Dust and dirt collecting unit for vacuum cleaner

The present invention relates to a dust and dirt collecting unit for a vacuum cleaner capable of simultaneously performing a primary cyclonic dust collection and a secondary filter dust collection. According to the present invention, there is provided a dust and dirt collecting unit for a vacuum cleaner, which is mounted to one side of a main body of the vacuum cleaner to filter sucked air containing foreign substances. The dust and dirt collecting unit of the present invention comprises a dust casing which has an inlet formed in a direction tangential thereto for introducing the air containing the foreign substances thereinto and of which a top portion is open; a cover which is used to open and close the top portion of the dust casing and is provided at the center thereof with an outlet for discharging air from which the foreign substances have been filtered out; a filter assembly which is installed at a bottom surface of the cover corresponding to the outlet and includes a cylindrical filter of which the interior communicates with the outlet; a protective cylindrical body which is formed to wrap around an outer periphery of the filter assembly and installed below the cover so that the interior thereof can communicate with the exterior thereof through a plurality of vent holes formed at a lower portion thereof; and a separating plate which is coupled with the bottom of the filter assembly and extends radially to be spaced apart from an inner circumferential surface of the dust casing by a predetermined gap.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a dust and dirt collecting unit for a vacuum cleaner, and more particularly, to a dust and dirt collecting unit for a vacuum cleaner wherein a filter in the cyclonic dust and dirt collecting unit can be protected from impact by foreign substances and its interior constitution can be more simplified.

2. Description of the Prior Art

A vacuum cleaner is an apparatus for sucking air containing foreign substances by means of vacuum pressure, which is generated by a vacuum motor installed within a main body of the vacuum cleaner, and then filtering out the foreign substances from the air in the main body thereof. Further, a paper filter taking the shape of an envelope has been generally used as a filter for filtering out the foreign substances to be sucked. Such a paper filter can filter out the foreign substances such as dust and dirt contained in the sucked air, because the paper filter is designed to allow the air to penetrate therethrough but the foreign substances to remain therein.

However, the vacuum cleaner with the paper filter used therein has inconvenience in use in that if the foreign substances are accumulated within the paper filter to a predetermined level after a certain period of use, suction power of the vacuum cleaner is reduced and thus the paper filter must be periodically replaced with a new one.

In order to solve the inconvenience, a vacuum cleaner in which the filtering action is performed in a cyclonic fashion has been proposed.FIG. 1shows a conventional cyclonic vacuum cleaner.

As shown in the figure, the vacuum cleaner comprises a main body20in which a suction means for sucking the air in the room is installed, a connection hose34which is made of a flexible material and connected to communicate with the interior of the main body20, a variable length extension tube32installed to communicate with an end of the connection tube34, and a suction nozzle31for sucking the air containing foreign substances from a floor by means of suction power generated from the main body20.

Further, a dust and dirt collecting unit21that is detachably mounted is installed in the rear of the main body20. The dust and dirt collecting unit21is formed with a handle21afor allowing a user to grasp the dust and dirt collecting unit when mounting or demounting the unit to or from the rear of the main body20of the vacuum cleaner. The dust and dirt collecting unit21is a part for causing the air containing the foreign substances sucked from the suction nozzle31to be introduced thereinto and then performing the filtering of the foreign substances. At a side of the main body20is formed a discharge portion29for discharging the air, from which the foreign substances are filtered out in the dust and dirt collecting unit21, to the atmosphere.

A pair of wheels28for causing the main body20to travel on the floor are rotatably installed on the bottom of the main body20. Further, a power cord26through which the vacuum cleaner is supplied with electric power is installed at the other side of the main body20. The power cord26is installed such that it can be wound around a cord reel (not shown) in the main body and be received in the main body. A handle24, which the user can grip when intending to carry the vacuum cleaner, is also installed at a top surface of the main body20.

When the vacuum cleaner constructed as such is operated, the suction power is transmitted to the suction nozzle31through the connection hose34and the extension tube32by means of the vacuum pressure generated in the main body. Here, the suction power can be adjusted by a switch33athat is installed on a grip portion33coupled with an upper portion of the extension tube32.

The air containing the foreign substances on the floor to be cleaned is introduced into the main body20, through the suction nozzle31, the extension tube32and the connection hose34, by means of the suction power. Then, the air is introduced into the dust and dirt collecting unit21. Next, the conventional dust and dirt collecting unit21will be discussed with reference toFIG. 2.

The conventional dust and dirt collecting unit21includes a dust casing23of which a top portion is open and which takes the shape of a container, and a cover22capable of opening and closing the top portion of the dust casing23. The dust casing23is provided with an inlet23athrough which the air containing the foreign substances sucked from the suction nozzle31is introduced. The inlet23ais formed in a direction tangential to the dust and dirt collecting unit21so that the air introduced into the dust and dirt collecting unit21can flow in the form of spiral airflow within the dust and dirt collecting unit.

A pair of semicircular separating plates23b,23care installed at a lower portion of the interior of the dust casing23. The separating plates23b,23ccan be supported within the dust casing23, by causing central shafts23d,23eof the separating plates to be pivotally mounted onto an inner circumferential surface of the dust casing23. Further, the separating plates23b,23care supported in a horizontal state and also installed such that they can pivot on the central shafts23d,23eonly upwardly from the shown horizontal state. For example, the separating plates23b,23cmay be horizontally supported by means of supporting projections (not shown) formed on the inner circumferential surface of the dust casing23.

Thus, the separating plates23b,23ccan pivot only upwardly from the horizontally supported state by means of the supporting projections that protrude from the inner circumferential surface of the dust casing23.

A dust and dirt collecting space for collecting the foreign substances therein is defined at the lower portion of the interior of the dust casing23by the separating plates23b,23c. Further, a communicating passage23fthrough which the foreign substances can fall down into the dust and dirt collecting space is formed at one side of the separating plate23b.

Furthermore, an outlet22ais formed in the center of the cover22. The outlet22ais a part which is formed such that the air from which the foreign substances have been filtered out in the dust casing23can be discharged through the discharge portion29.

A cylindrical filter25is installed below the outlet22a. The filter25is also detachably mounted to a bottom surface of the cover22so that the cylindrical interior thereof can be in communication with the outlet22a.

Next, the operation of the conventional vacuum cleaner and the dust and dirt collecting unit21constructed as such will be discussed. If a motor placed in the main body20of the vacuum cleaner is operated and the suction power is then generated, the air containing the foreign substances is introduced through the suction nozzle31. The air is introduced into the main body20via the extension tube32and the connection hose34, and then guided into the inlet23aof the dust casing23described above.

The air stream introduced into the dust casing23through the inlet23abecomes the spiral airflow that flows along the cylindrical inner circumferential surface of the dust casing23. While the spiral airflow is created as such, the relatively heavy foreign substances fall down into the lower portion of the dust casing23. Then, these foreign substances fall down onto a floor surface of the dust casing23through the communicating passage23fof the separating plate23b.

The air from which the relatively heavy foreign substances are filtered out in the cyclonic fashion passes through the filter25installed in the center of the dust casing23from the outside to the inside of the filter25. While the air passes into the filter25, the fine foreign substances contained in the air are sufficiently filtered out.

The air guided into the cylindrical filter25is discharged through the outlet22aformed on a top surface of the cover22. The air discharged through the outlet is used to cool the motor in the main body20while passing by the motor. Then, the air is completely discharged from the main body20through the discharge portion29.

As the vacuum cleaner is operated according to such a process, the foreign substances are accumulated in the dust casing23. That is, the foreign substances filtered out in the cyclonic dust-collecting manner are accumulated below the separating plates23b,23cin the dust casing23. Furthermore, if the amount of the accumulated foreign substances is greater than a predetermined level, the foreign substances must be emptied from the dust casing23.

To this end, the dust and dirt collecting unit21will be separated or demounted from the main body20. Then, the cover22is also separated from the separated dust and dirt collecting unit21. If the cover22is separated, the filter25mounted to the bottom surface of the cover can also be separated. Thus, the separated filter25may be cleaned or washed, if necessary.

In addition, if the user causes the dust casing23to be inverted so as to empty the foreign substances from the dust casing23, the separating plates23b,23cwill pivot downward on the supporting shafts23d,23e, respectively. Thus, the foreign substances, which have been accumulated below the separating plates in the dust casing before the dust casing is inverted, can be completely emptied.

However, the conventional vacuum cleaner and the dust and dirt collecting unit constructed as such have the following problems.

First, the foreign substances are also contained in the air introduced through the inlet23aas described above. Herein, the foreign substances contained in the air to be introduced through the inlet23ahave a velocity corresponding to the suction power and may collide against a surface of the filter. If the foreign substances, particularly large and heavy foreign substances, which collide against the surface of the filter as such, come into contact with the surface of the filter, the filter itself may be damaged. Thus, there is a problem in that suction performance or filtering efficiency of the vacuum cleaner may be deteriorated.

Further, it can be easily understood that the separating plates23b,23care further installed within the dust casing23so as to perform the dust and dirt collection in the cyclonic fashion. That is, the dust and dirt collecting unit is constructed such that the dust collecting space for accumulating the foreign substances therein is defined at the lower portion of the dust casing23by means of the separating plates23b,23cwhich are separately manufactured and then mounted in the dust casing23.

Therefore, since the pair of separating plates23b,23cmanufactured separately are installed in the dust casing23, the number of parts will be substantially increased, and consequently, the manufacturing process becomes complicated. That is, it can be easily understood that the problems such as increase of production costs and limitations on the productivity in the manufacturing process occur due to the increase of the number of parts.

SUMMARY OF THE INVENTION

The present invention is conceived to solve the above problems in the prior art. A primary object of the present invention is to provide a more simple dust and dirt collecting unit for use in a cyclonic vacuum cleaner.

Another object of the present invention is to provide a structure capable of protecting the filter installed within the dust and dirt collecting unit having a cyclonic dust collecting function from impact by foreign substances, and particularly, preventing mesh clogging of the filter.

According to an aspect of the present invention for achieving the object, there is provided a dust and dirt collecting unit for a vacuum cleaner, which is mounted to one side of a main body of the vacuum cleaner to filter sucked air containing foreign substances. The dust and dirt collecting unit comprises a dust casing which has an inlet formed in a direction tangential thereto for introducing the air containing the foreign substances thereinto and of which a top portion is open; a cover for opening and closing the top portion of the dust casing, said cover being provided at the center thereof with an outlet for discharging air from which the foreign substances have been filtered out; a filter assembly installed at a bottom surface of the cover corresponding to the outlet, said filter assembly including a cylindrical filter of which the interior communicates with the outlet; a protective cylindrical body which is cylindrically formed to wrap around an outer periphery of the filter assembly and installed below the cover so that the interior thereof can communicate with the exterior thereof through a plurality of vent holes formed at a lower portion thereof; and a separating plate which is coupled with the bottom of the filter assembly and extends radially to be spaced apart from an inner circumferential surface of the dust casing by a predetermined gap.

According to another aspect of the present invention, there is provided a dust and dirt collecting unit for a vacuum cleaner, which is mounted to one side of a main body of the vacuum cleaner to filter sucked air containing foreign substances. The dust and dirt collecting unit comprises a dust casing which has an inlet formed in a direction tangential thereto for introducing the air containing the foreign substances thereinto and of which a top portion is open; a cover for opening and closing the top portion of the dust casing, said cover being provided at the center thereof with an outlet for discharging air from which the foreign substances have been filtered out; a filter assembly installed at a bottom surface of the cover corresponding to the outlet, said filter assembly including a cylindrical filter of which the interior communicates with the outlet; a protective cylindrical body which is formed to wrap around an outer periphery of the filter assembly and installed below the cover so that the interior thereof can communicate with the exterior thereof through a plurality of vent holes formed at a lower portion thereof, a separating plate which is coupled with the bottom of the filter assembly and extends radially to come into close contact with an inner circumferential surface of the dust casing; and a communicating passage which is cut out inwardly and concavely in at least a portion of the separating plate for communicating with a space defined between the separating plate and the dust casing.

Preferably, the separating plate is detachably mounted to the protective cylindrical body.

Further, it is preferred that the filter assembly include a radially extending upper flange portion which comes into close contact with the bottom surface of the cover, and a body which extends downward from the upper flange portion and forms a cylindrical framework of the frame for allowing the air to pass therethrough.

More preferably, the filter is cylindrically shaped to have a predetermined mesh and installed at an outer face of the body so that the foreign substances can be filtered out.

In addition, it is preferred that a plurality of coupling grooves be formed at an upper end of the protective cylindrical body and a plurality of radially extending coupling projections be formed at an upper end of the filter assembly to be fitted into the coupling grooves, respectively, so that the filter assembly is simultaneously supported onto the cover by causing the protective cylindrical body to be detachably mounted to the cover.

More preferably, the protective cylindrical body is mounted to the bottom surface of the cover by causing peripheral projections of the protective cylindrical body formed on the upper end thereof at a predetermined interval to be coupled with a plurality of arcuate hooks formed on the bottom surface of the cover at the predetermined interval.

Furthermore, it is preferred that a top surface of the separating plate be formed to be inclined downwardly and outwardly.

Moreover, it is preferred that the separating plate be detachably coupled with the protective cylindrical body by causing coupling projections formed at the center of the bottom of the protective cylindrical body to be threading engaged with coupling holes formed at the center of the separating plate.

It is also preferred that a stop plate, which extends radially and protrudes upwardly, be formed on a floor surface of the dust casing.

Preferably, the vent holes are formed at a side of the protective cylindrical body located below the inlet of the dust casing through which the air is sucked.

More preferably, mesh nets are installed at the vent holes so as to filter out the foreign substances. Further, it is preferred that each of the mesh nets be sized to have a relatively larger mesh than that of the filter.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 3is an exploded perspective view of a dust and dirt collecting unit according to the present invention, andFIG. 4is a sectional front view of the dust and dirt collecting unit according to the present invention. As shown in these figures, the dust and dirt collecting unit of the present invention comprises a dust casing100of which a top portion is open, and a cover200which is detachably mounted to the open top portion of the dust casing100.

The dust casing100is formed to take the shape of a hollow cylinder of which a top end is open. A handle112, which a user grasps when intending to mount or demount the dust casing100into or from a rear portion of a main body of the vacuum cleaner, is formed at a rear portion of the dust casing100.

The dust casing100includes an inlet110through which air containing foreign substances is sucked. Since the inlet110is formed at an upper portion of the dust casing100in a direction tangential to an outer periphery of the dust casing to communicate with the dust casing100, an air stream sucked into the dust casing100through the inlet110becomes spiral airflow starting from an upper portion of the interior of the dust casing100.

The cover200is mounted to the open top portion of the dust casing100so that it can open and close the open top portion. A circular outlet210is formed in the center of the cover200so that air from which the foreign substances have been filtered out within the dust casing100can be discharged to the atmosphere.

A cylindrical filter assembly220is mounted to a bottom surface of the cover200. The filter assembly220comprises a cylindrical frame222and a net-type cylindrical filter224installed on an outer periphery of the frame.

The frame222is made of a synthetic resin material through injection molding. The frame222comprises a radially extending upper flange portion226which is close contact with the bottom surface of the cover200, and a body227which extends downward from the upper flange portion and forms a cylindrical framework of the frame for allowing the air to pass therethrough. That is, the body227for forming a central portion of the frame222is made in the shape of a lattice so as to allow the air to pass through the body. The filter224may be formed with a very fine mesh net and made of a fiber material, metallic material or the like. The filter224is to filter out the foreign substances contained in the air passing through the filter from the outside thereof.

Further, a protective cylindrical body240for protecting the filter224from the foreign substances introduced through the inlet110is installed at the outside of the filter assembly220. The protective cylindrical body240is formed to wrap around the filter assembly220and to extend downward up to a lower end of the filter224. An upper end of the protective cylindrical body240is detachably mounted to the bottom surface of the cover200. In addition, the bottom of the protective cylindrical body240is hermetically closed.

A plurality of vent holes242are formed on the periphery of the protective cylindrical body240at a lower end thereof. The vent holes242are configured such that the air in the dust casing100can flow toward the filter assembly220through the holes. Further, it is preferred that the vent holes224be formed at positions lower than the inlet110of the dust casing100.

Since the vent holes242are merely to allow the air in the dust casing100to be guided toward the filter assembly220, they cannot be limited in view of the positions where the holes are formed. For example, a plurality of vent holes may be formed on the periphery of the protective cylindrical body240at the lower end thereof, as described above. Alternatively, it will be apparent that the plurality of vent holes can be formed at the bottom243of the protective cylindrical body240.

Mesh nets245made of the fiber material, the metallic material or the like are attached to the vent holes242, respectively. Each of the mesh nets245is to again filter out the foreign substances contained in the air passing through the relevant vent hole242. It is also preferred that each of the mesh nets245be configured to have a mesh relatively larger than that of the aforementioned filter224.

An upper end of the protective cylindrical body240is detachably coupled to the bottom surface of the cover200, for example, in such a manner that a plurality of peripheral projections247, which extend radially from the upper end of the protective cylindrical body240to be spaced apart from one another in an angular direction, are coupled into a plurality of arcuate hooks212which are formed on the bottom surface of the cover200to be spaced apart from one another by a predetermined interval, respectively.

As shown inFIG. 3, a pair of coupling grooves248a,248bformed to be concave downward are formed at the upper end of the protective cylindrical body240. Further, a pair of radially extending coupling pieces228a,228bare formed at the upper flange portion226of the filter assembly220. When the filter assembly220is coupled with the protective cylindrical body240, the pair of coupling pieces228a,228bare securely seated into the pair of coupling grooves248a,248b, respectively, in a state where the upper flange portion226comes into close contact with an inner circumferential surface of an open upper portion of the protective cylindrical body. Thus, the filter assembly220can be supported on the inside of the protective cylindrical body240in such a manner.

Then, since the peripheral projections247of the protective cylindrical body240are coupled into the arcuate hooks212formed on the bottom surface of the cover200in such a state, both the filter assembly220and the protective cylindrical body240can be substantially supported on the bottom surface of the cover200.

As shown in the figures, since one coupling piece228aextends outward farther than the other one228b, the coupling piece228aprotrudes outward when the filter assembly220is coupled to the protective cylindrical body240. Thus, it can be understood that the coupling piece228ais used to allow a user to more easily grasp the coupling piece when intending to separate the filter assembly220from the protective cylindrical body240.

However, the present invention may not be limited to this preferred embodiment. That is, it is sufficient in the present invention that the filter assembly220can be mounted on the bottom surface of the cover200and that the protective cylindrical body240can be also mounted on the bottom surface of the cover200while wrapping around the filter assembly220.

In a state where they are coupled with one another as such, the interior of the filter assembly220is in communication with the outlet210formed at the center of the cover200. Thus, the air, from which the foreign substances are filtered out while the air passes through the filter assembly220from the outside to the inside, can be discharged through the outlet210to the atmosphere.

In the illustrated embodiment of the present invention, the filter assembly220can be more firmly coupled to the protective cylindrical body240by causing the a lower end229of the frame222of the filter assembly220to be fitted into a retaining groove249formed on a floor surface of the protective cylindrical body240.

A separating plate260is also attached to the bottom of the protective cylindrical body240. The separating plate260is to perform a function of dividing the interior of the dust casing100into two spaces, so that a dust collecting space114can be defined below the plate260. Further, the separating plate260is configured such that it extends radially further than the protective cylindrical body240but is slightly spaced apart from the inner circumferential surface of the dust casing100.

In the illustrated preferred embodiment of the present invention, a coupling projection244with a threaded portion formed on an outer periphery thereof is formed to extend downward from the center of the bottom of the protective cylindrical body240, and a coupling hole262with a threaded portion to be coupled with the threaded portion of the coupling projection244formed on an inner periphery thereof is formed at the center of the separating plate260. Thus, the separating plate260is coupled to the protective cylindrical body240by causing the coupling projection244and the coupling hole262to be threadingly engaged with each other.

The foreign substances, which are contained in the air introduced through the inlet110, will be able to fall down onto a floor surface of the dust casing100through a gap defined between the separating plate260and the inner circumferential surface of the dust casing100.

A top surface264of the separating plate260is formed as a surface downwardly inclined in an outward radial direction. Thus, the foreign substances, which fall down onto the inclined surface264while the dust collection is performed in the cyclonic fashion, can be more smoothly guided downward along the inclined surface264.

Further, a portion266extending substantially vertically and downwardly from the inclined surface264is formed at an outer edge of the inclined surface264. That is, the separating plate260is formed to be concave as viewed from below. Thus, the foreign substances contained in the spiral airflow generated during the cyclonic dust-collecting process can be more efficiently prevented from being lifted again from below to above the separating plate260.

In the preferred embodiment, the separating plate260is mounted to the bottom of the protective cylindrical body240by causing the coupling projection244and the coupling hole262to be threadingly engaged with each other. However, it is apparent that if the separating plate260can be mounted to the bottom of the protective cylindrical body240, various modifications can be made thereto.

In addition, in the illustrated embodiment of the present invention, the separating plate260is spaced apart from the inner circumferential surface of the dust casing100by the predetermined gap. However, since the separating plate260is merely to define a dust collecting space114below the plate within the dust casing, it is sufficient it the separating plate260is configured to be capable of communicating with the dust collecting space114. Alternatively, the separating plate260may be configured in such a manner that the plate260is almost brought into close contact with the inner circumferential surface of the dust casing100and a communication passage is formed on the outer edge of the separating plate260so that the foreign substances can fall down into the dust collecting space114through the communication passage.

Furthermore, a stop plate116is formed to protrude upwardly from the floor surface of the dust casing100. The stop plate116is designed to prevent the foreign substances fallen down onto the floor surface of the dust casing100from being continuously swirling within the dust casing due to the swirl airflow that has been generated by the air swirling within the dust casing100when the dust collection is made in the cyclonic fashion. That is, although the foreign substances temporarily swirl together with the air due to the spiral airflow generated in the dust casing, the foreign substances are caused to stop further swirling in the dust casing and are collected near the stop plate116when they collide against the stop plate. Moreover, the stop plate116allows the foreign substances to be kept in a stationary state and not to be lifted again from the floor surface of the dust casing100by the spiral airflow generated in the casing.

Next, the overall operation of the dust and dirt collecting unit of the present invention will be explained with reference toFIGS. 3 and 4.

When the vacuum cleaner is operated, a suction nozzle causes the air containing the foreign substances to be sucked by means of the suction power generated in the main body of the vacuum cleaner while traveling on the floor to be cleaned. The air containing the foreign substances is introduced into the dust casing100through the inlet110thereof.

The air introduced into the dust casing100of which the top portion is closed by the cover200becomes the spiral airflow because the inlet110is formed tangentially at the dust casing100.

The relatively heavy foreign substances included in the spiral airflow fall down due to their own weights. The foreign substances fall down onto the floor surface of the dust casing100through the gap defined between the separating plate260and the inner circumferential surface of the dust casing100. Some portions of the foreign substances fall down directly through the gap, whereas the other portions of them are guided along the inclined surface264of the separating plate260and then downward into the dust collecting space114through the gap defined between the separating plate260and the inner circumferential surface of the dust casing100.

Further, the foreign substances contained in the air introduced into the inlet110can be prevented from colliding directly against the filter224by means of the protective cylindrical body. Thus, the filter224can be sufficiently prevented from being damaged due to the collision of the foreign substances.

In such a manner, the foreign substances contained in the sucked air are primarily filtered out in accordance with the aforementioned cyclonic duct-collecting fashion. It is apparent that the relatively large foreign substances are filtered out during the process of the cyclonic dust collection.

Further, during the process of the cyclonic dust collection, the foreign substances accumulated on the floor surface of the dust casing100are not further swirled due to the stop plate114and are then collected near the stop plate.

As mentioned above, the cyclonic dust collection is primarily performed within the dust casing100so that the heavy foreign substances contained in the air can be accumulated onto the floor surface of the dust casing100while the air is swirling in the dust casing100. After the primary dust collection has been completed, the air passes through the vent holes242and then guided to the filter224installed at the center of the dust casing100.

Then, the foreign substances contained in the air are again filtered out by means of the mesh nets245installed at the vent holes242. Further, while the air passed through the mesh nets245passes through the filter224again, the foreign substances are again filtered out from the air. Even fine foreign substances such as substantially very fine dusts are completely filtered out by the filter224having a finer mesh than the mesh nets245.

The air passing through the filter224from the outside to the inside becomes clean air from which fine foreign substances have been completely filtered out by the filter224. Further, since the interior of the filter224is in communication with the outlet210of the cover200, the air is discharged through the outlet210. The air discharged through the outlet210cools the motor, for example, installed within the main body of the vacuum cleaner, and then, is completely discharged to the outside of the vacuum cleaner.

As described above, it can be easily understood that the present invention is configured in such a manner that the protective cylindrical body240is installed around the filter assembly220mounted on the bottom surface of the cover200for opening and closing the open top portion of the dust casing100and the sucked air passes through the filter via the vent holes242of the protective cylindrical body. Further, it can also be understood that the separating plate260is installed to the bottom of the protective cylindrical body240.

Next, a modified embodiment of the separating plate260according to the present invention will be discussed.

In the previous preferred embodiment, the predetermined gap is defined between the outer periphery of the separating plate260and the inner circumferential surface of the dust casing100. That is, the separating plate260is sized such that the outer periphery thereof is spaced apart from the inner circumferential surface of the dust casing100by the predetermined gap.

However, the separating plate260of the present invention basically functions to define a specific dust collecting space so that the foreign substances, which fall down onto the floor surface of the dust casing100during the cyclonic dust-collecting process, can be collected in the dust casing100. Thus, it is apparent that the separating plate260, which is attached to the bottom of the filter assembly220to collect the foreign substances in the dust casing100, may be modified in various manners.

For example, the separating plate260may be constructed such that the outer periphery thereof is brought into close contact with the inner circumferential surface of the dust casing100. In such a case, in order to guide the foreign substances into the dust collecting space defined below the separating plate260, the communicating passage through which the foreign substances can fall down into the dust collecting space should be formed by cutting out at least a portion of an outer periphery of the separating plate260.

It is apparent that the foreign substances can be guided down into the separating plate260through the communicating passage even by bringing the separating plate260into close contact with the inner circumferential surface of the dust casing100and cutting out at least a portion of the outer periphery of the separating plate260.

The present invention constructed as such has the following advantages:

First, the dust and dirt collecting unit of the present invention can smoothly perform the primary cyclonic dust collection and the second filter dust collection for filtering out the fine dust and dirt. Further, since dual filtering actions by the mesh nets245and the filter224are performed even during the filter dust collection, an efficiency of removing the foreign substances can be substantially maximized.

In addition, according to the present invention, since the filter assembly220is installed within the protective cylindrical body220, the foreign substances introduced through the inlet of the dust casing can be prevented from directly coming into contact with the filter224. Thus, since the filter224is sufficiently prevented from being damaged due to the impact of the introduced foreign substances against the filter, an advantage that the filter can be used to efficiently filter out the foreign substances for a long time is expected.

Furthermore, the separating plate260of the present invention can cause the foreign substances to be accumulated onto the floor surface of the dust casing in a remarkably simpler manner as compared with the conventional one, because the separating plate260is installed directly to the bottom of the protective cylindrical body240.

Moreover, it will be apparent that production cost reduction and productivity improvement in the manufacturing process of the vacuum cleaner can be expected due to reduction in the number of parts, because the separating plate260and its organic connection to the other parts of the present invention can be implemented in a relatively simple manner.

Although the present invention has been described in connection with the preferred embodiments, it is not limited thereto. Obviously, it can be understood by the skilled in the art that various changes and modifications of the present invention can be made within the scope of the basic technical spirit of the present invention. The present invention should be construed based on the appended claims.