GB2415609A

GB2415609A - Multi port nozzle unit and an associated vacuum cleaner

Info

Publication number: GB2415609A
Application number: GB0427492A
Authority: GB
Inventors: Jong-Kook Lim; Keon-Soo Choi
Original assignee: Samsung Gwangju Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2004-07-01
Filing date: 2004-12-15
Publication date: 2006-01-04
Anticipated expiration: 2024-12-15
Also published as: KR100642076B1; FR2872401A1; ITTO20050042A1; RU2281680C1; ES2273545A1; ITTO20050039A1; CN1714730A; GB0427492D0; AU2004237801B2; JP2006015112A; KR20060002083A; AU2004237801A1; US20060000053A1; RU2004137457A; ES2273545B1; GB2415609B; DE102004061856A1

Abstract

A nozzle (200, fig 2) for a vacuum cleaner comprises upper and lower housings (210, 222), a plurality of suction ports (226, 228) formed in the lower housing, and a plurality of suction paths (230, 232) formed in the upper and lower housings to guide the air drawn in through the suction ports. With this arrangement, the efficiency of cleaning at the lateral sides of the nozzle unit (200) can be enhanced, and thus a wide area can be efficiently cleaned. An associated vacuum cleaner is also disclosed.

Description

Nozzle Unit for a Vacuum Cleaner This invention relates to a vacuum

cleaner, and in particular to a nozzle unit for a vacuum cleaner for drawing in dust from a surface to be cleaned.

A vacuum cleaner draws in dust and other contaminants (hereinafter referred to as "dust") from a surface to be cleaned using a suction force generated by a vacuum source mounted in a main body thereof. As is known, a vacuum cleaner comprises a cleaner body containing a motor for generating a vacuum force, a nozzle unit facing a surface to be cleaned to draw in dust from that surface, and an extension path for guiding the dust drawn in by the nozzle unit to the cleaner body. The extension path may comprise an extension tube connector detachably connected to the nozzle unit, an extension tube connected to the extension tube connector, and a suction hose between the cleaner body and the extension tube.

Figures IA and 1B are perspective views schematically showing the bottom and top sides, respectively, of a known nozzle unit having an upper housing 10 and a lower housing 11. A suction port 14, for drawing in dust from a surface to be cleaned, is formed in the lower housing 11. The lower housing 11 also has respective dust-moving channels 12 formed at opposite sides of the suction port 14. The channels 12 terminate adjacent to the opposite sides S of the lower housing 11, and direct dust from positions adjacent to those sides towards the suction port 14.

This nozzle unit is provided with a single suction path for transmitting the vacuum force by F 2 which dust can be drawn in. As a result, the vacuum is most intense at the centre C of the suction port 14, but decreases away from the centre C. Therefore, cleaning efficiency is good at the centre C of the suction port 14, but degrades towards the sides S of the nozzle unit. Accordingly, this nozzle unit is not efficient in cleaning large surface areas. In addition, since the top of the nozzle unit is usually made from an opaque material, it is impossible to determine if dust is trapped in the nozzle unit. It is, therefore, necessary to check the entire suction path of the vacuum cleaner in order to find the position at which the suction path is obstructed. A nozzle unit that provides a more uniform vacuum, and which allows for a seethrough inspection of its suction path would be an improvement

over the prior art.

An aim of the invention is to provide an improved nozzle unit allowing efficient cleaning of a surface of large area, and to provide a vacuum cleaner having the same.

Another aim of the invention is to provide an improved nozzle unit allowing a visual check, from the outside of the nozzle unit, of its suction path, and to provide a vacuum cleaner having the same.

The present invention provides a nozzle unit comprising: upper and lower housings coupled to each other, the lower housing having a central part between first and second sides; a plurality of suction ports formed in the lower housing; and a plurality of suction paths formed in at least one of the upper and lower housings to guide air drawn in from the plurality of suction ports.

Advantageously, the suction ports comprise a first suction port and a second suction port which are spaced from each other, and wherein the paths comprise a first suction path and a second suction path, which communicate respectively with the first suction port and the second suction port. Preferably, the first suction port is formed between the central part and one side of the lower housing, and the second suction port is formed between the central part and the other side of the lower housing.

The nozzle unit may further comprise: lateral channels formed in the bottom surface of the lower housing and opening through the sides of the lower housing, the lateral channels being operatively coupled to the first and second suction ports; a central dust-moving channel formed in the bottom surface of the lower housing in such a manner that the first and second suction ports are fluidly coupled to each other; 1 5 and one or more front dust-moving channels formed in the bottom surface of the lower housing, and extending through the front of the lower housing in such a manner that the front end of the lower housing is fluidly coupled to the first and second suction ports.

In a preferred embodiment, the upper housing comprises a suction path cover defining the tops of the first and second suction paths and mounted on the lower housing, and a top cover located over the suction path cover and connected to the lower housing.

Preferably, the suction path cover is arch-shaped when viewed from a direction perpendicular to the flow direction of the drawn-in air.

A first joint part may be formed along the edge of the suction path cover, and a second joint part may be formed in the lower housing to correspond to the first joint part, the second joint part being engageable with the first joint part in an airtight manner. The upper and lower housings are, therefore tightly engagable with each other to minimise suction force losses caused by air leaks between the housings.

Advantageously, the first and second joint parts are formed with complementary stepped portions. Preferably, the first joint part is a connection rib, and the second joint part is a complementary connection recess.

Conveniently, the nozzle unit further comprises: a compression rib formed on the bottom surface of the top cover; and a guide rib formed on the top surface of the suction path cover, the guide rib having a complementary shape to that of the compression rib so that the compression rib can engage with the guide rib.

Preferably, the suction path cover is made of a transparent material so that the first and second suction paths can be inspected for obstructions from the outside. Consequently, it is not needed to check the entire suction path of the vacuum cleaner when dust might be caught in the nozzle unit.

A fluid guide rib may be formed in the first and second paths so as to guide the drawn-in air towards a vacuum source, while preventing swirling of the drawn-in air, whereby the loss of suction force can be further prevented. ! Advantageously, the flow guide rib comprises: a first flow guide rib part formed in the first path; and a second guide rib part formed in the second path in such a manner that one end of the second guide rib part is connected to one end of the first flow guide rib.

Preferably, each of the first and second flow guide rib parts is formed with a guide surface having a predetermined curvature.

In a preferred embodiment, the top cover is formed with a cut-out section having a shape corresponding to that of'the suction path cover, and the suction path cover is exposed to the outside through the cut-out section.

I'he invention will now be described in greater detail, by way of example, with reference to the drawings, in which: Figures I A and l B are perspective views schematically showing the top and bottom sides of a conventional nozzle unit; Figure 2 is a perspective view schematically showing a vacuum cleaner constructed according to the invention; Figure 3 is an exploded perspective view of the nozzle unit of the vacuum cleaner of Figure 2; Figure 4 is a perspective view schematically showing the bottom side of a lower housing of the nozzle unit of Figure 3; Figure S is a perspective view schematically showing a top cover of the nozzle unit of Figure 3; Figure 6 is a cross-section taken on the line VI-VT of Figure 3; Figure 7 is a cross-section taken on the line VII-VII of Figure 2; Figure 8 is a perspective view schematically showing the bottom side of the suction path; Figure 9 is a partially broken-away, perspective view schematically showing a swirling air stream as it is drawn into the nozzle unit, this view omitting the flow guide rib of the nozzle unit; Figure 10 is a partially broken-away perspective view schematically showing air streams drawn into the nozzle unit, this view showing the flow guide rib; and Figure 11 is a cross-sectional view, similar to that of Figure 7, showing a modified arrangement.

Referring to the drawings, Figure 2 shows a vacuum cleaner having a cleaner body 100 containing a vacuum source (not shown), a nozzle unit 200 for drawing in dust from a surface to be cleaned using a suction force generated by the vacuum source, and an extension path 110 connected to the nozzle unit and to the cleaner body. Dust is drawn in through the nozzle unit 200 to the cleaner body 100 through the extension path 110.

The extension path 110 comprises an extension tube connector 116, one end of which has a rotatable articulated joint or knuckle 118 that rotatably connects to the nozzle unit 200. A first end of an extension tube 114 is connected to the second (or opposite) end of the extension tube connector 116. One end of a suction hose 112 is connected to the extension tube 114, the other end of the suction hose being connected to the cleaner body 100. With this arrangement, dust-carrying air is drawn in through the nozzle unit 200 and moves to the cleaner body 100 via the extension tube connector 116, the extension tube 114, and the suction hose 112.

Figure 3 shows that the nozzle unit 200 comprises a moulded upper housing 210 defining the upper part of the nozzle unit, and a moulded lower housing 222 defining the lower part of the nozzle unit.

The upper housing 210 has a suction path cover 250 which, when assembled, is seated on a first joint part 234 formed by the lower housing 222. The upper housing 210 also has a top cover 212 positioned over the suction path cover 250, the top cover being connected to the lower housing 222.

The suction path cover 250 is generally arch-shaped, when viewed in the direction perpendicular to the direction of flow of the drawn-in air, and is made of a transparent plastics material so that the flow of drawn-in dust can be viewed from the outside to check whether dust gets trapped. The plastics material may be polycarbonate or ABS (acrylonitrile-butadiene-styrene terpolymer).

lithe top cover 212 is connected to the lower housing 222 by means ol a plurality of coupling holes 238 and a plurality of fasteners 236. The fasteners 236 can be threaded screws or threaded bolts, both of which are known to those of ordinary skill in the art. The suction path cover 250 extends through the top cover 212 and through a cut-out section 214 formed in the top cover 212. In addition, the rear end of the lower housing 222 and the rear end of the top cover 212 are provided with lower and upper extension tube connector mounts 224 and 264 in such a manner that the rotatable articulation joint 118 of the extension tube connector 116 can be rotatably seated.

The lower housing 222 is formed with first and second suction ports 226 and 228 laterally spaced *om each other. Each of the suction ports 226 and 228 is located between the central part C and the respective opposite side S of the lower housing 222. The suction ports 226 and 228 are preferably located substantially mid-way between the central part C 1 0 and the opposite sides S. With such an arrangement, the suction force generated by the vacuum source can be more evenly applied over the width of the nozzle unit 200, so that wide surfaces can be more effectively cleaned.

The lower housing 222 includes first and second suction paths 230 and 232 fluidly 1 5 communicating with the first and second suction ports 226 and 228, respectively. The first and second suction paths 230 and 232 are air conduits and spaces, formed in such a manner that the lower housing 222 defines the bottom surface 231 of the suction paths and the path cover 250 defines the top surfaces of the suction paths when the path cover is connected to the first joint part 234 formed in the lower housing 222. A flange 258 is formed along the edge of the path cover 250, and this flange is described in detail below.

Figure 4 shows that the bottom side of the lower housing 222 comprises lateral dust- moving channels 240 formed respectively one at each of the two opposite sides S of the lower housing, these channels being connected to the suction ports 226 and 228 so as to 9 allow dust located adjacent to the opposite sides S of the nozzle unit 200 to be drawn in and moved to the suction ports. Front dust-moving channels 244 are also formed in the lower housing 222 to allow dust in front of the nozzle unit 200 to be drawn in and moved to the suction ports 226 and 228 through central dustmoving channels 242 formed between the first suction port 226 and the second suction port 228.

lithe central dust-moving channels 242 are recessed from the bottom surface of the lower housing 222, and are located between the first and second suction ports 226 and 228. As shown, the central dust-moving channels 242 are separated from each other by a rib 246.

The separate central dust-moving channels 242 on the left and right sides of the rib 246 are connected to the first suction port 226 and to the second suction port 228, respectively.

With this arrangement, the dust drawn in from the central part C of the nozzle unit 200 is drawn into the suction ports 226 and 228 through the central dust-moving channels 242.

Figure 5 shows that the top cover 212 has a cut-out section 214 formed therethrough, through which the suction path cover 250 extends so that it is externally exposed. A compression rib 216 is formed around the cut-out section 214 in such a manner that the compression rib projects downwardly. The compression rib 216 is formed in a shape similar to that of the cutout section 214, and is seated on a guide rib 254 (see Figure 6) formed on the top surface of the suction path cover 250.

Figure 6 shows the cross-section of the path cover 250 taken in the direction perpendicular to the direction of flow of the drawn-in air, and shows that the guide rib 254 is formed to project upwardly along the edge of the suction path cover 250. The guide rib 254 is formed in a shape corresponding to the compression rib 216 (see Figure 5), and the compression rib is seated against the guide rib when the top cover 212 is coupled to the lower housing 222. A second joint part 262 is formed at the end of the bottom surface of the suction path cover 250. In this embodiment, the second joint part 262 is formed in a stepped shape, and engages with the first joint part 234 in an airtight manner. The first joint part 234 will be described below.

Figure 7 shows that the first joint part 234 is formed in a stepped shape in the lower housing 222, and the second joint part 262 is also formed in a stepped shape along the edge of the bottom surface of the suction path cover 250 to complement the first joint part. As the first joint part 234 and the second joint part 262 are engaged with each other, the suction path cover 250 (see Figure 3) and the lower housing 222 can be connected to one another in an airtight manner. Accordingly, the airtight state of the path can be maintained, and so loss of suction force can be prevented.

The guide rib 254 is formed along the edge of the top surface of the path cover 250 and projects upwardly therefrom. The compression rib 216 is formed on the bottom surface of the top cover 212, and has a shape corresponding to that of the guide rib 254. With this arrangement, the compression rib 216 compresses the flange 258 formed on the suction path cover 250 (see Figure 3). Therelore, the first joint part 234 and the second joint part 262 are compressed against each other by the compression rib 216, and so are more securely engaged with each other. With this engagement, airtightness can be more securely maintained. Meanwhile, the compression rib 216 is seated on the guide rib 254 while compressing the flange 258. Therefore, the top cover 213 can be prevented *om moving on the suction path cover 250.

Figure 8 shows a flow guide rib 270 formed at the central part of the front end of the inner wall of the suction path cover 250. The guide rib 270 comprises a first flow guide rib part 274 extending from the central front end of the suction path cover 250 towards the first suction port 226 (see Figure 3), and a second flow guide rib part 278 extending towards the second suction port 228 (see Figure 3). The front sides of the flow guide rib parts 274 and 278 are provided with guide surfaces 280 having a predetermined curvature, so that air drawn in along the guide surfaces changes its direction in such a manner that the drawn-in air is rotated or conducted to the vacuum source. The guide surfaces 280 have an optimum curvature, by which a swirling flow generated at the junction of the first and second paths 230 and 232 is reduced as much as possible. The optimum curvature of the guide surfaces 280 will depend on the airflow rate and other parameters, and is best obtained through by experimentation. By experimentally optimising the flow guide rib parts 274 and 278, the suction force loss caused by air flow direction change can be minimised. In the embodiment shown, the flow guide rib 270 is formed on the suction path cover 250. Since the flow guide rib 270 serves as means for changing the flow direction of drawn-in air, it may be alternatively provided in the lower housing 222 (see Figure 3). Alternatively, both the lower housing 222 and the suction path cover 250 may be provided a respective flow guide rib 270.

Figure 9 shows the swirling phenomena of the air drawn in into the nozzle unit 200, when the nozzle unit 200 is not provided with a flow guide rib 270, and Figure 10 schematically shows the drawn-in air streams when the nozzle unit is provided with a flow guide rib.

Referring to Figure 9, the air drawn in into the first and second suction ports 226 and 228 moves along the first and second paths 230 and 232. The air streams moving along the first and second paths 230 and 232 collide with each other at the junction of the two paths, because the flow directions thereof are not smoothly changed. Owing to such collision, a swirling turbulent flow is generated at the junction. The swirling turbulent flow not only reduces the flow rate of the drawn-in air, but also results in loss of suction force.

Referring to Figure 10, when the nozzle unit 200 is provided with a flow guide rib 270, the air streams drawn in through the first and second suction ports 226 and 228 move along the first and second paths 230 and 232, and their flow directions are smoothly changed at the junction of the two paths by the flow guide rib 270. Consequently, the swirling flow generated at the junction can be significantly reduced, thereby reducing suction loss.

1 5 Figure 11 shows that the first and second joint parts 234 and 262 consist respectively of a rib and a groove in order to further enhance the airtightness of the path. In addition, it would also be possible to provide further means for maintaining airtightness, such as a rubber seal.

The nozzle unit 200 described above is assembled in the following manner: Firstly, the rotatable articulated joint 118 of the extension tube connector 116 is connected to the lower side extension tube connector mount 224 formed at the rear end of the lower housing 222, and then the suction path cover 250 is seated on the lower housing 222. The seating is performed by coupling the first and second joint parts 234 and 262 (see Figure 7).

Next, the top cover 212 is put over the lower housing 222 and the suction path cover 250.

At this time, the articulated joint 118 of the extension tube connector 116 is connected to the upper side extension tube connector mount 264 formed on the top cover 212, so that the extension tube connector is pivotally connected to the upper housing 210.

Then, the coupling elements (such as screws) are fitted into the coupling holes 238 formed in the top cover 212 and in the lower housing 222. At this time, the compression rib 216 (see Figure 5) formed on the bottom surface of the cut-out section 214 of the top cover is engaged with the guide rib 254 (see Figure 6) formed at the end of the flange 258, simultaneously compressing the flange. Therefore, the suction path cover 250 is safely connected while maintaining airtightness.

In this embodiment, the suction path cover 250 is installed in the nozzle unit 200 and is positioned between the top cover 212 and the lower housing 222. However, it is also possible to form the suction path cover 250 integrally with the top cover 212.

Because two suction paths 230 and 232 are formed in the nozzle unit 200, the efficiency for cleaning at the lateral sides of the nozzle unit is enhanced. Wide surfaces can, therefore, be efficiently cleaned.

in addition, by forming the suction path cover 250 of a transparent material, dust drawn into, and flowing through, the nozzle unit 200 can be visually checked from the outside.

Therefore, there is no need to cheek the entire suction path of the vacuum cleaner to solve a problem caused by dust trapped in the nozzle unit 200.

Moreover, the flow guide rib 270 formed in the suction path reduces the swirling phenomena of drawn-in air, thereby reducing the loss of suction force.

As the first joint part 234 engages the second joint part 262, the suction path cover 250 is seated on the lower housing 222, and the top cover 212 compresses the first and second joint parts. As a result, assembly is facilitated and airtightness can be securely maintained.

Owing to such airtightness, a loss of suction force can be prevented.

While certain embodiments of the present invention have been shown and described in order to exemplify the principle of the present invention, the present invention is not limited to those embodiments. It will be understood that various modifications and changes can be made by those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, it should be considered that such modifications, changes and equivalents thereof are all included within the scope of the present invention.

Claims

Claims 1. A nozzle unit comprising: upper and lower housings coupled to

each other, the lower housing having a central part between first and second sides; a plurality of suction ports formed in the lower housing; and a plurality of suction paths formed in at least one of the upper and lower housings to guide air drawn in from the plurality of suction ports.
2. A nozzle unit as claimed in claim 1, wherein the suction ports comprise a first suction port and a second suction port which are spaced from each other, and wherein the paths comprise a first suction path and a second suction path, which communicate respectively with the first suction port and the second suction port.
3. A nozzle unit as claimed in claim 2, wherein the first suction port is formed between the central part and one side of the lower housing, and the second suction port is formed between the central part and the other side of the lower housing.
4. A nozzle unit as claimed in claim 2 or claim 3, further comprising: lateral channels formed in the bottom surface of the lower housing and opening through the sides of the lower housing, the lateral channels being operatively coupled to the first and second suction ports; a central dust-moving channel formed in the bottom surface of the lower housing in such a manner that the first and second suction ports arc fluidly coupled to each other; and one or more front dust-moving channels formed in the bottom surface of the lower housing, and extending through the front of the lower housing in such a manner that the front end of the lower housing is fluidly coupled to the first and second suction ports.
5. A nozzle unit as claimed in any one of claims 2 to 4, wherein the upper housing comprises: a suction path cover defining the tops of the first and second suction paths and mounted on the lower housing; and a top cover located over the suction path cover and connected to the lower housing.
6. A nozzle unit as claimed in claim 5, wherein the suction path cover is arch- shaped when viewed from a direction perpendicular to the flow direction of the drawn-in 1 5 air.
7. A nozzle unit as claimed in claim 6, further comprising: a first joint part formed along the edge of the suction path cover; and a second joint part formed in the lower housing to correspond to the first joint part, the second joint part being engageable with the first joint part in an airtight manner.
8. A nozzle unit as claimed in claim 7, wherein the first and second joint parts are formed with complementary stepped portions.
9. A nozzle unit as claimed in claim 7 or claim 8, wherein the first joint part is a connection rib, and the second joint part is a complementary connection recess.
10. A nozzle unit as claimed in any one of claims 7 to 9, further comprising: a compression rib formed on the bottom surface of the top cover; and a guide rib formed on the top surface of the suction path cover, the guide rib having a complementary shape to that of the compression rib so that the compression rib can engage with the guide rib.
11. A nozzle unit as claimed in any one of claims 5 to 10, wherein the suction path cover is made of a transparent material.
12. A nozzle unit as claimed in any one of claims 2 to 11, further comprising a now guide rib in the first and second paths, by means of which the drawn-in air can be guided towards a vacuum source.
13. A nozzle unit as claimed in claim 12, wherein the flow guide rib comprises: a first flow guide rib part formed in the first path; and a second guide rib part formed in the second path in such a manner that one end of the second guide rib part is connected to one end of the first flow guide rib.
14. A nozzle unit as claimed in claim 13, wherein each of the first and second flow guide rib parts is formed with a guide surface having a predetermined curvature.
15. A nozzle unit as claimed in any one of claims 5 to 14, wherein the top cover is formed with a cut-out section having a shape corresponding to that of the suction path cover, and the suction path cover is exposed to the outside through the cut-out section.
16. A vacuum cleaner comprising: a cleaner body housing a vacuum source; a vacuum extension path having first and second ends, the first end being connected to the cleaner body in such a manner that air can pass through the extension path to the vacuum source; and a nozzle unit connected to the second end of the vacuum extension path, the nozzle unit having upper and lower housings, a plurality of suction ports formed in the lower housing, and a plurality of suction paths formed in the upper and lower housings to guide the air drawn in from the suction ports.
17. A vacuum cleaner as claimed in claim 16, wherein the suction ports comprise a first suction port and a second suction port spaced from each other, and the suction paths comprise a first path and a second path that communicate respectively with the first suction port and the second suction port.
18. A vacuum cleaner as claimed in claim 17, wherein the upper housing comprises: a suction path cover defining the tops of the first and second suction paths and connected to the lower housing; and a top cover located over the suction path cover and connected to the lower housing.
19. A vacuum cleaner as claimed in claim 18, wherein the nozzle unit further comprises: a first joint part formed along the edge of the suction path cover; and a second joint part formed in the lower housing to correspond to the first joint part, the second joint part being engageable with the first joint part.
20. A vacuum cleaner nozzle unit substantially as hereinbefore described with reference to, and as illustrated by, Figures 2 to 10 or Figures 2 to 10 as modified by Figure I I.
21. A vacuum cleaner substantially as hereinbefore described with reference to, and as illustrated by, Figures 2 to 10 or Figures 2 to 10 as modified by Figure 11.

20. A vacuum cleaner as claimed in claim 19, wherein the nozzle unit further comprises: a compression rib formed on the bottom surface of the top cover; and a guide rib formed on the top surface of the suction path cover, the guide rib having a complementary shape to that of the compression rib.

21. A vacuum cleaner as claimed in claim 19 or claim 20, wherein the nozzle unit further comprises: a flow guide rib in the first and second paths, by means ol which so that the drawn-in air can be guided towards a vacuum source.

Amendments to the claims have been filed as follows 1. A nozzle unit comprising: upper and lower housings coupled to each other, the lower housing having a central part between first and second sides; a plurality of suction ports formed in the lower housing; and a plurality of suction paths formed in at least one of the upper and lower housings to guide air drawn in from the plurality of suction ports; wherein the upper housing comprising a suction path cover defining the tops of the suction paths and mounted on the lower housing; and a top cover located over the suction path cover and connected to the lower housing, the suction path cover extending through an aperture formed in the top cover.

2. A nozzle unit as claimed in claim], wherein the suction ports comprise a first suction port and a second suction port which are spaced from each other, and wherein the paths comprise a first suction path and a second suction path, which communicate respectively with the first suction port and the second suction port.

3. A nozzle unit as claimed in claim 2, wherein the first suction port is formed between the central part and one side of the lower housing, and the second suction port is formed between the central part and the other side of the lower housing.

4. A nozzle unit as claimed in claim 2 or claim 3, further comprising: lateral channels formed in the bottom surface of the lower housing and opening through the sides of the lower housing, the lateral channels being operatively coupled to the first and second suction ports; a central dust-moving channel formed in the bottom surface of the lower housing in such a manner that the first and second suction ports are fluidly coupled to each other; and one or more front dust-moving channels formed in the bottom surface of the lower housing, and extending through the front of the lower housing in such a manner that the front end of the lower housing is fluidly coupled to the first and second suction 1 0 ports.

5. A nozzle unit as claimed in any one of claims I to 4, wherein the suction path cover is arch-shaped when viewed from a direction perpendicular to the flow direction of the drawn-in air.

6. A nozzle unit as claimed in claim 5, further comprising: a first joint part formed along the edge of the suction path cover; and a second joint part formed in the lower housing to correspond to the first joint part, the second joint part being engageable with the first joint part in an airtight manner.

7. A nozzle unit as claimed in claim 6, wherein the first and second joint parts are formed with complementary stepped portions.

8. A nozzle unit as claimed in claim 6 or claim 7, wherein the first joint part is a connection rib, and the second joint part is a complementary connection recess.

9. A nozzle unit as claimed in any one of claims 6 to 8, further comprising: a compression rib formed on the bottom surface of the top cover; and a guide rib formed on the top surface of the suction path cover, the guide rib having a complementary shape to that of the compression rib so that the compression rib can engage with the guide rib.

10. A nozzle unit as claimed in any one of claims l to 9, wherein the suction path cover is made of a transparent material.

I 1. A nozzle unit as claimed in any one of claims 2 to 10, further comprising a How guide rib in the first and second paths, by means of which the drawn-in air can be guided towards a vacuum source.

12. A nozzle unit as claimed in claim 11, wherein the flow guide rib comprises: a first flow guide rib part formed in the first path; and a second guide rib part formed in the second path in such a manner that one end of the second guide rib part is connected to one end of the first flow guide rib.

13. A nozzle unit as claimed in claim 12, wherein each of the first and second flow guide rib parts is formed with a guide surface having a predetermined curvature. 2-3

14. A nozzle unit as claimed in any one of claims I to 13, wherein the top cover is formed with a cut-out section having a shape corresponding to that of the suction path cover, and the suction path cover is exposed to the outside through the cut-out section.

1 S. A vacuum cleaner comprising: a cleaner body housing a vacuum source; a vacuum extension path having first and second ends, the first end being connected to the cleaner body in such a manner that air can pass through the extension path to the vacuum source; and a nozzle unit connected to the second end of the vacuum extension path, the nozzle unit having upper and lower housings, a plurality of suction ports formed in the lower housing, and a plurality of suction paths formed in at least one of the upper and lower housings to guide the air drawn in from the suction ports; wherein the upper housing comprising a suction path cover defining the tops of the suction paths and mounted on the lower housing; and a top cover located over the suction path cover and connected to the lower housing, the suction path cover extending through an aperture formed in the top cover.

16. A vacuum cleaner as claimed in claim 15, wherein the suction ports comprise a first suction port and a second suction port spaced from each other, and the suction paths comprise a first path and a second path that communicate respectively with the first suction port and the second suction port. l Am

17. A vacuum cleaner as claimed in claim 15 or claim 16, wherein the nozzle unit further comprises: a first joint part formed along the edge of the suction path cover; and a second joint part formed in the lower housing to correspond to the first joint part, the second joint part being engageable with the first joint part.

18. A vacuum cleaner as claimed in claim 17, wherein the nozzle unit further comprises: a compression rib formed on the bottom surface of the top cover; and a guide rib formed on the top surface of the suction path cover, the guide rib having a complementary shape to that of the compression rib.

19. A vacuum cleaner as claimed in claim 17 or claim 18, wherein the nozzle unit further comprises: a flow guide rib in the first and second paths, by means of which so that the drawn-in air can be guided towards a vacuum source.