Abstract:
A device to separate particles from a gas stream. The device may be a vacuum cleaner ( 10 ) or an industrial dust extraction device. The vacuum cleaner ( 10 ) includes a rotor assembly ( 20 ) to which the gas stream is delivered, the rotor assembly ( 20 ) having a plurality of gates ( 42 ) that collect dust and open to deliver dust to an outlet chamber ( 23 ). The gates ( 42 ) include Cone or more gates ( 42 ) that may include a resilient deflectable flange that is movable between an open and a closed position to provide for passage of the dust to the chamber ( 23 ).

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to devices to separate material such as dust from a gas stream, and more particularly but not exclusively to vacuum cleaners. 
       BACKGROUND OF THE INVENTION 
       [0002]    There are various devices used to remove particles from air streams. Typically, in industrial applications, the devices are “cyclonic” devices that cause an air stream to rotate within a hollowed body so that particles move radially outward and engage the wall of the body so as to be removed. 
         [0003]    Vacuum cleaners also use cyclonic devices and/or filters to remove particles and/or filaments. However, typically, domestic vacuum cleaners, and vacuum cleaners employed by professional cleaning staff, include at least one filter through which the air passes before it exits via the exhaust of the vacuum cleaner. 
         [0004]    A disadvantage of “cyclonic” separators is that they do not remove all the material required. To address this issue, frequently filters are added at a position downstream of the “cyclonic” separator. However, this combination suffers from the disadvantage that the filters become blocked and the efficiency of the device diminishes. 
         [0005]    The centrifugal systems also employ a filter located generally downstream of the main centrifugal part of the system. These filters also become blocked and therefore this is a disadvantage since flow rates through the system diminish. 
         [0006]    The abovementioned “cyclonic” separators has a further disadvantage in that they operate efficiently only within relatively narrow ranges of operating conditions. For example, if air flow rates diminish, the separators become inefficient. 
       OBJECT OF THE INVENTION 
       [0007]    It is the object of the present invention to overcome or substantially ameliorate at least one of the above disadvantages. 
       SUMMARY OF THE INVENTION 
       [0008]    There is disclosed herein a device to separate particles from a gas stream, the device including: 
         [0009]    a chamber having an inlet and an outlet between which the gas flows in a predetermined direction through the chamber; 
         [0010]    a rotor mounted in the chamber for rotation about a rotation axis, the rotor including, 
         [0011]    a longitudinal passage extending through the rotor along which air passes in moving from the inlet to the outlet of the chamber, and 
         [0012]    a plurality of gates located radially outward of the passage which collect the particles from gas passing through the passage, the gates being operable to move between a closed position collecting the particles, and an open position providing for delivery of collected particles from a position exterior of the passage; and 
         [0013]    a cavity into which the particles is delivered from the gates. 
         [0014]    Preferably, each gate includes an upstream gate portion and a downstream gate portion, with the upstream gate portion being operable in an open position and a closed position, with the upstream gate portion in the open position providing for the flow of particles to the downstream gate portion, with the downstream gate portion being operable in an open position and a closed position, with the downstream gate portion in the open position providing for the delivery of particles to said cavity. 
         [0015]    Preferably, each gate is annular in configuration. 
         [0016]    Preferably, each gate includes a resilient flange resiliently urged to the closed position. 
         [0017]    In an alternative preferred form, each gate includes a gate member angularly movable to provide for the passage of particles past the gate. 
         [0018]    In a still further alternative preferred form, each gate includes an annular resilient flange having an upstream portion and a downstream portion, each portion being resilient movable between an open position and a closed position. 
         [0019]    Preferably, said inlet includes an inlet duct causing the gas stream to follow an arcuate path to urge particles in a predetermined direction, and said device further includes an inlet gate which collects particles, the inlet gate being operable in an open position and a closed position, with the inlet gate in the open position providing for the removal of particles from the gas stream. 
         [0020]    Preferably, said inlet includes a plurality of bars on said path between which the gas stream passes, with the bars being adapted to engage particles to aid in removing particles from the gas stream for delivery to said inlet gate. 
         [0021]    Preferably, said inlet includes an upstream inlet portion and a downstream inlet portion, said downstream inlet portion communicating with said rotor and causing particles to pass along an arcuate path to urge particles in a predetermined direction so as not to enter the rotor. 
         [0022]    Preferably, said cavity is a first chamber to receive the particles, and said device includes a second chamber, with said first chamber being in communication with the downstream inlet portion so as to receive particles therefrom, and a second chamber, the second chamber communicating with the upstream inlet portion so as to receive particles therefrom. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]    Preferred forms of the present invention will now be described by way of example with reference to the accompanying drawings wherein: 
           [0024]      FIG. 1  is a schematic sectioned side elevation of a vacuum cleaner; 
           [0025]      FIG. 2  is a schematic isometric view of a portion of a vacuum cleaner of  FIG. 1 ; 
           [0026]      FIG. 3  is a schematic section side elevation of a rotor assembly employed in the vacuum cleaner of  FIG. 1 ; 
           [0027]      FIG. 4  is a schematic isometric view of an end portion of the rotor assembly of  FIG. 3 ; 
           [0028]      FIG. 5  is a schematic isometric view of an intermediate portion of the rotor assembly of  FIG. 3 ; 
           [0029]      FIG. 6  is a sequence of schematic side elevations illustrating operation of gates employed in the rotor assembly of  FIG. 3 ; 
           [0030]      FIG. 7  is a sequence of schematic side elevations illustrating an alternative gate assembly to that of  FIG. 6 ; 
           [0031]      FIG. 8  is a sequence of schematic side elevations illustrating an alternative gate arrangement to that of  FIG. 6 ; 
           [0032]      FIG. 9  is a schematic part section isometric view of an upper stream portion of the vacuum cleaner of  FIG. 1 ; 
           [0033]      FIG. 10  is a schematic side elevation of a modification of the vacuum cleaner of  FIG. 1 ; 
           [0034]      FIG. 11  is a further schematic isometric view of the vacuum cleaner portion of  FIG. 1 ; and 
           [0035]      FIG. 12  is a schematic side elevation of a modification of the gates employed in  FIGS. 4 ,  5  and  6 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0036]    In the accompanying drawings there is a schematically depicted a vacuum cleaner  10 . The vacuum cleaner  10  includes an inlet  11  to which air containing particles  12  is delivered. The inlet  11  communicates with a first particle chamber  13  to which heavier particles are delivered. Air enters the inlet  11  in the direction  14  so the heavier particles  12  are directed towards the chamber  13  to be collected therein. The chamber  13  would have a removable wall and/or maybe removable in its entirety to provide for emptying of the chamber  13 . 
         [0037]    Air entering into the inlet  11  passes along a first duct  15  with an outlet  16  (more fully depicted in  FIG. 9 ). Air leaving the outlet  16  moves angularly into a second duct  17 . As the air accelerates to change direction to the direction  70 , again particles are caused to move into engagement with an inlet gate  19 . As an example, the gate  19  may be movable angularly from a closed (collecting) position, to an open position at which the particles are delivered to the chamber  13 . The gate  19  may be opened as a result of weight of the particles engaged by the gate  19 , or maybe mechanically opened. Preferably, the gate  19  would be urged to the closed position. 
         [0038]    A duct  58  extends to a rotor assembly  20  having an inlet  21 . The inlet  21  is best seen in  FIG. 2 . From the inlet  21  air is delivered to a rotor  22  contained in a chamber  23 . The chamber  23  communicates with an outlet  24  via which air exits. 
         [0039]    The inlet  21  provides an end mounting  25  for the drive shaft  26 . Surrounding the mounting  25  is a wall  27 . The wall  27  is arcuate and extends angularly about the longitudinal axis  27 . The axis  67  being the longitudinal axis of the shaft  26  and chamber  23 . 
         [0040]    The chamber  23  is surrounded by a wall  28  that extends from the wall  27 . The wall  27  surrounds a cavity  29  to which the air is delivered from a duct  18 . However, air entering the chamber  29  from the duct  18  changes direction causing particles (generally heavier) to enter the particle outlet  30  so as to be directed to a dust receiving chamber  31 . 
         [0041]    Air enters the chamber  29  and is caused to circulate about the axis  67  with all the air being directed through annular opening  32 . The annular opening  32  surrounds a flange  33  fixed to an adjacent one end of the shaft  26 . The flange  33  has radially fins  34  that engaged the air and further enhance angular movement of the air about the axis  27 . The fins  34  also cause the air to move axially relative to the axis  67 . 
         [0042]    The annular opening  32  delivers air to an annular passage  35  extending through the rotor  22 . 
         [0043]    The rotor  22  includes the shaft  26 , supported by bearings  37 , that is driven by pulley  38 . The rotor  22  further includes fan blades  50  which causes the air to move longitudinally of the passage  35  as well as angularly about the axis  67 . The rotor  22  also includes an inner sleeve  39  that extends longitudinally of and angularly about the axis  67  and provides a plurality of annular ridges  40 . The sleeve  39  is attached to the shaft  26  and therefore rotates with the shaft  26  together with the blades  50 . 
         [0044]    The rotor  22  further includes an outer sleeve  36 . The sleeve  36  has a gate assembly  41  that surrounds the passage  35 , with the passage  35  being located between the assembly  41  and the sleeve  39 . The gate assembly  41  includes a plurality of gates  42 . In this embodiment, the gates  42  include annular resilient flanges  43  and  44 . The flanges  43  and  44  are supported by annular mountings  45  and  46 . The flanges  43  and  44  are formed of resilient flexible material and are movable from a closed position (as shown in  FIG. 5 ) to an open position allowing collected particles to enter the annular cavity  23  surrounding the sleeve  36 . From the cavity  23 , collected material is moved via air to the outlet  30 . The flanges  43  and  44  are resiliently urged to the closed position. 
         [0045]    The opening  32  is surrounded by an annular flange  48 , at the extremity of which there is provided an annular passage  49  which provides for the delivery of air and collected material to the outlet  30  from the cavity  23 . The flange  48  is part of the rotor assembly  20 . 
         [0046]    Each of the flanges  43  and  44  is mounted adjacent its radially inner edge and is movable angularly as best seen in the sequence of illustrations contained in  FIG. 6 . Initially, the flanges  43  and  44  are in a closed position until they collect sufficient material. Centrifugal force, resulting form rotation of the rotor  22 , is applied to the material which causes one or both the flanges  43  to deflect to an open position. The collected material then flows to engage flange  44 . The material again accumulates until centrifugal force opens the flange  44  to provide the delivery of collected material to the cavity  47 . The flanges  43  and  44  are resiliently urged to the closed position. 
         [0047]    The ridges  40  aid in directing particle matter toward the gates  42 . 
         [0048]    At the downstream end of the passage  35  there is provided an annular wall  65 , that closes the cavity  47 , that is fixed to the wall  28 . 
         [0049]    The mounting  45  has surfaces  51  and  52  that converge toward the axis  27  so as to provide an apex. The surfaces  51  and  52  are annular. The mounting  46  provides annular surfaces  53  and  54  that converge radially outward. 
         [0050]    Internally of the duct  17 , there is provided a plurality of shaped bars  55  between Which air passes to flow from the outlet  16  to the duct  18 . The bars  55  engage particles to aid in directing particles to the gate  19  for collection. Air passes between the bars  55 , with at least some particles engaging the bars  55  so as to he removed from the airstream for delivery to the gate  19 . 
         [0051]    In  FIG. 7 , there is schematically depicted an alternative construction for the gate assemblies  41 . In the embodiment of  FIG. 7 , the mounting  46  has two annular portions  56  and  57  that cooperate with a single resiliently formed gate flange  58 . The portions  56  and  57  are inclined, while the flange  58  has a first portion  59  joined to a second portion  60 . The portions  59  and  60  resiliently deform to essentially replace the two flanges  43  and  44  of the previous embodiment. The flange  58  initially collects the dust particles adjacent the portion  56 . When sufficient material has been accumulated, the centrifugal force applied to that material deforms the flange  58  so that the material passes to adjacent the portion  57 . When again sufficient material is collected, material is expelled by resilient deformation of the flange  58 . 
         [0052]    In the embodiment of  FIG. 8 , the flanges  43  and  44  arc replaced by a rotatable gate member  61 . The gate member  61  has a central shaft  62  from which there extends radially veins  63 . The veins  63  provide compartment  64  that collect the material and provide for delivery to the cavity  47 . Preferably, a resistance would be applied to the shaft  62  so that the member  61  only rotates as a result of centrifugal force being applied to the collected material. 
         [0053]    In the embodiment of  FIG. 10 , the cavity  47  is replaced with a collection chamber  62 . 
         [0054]    In  FIG. 11  there is schematically depicted the inlet  21  of  FIG. 2 . The wall  27  is provided with a surface  66  that aids in directing particles to the outlet  30 . The surface  66  may include a sloped portion that terminates with a surface  67 , or a ridge or fin (not illustrated) to aid in directing particles to the outlet  30 . The surface  66  may also include a slot  68  that receives collected particles and directs them to the outlet  30 . The slot  68  could be positioned adjacent the abovementioned ridge or fin. 
         [0055]    In the embodiment of  FIG. 12 , the previous gates  42  are modified. In this embodiment the annular mounting flanges  45  and  46  converge radially outwardly, with the mounting flange  46  having a radially extending annular plate  48 . Extending radially from the mounting flange  45  is a deformable annular flange  69 . The annular flange  69  is deflectable angularly in the direction  70  to provide for the flow of collected dust  72  past the gate  42 . If required annular sealing rings  71  can he provided between the flanges  68  and  69  to aid in retaining dust until the valve  42  is open.  FIG. 12  shows the sequence of operation of the gate  42 .