Patent Description:
A robot cleaner is a device that sucks foreign substances such as dust from a floor while traveling by itself on an area to be cleaned.

A robot cleaner includes a suction nozzle module, and the suction nozzle module is brought into contact with a surface to be cleaned to suck foreign substances such as dust on the surface together with air. In particular, a robot cleaner is mainly operated in a floor environment.

Meanwhile, when a robot cleaner travels in a state in which a suction nozzle is fixed to the robot cleaner, a height of a floor may be changed according to various types of floor environments.

For example, while a robot cleaner is traveling, various types of travel environments exist, such as floor plates, floorings, door frames, tiles, rugs, and carpets.

However, the related art robot cleaner travels in a state in which a suction nozzle is in close contact with a floor, whereby the suction nozzle may encounter a phenomenon of being caught due to a difference in height for each type of floor.

For example, in a floor environment such as a carpet, depending on a degree of softness of the carpet, driving wheels of the robot cleaner may sink below a surface of the carpet, whereby the suction nozzle may be caught by the carpet.

Due to such a phenomenon of a caught of the suction nozzle, travel performance may be deteriorated.

That is, a friction force between the driving wheels and the floor decreases, causing slippage of the driving wheels, and increasing a driving load of the wheels, thereby reducing a traveling time of the robot cleaner and reducing a quality.

In addition, due to an increase in a load of a rotation brush or the like, a rotating speed of the brush is decreased and cleaning performance is deteriorated.

In order to reduce the phenomenon of being caught, the prior art <CIT>) discloses a suction structure of a robot cleaner that move up or down according to a surface condition of a floor.

The robot cleaner includes a first supporting portion and a second supporting portion protruding from one side of a suction portion and spaced apart in a lengthwise direction. Ends of the first supporting portion and the second supporting portion form a rotation shaft according to an upward movement or a downward movement of the suction portion. Accordingly, as the suction portion rotates to be movable up and down about the rotation shaft formed at the ends of the first supporting portion and the second supporting portion, the suction portion may move up or down according to a condition of a floor surface.

However, the prior art robot cleaner needs to implement a climbing angle variable operation that helps to climb an obstacle in addition to an up-down movement of the suction nozzle.

<CIT> presents a brush equipment having an electric motor and one or multiple propelled rollers, particularly bristle rollers. The roller interacts with a spring within two vertically dissociated portions, where spring section is directly subjected to the roller by elevator procedure of the spring.

<CIT> presents a height adjusting structure of a suction head of a robot cleaner. The height adjusting structure is composed of a suction head sucking the impurities of the floor; a head receiving part formed at the lower side of the body and received with the suction head; and at least one height adjusting part supported on the upper surface of the suction head and on the inner surface of the head receiving part to longitudinally move the suction head. The suction head contains an agitator shaking and lifting the impurities of the floor, and an agitator mounting part rotatably installed with the agitator. The height adjusting part is a spring having a predetermined elasticity.

<CIT> discloses a robot cleaner wherein the nozzle support portion is rotatably connected to the cleaner body.

The present disclosure has been created to solve the related art problems, and has a first aspect to provide a robot cleaner capable of easily responding to changes in a height of a floor to improve travel performance and implement an operation that can help in climbing obstacles.

A second aspect of the present disclosure is to provide a robot cleaner capable of improving cleaning performance by maintaining a surface pressure of a suction nozzle and increasing a suction pressure even when a height difference of a floor is large.

One or more objects are achieved by the invention set out by the features of the independent claims <NUM>, <NUM> and <NUM>. Advantageous embodiments of the robot cleaner according to the claimed invention are defined in the dependent claims.

In order to achieve the above aspect and other advantages of the present disclosure, there is provided with a robot cleaner, including a cleaner main body configured to travel autonomously, a suction nozzle mounted to be able to move up and down or swing with respect to the cleaner main body, and a supporter to support the suction nozzle to be able to move up and down or swing.

According to the present invention in an embodiment, the supporter including a plurality of ball joints is coupled to the cleaner main body and the suction nozzle, respectively, by the plurality of ball joints to support the suction nozzle to be able to move up and down or swing in a front-rear direction, and the plurality of ball joints may include a first joint housing coupled to the cleaner main body, a second joint housing coupled to the suction nozzle, and a plurality of ball portions accommodated in each of the first joint housing and the second joint housing.

According to an embodiment of the present disclosure, the supporter may further include a connecting bar to connect the plurality of ball portions, and one end portion of the connecting bar connected to a ball portion accommodated in the second joint housing may be located higher than another end portion of the connecting bar connected to a ball portion accommodated in the first joint housing, and the suction nozzle may be supported by being suspended from the one end portion of the connecting bar.

According to an embodiment of the present disclosure, the plurality of ball joints may include a first ball joint provided at the cleaner main body, and a second ball joint provided at the suction nozzle, and the first ball joint and the second ball joint may be positioned in the front-rear direction with a height difference.

According to an embodiment of the present disclosure, the suction nozzle may be formed to be elongated in a direction crossing a traveling direction of the cleaner main body, the ball joint provided at the suction nozzle may be disposed at a central portion in a lengthwise direction of the suction nozzle, the cleaner main body may have an accommodating portion to accommodate the suction nozzle, and the ball joint provided in the cleaner main body may be disposed at a central portion in a lengthwise direction of the accommodating portion.

According to an embodiment of the present disclosure, the supporter may be installed inside the cleaner main body and disposed in front of the suction nozzle.

According to an embodiment of the present disclosure, the ball joint may support the suction nozzle to be able to swing in a left-right direction with respect to a center in a lengthwise direction of the suction nozzle.

According to an embodiment of the present disclosure, the ball joint may further include a plurality of joint covers each mounted to cover an opening of each of the first joint housing and the second joint housing, and a guide groove surrounding the ball portion may be formed inside each of the first joint housing, the second joint housing, and the plurality of joint covers, in a shape corresponding to the ball portion.

According to an embodiment of the present disclosure, each of the plurality of joint covers may have a cutout groove, and a part of the connecting bar connecting the plurality of ball portions may protrude from the ball portion through the cutout groove to move in the front-rear direction and a left-right direction with respect to the joint cover.

According to an embodiment of the present disclosure, the first ball joint may be provided with a first ball portion accommodated in the first joint housing, and the first ball portion may roll in a front-rear direction or a left-right direction with respect to the first joint housing to support the suction nozzle to be able to move up and down or to be able to partially move up and down in the left-right direction.

According to an embodiment of the present disclosure, the second ball joint may be provided with a second ball portion accommodated in the second joint housing, and the second joint housing may rotate relative to the second ball portion to support the suction nozzle to be able to swing in a front-rear direction or a left-right direction.

According to an embodiment of the present disclosure, the plurality of ball portions may include a first ball portion accommodated in the first joint housing, and a second ball portion accommodated in the second joint housing, and the supporter may further include a connecting bar extending from the first ball portion to the second ball portion and configured to surround a part of a front surface and an upper surface of the suction nozzle.

According to the present invention in another embodiment, the supporter supports the suction nozzle to be movable up and down, and the supporter includes a plurality of guide protrusions protruding from both end side surfaces of the suction nozzle, and a plurality of guide holders mounted on both end portions of an accommodating portion provided in the cleaner main body, and each provided with a plurality of guide slots to accommodate the guide protrusions such that the plurality of guide protrusions is movable up and down.

According to another embodiment of the present disclosure, each of the plurality of guide protrusions may be formed to protrude in a cylindrical shape, and each of the plurality of guide slots may be formed in a rectangular shape whose vertical length in an up-down direction is longer than its horizontal length.

According to another embodiment of the present disclosure, each of the plurality of guide slots may have the horizontal length corresponding to a diameter of the guide protrusion, and may have the vertical length extending longer than a diameter of the guide protrusion.

According to another embodiment of the present disclosure, the plurality of guide protrusions may pass through the plurality of guide slots at a height same as each other, and the plurality of guide slots may extend parallel to each other by a height same as each other on the guide holder.

According to another embodiment of the present disclosure, the guide protrusion may have a circular cross-sectional shape, and an upper end portion of the guide slot may be formed in a semicircular shape to surround an upper semicircle of the guide protrusion, a lower end portion of the guide slot may be formed in a semicircular shape to surround a lower semicircle of the guide protrusion, and the upper end portion and the lower end portion of the guide slot may limit a movable height of the protrusion in an up-down direction.

According to another embodiment of the present disclosure, the guide protrusion may be located at a lower end portion of the guide slot, and may move up and down according to a height of a floor during traveling.

According to another embodiment of the present disclosure, the accommodating portion may have a rectangular shape extending long in one direction crossing a traveling direction of the cleaner main body and protrude upward from a lower surface of the cleaner main body, each of a plurality of mounting portions may be formed to be penetrated in the one direction and be formed to be opened upward at both end portions of the accommodating portion, and a plurality of rail portions may protrude from both end portions of the guide holder to overlap inner end portions of the mounting portion in a thickness direction.

According to another embodiment of the present disclosure, the plurality of guide protrusions may be slidably coupled to be movable up and down the plurality of guide slots so that the suction nozzle is entirely moved up and down or any one end portion of both end portions of the suction nozzle is selectively partially moved up and down.

According to the present invention in still another embodiment, the supporter supports the suction nozzle to be movable up and down, and the supporter includes a plurality of guide ribs each protruding from a front surface and a rear surface of the suction nozzle with respect to a traveling direction of the cleaner main body, and a plurality of guide holders each provided with guide slits to accommodate the guide ribs so that the guide ribs are vertically movable and each provided at a front portion and a rear portion of an accommodating portion provided in the cleaner main body.

According to still another embodiment of the present disclosure, each of the plurality of guide ribs may be formed in a rectangular shape and protrude from the front surface and the rear surface of the suction nozzle in a front-rear direction, and each of the plurality of guide holders may be formed in a rectangular shape and protrude from the front portion and the rear portion of the accommodating portion, and the guide slits each may enclose the guide rib in an inner side of the guide holder and extend vertically longer than a vertical length of the guide rib.

According to still another embodiment of the present disclosure, the accommodating portion may have a rectangular shape extending long in one direction crossing the traveling direction of the cleaner main body, and may protrude upward from a lower surface of the cleaner main body, and the plurality of guide holders may be spaced apart from each other in the one direction on the front portion and the rear portion of the accommodating portion.

According to still another embodiment of the present disclosure, the guide slit may extend in a vertical direction of the guide holder, a width of the guide slit may correspond to a thickness of the guide rib, and the guide slit may be formed in a rectangular shape whose vertical length is longer than its horizontal length.

According to still another embodiment of the present disclosure, the supporter may further include a lower stopper formed at a lower end portion of the guide holder in a structure blocking a lower surface of the guide holder so as to limit a lowest downwardly movable height of the guide rib.

According to still another embodiment of the present disclosure, an upper portion of the guide holder may be formed to be opened, and the supporter may further include an upper stopper mounted at an upper end portion of the guide holder to cover the upper portion of the guide holder so as to limit a highest upwardly movable height of the guide rib.

According to another embodiment of the present disclosure, the upper stopper may include a stopper body, and a plurality of hooks protruding downward from the stopper body with the upper end portion of the guide holder therebetween, and a lower end of each of the plurality of hooks may be provided with a locking portion protruding therefrom to be engaged with each of a plurality of coupling holes formed at the accommodating portion.

Effects of a robot cleaner according to the present disclosure will be described as follows.

First, the supporter is provided between the cleaner main body and the suction nozzle, and supports the suction nozzle with the ball joint provided at a portion connected to the cleaner main body or to the suction nozzle to be able to swing in the front-rear direction and the left-right direction or move up and down. And, accordingly, the suction nozzle can actively respond to changes in the height of the floor, thereby improving travel performance.

Second, the ball joint includes the first ball joint at the cleaner main body and the second ball joint at the suction nozzle. The first ball joint may support the suction nozzle to be able to move up and down, and the second ball joint may support the suction nozzle to be able to swing in the front-rear direction and the left-right direction.

Third, the ball joint includes the joint housing and the ball portion. The joint housing includes the first j oint housing provided at the cleaner main body and the second j oint housing provided at the suction nozzle. The ball portion includes the first ball portion accommodated in the first joint housing and the second ball portion accommodated in the second joint housing. Each of the first ball portion and the second ball portion may perform joint motion by rolling along a guide groove formed in the first joint housing and second joint housing, respectively.

Fourth, the first ball portion rolls in the front-rear direction and the left-right direction with respect to the first joint housing, the suction nozzle may move up and down or partially move up and down.

Fifth, as the second ball portion rolls in the front-rear direction and the left-right direction with respect to the second joint housing, the suction nozzle may swing in the front-rear direction and the left-right direction by the second ball joint.

Sixth, the first ball j oint is located at the lower surface of the cleaner main body, the second ball joint is located at an upper portion the suction nozzle, and the supporter is provided with the connecting bar extending from the first ball portion to the second ball portion to support the suction nozzle with a structure of the suction nozzle being suspended.

Seventh, each of the first ball portion and the second ball portion is formed in a shape of a sphere, so that the suction nozzle can easily follow a climbing angle and a height difference according to a floor environment.

Eighth, guide slots and guide protrusions are provided between the cleaner main body and the suction nozzle, respectively, and guide the suction nozzle to be able to move up and down as the guide slots move up and down along the guide slots. And, accordingly, the suction nozzle can actively respond to changes in the height of the floor, thereby improving travel performance.

Ninth, as the guide slots are spaced apart from each other and extend up and down by a height same as each other at both side surfaces of the accommodating portion accommodating the suction nozzle, and the guide protrusions protrude in a lateral direction from both end portions of the suction nozzle to be accommodated in the guide slots so as to move up and down along the guide slots, the suction nozzle can move up and down according to the height difference of the floor by following the floor. Therefore, cleaning performance can be improved by maintaining a contact stress and increasing a suction pressure of the suction nozzle.

Tenth, although driving wheels sink when the cleaner main body travels on a soft floor such as a carpet, the guide ribs move up along the guide slits by a height of the floor when an agitator of the suction nozzle is brought into contact with the floor, and the suction nozzle moves up with respect to the cleaner main body by the height of the floor, so that travel performance can be improved by preventing a phenomenon of being caught by the floor.

Eleventh, as the suction nozzle moves up with respect to the cleaner main body, a compression force between the agitator and the floor decreases to increase a suction pressure for sucking air through the suction port, thereby improving cleaning performance.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings, and the same reference numerals are used to designate the same/like components and redundant description thereof will be omitted. In general, a suffix such as "module" and "unit" may be used to refer to elements or components. Use of such a suffix herein is merely intended to facilitate description of the specification, and the suffix itself is not intended to give any special meaning or function. In describing the present disclosure, if a detailed explanation for a related known function or construction is considered to unnecessarily divert the gist of the present disclosure, such explanation has been omitted but would be understood by those skilled in the art. The accompanying drawings are used to help easily understand the present disclosure and it should be understood that the present disclosure is not limited by the accompanying drawings.

It will be understood that when an element is referred to as being "connected with" another element, the element can be connected with the another element or intervening elements may also be present. In contrast, when an element is referred to as being "directly connected with" another element, there are no intervening elements present.

<FIG> is a conceptual view illustrating a state in which a suction nozzle <NUM> according to the present disclosure is mounted on a cleaner main body <NUM> of a robot cleaner. <FIG> is a bottom view illustrating a bottom surface of the cleaner main body <NUM> of <FIG>.

The robot cleaner includes the cleaner main body <NUM>, a wheel unit, and the suction nozzle <NUM>.

The cleaner main body <NUM> defines an appearance of the robot cleaner. The cleaner main body <NUM> may be formed in a flat cylindrical shape whose height is relatively small compared to its diameter.

The wheel unit may include a plurality of driving wheels <NUM> and an auxiliary wheel <NUM>. The plurality of driving wheels <NUM> is rotatably mounted on the cleaner main body <NUM> to move the robot cleaner. The plurality of driving wheels <NUM> is configured to allow the robot cleaner to travel autonomously. The plurality of driving wheels <NUM> may be provided on a left side and a right side of the cleaner main body <NUM>, respectively.

Each of the plurality of wheels <NUM> may be connected to a wheel driving motor. The wheel driving motor is configured to independently drive each of the plurality of driving wheels <NUM>. As a rotation speed of the wheel driving motor is controlled, the driving wheel <NUM> on the left side and the driving wheel <NUM> on the right side may be rotated at different speeds. As each of the driving wheels <NUM> is independently operated, steering such as left and right turning and forward and backward movements of the robot cleaner may be performed.

The auxiliary wheel <NUM> may be rotatably installed at a front side or a rear side of the cleaner main body <NUM>. The auxiliary wheel <NUM> serves to assist the driving wheels <NUM> to facilitate steering of the cleaner main body <NUM>.

An accommodating portion <NUM> may protrude upward from a lower surface of the cleaner main body <NUM>. The accommodating portion <NUM> may be formed in a rectangular box shape having a long length in a left-right direction of the cleaner main body <NUM>.

A communication hole may be formed in the accommodating portion <NUM>. The communication hole may be penetrated in a vertical direction to communicate with a floor on a traveling path of the robot cleaner.

The suction nozzle <NUM> is accommodated in the accommodating portion <NUM>. The suction nozzle <NUM> is mounted on the cleaner main body <NUM>.

A round portion <NUM> or a tapered portion may be formed at a lower front end portion and at a lower rear end portion of the suction nozzle <NUM>, respectively. In this embodiment, the round portion <NUM> is formed at the lower front end portion and at the lower rear end portion of the suction nozzle <NUM>, respectively.

With this configuration, the round portion <NUM> or the tapered portion may obtain an effect of reducing a phenomenon of a caught of the suction nozzle <NUM> due to a change in height of the floor or encountering an obstacle when moving forward or backward on the floor on the traveling path.

The suction nozzle <NUM> is mounted to be suspended from an upper portion of a supporter <NUM>.

The suction nozzle <NUM> may be mounted to be movable up and down with respect to the cleaner main body <NUM>. The suction nozzle <NUM> is mounted to be able to swing in a front-rear direction and the left-right direction.

<FIG> is an exploded view illustrating a state in which the suction nozzle <NUM> is disassembled from the cleaner main body <NUM> of <FIG>. <FIG> is a sectional front view illustrating the suction nozzle <NUM> mounted to be suspended by a ball joint, taken along line IV-IV in <FIG>. <FIG> is a sectional side view illustrating the suction nozzle <NUM> mounted to be suspended by the ball joint, taken along line V-V in <FIG>. <FIG> is a sectional rear view illustrating a ball portion accommodated in a joint housing, taken along line VI-VI in <FIG>.

The suction nozzle <NUM> is configured to suck foreign substances on a floor on a traveling path.

To this end, the suction nozzle <NUM> includes a nozzle body <NUM>, a suction port <NUM>, an agitator <NUM>, and a flow path connection portion <NUM>.

The nozzle body <NUM> extends long in the left-right direction of the cleaner main body <NUM> to be accommodated in the accommodating portion <NUM>. The nozzle body <NUM> has an accommodation space formed therein.

The suction port <NUM> is formed at a lower surface of the nozzle body <NUM>. The suction port <NUM> is disposed inside the communication hole, and is formed to communicate with a floor on a traveling path. The suction port <NUM> is configured to suck foreign substances and air on the floor on the traveling path into the nozzle body <NUM>.

The agitator <NUM> is rotatably mounted to the suction port <NUM> of the nozzle body <NUM>. Shaft support grooves may be concave at both ends of the agitator <NUM>. A rotation shaft may protrude from each of inner side surfaces of both side walls of the nozzle body <NUM>. The rotation shaft is accommodated in the shaft support grooves, and the agitator <NUM> is rotatably mounted inside both side walls of the nozzle body <NUM>.

The agitator <NUM> may be configured to be rotated by a separate motor for the agitator <NUM>.

The agitator <NUM> is formed in a cylindrical shape whose length longer than its diameter. A plurality of blades may be provided on an outer circumferential surface of the agitator <NUM>. The plurality of blades may be spaced apart from each other in a circumferential direction.

As the agitator <NUM> rotates, the plurality of blades is configured to sweep away foreign substances accumulated on or attached to the floor while sweeping up the foreign substances through the suction port <NUM>. A brush may be further provided between the plurality of blades. The brush may brush off foreign substances attached to the floor or sweep the foreign substances up through the suction port <NUM>.

An auxiliary brush <NUM> may be installed behind the suction port <NUM> of the suction nozzle <NUM>. The auxiliary brush <NUM> is disposed vertically in an up-down direction to brush off foreign substances on the floor or sweep foreign substances in a traveling direction.

The flow path connection portion <NUM> is formed at a rear upper portion of the suction nozzle <NUM> and is configured to transfer foreign substances in a sucked air to a dust collector. The flow path connection portion <NUM> may have a flow path outlet of the suction nozzle <NUM>.

The flow path connection portion <NUM> may communicate with an accommodation space of the nozzle body <NUM>. The flow path connection portion <NUM> may be formed in a manner that an area thereof gradually reduces as it goes from an upper rear portion of the nozzle body <NUM> to the flow path outlet.

As the area of the flow path connection portion <NUM> gradually decreases toward the flow path outlet, a flow velocity of the sucked air containing foreign substances may be gradually increased.

The suction nozzle <NUM> is in close contact with the floor so that foreign substances on the floor on the traveling path can be quickly sucked into the accommodation space of the nozzle body <NUM>.

The suction nozzle <NUM> is connected to be communication with a suction fan for suctioning air through the flow path connection portion <NUM> to form suction pressure of air. The suction fan is connected to a suction motor to be rotated by the suction motor.

The dust collector is mounted inside the cleaner main body <NUM>. The dust collector is connected to be in communication with the suction nozzle <NUM> and is configured to collect foreign substances in the air sucked through the suction nozzle <NUM>.

The suction nozzle <NUM> can minimize a phenomenon of being caught caused by a difference in height of the floor according to changes in an environment of the floor during traveling.

To this end, the suction nozzle <NUM> may be mounted to be movable up and down with respect to the cleaner main body <NUM>. The suction nozzle <NUM> can freely move up and down according to changes in the height of the floor.

The suction nozzle <NUM> of the present disclosure may set an initial position with respect to a height between the floor and the nozzle body <NUM> based on a hard floor such as a floor plate.

In addition, the suction nozzle <NUM> is mounted to be able to swing in the front-rear direction with respect to the traveling direction. Swing refers to a rotation within a predetermined angle range in the circumferential direction.

The suction nozzle <NUM> is configured to be able to perform a variable operation or a swing operation in which a climbing angle of the suction nozzle <NUM> is inclined, so that the suction nozzle <NUM> can actively operate even in a change on a floor having a large height difference.

The suction nozzle <NUM> of the present disclosure may be referred to as a floating nozzle. The floating nozzle refers to a nozzle capable of moving up and down according to a change in a height of a floor or capable of swinging in the front-rear direction and the left-right direction.

The floating nozzle according to the present disclosure may be applied not only to a robot cleaner but also to a cleaner that collects foreign substances in a sucked air.

The supporter <NUM> includes a plurality of ball joints and a connecting bar <NUM> in order to support the suction nozzle <NUM> to be able to move up and down or swing.

The suction nozzle <NUM> is coupled to the cleaner main body <NUM> by the ball joint. The suction nozzle <NUM> may be supported to be able to move up and down or swing with respect to the cleaner main body <NUM> by the ball joint.

The ball joint may include a first ball joint <NUM> and a second ball joint <NUM>. If necessary, but not according to the claimed invention, only one of the first ball joint <NUM> and the second ball joint <NUM> may be applied. In this embodiment, the first ball joint <NUM> and the second ball joint <NUM> are applied.

The first ball joint <NUM> is provided at the cleaner main body <NUM>. The second ball joint <NUM> is provided at the suction nozzle <NUM>.

Both the first ball joint <NUM> and the second ball joint <NUM> may include components same as each other. Accordingly, in this embodiment, the components of the first ball joint <NUM> may be commonly applied to the second ball joint <NUM>.

However, the first ball joint <NUM> and the second ball joint <NUM> are different in that they are applied to different positions. The first ball joint <NUM> may be referred to as a lower ball joint according to an arrangement relationship. The second ball joint <NUM> may be referred to as an upper ball joint.

The second ball joint <NUM> is disposed higher than the first ball joint <NUM>.

The first ball joint <NUM> may be located at a lower surface of the cleaner main body <NUM> and the second ball joint <NUM> may be located at an upper portion of the suction nozzle <NUM>.

The first ball joint <NUM> is provided inside the cleaner main body <NUM>. The first ball joint <NUM> is disposed outside the accommodating portion <NUM>. The first ball joint <NUM> may be disposed at a front center of a front surface of the accommodating portion <NUM>. The first ball joint <NUM> may be disposed in front of the suction nozzle <NUM>.

The second ball joint <NUM> is disposed at the upper portion of the suction nozzle <NUM>. The second ball joint <NUM> is disposed on an upper center of the suction nozzle <NUM>.

The first ball joint <NUM> is located at a center of the accommodating portion <NUM> and the second ball joint <NUM> is located at a center of the suction nozzle <NUM>. Here, the center of the accommodating portion <NUM> and the center of the suction nozzle <NUM> refer to a center in a lengthwise direction.

The reason the first ball joint <NUM> is located at the center of the accommodating portion <NUM> and the second ball joint <NUM> is located at the center of the suction nozzle <NUM> in the lengthwise direction is to prevent a difference in suction performance caused by a difference in heights from the floor at each end portion of the suction nozzle <NUM> when a left end portion and a right end portion of the suction nozzle <NUM> swing in the left-right direction. Accordingly, both end portions of the suction nozzle <NUM> are spaced apart from the second ball joint <NUM> by identical distances in the lengthwise direction of the suction nozzle <NUM>.

The first ball joint <NUM> may include a first joint housing <NUM>, a first ball portion <NUM>, and a first joint cover <NUM>. The first joint housing <NUM> is provided at the lower surface of the cleaner main body <NUM>. The first joint housing <NUM> is configured to guide a rolling of the first ball portion <NUM> by a guide groove formed in the first joint housing <NUM>.

The guide groove may be formed in a shape corresponding to the first ball portion <NUM>. The guide groove may be formed in a shape of a half sphere. An upper portion of the guide groove may be opened.

The first ball portion <NUM> may be formed in a shape of a sphere. The first ball portion <NUM> is accommodated inside the first joint housing <NUM>.

The first joint cover <NUM> is coupled to an upper portion of the first joint housing <NUM> to cover the upper portion of the first joint housing <NUM> that is opened. Coupling holes are formed at both sides of the first joint cover <NUM> and at both sides of the first joint housing <NUM>, so that the first joint cover <NUM> and the first j oint housing <NUM> are coupled by coupling members such as screws being inserted through the coupling holes.

A guide groove may be formed at an inner side of the first joint cover <NUM>. The guide groove of the first joint cover <NUM> may also be formed in a shape of a sphere, like the guide groove of the first joint housing <NUM>. The first joint cover <NUM> is configured to cover an upper portion of the first ball portion <NUM>. The first joint cover <NUM> is configured to prevent the first ball portion <NUM> from being separated from the first joint housing <NUM>.

The guide groove of the first joint housing <NUM> and the guide groove of the first joint cover <NUM> may be formed in a single spherical shape to surround an outer circumferential surface of the first ball portion <NUM>.

A cutout portion <NUM> may be formed in the first joint cover <NUM> to be opened toward the connecting bar <NUM>. The cutout portion <NUM> is provided to allow one side of the connecting bar <NUM> for connecting the first ball portion <NUM> and the second ball portion <NUM> to upwardly protrude from the first ball portion <NUM> in a state where the first ball portion <NUM> is accommodated in the first joint housing <NUM>, and to allow the first joint cover <NUM> to be easily assembled to the upper portion of the first joint housing <NUM>.

According to this configuration, the first ball portion <NUM> may roll in the front-rear direction with respect to the first joint housing <NUM> along the guide groove in the first joint housing <NUM>.

The second ball joint <NUM> may include a second joint housing <NUM>, the second ball portion <NUM>, and a second joint cover <NUM>. The second joint housing <NUM>, the second ball portion <NUM>, and the second joint cover <NUM> may also be configured equally or similarly to the first joint housing <NUM>, the first ball portion <NUM>, and the first joint cover <NUM>. In addition, a cutout portion <NUM> may be formed in the second joint cover <NUM> to be opened toward the connecting bar <NUM>.

However, the second joint housing <NUM> may be provided on the upper portion of the suction nozzle <NUM>, the second ball portion <NUM> may be accommodated inside the second joint housing <NUM>, and the second joint cover <NUM> may be coupled to an upper portion of the second joint housing <NUM> by a coupling member.

The first ball portion <NUM> and the second ball portion <NUM> may be connected to each other by the connecting bar <NUM>. The one side of the connecting bar <NUM> may be connected to the upper portion of the first ball portion <NUM>, and another side of the connecting bar <NUM> may be connected to an upper portion of the second ball portion <NUM>.

The connecting bar <NUM> extends from the first ball portion <NUM> to the second ball portion <NUM>. A vertical portion may be vertically extended at the one side of the connecting bar <NUM>. A horizontal portion may be horizontally extended at the another side of the connecting bar <NUM>. A curved portion may be extended at a middle of the connecting bar <NUM> by being curved at a predetermined curvature so as to connect an upper end of the vertical portion and one end of the horizontal portion. An extending portion extending downwardly from another end of the horizontal portion may be formed to connect the second ball portion <NUM> and the extending portion.

The first ball portion <NUM>, the connecting bar <NUM>, and the second ball portion <NUM> may be connected to each other in one body.

The another side of the connecting bar <NUM> may be curved in the front-rear direction and the up-down direction with respect to the one side of the connecting bar <NUM>. The connecting bar <NUM> may have an elastically deformable structure.

<FIG> and <FIG> are operation state views illustrating a state in which the suction nozzle <NUM> moves up and down with respect to the cleaner main body <NUM> in <FIG>. <FIG> is an operation state view illustrating a state in which the suction nozzle <NUM> partially moves up and down with respect to the cleaner main body <NUM> in <FIG>. <FIG> are operation state views illustrating a state in which the suction nozzle <NUM> swings in the front-rear direction with respect to the cleaner main body <NUM> in <FIG>.

<FIG> illustrates a state in which the suction nozzle <NUM> is moved up with respect to the cleaner main body <NUM>. The supporter <NUM> may support the suction nozzle <NUM> to be upwardly movable.

For example, when the cleaner main body <NUM> travels on a high floor such as a carpet, the suction nozzle <NUM> may receive an upward pressure from the floor.

An upper portion of the connecting bar <NUM> of the supporter <NUM> is configured to rotate about the first ball joint <NUM> by an upward pressure. The first ball portion <NUM> may roll counterclockwise with respect to the first joint housing <NUM>. The upper portion of the connecting bar <NUM> may be elastically deformed upwardly.

According to this configuration, the suction nozzle <NUM> may be moved up according to a height of a floor.

Referring to <FIG>, when the cleaner main body <NUM> travels on a hard floor such as a general floor, an upward pressure is released as the cleaner main body <NUM> moves to a lower general floor.

The upper portion of the connecting bar <NUM> of the supporter <NUM> moves to its original position by rotating in an opposite direction about the first ball joint <NUM>. The first ball portion <NUM> may roll clockwise with respect to the first joint housing <NUM>. The upper portion of the connecting bar <NUM> may return to its original position by an elastic force.

According to this configuration, the suction nozzle <NUM> may move down to its original position when traveling to a lowered general floor.

Referring to <FIG>, according to a position of a floor while the cleaner main body <NUM> is traveling, for example, when a left wheel between the driving wheels is located on a higher floor and a right wheel between the driving wheels is located on a lower floor, a left side and a right side of the suction nozzle <NUM> may receive different upward pressures from the floor.

The left side of the suction nozzle <NUM> may move up, and the right side of the suction nozzle <NUM> may move down (partial up-down movement) with respect to a central portion of the suction nozzle <NUM> in a lengthwise direction, that is, the second ball joint <NUM>. The suction nozzle <NUM> may rotate in a left-right direction (clockwise direction in the drawing) about the second ball joint <NUM> with respect to the cleaner main body <NUM>. The second joint housing <NUM> may roll in a left-right direction with respect to the second ball portion <NUM>. The second joint housing <NUM> may roll in a clockwise direction with respect to the second ball portion <NUM>.

Similarly, when the right wheel between the driving wheels is located on a higher floor and the left wheel between the driving wheels is located on a lower floor, the suction nozzle <NUM> may swing in the left-right direction with respect to the cleaner main body <NUM>.

When the cleaner main body <NUM> travels on an uphill slope or a downhill slope, upward pressures received by a front end portion and a rear end portion of the suction nozzle <NUM> may be different.

For example, referring to <FIG>, when the cleaner main body <NUM> travels on an uphill slope, the front end portion of the suction nozzle <NUM> receives a higher upward pressure than the rear end portion of the suction nozzle <NUM>.

The suction nozzle <NUM> may swing in a front-rear direction about the second ball joint <NUM>. The suction nozzle <NUM> may swing such that the front end portion of the suction nozzle <NUM> moves up and the rear end portion of the suction nozzle <NUM> moves down. The suction nozzle <NUM> may rotate by a rotation angle of θ1. The second joint housing <NUM> may roll in a clockwise direction about the second ball portion <NUM>.

Referring to <FIG>, when the cleaner main body <NUM> travels on a flat floor, the front end portion and the rear end portion of the suction nozzle <NUM> are in a neutral state without inclining to either side in the front-rear direction.

Meanwhile, referring to <FIG>, when the cleaner main body <NUM> descends on a downhill slope or climbs backward, the rear end portion of the suction nozzle <NUM> receives an upward pressure greater than an upward pressure that the front end portion of the suction nozzle <NUM> receives.

The suction nozzle <NUM> may swing in the front-rear direction about the second ball joint <NUM>. The suction nozzle <NUM> may swing such that the rear end portion of the suction nozzle <NUM> moves up and the front end portion of the suction nozzle <NUM> moves down.

The suction nozzle <NUM> may rotate by a rotation angle of θ2. The second joint housing <NUM> may roll in a counterclockwise direction about the second ball portion <NUM>.

Therefore, according to the present disclosure, the supporter <NUM> is provided between the cleaner main body <NUM> and the suction nozzle <NUM>, and supports the suction nozzle <NUM> with the ball joint provided at a portion connected to the cleaner main body <NUM> or to the suction nozzle <NUM> to be able to swing in the front-rear direction and the left-right direction or move up and down. And, accordingly, the suction nozzle <NUM> can actively respond to changes in the height of the floor, thereby improving travel performance.

In addition, the ball joint includes the first ball joint <NUM> at the cleaner main body <NUM> and the second ball joint <NUM> at the suction nozzle <NUM>. The first ball joint <NUM> may support the suction nozzle <NUM> to be able to move up and down, and the second ball joint <NUM> may support the suction nozzle <NUM> to be able to swing in the front-rear direction and the left-right direction.

In addition, the ball joint includes the joint housing and the ball portion. The joint housing includes the first joint housing <NUM> provided at the cleaner main body <NUM> and the second joint housing <NUM> provided at the suction nozzle <NUM>. The ball portion includes the first ball portion <NUM> accommodated in the first joint housing <NUM> and the second ball portion <NUM> accommodated in the second joint housing <NUM>. Each of the first ball portion <NUM> and the second ball portion <NUM> may perform joint motion by rolling along a guide groove formed in the first joint housing <NUM> and second joint housing <NUM>, respectively.

In addition, as the first ball portion <NUM> rolls in the front-rear direction and the left-right direction with respect to the first joint housing <NUM>, the suction nozzle <NUM> may move up and down or partially move up and down.

Moreover, as the second ball portion <NUM> rolls in the front-rear direction and the left-right direction with respect to the second joint housing <NUM>, the suction nozzle <NUM> may swing in the front-rear direction and the left-right direction by the second ball joint <NUM>.

In addition, the first ball joint <NUM> is located at the lower surface of the cleaner main body <NUM>, the second ball joint <NUM> is located at an upper portion the suction nozzle <NUM>, and the supporter <NUM> is provided with the connecting bar <NUM> extending from the first ball portion <NUM> to the second ball portion <NUM> to support the suction nozzle <NUM> with a structure of the suction nozzle <NUM> being suspended.

In addition, each of the first ball portion <NUM> and the second ball portion <NUM> is formed in a shape of a sphere, so that the suction nozzle <NUM> can easily follow a climbing angle and a height difference according to a floor environment.

<FIG> is a conceptual view illustrating a state in which a suction nozzle <NUM> according to a second embodiment of the present disclosure is mounted on a cleaner main body <NUM> of a robot cleaner. <FIG> is a bottom view illustrating a bottom surface of the cleaner main body <NUM> of <FIG>.

An accommodating portion <NUM> is provided in the cleaner main body <NUM>. The accommodating portion <NUM> is configured to accommodate the suction nozzle <NUM>. The accommodating portion <NUM> may be provided at a central portion of the cleaner main body <NUM>.

The accommodating portion <NUM> may be penetrated to communicate with a floor on which the cleaner main body <NUM> travels.

The accommodating portion <NUM> may be formed in a rectangular shape. The accommodating portion <NUM> may have a rectangular shape whose horizontal length is longer than its vertical length. In this specification, a long horizontal surface of the accommodating portion <NUM> may form a right angle with a short vertical surface of the accommodating portion <NUM>.

The accommodating portion <NUM> may be formed to be long in a direction crossing a traveling direction of the cleaner main body <NUM>.

The accommodating portion <NUM> may have a rectangular shape and may be formed to protrude upward from a lower surface of the cleaner main body <NUM>.

In this specification, front, rear, or a front-rear direction of each component are determined with respect to the traveling direction of the cleaner main body <NUM>.

In this specification, a left-right direction of each component refers to a direction crossing the traveling direction of the cleaner main body <NUM>.

For example, a lateral direction of the accommodating portion <NUM> refers to a direction crossing the traveling direction of the cleaner main body <NUM> when traveling straight. Alternatively, a front-rear direction of the accommodating portion <NUM> refers to a direction parallel to the traveling direction of the cleaner main body <NUM> when traveling straight.

<FIG> is an exploded view illustrating a state in which the suction nozzle <NUM> is disassembled from the cleaner main body <NUM> of <FIG>. <FIG> is an enlarged view of a part "VIII" in <FIG>. <FIG> is a sectional view illustrating a coupling relationship between a rail portion <NUM> of a guide holder <NUM> and the accommodating portion <NUM>, taken along line XIV-XIV in <FIG>. <FIG> is a sectional view, taken along line XV-XV in <FIG>.

The suction nozzle <NUM> is configured to suck foreign substances on a floor on the traveling path.

The suction nozzle <NUM> may be formed in a rectangular shape whose horizontal length is longer than its vertical length when viewed from above. However, the suction nozzle <NUM> is formed to have a size smaller than that of the accommodating portion <NUM> and is accommodated inside the accommodating portion <NUM>.

In a state where the suction nozzle <NUM> is accommodated inside the accommodating portion <NUM>, each of front and rear surfaces and left and right surfaces of the suction nozzle <NUM> is spaced apart from each of front and rear surfaces and left and right surfaces of the accommodating portion <NUM>.

However, in order to maximize a suction pressure and an amount of sucked air of the suction nozzle <NUM>, each of the front and rear surfaces and the left and right surfaces of the suction nozzle <NUM> may be disposed adjacent to each of front and rear surfaces and left and right surfaces of the accommodating portion <NUM>.

A round portion <NUM> or a tapered portion may be formed at a lower front end portion and at a lower rear end portion of the suction nozzle <NUM>, respectively. In this embodiment, the round portion <NUM> is formed at the lower front end portion or at the lower rear end portion of the suction nozzle <NUM>, respectively.

The suction nozzle <NUM> includes a nozzle body <NUM>, a suction port <NUM>, an agitator <NUM>, and a flow path connection portion <NUM>.

The suction port <NUM> is formed at a lower surface of the nozzle body <NUM>. The suction port <NUM> is disposed inside the accommodating portion, and is formed to communicate with a floor on a traveling path. The suction nozzle <NUM> is configured to suck foreign substances and air on the floor on the traveling path through the suction port <NUM> into the nozzle body <NUM>.

The agitator <NUM> is formed in a cylindrical shape whose length in the lateral direction of the nozzle body <NUM> is longer than its diameter. A plurality of blades may be provided on an outer circumferential surface of the agitator <NUM>. The plurality of blades may be spaced apart from each other in a circumferential direction.

As the agitator <NUM> rotates, the plurality of blades sweeps away foreign substances accumulated on or attached to the floor while sweeping up the foreign substances through the suction port <NUM>.

A brush may be further provided between the plurality of blades. The brush may brush off foreign substances attached to the floor or sweep the foreign substances up through the suction port <NUM>.

An auxiliary brush <NUM> may be installed behind the suction port <NUM> of the suction nozzle <NUM>. The auxiliary brush <NUM> is disposed vertically in the up-down direction to brush off foreign substances on the floor or sweep foreign substances in the traveling direction.

The flow path connection portion <NUM> is formed at a rear upper portion of the suction nozzle <NUM> and is configured to transfer foreign substances in a sucked air to a dust collector. The flow path connection portion <NUM> may form a flow path outlet of the suction nozzle <NUM>.

In the suction nozzle <NUM>, a lower surface of the nozzle body <NUM> may be disposed adjacent to the floor so as to rapidly suck foreign substances on the floor on the traveling path into the accommodation space of the nozzle body <NUM>.

As the outer circumferential surface of the agitator <NUM> accommodated in the suction nozzle <NUM> is disposed to be in close contact with the floor, the agitator <NUM> may receive an upward pressure from the floor according to a change in a height of the floor.

The suction nozzle <NUM> is connected to be in communication with a suction fan for suctioning air through the flow path connection portion <NUM> to form suction pressure of air. The suction fan is connected to a suction motor to be rotated by the suction motor.

The suction nozzle <NUM> is mounted to be movable up and down relative to the cleaner main body <NUM> according to a change in the height of the floor.

A supporter <NUM> includes a plurality of guide protrusions <NUM> and a plurality of guide slots <NUM>. Each of the plurality of guide protrusions <NUM> is accommodated in each of the plurality of guide slots <NUM> and moves up and down along each of the plurality of guide slots <NUM>, thereby guiding the suction nozzle <NUM> to be movable up and down with respect to the cleaner main body <NUM>. The suction nozzle <NUM> may be supported by the supporter <NUM> to be movable up and down.

The supporter <NUM> may be disposed at both end side surfaces of the suction nozzle <NUM> and at both end side surfaces of the accommodating portion <NUM>, respectively, or may be disposed at a front surface and a rear surface of the suction nozzle <NUM> and the accommodating portion <NUM>, respectively.

In this embodiment, the supporter <NUM> is disposed at both end side surfaces of the suction nozzle <NUM> and the both end side sides of the accommodating portion <NUM>, respectively.

The plurality of guide protrusions <NUM> may be provided at both end side surfaces of the suction nozzle <NUM>, and the plurality of guide slots <NUM> may be provided at both side surfaces of the accommodating portion <NUM>.

However, it is not limited thereto, and the plurality of guide protrusions may be provided at both side surfaces of the accommodating portion <NUM>, and the plurality of guide slots may be provided at both end side surfaces of the suction nozzle <NUM>.

The plurality of guide protrusions <NUM> may be formed to protrude in a lateral direction from both end side surfaces of the suction nozzle <NUM> in a lengthwise direction.

Each of the plurality of guide protrusions <NUM> may be formed in a cylindrical shape.

The plurality of guide protrusions <NUM> may be spaced apart in a front-rear direction of the suction nozzle <NUM>. The plurality of guide protrusions <NUM> may be positioned at a height same as each other. Mounting portions <NUM> may be provided at both end side surfaces of the accommodating portion <NUM> in the lateral direction, respectively. Each of the plurality of mounting portions <NUM> may be penetrated in the lateral direction of the accommodating portion <NUM>. Each of the plurality of mounting portions <NUM> may be opened upward. A plurality of guide holders <NUM> may be respectively mounted on the plurality of mounting portions <NUM>. The guide holder <NUM> may be formed in a shape of a plate.

The guide holder <NUM> may be disposed to face the both end side surfaces of the suction nozzle <NUM>.

Each of the plurality of guide holders <NUM> includes a plurality of guide slots <NUM> and a plurality of rail portions <NUM>. Both end portions of each of the plurality of rail portions <NUM> are formed to protrude from both ends of the guide holder <NUM> in a front-rear direction of the guide holder <NUM>, and may extend in a front-rear direction of the mounting portion <NUM> to surround to cover each of inner both end portions of the mounting portion <NUM>. Both end portions of each rail portion <NUM> may be disposed to overlap inner end portions of the mounting portion <NUM> in a thickness direction.

Each of the plurality of rail portions <NUM> may extend in a vertical direction. Slide grooves each may be formed at an inner side of the rail portion <NUM>. Each of the plurality of rail portions <NUM> may be formed in a U-shape.

The slide grooves each formed at an inner side of the rail portion <NUM> may be opened toward inner end portions of the mounting portion <NUM> at both inner end portions of the guide holder <NUM> in the front-rear direction.

An inner front end portion and an inner rear end portion of the mounting portion <NUM> are respectively accommodated in the slide groove of the rail portion <NUM>, and each of the plurality of rail portions <NUM> may be vertically slidably coupled to the inner front end portion and the inner rear end portion of the mounting portion <NUM>, respectively.

The guide holder <NUM> may be disposed perpendicular to a protruding direction of the plurality of guide protrusions <NUM>. The plurality of guide slots <NUM> is formed to penetrate in a thickness direction of the guide holder <NUM>, so that the guide protrusions <NUM> pass through the guide holder <NUM> through the guide slots <NUM>.

Each of the plurality of guide slots <NUM> may extend vertically in an up-down direction of the guide holder <NUM>. The guide slot <NUM> may be formed in a rectangular shape whose vertical length in the up-down direction is longer than its horizontal length in the front-rear direction.

A horizontal length of the guide slot <NUM> may be formed to correspond to a diameter of the guide protrusion <NUM>. A vertical length of the guide slot <NUM> may be formed to be longer than the diameter of the guide protrusion <NUM>.

The guide protrusion <NUM> is accommodated in the guide slot <NUM> to be moved vertically along the guide slot <NUM>.

An upper end portion and a lower end portion of the guide slot are formed in a semicircular shape to surround an upper semicircle or a lower semicircle in an outer circumferential surface of the guide protrusion to limit a movable range in an up-down direction of the guide protrusion.

According to this configuration, a lower end of the guide slot <NUM> may limit a lowest downwardly movable height of the guide protrusion <NUM>, and an upper end of the guide slot <NUM> may limit a highest upwardly movable height of the guide protrusion <NUM>.

When the guide protrusion <NUM> is brought into contact with the upper end of the guide slot <NUM>, the guide protrusion <NUM> stops moving up, and the guide protrusion <NUM> is positioned at a highest point.

When the guide protrusion <NUM> is brought into contact with the lower end of the guide slot <NUM>, the guide protrusion <NUM> stops moving down, and the guide protrusion <NUM> is positioned at a lowest point.

The guide protrusion <NUM> may linearly move in the up-down direction between the highest point and the lowest point along the guide slot <NUM>.

According to this configuration, when the agitator <NUM> receives an upward pressure from the floor as the height of the floor increases, the guide protrusion <NUM> vertically moves upward along the guide slot <NUM>, and the suction nozzle <NUM> moves up with respect to the cleaner main body <NUM>.

On the other hand, when the agitator <NUM> moves down to the floor by gravity as the height of the floor decreases, the guide protrusion <NUM> vertically moves downward along the guide slot <NUM>, and the suction nozzle <NUM> moves down with respect to the cleaner main body <NUM>.

Therefore, according to the present disclosure, although the driving wheels <NUM> sink when the cleaner main body <NUM> travels on a soft floor such as a carpet, the guide ribs <NUM> move up along the guide slits <NUM> by a height of the floor when the agitator <NUM> of the suction nozzle <NUM> is brought into contact with the floor, and the suction nozzle <NUM> moves up with respect to the cleaner main body <NUM> by the height of the floor, so that travel performance can be improved by preventing a phenomenon of being caught by the floor.

In addition, as the suction nozzle <NUM> moves up with respect to the cleaner main body <NUM>, a compression force between the agitator <NUM> and the floor decreases to increase a suction pressure for sucking air through the suction port, thereby improving cleaning performance.

<FIG> is a conceptual view illustrating a state in which a suction nozzle <NUM> according to a third embodiment of the present disclosure is mounted on a cleaner main body <NUM>. <FIG> is a bottom view illustrating a bottom surface of the cleaner main body <NUM> to which the suction nozzle <NUM> is mounted in <FIG>. <FIG> is an exploded view illustrating a state in which the suction nozzle <NUM> is disassembled from the cleaner main body <NUM> of <FIG>. <FIG> is an enlarged view of a part "XIX" in <FIG>. <FIG> is a sectional view, taken along line XX-XX in <FIG>. <FIG> is a sectional view, taken along line XXI-XXI in <FIG>. <FIG> is a sectional view, taken along line XXII-XXII in <FIG>.

This embodiment is different from the supporter <NUM> of the second embodiment (<FIG>) described above in that a supporter <NUM> is disposed on a front surface and a rear surface of the accommodating portion <NUM> and on a front surface and a rear surface of the suction nozzle, respectively. Other components are the same or similar to those of the second embodiment, and thus, redundant descriptions will be omitted and different components will be mainly described.

The supporter <NUM> includes a plurality of guide ribs <NUM> and a plurality of guide slits <NUM>.

The plurality of guide ribs <NUM> may be formed to protrude in a front-rear direction from a front surface and a rear surface of the suction nozzle <NUM>, respectively.

Each of the plurality of guide ribs <NUM> may be formed in a rectangular plate shape. Each of the plurality of guide ribs <NUM> may extend in a vertical direction.

Each of the plurality of guide ribs <NUM> may be formed in a rectangular shape whose vertical length in the vertical direction is longer than its horizontal length in the front-rear direction.

The plurality of guide ribs <NUM> may be disposed to be spaced apart in a lateral direction of the suction nozzle <NUM> on the front surface of the suction nozzle <NUM>.

The plurality of guide ribs <NUM> may be disposed to be spaced apart in the lateral direction of the suction nozzle <NUM> on the rear surface of the suction nozzle <NUM>.

The plurality of guide ribs <NUM> is disposed close to both ends in the lateral direction of the suction nozzle <NUM> on the front surface or on the rear surface of the suction nozzle <NUM> to stably support a vertical movement of the suction nozzle <NUM>.

The plurality of guide ribs <NUM> may be formed to protrude in parallel from a front vertical plane and a rear vertical plane of the suction nozzle <NUM>, respectively.

A plurality of guide holders <NUM> may be formed to protrude from a front surface and a rear surface of the accommodating portion <NUM> of the cleaner main body <NUM> in a direction same as a protruding direction of the plurality of guide ribs <NUM>.

The guide holder <NUM> may extend perpendicularly upward in a height direction of the accommodating portion <NUM>. The guide holder <NUM> may be formed in a rectangular shape whose vertical length is longer than its horizontal length.

The plurality of guide holders <NUM> may be spaced apart from each other in a lateral direction of the accommodating portion <NUM> on the front surface and the rear surface of the accommodating portion <NUM>, respectively. The guide holders <NUM> may be disposed at the accommodating portion <NUM> to face the guide ribs <NUM>.

A guide slit <NUM> is formed at an inner side of the guide holder <NUM>. The guide slit <NUM> may be formed in a rectangular shape whose vertical length is longer than its horizontal length.

A width of the guide slit <NUM> may correspond to a thickness of the guide rib <NUM>. The guide slit <NUM> may be formed to be concave in the guide holder <NUM>. Accordingly, the guide rib <NUM> is accommodated in the guide slit <NUM>, and the guide holder <NUM> surrounds both side surfaces of the guide rib <NUM>.

A vertical length of the guide slit <NUM> extends longer than a vertical length of the guide rib <NUM> in the vertical direction.

The guide rib <NUM> may be accommodated inside the guide holder to be linearly moved in the vertical direction along the guide slit <NUM>.

A lower stopper <NUM> may be provided at a lower portion of the guide holder <NUM>. The lower stopper <NUM> may extend horizontally from a lower surface of the guide holder <NUM> to cover a lower portion of the guide slit <NUM>. The lower stopper <NUM> is configured to limit a lowest point to which the guide rib <NUM> moves down along the guide slit <NUM>.

An upper portion of the guide slit <NUM> may be opened.

A plurality of upper stoppers <NUM> may be respectively mounted on upper portions of the plurality of guide holders <NUM> to cover upper portions of the guide slits <NUM>.

Each of the plurality of upper stoppers <NUM> may include a stopper body <NUM> and a plurality of hooks <NUM>. The stopper body <NUM> may be formed in a rectangular shape whose horizontal length in the lateral direction of the accommodating portion <NUM> is longer than its vertical length in a vertical direction of the accommodating portion <NUM>. The stopper body <NUM> may extend horizontally in the lateral direction of the accommodating portion <NUM>.

The stopper body <NUM> may be disposed to cover an upper end portion of the guide holder <NUM>.

The stopper body <NUM> has the horizontal length in the lateral direction extending longer than a horizontal length in the lateral direction of the guide holder <NUM>, and both end portions of the stopper body <NUM> protrude from both side surfaces of the guide holder <NUM> in the lateral direction of the accommodating portion <NUM>.

When the stopper body <NUM> is viewed from a top of the accommodating portion <NUM>, the stopper body <NUM> may be formed in a rectangular shape whose horizontal length in the lateral direction is longer than its vertical length in the front-rear direction.

The vertical length of the stopper body <NUM> may be longer than a vertical length of the guide holder <NUM>. One end portion of the stopper body <NUM> in the front-rear direction may protrude inward to the accommodating portion <NUM>.

A guide groove may be formed at an inner side of the stopper body <NUM>. The guide groove is formed in a shape corresponding to the guide rib <NUM>, and is configured to accommodate an upper end portion of the guide rib <NUM> when the guide rib <NUM> moves up.

The plurality of hooks <NUM> may extend to protrude downward from both sides of the stopper body <NUM> with the guide holder <NUM> interposed therebetween. At a lower end of each of the plurality of hooks <NUM>, a locking portion <NUM> may be formed to protrude toward the accommodating portion <NUM> in a wedge shape.

A plurality of coupling holes <NUM> at the accommodating portion <NUM> may be formed to face the locking portion <NUM> of the hook <NUM>. Since each of the locking portions <NUM> of each of the hooks <NUM> is fitted into the coupling hole <NUM>, the upper stopper <NUM> may be fixed to the accommodating portion by the hook <NUM>.

According to this configuration, the upper stopper <NUM> may limit a highest point of the guide rib <NUM> when the guide rib <NUM> moves upward along the guide slit <NUM>.

Therefore, according to the present disclosure, although driving wheels <NUM> sink when the cleaner main body <NUM> travels on a soft floor such as a carpet, the guide ribs <NUM> move up along the guide slits <NUM> by a height of the floor when an agitator <NUM> of the suction nozzle <NUM> is brought into contact with the floor, and the suction nozzle <NUM> moves up with respect to the cleaner main body <NUM> by the height of the floor, so that travel performance can be improved by preventing a phenomenon of being caught by the floor.

In addition, as the suction nozzle <NUM> moves up with respect to the cleaner main body <NUM>, a compression force between the agitator <NUM> and the floor decreases to increase a suction pressure for sucking air through a suction port, thereby improving cleaning performance.

The suction nozzle <NUM> of the present disclosure may set an initial position with respect to a height between a floor and the nozzle body <NUM> based on a hard floor such as a floor plate.

The suction nozzle <NUM> of the present disclosure may be referred to as a floating nozzle. The floating nozzle refers to a nozzle that moves up and down according to a change in a height of a floor.

Claim 1:
A robot cleaner, comprising:
a cleaner main body (<NUM>) configured to travel autonomously;
a suction nozzle (<NUM>) mounted to be able to move up and down or swing with respect to the cleaner main body (<NUM>); and
a supporter (<NUM>) supporting the suction nozzle (<NUM>) to be able to move up and down or swing;
characterized in that:
the supporter (<NUM>) comprises a plurality of ball joints (<NUM>, <NUM>) and is coupled to the cleaner main body (<NUM>) and the suction nozzle (<NUM>), respectively, by the plurality of ball joints to support the suction nozzle (<NUM>) to be able to move up and down or swing in a front-rear direction.