Abstract:
A hand held blower/vacuum device includes an impeller mounted in a scroll housing and a handle by which the device may be suspended and which is rotatably mounted to turn between vacuum and blower positions. In both of the blower and vacuum positions a longitudinal axis of the grip generally lies in an upright plane that passes through a centre of gravity of the device, and the grip is disposed above the centre of gravity, such that the device hangs below the grip in different balanced orientations in the blower and vacuum positions.

Description:
RELATED APPLICATION DATA 
       [0001]    This application claims priority under 35 U.S.C. §119(a) to PCT/CN2013/075563 filed May 13, 2013, the entire contents of which are incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    The present invention relates to blower-vacuum devices, commonly referred to as blowervacs, which are typically used for collecting garden waste, such as leaves, grass cuttings and twigs. 
         [0003]    Blowervacs have both vacuum and blower modes of operation and generally comprise a motor having an output shaft connected to an impeller. The impeller is enclosed within a volute or scroll housing and is configured to draw air in along its axis of rotation through an inlet and expel air out tangentially from an outlet when the impeller is driven by the motor. In the blowing mode of operation, clean air is drawn axially into the scroll housing from the atmosphere and a blower tube is attached to the outlet in order to concentrate and direct the expelled air into a jet. In the vacuuming mode, waste is most commonly drawn in through the inlet via a vacuum tube, and an air-porous receptable is attached directly to the outlet from the scroll housing, so that the impeller comminutes the waste. 
         [0004]    U.S. Pat. No. 4,644,606 describes a blowervac with a main handle integral with the impeller housing and comprising first and sections acutely inclined to one another, the first section having an axis generally parallel to the axis of the air outlet. When the first section of the handle is gripped by an operator the device will be in the vacuum mode with the air outlet in a generally horizontal position. When the second section of the handle is gripped, the device will be in the blower mode with the air outlet facing ahead of the operator at a downward angle. Owing to this arrangement, for satisfactory ergonomic performance, particularly when raising and lowering the vacuum tube in use, a secondary handle must also be provided to allow the user to apply the requisite torque to the device. Thus, while single-handed blowing operation is possible, but both hands are required for a vacuum operation. It is an object of the present invention to overcome or substantially ameliorate the above disadvantages or, more generally, to provide an improved blower/vacuum device. 
       SUMMARY 
       [0005]    According to one aspect of the present invention there is provided a hand held blower/vacuum device comprising: 
         [0006]    an impeller having an impeller axis; 
         [0007]    a motor for rotating the impeller; 
         [0008]    a body for supporting the motor and impeller, the body including a scroll housing for enclosing the impeller; 
         [0009]    an air inlet in the scroll housing that is aligned axially; 
         [0010]    an air outlet in the scroll housing, and 
         [0011]    a handle having an elongate grip, the handle being rotatably connected to the body to turn between at least two positions, a blower position for operation in a blower mode in which the air inlet is generally horizontal and the air outlet is generally inclined at a downward angle, and a vacuum position for operation in a vacuum mode in which the air inlet is generally inclined at a downward angle, wherein in both of the blower and vacuum positions a longitudinal axis of the grip generally lies in an upright plane that passes through a centre of gravity of the device, and the grip is disposed above the centre of gravity, such that the device hangs below the grip in different balanced orientations in the blower and vacuum positions. 
         [0012]    Preferably the handle is connected to the body by a pivot having a pivot axis that passes through the centre of gravity. 
         [0013]    Preferably the pivot axis is generally perpendicular to, and intersects with, the impeller axis. 
         [0014]    Preferably the pivot axis is generally coplanar with the longitudinal axis of the grip. 
         [0015]    Preferably the handle is the only handle on the device. 
         [0016]    Preferably the handle has longitudinally opposing distal and proximal ends. 
         [0017]    Preferably the longitudinal axis of the grip is curved, and a section of the longitudinal axis adjacent the distal end is approximately parallel to the pivot axis. 
         [0018]    Preferably the device further comprises a clamp for clamping the proximal end in the blower and vacuum positions. 
         [0019]    This invention provides a device which is effective and efficient in operational use, and which has an overall simple design which minimizes manufacturing costs and maximizes performance, by providing improved ergonomic performance that allows safe and comfortable single-handed operation for both blowing and vacuuming. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]    Preferred forms of the present invention will now be described by way of example with reference to the accompanying drawings, wherein: 
           [0021]      FIG. 1  is a view the device of the present invention in the blower mode; 
           [0022]      FIG. 2  is a section through the scroll housing of the device of  FIG. 1  perpendicular to the impeller axis; 
           [0023]      FIG. 3  is a view the device of the device of  FIG. 1  in the vacuum mode; 
           [0024]      FIGS. 4 and 5  are side and end views, respectively, of the device of  FIG. 1  in the vacuum mode; 
           [0025]      FIG. 6  is a view of a user using the device of  FIG. 1  in the vacuum mode; 
           [0026]      FIGS. 7 and 8  are side and end views, respectively, of the device of  FIG. 1  in the vacuum mode, and 
           [0027]      FIG. 9  is a view of a user using the device of  FIG. 1  in the blower mode. 
       
    
    
     DETAILED DESCRIPTION 
       [0028]    Referring to  FIGS. 1 and 2 , a hand held blowervac device  10  includes a body  11  that supports an impeller  53  and a motor  21 . The body  11  may be an assembly of multiple parts and provides a structural frame for the tool. The body  11  may comprise an impeller scroll housing  11   a  and motor mounting section  11   b.  The scroll housing  11   a  encloses the impeller  53  and has an air inlet  50  aligned with impeller axis  12 . An air outlet  51  redirects the generally tangential airflow generally along an outlet air flow axis  52  that may be aligned generally radially. The motor  21  is mounted in the motor mounting section  11   b,  which may be integral with a shell of the scroll housing  11   a.  The air outlet  51  may have an elongate blower nozzle  20  mounted thereon, for use in a blower mode. A handle  14  is elongate and includes an elongate grip  16 . The handle  14  may have a cantilever-type construction with the grip  16  adjacent its distal end  56 . A proximal end  54  the handle  14  is fixed by a pivot  15  to the body  11 . The grip  16  may be ovoid in cross-section and have a curved longitudinal axis  17  that generally lies within a handle plane  18  that intersects with a pivot axis  27  of the pivot  15 . The pivot axis  27  is thus generally coplanar with the longitudinal axis  17  of the grip  16 , and the handle plane  18  bisects the grip longitudinally. The handle  14  and handle plane  18  are illustrated in  FIG. 1  in a blower position for use as a blower, but shown in dashed outlines in a vacuum position, about 90° from the blower position. 
         [0029]    The pivot  15  may comprise a screw fastener  25  having a head  25   a  by which it may be gripped. The screw fastener  25  extends through an opening in the proximal end  54 , and is received in a complementary screw threaded aperture in the body  11 , such that the screw fastener provides a clamp for clamping the proximal end  54  in the blower and vacuum positions. By releasing the screw fastener  25  the handle  14  may be rotated. The blower and vacuum positions may be defined by stops (not shown) that are preferably 90° apart so as to restrain the angular movement. But alternatively the handle  14  could be rotated by 270° between operating positions. 
         [0030]    The pivot axis  27  of the pivot  15  may be transverse to the impeller axis  12  and, in particular may be aligned perpendicular to, and intersecting with, the impeller axis  12 . The pivot axis  27  may also generally lie in the handle plane  18 , in which with the longitudinal axis  17  of the grip  16  lies. Also, as shown in  FIGS. 4 ,  5 ,  7  and  8 , the pivot axis  27  may pass through a centre of gravity  60  of the device located, for instance, at the intersection of the axis  27  and the impeller axis  12 . 
         [0031]    The vacuum position is further shown in  FIGS. 3 to 5 , which illustrates the device  10  with a vacuum bag  30  attachable (or attached, as in  FIG. 4 ) to the air inlet  50  and a vacuum nozzle  31  attached. The blower position of the handle  14  is shown in dashed outline in  FIGS. 4  and  5 . The vacuum nozzle  31  may include a straight portion aligned with the impeller axis  12  and which is connected to the air inlet  50 . The vacuum nozzle  31  may taper to reduce in cross section toward an outer end  32 , which may be angled to the central axis  58 . 
         [0032]    As best seen in  FIGS. 4-6 , the handle  14  is turned to and fixed its vacuum position for use in a vacuum mode in which the impeller axis  12  generally lies in the handle plane  18 , which is upright, as shown. In this vacuum position, when carried by the grip  16  the centre of gravity  60  of the device  10  is below the grip  16 , thus gravity applies a stabilising moment that tends to maintain a balanced orientation in which the centre of gravity  60  lies in the handle plane  18  directly below the grip  16 . Owing to the alignment of the handle and grip  16 , a user is thus able to hold the blower/vacuum device at his side in this vacuum position, with the grip  16  aligned fore-and-aft, as shown in  FIG. 6 . The air inlet  50  and the impeller axis  12  are generally inclined at a downward angle, placing the outer end  32  of the vacuum nozzle  31  lowermost. By adjusting a grip position longitudinally along the grip  16  the user can move the centre of gravity  60  fore-and-aft to vary the downward angle of the impeller axis  12  in its stable, balanced position. Held in this way, the user can readily swing the device about a transverse horizontal axis perpendicular to the handle plane  18 . On the other hand, the user has little ability to apply a moment about a fore-and-aft horizontal axis in the same sense as the gravity-impelled stabilising moment. This allows the device to be readily used with a single hand. In this vacuum position, the distal end  56  projects forward and the air outlet  51  extends downward to the vacuum bag  30 . The vacuum bag  30  is releasably attached to air outlet  51 , and may be supported on the user by a shoulder strap  40  fixed to the vacuum bag  30  at a position spaced apart from the air outlet  51 . A control switch  41  may be mounted to the handle  14  near the distal end  56 , so as to be readily actuable in either blower or vacuum mode. 
         [0033]    The blower position of the handle  14  is shown in  FIGS. 7-9 , and in dashed outline the vacuum position of the handle  14 , as are the vacuum bag  30  and the vacuum nozzle  31 . The device is supported in a similar manner to that provided in the vacuum position, in as far as the grip  16  is held in a like orientation with the grip axis  17  extending fore-and-aft in the upright handle plane  18  and the centre of gravity  60  hanging below the grip  16 . However, as the drawings show, the rotation of the body  11  places it in a different balanced orientation relative to the handle  14 , and the handle is also rotated relative to the user, such that the distal end  56  projects rearward. The inlet and impeller axis  12  of the air inlet  50  is generally horizontal and the air outlet  51  and the outlet air flow axis  52  are generally inclined at a downward angle in the blower position. However, as the grip axis  17  is also aligned in the handle plane  18 , the device has like characteristics to the vacuum position, whereby adjusting the grip position longitudinally along the grip  16  allows the downward angle to be varied, and the orientation of the grip  16  provides good purchase for swinging the device about the transverse axis. 
         [0034]    Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof.