Abstract:
A floor sweeper that picks up large particles without compromising the ability to collect dust. First and second rotary brush parts received in respective concavities in a base of the sweeper, have mouths disposed at different heights.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a floor sweeper including rotary brushes for sweeping matter into an on-board container. 
       BACKGROUND OF THE INVENTION 
       [0002]    Various different configurations of rotary brush sweepers are known in the art, and these lightweight devices are a low cost alternative to vacuum cleaners. Such sweepers typically include a housing, one or more power-driven rotary brushes that brush the carpet or other floor surface in order to lift dust, dirt particles, and other soiling material from the floor, and rollers, or glide elements that roll or glide along the floor so as to support the sweeper. 
         [0003]    U.S. Pat. No. 7,152,267 describes a portable floor sweeper having motorised rotary brushes mounted around all four sides of the sweeper head. Together with an elongate handle mounted by a universal joint this allows the sweeper to provide cleaning action in any direction in which it is moved. The sweeper performs satisfactorily for picking up dust, dirt and like small particles, however the very low profile sweeper head means that performance for sweeping up larger pieces is compromised. It is an object of the present invention to overcome or substantially ameliorate the above disadvantages or more generally to provide an improved handheld floor sweeper. 
       DISCLOSURE OF THE INVENTION 
       [0004]    According to one aspect of the present invention there is provided a portable floor sweeper, comprising:
       a body having a periphery, a base and a top;   a container for receiving debris;   first and second brush parts, each brush part comprising at least a portion of one or more elongate rotary brushes mounted to the body;   drive means to rotate the brush parts;   first and second concavities in the base adjacent the periphery of the body, each concavity holding a respective one of the first and second brush parts the sweeper defining a floor-simulating plane which simulates a planar floor supporting the sweeper in use, a mouth of each concavity having a height measured perpendicular to the floor-simulating plane, each brush part having a periphery engaging or spaced apart from the floor-simulating plane such that debris entering through each mouth and engaged by one of the brush parts is propelled into the container, and wherein the heights of the mouths of the concavities vary relative to one another such that matter too large to enter the mouth of one concavity may enter the mouth of the other concavity.       
 
         [0010]    The concavities may be adjacent, or non-adjacent, contiguous, or non-contiguous. The brush parts may rotate about the same axis or different axes. The periphery of each brush part may have a constant diameter, or a variable diameter. One brush may include two brush parts of different diameters, for instance. 
         [0011]    Preferably the sweeper further comprises an elongate handle for moving the body across a floor, the periphery of the body is substantially polygonal, each of the brushes having a linear axis. Preferably the axes are arranged substantially orthogonal to one another. Alternatively, the periphery of the body may, for instance, be circular, with each brush having an arcuate form complementary to the circular periphery. 
         [0012]    Preferably the first and second brush parts comprise, respectively, first and second elongate rotary brushes, the body is substantially rectangular with a pair of short sides and a pair of long sides, and the first and second concavities lie adjacent one of the long sides and one of the short sides respectively and the sweeper further comprises:
       third and fourth concavities in the base adjacent the other of the of the long sides and the short sides respectively;   third and fourth elongate rotary brushes received in the third and fourth concavities respectively;   a mouth of each concavity having a height measured perpendicular to the floor-simulating plane, such that debris entering through each mouth and engaged by a respective one of the brushes is propelled by the respective one of the brushes into the container.       
 
         [0016]    Preferably the heights of the mouths of the first and third concavities are substantially the same, and the heights of the mouths of the second and fourth concavities are substantially the same. 
         [0017]    Preferably each mouth has an edge substantially parallel to the floor-simulating plane. 
         [0018]    Optionally the height of the mouth of the second concavity exceeds that of the first concavity, the first brush part engages the floor-simulating plane and the second brush part is spaced from the floor-simulating plane. 
         [0019]    Optionally the first and second brush parts comprise, respectively, first and second elongate rotary brushes, the sweeper further includes a concavity wall bounding the second concavity and moveably mounted to the body, such that the concavity wall defines the mouth of the second cavity whereby movement of the concavity wall varies the height of the mouth of the second concavity relative to the height of the mouth of the first concavity. 
         [0020]    Preferably the concavity wall is moveable relative to the body to maintain the edge of the mouth parallel with the floor-simulating plane, for instance by sliding or pivoting. 
         [0021]    Preferably the second rotary brush is fixed to move with the concavity wall. 
         [0022]    Preferably the body defines a passage extending between the mouth and the container, the passage includes a narrow throat and the concavity wall is moveable relative to the body to simultaneously increase the height of the mouth and the size of the throat. 
         [0023]    Optionally the sweeper further includes a floor-engaging support moveably mounted to the body for supporting the sweeper for movement around the floor, the support having a portion intersecting the floor-simulating plane whereby movement of the support varies the height of the mouth of the second concavity relative to the height of the mouth of the first concavity. 
         [0024]    In another aspect the invention provides a portable floor sweeper, comprising:
       a body having a periphery, a base and a top;   a container for receiving debris;   an elongate rotary brush mounted to the body;   drive means to rotate the rotary brush;   a concavity in the base adjacent the periphery of the body holding the first brush such that the brush engages a floor-simulating plane which simulates a planar floor supporting the sweeper in use, a mouth of the concavity having a height measured perpendicular to the floor-simulating plane, such that debris entering through the mouth is propelled by the brush into the container;   support means for engaging the floor-simulating plane to support the sweeper upon a floor, and wherein the concavity is moveably mounted such that the height of the mouth of the concavity may be varied.       
 
         [0031]    The support means may comprise, for instance, one or more glide elements, castor wheels, rollers etc. Preferably the elongate rotary brush is mounted to the concavity to move with the concavity relative to the body. 
         [0032]    Optionally the portable floor sweeper further comprises a pivot connecting the concavity to the body whereby the concavity is moveably mounted such that the height of the mouth of the concavity may be varied. The portable floor sweeper may further comprise a first mechanism including a pedal manually actuable to rotate the concavity about the pivot. A debris passage extending between the mouth of the concavity and the dirt container includes a throat, and the concavity is configured such that raising the concavity to its raised position increases the dimension of the throat. 
         [0033]    Optionally the portable floor sweeper further comprises a second mechanism connecting the support means on at least one side of the body, and actuable for extending and retracting the support means relative to the body, and by which the concavity and attached body are mounted to move together such that the height of the mouth of the concavity may be varied. Preferably the second mechanism includes a pedal and operates with a toggle action. 
         [0034]    The first and second mechanisms may directly connect a respective pedal to the concavity or support means respectively, such that pressing and releasing the pedal directly raises and lowers the concavity. Alternatively, the first and second mechanisms may operate with a toggle action, whereby one push on the pedal extends the concavity or support means and latches it in the extended position, while a subsequent push unlatches and lowers the concavity or support means. In other embodiments (not shown) the mechanisms may be operated by a button on the handle, instead of by a pedal. The mechanisms may be entirely mechanical, or it may include powered actuators such as rotary or linear motors. The button may be connected by a conductor or a wireless connection to a controller for operating the powered actuators. 
         [0035]    This invention provides a sweeper which is effective and efficient in operational use, and which allows the user to readily sweep material of a range of sizes, from small particles to larger pieces, while still providing a device that may be economically constructed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0036]    Preferred forms of the present invention will now be described by way of example with reference to the accompanying drawings, wherein: 
           [0037]      FIG. 1  is a perspective view from above of a first embodiment of a sweeper of the invention; 
           [0038]      FIG. 2  is a perspective view from below of the sweeper head of the sweeper of  FIG. 1 ; 
           [0039]      FIG. 3  is a perspective view from above of the principal operating components of the sweeper head of  FIG. 1 ; 
           [0040]      FIG. 4  is a transverse section through a sweeper head of the sweeper of  FIG. 1 ; 
           [0041]      FIG. 5  is a longitudinal section through a sweeper head of the sweeper of  FIG. 1 ; 
           [0042]      FIGS. 6   a  and  6   b  are fragmentary side and end views respectively of a second embodiment of a sweeper head of the invention; 
           [0043]      FIGS. 7   a  and  7   b  are schematic sections through a third embodiment of a sweeper head of the invention, showing two operating positions; 
           [0044]      FIG. 8  is a longitudinal section through a fourth embodiment of a sweeper head of the invention, showing two operating positions, and 
           [0045]      FIG. 9  is a fragmentary detail of an alternative transmission for transmitting torque between two brushes of a sweeper head of the invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0046]    Referring to  FIGS. 1 and 2 , a first embodiment of a sweeper  10  of the present invention includes a sweeper head  11  connected to an elongate handle  12  by a universal joint  13 . The handle  12  is assembled from three elongate generally tubular sections  14 - 16  releasably connected end to end. The innermost tubular section  14  bifurcates at its end to from a yoke  17  of the universal joint  13 . The intermediate tubular section  15  serves to hold a battery pack, receiving a plurality of battery cells stacked therein. The batteries provide power to the sweeper head  11  via a conductor  155  which may be coiled. At an end of the outermost tubular section  16  is a grip  19  which is grasped by the user to move the sweeper  10  over a floor. Alternatively, an external battery pack (not shown) may be releasably mounted to the handle  12  for supplying power to the sweeper head  11 . Furthermore, it will be understood that the sweeper  10  may be powered from an external source, as by an electrical cord (not shown) connected to a mains power supply. The universal joint  13  includes two mutually perpendicular pivots, although other types of universal pivot connections can be utilized as will be apparent to those skilled in the art of mechanical pivot connections. It is important that the handle  12  freely rotates about the point of connection between the sweeper head  11  and the handle  12 . 
         [0047]    The sweeper head  11  may have a generally rectangular form, with a central recess in its upper side in which the universal joint  13  is located. The head  11  has a body  21  comprised of a top  22 , and a periphery including opposing short sides  23  and  24  and long sides  25  and  26 . Opposite the top  22  is a bottom  27 . 
         [0048]    Formed in the body  21  so as to open in the bottom  27  are four concavities  28 - 31 , each adjacent a respective one of the sides  23 - 26 , and each receiving a rotary brush  33 - 36 . The brushes  33 - 36  are arranged adjacent the sides of a generally rectangular dirt container  32  having a closure  37 . The closure  37  is connected to the body to pivot about an axis along its long edge. A push-button  94  unlatches the closure  37  allowing it to swing outwardly to empty the dirt container  32 . The closure is latched in the closed position (shown in the drawings) and the latching mechanism connected to the push-button  94  is not shown. 
         [0049]    Each of the brushes  33 - 36  includes a plurality of soft, flexible fingers  38  formed of an elastomeric material, and protruding from a shaft  39 . Alternatively, some or all of the fingers  38  may be in the form of tufts of individual elongate fibres or bristles. The fingers  38  contact the floor surface to be cleaned and sweep the debris up into the container  32 . The fingers  38  may protrude radially, and may be spaced as shown in a helical pattern along each brush. The diameter of each brush, defined by the tips of the fingers  38 , is the same in the embodiment shown, but brushes with different diameters may also be used. Opposite ends of each shaft  39  are mounted to the sweeper head  11  for rotation by means of journals  40  supported by mounts  43  disposed in the corners of the body  21 , each mount  43  comprising inner and outer parts  41 ,  42 . A rotary electric motor  44  disposed in the dirt container  32  is provided for rotating the brushes  33 - 36  and is operatively connected to the brush  33  by a right-angle gear drive including pinion  46  and wheel  45 . A gear train  47  (described in detail with reference to  FIG. 9 ) is disposed in each corner of the sweeper head, by which adjacent brushes are meshed with one another, thereby torque is transmitted via brush  33  to the brushes  34  and  36 , which in turn transmit torque to the brush  35 . In an alternative embodiment (not shown) pulleys or toothed wheels may be fixed to the ends of the brushes, and a plain or toothed belt or a chain used to transmit torque between adjacent brushes. 
         [0050]    Four coplanar glide elements  48  on the mounts  42  have a soft or smooth surface and serve to support the sweeper head  11 , allowing it to easily slide over the floor in any direction. Optionally, the glide elements  48  may comprise textile pads, polymer blocks or like known glide elements. 
         [0051]    Referring to  FIG. 4 , the concavities  28  and  30  adjacent the long sides  25  and  26  and their respective long brushes  35  and  33  are shown in cross section, with reference to a floor-simulating plane  50  upon which the glide elements  48  rest in use such that both of the brushes  35 ,  33  engage the plane  50 . A mouth  53   a  of each concavity  28 ,  30  has a height  51   a  measured perpendicular to the floor-simulating plane  50  and defined by an edge  54  of the body  21 . Debris entering through each mouth  53   a  may be propelled by one of the brushes up the inclined face  52  into the container  32 . The axes of the long brushes  35 ,  33  are coplanar, as are the edges  54  bounding the long concavities  28 ,  30 . 
         [0052]    Correspondingly,  FIG. 5  shows the concavities  29  and  31  adjacent the short sides  24  and  23  and their respective short brushes  34  and  36  with reference to the floor-simulating plane  50 . A mouth  53   b  of each concavity  29 ,  31  has a height  51   b  measured perpendicular to the floor-simulating plane  50  and defined by an edge  55  of the body  21 . The axes of the short brushes  34 ,  36  are coplanar, as are the edges  55  bounding the short concavities  29 ,  31 . 
         [0053]    In this first embodiment of the invention the height  51   b  of both mouths  53   b  exceeds the height  51   a  of both mouths  53   a.  To allow larger debris to pass, the short brushes  34 ,  36  are spaced apart from the plane  50 , as well as being further apart from the inclined face  52  than is the case with the long brushes  33 ,  35 . However, it will be understood that the short brushes  34 ,  36  need not be spaced apart from the plane  50 , and from the inclined face  52  and that the small diameter brushes  34 ,  36  shown could be replaced by larger diameter brushes, as indicated by the dashed outline  34   a.  In use, the sweeper  10  may be moved generally parallel to its long axis and if some matter is found to be too large to enter the mouths  51   a,  the tool may be turned to enter the matter through one of the mouths  51   b.    
         [0054]    In a second embodiment of the sweeper head  211 , shown in  FIGS. 6   a  and  6   b , three motor-driven brushes  60 ,  61 ,  62  are received in respective concavities  65 ,  66 ,  67  spaced end-to-end along the long side of a sweeper head, for instance to replace a single brush  33 ,  35  of the first embodiment. However in other respects the sweeper head  211 , but may otherwise have like construction to the sweeper head  11  of the first embodiment. The brushes  60 - 62  are elongate and fixed to the sweeper head  211  to rotate about respective parallel axes. Opposing ends of the central brush  61  are connected, as by belt drives  64  to the inner ends of the outer brushes  60  and  62  such that all are rotated simultaneously. The brush  62  engages the plane  50 , while brushes  60  and  61  are spaced apart from the plane  50 , with brush  60  uppermost. The edges of the mouths of the concavities  65 ,  66 ,  67  are parallel to the axes of the brushes, and at respective heights  51   e,    51   d  and  51   c,  such that matter found to be too large to enter the mouths of concavities  67  and  66 , may enter the mouth of concavity  65 . 
         [0055]    A third embodiment of the invention is illustrated in  FIGS. 7   a  and  7   b , in which the height of the mouth  70  of a concavity  71  may be varied between heights  51   f  and  51   g,  preferably together with a corresponding variation in the spacing of the brush  72  from the plane  50 . The concavity  71  holding the brush  72  is formed in a housing section  73  connected to the body of the sweeper head  311  by a pivot  75  and to which the opposing ends of the brush  72  are mounted in journals (not shown). A belt drive (not shown) may provide torque to the brush  72  via a pulley coaxial with the pivot  75 . A pedal  79  connected to a cavity-extending mechanism  76  is operatively connected to the housing section  73  for moving it from its lowered position (shown in  FIG. 7   b ) to its raised position (shown in  FIG. 7   a ). The debris passage extending between the mouth  70  and the dirt container  32  includes a throat  77 , and is configured such that raising the housing section  73  to its raised position increases the dimension of the throat  77 . The sweeper head  311  may be supported on the plane  50  upon one or more wheels, such as castors  78 . The sweeper head  311  is rectangular and the housing section  73  is provided along one side, while the other three sides may be constructed substantially like construction to the sweeper head  11  of the first embodiment. In use, the user actuates the mechanism  76  to raise the housing section  73  to sweep up pieces  78  too large to be picked up otherwise, before moving the sweeper head  311  to enter the pieces  78  into the mouth  70 , whereupon the mechanism  76  may be released. The housing section  73  may drop, assisting in pushing the pieces  78  into the container  32 . 
         [0056]    Referring to  FIG. 8 , in a fourth embodiment of the invention has generally like construction to the sweeper head  11  of the first embodiment, however in place of at least one of the glide elements, the sweeper head  411  is supported upon one or more wheels, such as castor  74 . A wheel-extending mechanism  80  is operatively connected to the castor  74  and is actuable by pedal  81  to move the castor  74  between the extended and retracted positions shown. The mechanism  80  may operate with a toggle action, whereby one push on the pedal  81  extends the castor  74  to raise at least one side of the sweeper head  411  and latches it in the extended position, while a subsequent push unlatches the castor  74 , lowering the sweeper