and 136 b return to the original location, the first and second main wheels 41 and 42 also return to the original location, and the user can move the suction port assembly 20 in a straight line.
The operation of the upright vacuum cleaner according to a third exemplary embodiment of the present disclosure will be explained in detail with reference to FIGS. 10 to 12. Elements in common with the first exemplary embodiment are omitted from the description of the third exemplary embodiment, and only the steering unit 230, which differs from that of the first exemplary embodiment, will be explained.
The steering unit 230 of the third exemplary embodiment of the present disclosure is disposed between the cleaner body 10 and the suction port assembly 20, and includes a support housing 231, a steering portion 233, a support wheel 238, and first and second main wheels 41 and 42.
The support housing 231 encloses a lower portion of the cleaner body 10, and the left and right sides thereof are hinged to the cleaner body 10.
The steering portion 233 includes first and second supports 234 a and 234 b, and first and second dampers 235 and 236. One end of each of the first and second supports 234 a and 234 b is hingeably connected to the support housing 231. The opposite end of each of the first and second supports 234 a and 234 b is connected to a rear portion of the support housing 231. The first and second main wheels 41 and 42 are rotatably connected to the opposite end of each of the first and second supports 234 a and 234 b, respectively. The first and second dampers 235 and 236 include respective elastic rods 235 a and 236 a, and return springs 235 b and 236 b. One end of each of the elastic rods 235 a and 236 a is hinged to a respective side of the support housing 231, and the opposite end of each of the elastic rods 235 a and 236 a is hinged to an upper central portion of the first and second supports 234 a and 234 b, respectively. The elastic rods 235 a and 236 a are implemented as telescopic structures that are elastically extensible. The return springs 235 b and 236 b coil around the circumference of the elastic rods 235 a and 236 a, when the length of the elastic rods 235 a and 236 a is reduced, the return springs 235 b and 236 b are compressed.
The steering portion 233 may include a pair of torsion springs 335 and 336 instead of the first and second dampers 235 and 236, as shown in FIG. 13. The torsion springs 335 and 336 of FIG. 13 are disposed between the first and second supports 234 a and 234 b, and are hinged to respective sides of the support housing 231, so that the first and second supports 234 a and 234 b are elastically connected to the support housing 231.
The support wheel 238 is rotatably connected to a support 237 that protrudes from a lower central portion of the support housing 231. The support wheel 238 forms a tapered surface around the circumference of the left and right sides 238 a and 238 b about the support 237. When the cleaner body 10 leans to the right or left, a taper surface of the left or right side 238 a or 238 b of the support wheel 238 contacts a surface being cleaned and stably supports the cleaner body 10, enabling the vacuum cleaner to move smoothly across a surface being cleaned in the same manner as the first and second main wheels 41 and 42.
The steering operation of the upright vacuum cleaner according to the third exemplary embodiment of the present disclosure will be explained below.
In order to change the direction of the suction port assembly 20 to the right, the user grabs the manipulation handle 11, and rotates it in the direction of rotation of the rotating shaft (not shown). As a result, the center of gravity of the cleaner body 10 shifts to the right.
As a result, the weight of the cleaner body 10 is transmitted to the steering portion 233 of the steering unit 230, and the first support 234 a of the steering portion 233 that is disposed on the side to which the vacuum cleaner rotates at a predetermined angle, and the second support 234 b does not rotate. The length of the elastic rod 235 a of the first damper 235 is reduced, and the return spring 235 b is compressed.
The first and second main wheels 41 and 42, and the support wheel 238 are implemented to be inclined at a predetermined angle to the right.
A user can maneuver the suction port assembly 20 conveniently by simply rotating the manipulation handle 11 to the right.
In order to adjust the direction of the suction port assembly 20 from the heading in a rightward to heading straight ahead, the user rotates the manipulation handle 11 to the left at a predetermined angle, and the cleaner body 10 thus rotates in the direction of rotation of the rotating shaft.
The weight of the cleaner body 10 is removed from the first damper 235 of the steering portion 233, the elastic rod 235 a is reduced to the original length by the elasticity of the return spring 235 b, the first support 234 a rotates and returns to its original position, the cleaner body 10 returns to its original position and the first and second main wheels 41 and 42 are arranged in their original positions. Accordingly, the user can move the suction port assembly 20 straight ahead.
According to the exemplary embodiments of the present disclosure, a steering unit having a simple structure is provided, to reduce the number of assembled parts, increase productivity, and greatly reduce the cost of repair and maintenance.
Furthermore, a user of an upright vacuum cleaner can easily move the suction port assembly, by simply moving a manipulation handle and return the cleaner body to its original position with minimal effort.
The foregoing exemplary embodiments and advantages are merely exemplary and are not to be construed as limiting the present invention. The present teaching can be readily applied to other types of apparatuses. Also, the description of the exemplary embodiments of the present invention is intended to be illustrative, and not to limit the scope of the claims, and many alternatives, modifications, and variations will be apparent to those skilled in the art.

Claims

1. An upright vacuum cleaner, comprising:

a cleaner body having a manipulation handle at the top thereof;

a suction port assembly that is connected to a lower portion of the cleaner body; and

a steering unit that is disposed between the cleaner body and the suction port assembly, wherein the steering unit elastically supports the cleaner body in order to shift the center of gravity of the cleaner body to the left or right, so that the direction of the cleaner body is changed.

2. The upright vacuum cleaner of claim 1, wherein the steering unit comprises:

a support housing that is hinged to a lower portion of the cleaner body forward and backward, and a front portion of which is contacted by the suction port assembly;

first and second main wheels; and

a steering portion that is formed in such a manner that the first and second main wheels are disposed at both ends thereof, and that is elastically disposed on the support housing.

3. The upright vacuum cleaner of claim 2, wherein the suction port assembly is formed in such a manner that a rear portion thereof contacts the support housing about a shaft, and the center of the shaft is disposed so as to slope downward from the front portion of the cleaner body towards a rear portion of the cleaner body.

4. The upright vacuum cleaner of claim 2, wherein the steering portion is made of a metal or synthetic resin having elasticity, and if a user tilts the cleaner body, the steering portion is twisted, and if the user moves the cleaner body vertically, the steering portion is restored, in order to change the direction of the suction port assembly.

5. The upright vacuum cleaner of claim 4, wherein the steering portion is formed in such a manner that the center is fixed to the bottom of the support housing, and is bent progressively toward the rear portion.

6. The upright vacuum cleaner of claim 4, wherein the steering portion comprises:

a first portion of which the center is fixed to the bottom center of the support housing, and that is disposed so as to slope downward toward at the rear of the support housing;

a second portion that extends from the rear of the first portion, and is disposed so as to slop upward toward the rear of the support housing; and

a third portion that extends from both sides of the rear of the second portion, and is rotatably connected to the first and second main wheels.

7. The upright vacuum cleaner of claim 2, wherein the steering portion comprises:

a rotating portion that is rotatably connected to the bottom center of the supporting housing;

first and second main rods that are formed in such a manner that one end of each is connected to a respective side of the rotating portion, and the other end of each faces the rear of the support housing, and to which the first and second main wheels are rotatably disposed;

a fixing portion that is fixed to the bottom center of the support housing; and

first and second sub rods that are formed in such a manner that one end of each is pivotally fixed to a respective side of the fixing portion, and the other end of each is pivotally fixed to the first and second main rods, respectively.

8. The upright vacuum cleaner of claim 1, wherein the steering unit comprises:

a support housing that is hinged to the bottom of the cleaner body, and of which the suction port assembly is connected to a front portion so that the suction port assembly rotates according to the direction of the shaft;

first and second main wheels;

first and second supports that are formed in such a manner that one end of each is connected to a respective side of the support housing, and the opposite end of each comprises the first and second main wheels, respectively; and

first and second elastic member that elastically connect the first and second supports to the support housing, respectively,

and wherein one of the first and second supports is disposed so as to be closer to the cleaner body than the other of the first and second supports, and rotates at a greater angle than the other of the first and second supports.

9. The upright vacuum cleaner of claim 8, wherein the first and second elastic members are formed in such a manner that one end of each is hinged to the supporting housing, and the other end of each is formed as a damper hinged to the first and second supports, respectively.

10. The upright vacuum cleaner of claim 8, wherein the first and second elastic members are torsion springs.

11. The upright vacuum cleaner of claim 8, wherein the support housing comprises a support wheel on a lower central portion thereof.

12. The upright vacuum cleaner of claim 8, wherein the support wheel tapers symmetrically toward the left and right sides.