Abstract:
A bagless vacuum cleaner having a removable dust extraction and collection unit. The removable dust extraction and collection unit has an enclosed inlet chamber and an enclosed outlet chamber. The bottom wall of the enclosed inlet chamber is pivotally hinged such that the bottom wall can be alternatively opened and closed. When opened, accumulated dust within the inlet chamber is conveniently gravitated out of the dust extraction and collection unit.

Description:
[0001]    This invention relates generally to vacuum cleaners and, more particularly, to bagless vacuum cleaners.  
         BACKGROUND OF THE INVENTION  
         [0002]    Bagless vacuum cleaners have become very popular over the last several years. This popularity is due in large part to the ease with which dust and dirt can be removed from such vacuum cleaners. In old style cloth bag-containing vacuum cleaners, dust and dirt removal is a difficult and awkward process, frequently requiring the user to extend his or her hand into the cloth bag to physically disengage dust clumps. Vacuum cleaners using disposable liner bags minimize the problems associated with cloth bags, but the use of such vacuum cleaners requires the continuous replenishment and installation of disposable liner bags. (Also, owners of older model disposable liner bag-containing vacuum cleaners often find it difficult to locate a source of properly sized replacement liner bags.)  
           [0003]    Contrary to these problems associated with bag-containing vacuum cleaners, dirt and dust vacuumed up using bagless vacuum cleaners is conveniently deposited into an easily removable permanent container, from which dust and dirt can be disposed of without the effort associated with cloth bag-containing vacuum cleaners and without having to continually purchase and reinstall disposable liner bags.  
           [0004]    Bagless vacuum cleaners of the prior art, however, have not been filly satisfactory. Most bagless vacuum cleaners have not demonstrated the ability to fully disengage dust and dirt from the vacuum air stream.  
           [0005]    Accordingly, there is a need for a bagless vacuum cleaner which avoids these problems with the prior art.  
         SUMMARY  
         [0006]    The invention satisfies this need. The invention is a vacuum cleaner having (a) a chasse having a base unit and a housing unit, the base unit having an air inlet and roller means for moving the vacuum cleaner across a flat surface; (b) an air blower disposed within the chasse; (c) a removable dust extraction and collection unit disposed within the housing unit, the dust extraction and collection unit comprising: (i) an enclosed inlet chamber, the inlet chamber being substantially cylindrical in shape, the inlet chamber comprising a bottom wall, at least one generally vertical sidewall, an upper section, a lower section and an inlet opening, the upper section of the inlet chamber having an air inlet opening through the sidewalls; and (ii) an enclosed outlet chamber disposed concentrically within the upper section of the inlet chamber, the outlet chamber having a bottom wall and a top wall, the top wall having a top wall opening, the sidewalls having a plurality of inlet apertures, the inlet apertures being disposed in a band around the sidewalls of the outlet chamber; and (d) duct work for serially connecting in fluid communication the air inlet in the base unit, the inlet chamber, the outlet chamber and the air blower; wherein, the bottom wall of the enclosed inlet chamber of the dust extraction and collection unit is pivotally hinged to the at least one side wall such that the bottom wall can be alternatively pivoted between (i) a closed bottom wall position wherein the bottom wall is sealed against the at least one side wall so that dust can be retained within the enclosed inlet chamber and (ii) an open bottom wall position wherein the bottom wall is pivoted away from the at least one side wall such that dust within the enclosed inlet chamber can be dumped out of the enclosed inlet chamber. 
       
    
    
     DRAWINGS  
       [0007]    These features, aspects and advantages of the present invention will become better understood with regard to the following description, appended claims and accompanying figures where:  
         [0008]    [0008]FIG. 1 is a front view of a vacuum cleaner having features of the invention;  
         [0009]    [0009]FIG. 2 is a rear view of the vacuum cleaner illustrated in FIG. 1;  
         [0010]    [0010]FIG. 3 is a diagrammatic cutaway front view of the vacuum cleaner illustrated in FIG. 1;  
         [0011]    [0011]FIG. 4 is a diagrammatic cutaway side view of the vacuum cleaner illustrated in FIG. 1;  
         [0012]    [0012]FIG. 5 is a first isometric view of a dust extraction and collection unit useable in the vacuum cleaner illustrated in FIG. 1;  
         [0013]    [0013]FIG. 6 is a second isometric view of a dust extraction and collection unit useable in the vacuum cleaner illustrated in FIG. 1;  
         [0014]    [0014]FIG. 7 is an isometric view of the vacuum cleaner illustrated in FIG. 1 with its dust extraction and collection unit removed;  
         [0015]    [0015]FIG. 8 is a cross-sectional side view of the dust extraction and collection unit illustrated in FIG. 5, taken along line  8 - 8 ;  
         [0016]    [0016]FIG. 9 is a cross-sectional side view of the dust extraction and collection unit illustrated in FIG. 5, taken along line  9 - 9 ; and  
         [0017]    [0017]FIG. 10 is an exploded view of the dust extraction and collection unit illustrated in FIG. 5. 
     
    
     DETAILED DESCRIPTION  
       [0018]    The following discussion describes in detail one embodiment of the invention and several variations of that embodiment. This discussion should not be construed, however, as limiting the invention to those particular embodiments. Practitioners skilled in the art will recognize numerous other embodiments as well.  
         [0019]    The invention is a vacuum cleaner  10  having features which improve upon the vacuum cleaner disclosed in my prior patent, U.S. Pat. No. 6,269,518 B1. As illustrated in FIGS.  1 - 4 , the vacuum cleaner  10  has a chasse  12 , an air blower  14  and a dust extraction and collection unit  16 .  
         [0020]    The chasse  12  comprises a base unit  18  and a housing unit  20 . The base unit  18  has an air inlet  22  wherein dust and dirt is sucked up into the chasse  12 . In a typical embodiment, the base unit  18  includes a rotating horizontal floor brush  24 .  
         [0021]    The base unit  18  further comprises roller means for moving the vacuum cleaner  10  across a flat surface. In the embodiment illustrated in the drawings, such roller means includes a plurality of wheels  26  disposed, for example, at each of the four corners of the base unit  18 .  
         [0022]    The air blower  14  is disposed within the chasse  12 . The air blower  14  is typically an electrically driven air blower having a capacity between about 50 m 3 /hour and about 200 m 3 /hour. A typical electrical motor  28  for driving the blower operates on ordinary house current and has a power capacity between about 800 watts and about 2000 watts. In the embodiment illustrated in the drawings, the rotating brush  24  within the base unit  18  is rotated by a drive belt  30  which is powered by the air blower motor  28 .  
         [0023]    The dust extraction and collection unit  16  is disposed within the housing unit  20 . The dust extraction and collection unit  16  comprises an enclosed inlet chamber  32  and an enclosed outlet chamber  34 . The dust extraction and collection unit  16  is illustrated in detail in FIGS. 5, 6 and  8 - 10 .  
         [0024]    The inlet chamber  32  is substantially cylindrical in shape with an internal diameter between about 130 mm and about 200 mm, preferably between about 150 mm and about 180 mm. The inlet chamber  32  comprises a body portion  35 . The body portion  35  has a bottom wall  36 , generally vertical sidewalls  38  and a top wall  40 . The sidewalls  38  typically have an interior height between about 200 mm and about 250 mm, most typically between about 220 mm and about 230 mm.  
         [0025]    The inlet chamber  32  has an upper section  42  and a lower section  44 . The sidewalls in the upper section  42  of the inlet chamber  32  define an inlet opening  46  for allowing the ingress of dusty air from the base unit  18 . The inlet opening  46  of the inlet chamber  32  is configured to provide the ingress of dusty air into the inlet chamber  32  in tangential fashion wherein the ingressing dusty air is caused to downwardly spiral around the internal surface  48  of the inlet chamber sidewalls  38 . In this regard, the lateral edges of the inlet opening  46  are beveled, the exterior wall at the upstream lateral edge of the inlet opening  46  being beveled and the interior surface of the downstream lateral edge of the inlet opening  46  being beveled.  
         [0026]    The inlet chamber  32  is preferably reversibly installable and deinstallable within the chasse  12 . In the embodiment illustrated in the drawings, the inlet chamber  32  is reversibly installable and deinstallable within the chasse  12  via a snap-on connection between the inlet chamber walls and the walls of the chasse  12 . In another embodiment (not shown), the inlet chamber  32  is reversibly installable and deinstallable within the chasse  12  using a press-fit connection.  
         [0027]    The outlet chamber  34  is disposed concentrically within the upper section  42  of the inlet chamber  32 . The outlet chamber  34  is suspended from the top wall  40  of the inlet chamber  32  by a chamber collar  47 . The outlet chamber  34  has a bottom wall  50 , a top wall  52  and generally vertical sidewalls  54 . The sidewalls  54  have an interior height between about 50 mm and about 100 mm, preferably between about 80 mm and about 90 mm.  
         [0028]    The sidewalls  54  of the outlet chamber  34  are perforated with a plurality of inlet apertures  56 , each defining an area between about 3 mm 2  and about 30 mm 2 . In a typical embodiment, the sidewalls  54  define between about 1000 and about 1500 inlet apertures  56 , preferably between about 1300 and about 1400 inlet apertures  56 . Typically each of the inlet apertures  56  is separated from adjoining inlet apertures  56  by a distance of between about 1.5 mm and about 5 mm. The inlet apertures  56  are preferably disposed in a band  58  around the sidewalls  54  of the outlet chamber  34 . Typically, the band  58  has a width between about 20 mm and about 50 mm, preferably between about 30 mm and about 40 mm. The band  58  defines a median line (not shown) which divides the uppermost apertures  56  from a substantially equal number of lowermost apertures  56 . Typically, the median line is disposed between about 30 mm and about 100 mm above the bottom wall  50  of the outlet chamber  34 , preferably between about 50 mm and about 60 mm above the bottom wall  50 .  
         [0029]    The outlet chamber  34  has an upper section  66  and a lower section  68 . Disposed around the sidewalls  54  in the lower section  68  of the outlet chamber  34  is an exterior perimeter edge member  70 . The purpose of the exterior edge member  70  is to provide a narrowing of the open annulus  72  between the interior surface  48  of the inlet chamber  32  and the exterior surface  74  of the outlet chamber  34  proximate to the bottom wall  50  of the outlet chamber  34 . In a typical embodiment, the exterior edge member  70  has a diameter between about 10 mm and about 60 mm less than the internal diameter of the inlet chamber  32 , preferably between about 10 mm and about 20 mm less than the internal diameter of the inlet chamber  32 .  
         [0030]    In a preferred embodiment, a cylindrical filter  76  is disposed vertically and  25  concentrically within the outlet chamber  34 . In the embodiments illustrated in the drawings, the bottom wall  50  of the outlet chamber  34  has an X-shaped wall  77  which projects vertically above the bottom wall  50 . This X-shaped wall  77  supports the cylindrical filter  76 . Typically, such cylindrical filter  76  is made from polypropylene, paper, ceramic or polytetrafluoroethylene having a thickness between about 1.5 mm and about 5 mm.  
         [0031]    The top wall  52  of the outlet chamber  34  defines a top wall opening  78 . Typically, the top wall opening  78  is disposed in the center of the top wall  52 .  
         [0032]    In another preferred embodiment, the outlet chamber  34  comprises a planar filter  80  disposed across the top wall  78  opening of the outlet chamber  34 . In a typical embodiment, such planar filter  80  is made from sponge, fibrous polyethylene, fibrous polypropylene or paper, and typically has a thickness between about 5 mm and about 15 mm.  
         [0033]    [0033]FIG. 10 illustrates an exploded view of the dust extraction and collection unit  16 . As is seen in FIG. 10, the dust extraction and collection unit  16  further comprises an outlet plenum cover  82  for enclosing an outlet plenum  84  which carries air out of the dust extraction and collection unit  16 . The outlet plenum cover  82  is sealed to the outlet plenum  84  by a plenum cover seal  86 .  
         [0034]    Attached to the body portion  35  is a handle  88  having a latch mechanism  90  configured to snap into a corresponding recess (not shown) in the chassis  12 . The latch mechanism  90  is biased by a latch mechanism spring  93  to be in an uppermost (latched) position. The latch mechanism  90  can be easily unlatched by depressing an unlatch button  91  which protrudes through the top of the handle  88 .  
         [0035]    The bottom wall  36  of the inlet chamber  32  is hingeably attached to the body portion  35  at a hinge  95 . A bottom wall sealing ring  96  is used to seal the bottom wall  36  to the body portion  35 . The bottom wall  36  is retained in a closed position by a bottom wall hook latch  98 . The hook latch  98  is pivotally attached to the body portion  35  of the dust extraction and collection unit  16 . When in the latched position, the hook latch  98  can be disengaged from the bottom wall  36  by the depression of a locking pin button  100 . The locking pin button  100  is biased away from the unlatched position by a bottom wall hook latch spring  102 .  
         [0036]    The invention further comprises duct work  92  for serially connecting in fluid communication the air inlet  22  in the base unit  18 , the inlet chamber  32 , the outlet chamber  34  and the air blower  14 .  
         [0037]    It is very important that all such duct work  92  and all connection points within the duct work and between various components in the system and/or the duct work  92  be well-sealed. Even small leaks within the system can markedly decrease efficiency and increase power requirements.  
         [0038]    In a preferred embodiment, a blower filter  94  is operatively disposed downstream of the air blower  14 . Preferably, such blower filter  94  is a HEPA filter.  
         [0039]    In operation, the blower motor  28  is first engaged so as to activate the air blower  14  and to rotate the floor brush  24  via the brush drive belt  30 . The vacuum cleaner  10  is then pushed across a dusty horizontal surface, such as a floor or a rug, using the handle  96  disposed at the top of the chasse  12 .  
         [0040]    As the vacuum cleaner  10  is pushed across the dusty horizontal surface, dust from the horizontal surface is drawn upwardly within a dusty air stream and enters the vacuum cleaner  10  through the air inlet  22  in the base unit  18 . The duct work  92  directs the incoming dusty air stream into the inlet chamber  32  in tangential fashion, such that the incoming air stream within the inlet chamber  32  spirals downwardly about the internal surface  48  of the sidewalls  38  of the inlet chamber  32 . After the dust-laden air stream swirls into the lower section  44  of the inlet chamber  32 , the air stream reverses direction, drops in velocity and proceeds upwardly towards the outlet chamber  34 . As the air reverses direction and drops in velocity, most of the entrained dust and dirt within the air stream falls out of the air stream falls out of the air stream and collects at the bottom of the inlet chamber  32 . The air stream then flows upwardly past the exterior perimeter edge member  70  of the outlet chamber  34  and then into the outlet chamber  34  via the plurality of inlet apertures  56 . Within the outlet chamber  34 , the air stream passes through the cylindrical filter  76 , where additional dust within the air stream is removed. The air stream is then drawn upwardly through the top wall opening  78  of the outlet chamber  34 . As the air passes through the top wall opening  78 , it is filtered a second time through the planar filter  80  disposed across the top wall opening  78 . The air exiting the outlet chamber  34  is then drawn into the blower  14  via the duct work  92 . At the outlet of the blower  14 , the air is filtered a third time through the blower filter  94 . After exiting the blower filter  94 , the air is exhausted to the atmosphere.  
         [0041]    Dust and dirt which collects within the lower section  44  of the dust extraction and collection unit  16  can be easily removed from the inlet chamber  32 . The user depresses the unlatch button  91  at the upper portion of the handle. This action depresses the latch mechanism  90  out of the corresponding recess in the chasse  12  and allows the dust extraction and collection unit  16  to be removed from the chasse  12 . After removal from the chasse  12 , the dust extraction and collection unit  16  is taken to a refuse bin. At this point, the locking pin button  100  is depressed on the hook latch  98  to disengage the hook latch  98  from the bottom wall  36 . This action allows the bottom wall  36  to pivot away from the body portion  35 , thereby opening the inlet chamber  32  and allowing dust and dirt disposed within the inlet chamber  32  to gravitate out of the inlet chamber  32  into the refuse bin. Once all dust and dirt has been removed from the inlet chamber  32 , the bottom wall  36  is pivoted back into abutment with the body portion  35  and the hook latch  98  is snapped into place so as to retain the bottom wall  36  against the body portion  35 . The dust collection and extraction unit  16  is then reinstalled within the chasse  12 , and the vacuum cleaner  10  is again ready for operation.  
         [0042]    The invention has been found to provide a vacuum cleaner with all the conveniences of prior art vacuum cleaners, but with increased dust removal efficiency and without excessive mechanical complexity and resulting expense of manufacture. The invention further provides a simple and convenient method of removing accumulated dust and dirt from the vacuum cleaner using a unique dust extraction and collection unit having a bottom wall capable of pivotally opening downwardly.  
         [0043]    Having thus described the invention, it should be apparent that numerous structural modifications and adaptations may be resorted to without departing from the scope and fair meaning of the instant invention as set forth hereinabove and as described hereinbelow by the claims.