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The subject patent application claims priority to and all the benefits of Chinese Patent Application No. 2007-10023276.1, which was filed on 14 Jun. 2007 with the State Intellectual Property Office of the People&#39;s Republic of China. 
   FIELD OF THE INVENTION 
   The present invention relates to a portable blower-vacuum device. 
   BACKGROUND 
   A portable blower-vacuum device can be converted between a blowing mode or vacuum mode. Convertible blower-vacuum devices are widely used by homeowners and grounds keepers to keep outdoor areas clear of leaves, grass clippings and debris. 
   A conventional blower-vacuum device disclosed in U.S. Pat. No. 6,141,823 comprises a vacuum nozzle and a blower nozzle extending in parallel to each other and connected to a main body housing a fan and a motor. The main body is provided with a dust bag. In the vacuum mode, air is directly sucked from the vacuum nozzle and introduced into the dust bag by the rotation of the fan. In the blower mode, the air is similarly sucked from the vacuum nozzle and is directed towards the blower nozzle. The blower nozzle is tapered such that its diameter is gradually reduced towards the blower port in order to increase air velocity blowing through the blower nozzle. The vacuum nozzle has a constant diameter along its length. 
   Another blower-vacuum device is disclosed in U.S. Pat. No. 6,735,813. The blower-vacuum device includes a fan, a main body and a single nozzle. The main body is formed with a vacuum pathway upstream from the fan and a blower pathway downstream from the fan with respect to the flow of air. The main body is formed with an attachment hole in fluid communication with both the vacuum pathway and the blower pathway. The attachment hole supports the nozzle rotationally between a vacuum mode orientation and a blower mode orientation. 
   U.S. Pat. No. 4,476,607 discloses a lightweight portable vacuum cleaner and attachment nozzle which may be readily carried by an operator to vacuum both normally accessible and normally inaccessible areas. The vacuum cleaner comprises an elbow-shaped plastic housing which encloses a filter bag and blower motor. The vacuum is carried under the arm of the operator supported from a strap that goes over the operator&#39;s shoulder. 
   The aforementioned blower-vacuum devices are all provided with a straight vacuum nozzle having a length consistent with safety standards. This means that the vacuum nozzle or the blower/vacuum nozzle generally have a lengthy configuration. However the elongate nozzle leads to blower-vacuum device with a discordant design which makes it difficult to hold with only one handle when the operator converts it between the vacuum mode and the blower mode. 
   SUMMARY OF THE INVENTION 
   In order to overcomes certain disadvantages of the prior art, it is an object of the present invention to provide an improved blower-vacuum design which minimizes the length of the vacuum nozzle, whilst making the vacuum more effective and its operating more comfortable. 
   Thus viewed from the present invention provides a blower-vacuum device comprising: 
   a main body; 
   a motor operated by a switch which is housed in the main body; 
   a motor-driven fan capable of generating an air flow; 
   a vacuum nozzle associated with the main body upstream of the motor-driven fan and a blower nozzle associated with the main body downstream of the motor-driven fan, 
   wherein the vacuum nozzle comprises an elongate main portion extending substantially coaxially with an axis Z 1  of the main body and a terminal portion extending along an axis Z 2  angularly with respect to the axis Z 1  of the main body. 
   The vacuum nozzle may have a non-linear configuration. The configuration may be flat, tapered, round, trapezoidal or curved. The axis Z 2  may be offset from the axis of the fan. The blower nozzle may have any non-linear configuration. The configuration may be flat, tapered, round, trapezoidal or curved. 
   Typically the angle β between the axis Z 1  and the axis Z 2  is obtuse. Preferably the angle is in the range 90 to 180°, particularly preferably 120 to 150°. 
   Preferably the terminal portion extends along an axis Z 2  angularly away from the blower nozzle (eg upwardly away from the ground). 
   The vacuum nozzle may be positioned superior to (eg over) the blower nozzle. The blower nozzle may be positioned superior to (eg over) the vacuum nozzle. 
   Typically the terminal portion, the elongate main portion and the blower nozzle are substantially coplanar. 
   Preferably the length of the terminal portion is in the range 5 mm to 1 m. 
   Preferably the vacuum nozzle is positioned superior to (eg over) the blower nozzle. 
   Particularly preferably the vacuum nozzle is positioned superior to the blower nozzle and the vacuum nozzle has a deflection point, wherein the blower nozzle has a blower port at its distal end substantially adjacent to the deflection point. 
   Preferably the blower port is tapered substantially equiangularly to the angle β between the axis Z 1  and the axis Z 2   
   Preferably the vacuum nozzle and the blower nozzle are detachably associated with the main body and the vacuum nozzle is fixed to the blower nozzle. 
   Preferably the main body comprises: a motor housing the motor and a volute housing the fan, wherein the motor housing is formed integrally with the volute housing. 
   Preferably the blower-vacuum device further comprises: 
   a handle assembly, wherein the handle assembly comprises: a first grip section disposed on the main body and a second grip section disposed on the vacuum nozzle. 
   Preferably the blower-vacuum device further comprises: 
   a safety interlock, wherein the safety interlock is disposed between the first grip section and the second grip section such that only when the vacuum nozzle is attached to the main body is the motor activatable and only when the motor is inactive is the vacuum nozzle detachable. 
   Preferably the blower-vacuum device further comprises: 
   a variable airflow adjustment including an aperture in the blower nozzle and a rotatable collar mounted rotationally about the blower nozzle over the aperture. 
   Preferably the blower-vacuum device further comprises: 
   an airflow guide mechanism disposed between the vacuum nozzle and blower nozzle for guiding the airflow blowout from the aperture. 
   Viewed from a further aspect the present invention provides a blower-vacuum device comprising: 
   a main body; 
   a motor operated by a switch which is housed in the main body; 
   a motor-driven fan capable of generating an air flow; and 
   a vacuum nozzle associated with the main body upstream of the motor-driven fan and a blower nozzle associated with the main body downstream of the motor-driven fan, wherein the vacuum nozzle is curved and attached superiorly adjacent to the blower nozzle. 
   Viewed from a yet further aspect the present invention provides a blower-vacuum device convertible between a blower mode and a vacuum mode comprising: 
   a main body; 
   a motor operated by a switch which is housed in the main body; 
   a motor-driven fan capable of generating an air flow; 
   a nozzle attachment associated with the main body wherein the nozzle attachment comprises a vacuum nozzle which is curved. 
   The motor may comprise an electric motor, internal combustion engine or other type of power supply 
   The fan may include a debris engaging structure or serrations for facilitating a finer mulch of air-entrained debris. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will now be described in a non-limitative sense with reference to the accompanying Figures in which common reference numerals represent corresponding parts throughout: 
       FIG. 1  illustrates an embodiment of the blower-vacuum device of the present invention; 
       FIG. 2  is a cross-sectional view according to  FIG. 1 , wherein the nozzle attachment is disengaged from the main body; 
       FIG. 3  is a cross-sectional view according to  FIG. 1 ; 
       FIG. 4A  is an enlarged view taken along line A-A in  FIG. 1 , wherein the aperture of the blower nozzle is closed by the collar of airflow adjustment; 
       FIG. 4B  is an enlarged view taken along line A-A in  FIG. 1 , wherein the aperture communicates with the external atmosphere; 
       FIG. 5  is a partial enlarged view according to mark B in  FIG. 3 , wherein the interlock mechanism is shown; 
       FIG. 5A  is a schematic view according to  FIG. 5 , wherein the nozzle attachment is disengaged from the main body; 
       FIG. 5B  is a schematic view according to  FIG. 5 , wherein the nozzle attachment is engaged with the main body; 
       FIG. 5C  is a schematic view according to  FIG. 5 , wherein the nozzle attachment is engaged with the main body and the actuator is switched on; 
       FIG. 6A  is a schematic view according to the present invention, wherein the user holds the blower-vacuum with one hand in the vacuum mode; and 
       FIG. 6B  is a schematic view according to the present invention, wherein the user holds the blower-vacuum with one hand in the blower mode; 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   An embodiment of a portable blower-vacuum device  1  according to the invention is illustrated in  FIGS. 1 to 3 . The portable blower-vacuum device  1  comprises a main body  2  to which is connected stably and detachably an elongate nozzle attachment  10  and a collecting container (not shown). For the sake of illustration, arrow F indicates the front direction and arrow R indicates the rear direction of the blower-vacuum device  1 . 
   The main body  2  comprises a motor housing  2   a  which houses a motor  3  and a volute housing  2   b  formed integrally with the motor housing  2   a  which houses a fan  4 . The motor  3  imparts a rotational force to the fan  4  via an output shaft  3   a  which defines an axis Y. The fan  4  includes a plurality of vanes for generating an air-flow as the fan  4  is driven by the motor  3 . The volute housing  2   b  includes an inlet port  30  and an outlet port  31 . The elongate nozzle attachment  10  includes a vacuum nozzle  11  having a vacuum port  11   a  at its front end and a blower nozzle  12  having a blower port  12   a  at its front end. The vacuum nozzle  11  is connected superiorly adjacent to the blower nozzle  12  and forms a one-piece elongate nozzle attachment  10 . The vacuum nozzle  11  is substantially cylindrical and has a substantially constant diameter along its length. A dust nozzle  15  is connected to and positioned beneath the volute housing  2   b.    
   A rear end of the vacuum nozzle  11  is mounted on the inlet port  30  and a rear end of the blower nozzle  12  is mounted on the outlet port  31 . A safety interlock  20  is disposed between the main body  2  and elongate nozzle attachment  10  to ensure the safety of the operator. An electric cord  6  is attached to the rear end of the motor housing  2   a  for supplying power to the motor  3 . 
   A handle assembly  5  comprises an elongate first grip section  5   a  defining a first elongate central axis X 1  and a second grip section  5   b  defining a second central axis X 2  which are disposed respectively on the main body  2  and the vacuum nozzle  11 . When the elongate nozzle attachment  10  is attached to the main body  2 , the first grip section  5   a  is connected to the second grip section  5   b  forming an integrated operating handle  5 . The first axis X 1  and the second central axis X 2  form an integrated central axis of the handle assembly  5 . 
   A change-over switch  17  comprises a knob  17   a  disposed exteriorly to the main body  2  and a flap  17   b  disposed interiorly to the main body  2  for switching the device  1  between the blower mode and the vacuum mode. The operator can select the different operating modes only by rotating the knob  17   a  according to the orientations marked on the main body  2 . When the knob  17   a  is rotated in a counterclockwise direction from a first position to a second position (which is indicated with a broken line in  FIG. 1 ), the flap  17   b  engages the upper wall of the blower nozzle  12  so as to shut off the outlet port  31  (as indicated by a broken line in  FIG. 3 ). The volute housing  2   b  is in communication with the dust nozzle  15  and out of communication with the blower nozzle  12 . This arrangement constitutes the vacuum mode. By rotation of the knob  17   a  in a clockwise direction, the flap  17   b  engages a wall of the dust nozzle  15 . Thus the outlet port  31  is opened and the volute housing  2   b  is in communication with the blower nozzle  12 . This arrangement constitutes the blower mode in which the fan  4  rotates (as in the vacuum mode) so that air is sucked through the vacuum port  11   a  of the vacuum nozzle  11  and is introduced into the volute housing  2   b . The sucked air passes through the fan  4  and the outlet port  31  and is introduced into the blower nozzle  12  from where it is discharged through the blower port  12   a . The blower nozzle  12  has a tapered cylindrical configuration in which its diameter decreases gradually towards the blower port  12   a  such that air velocity blowing from the blower nozzle  12  is higher than air velocity sucked into the vacuum nozzle  11 . Accordingly, larger dust (and other) particles will not be sucked in through the vacuum port  11   a  in the blower mode. 
   The vacuum nozzle  11  has a main elongate portion  14   a  which extends along a longitudinal axis Z 1  and a deflected end portion  14   b  which extends along an axis Z 2 . In this embodiment, an angle β of approximately 145 degrees exists between Z 1  and Z 2 . The length of the blower nozzle  12  is shorter than the vacuum nozzle  11  and the blower port  12   a  of the blower nozzle  12  is approximately aligned with the point of deflection of the vacuum nozzle  11 . 
   A variable airflow adjustment  16  is made possible by an aperture  8  in the wall of the blower nozzle  12 . Mounted for rotation about the wall directly over the aperture  8  is a rotatable collar  13 . Referring to  FIG. 4A  and  FIG. 4B , the rotatable collar  13  has a partial apertured portion  13   a . By rotating collar  13 , the whole or a portion of aperture  8  in the tubular wall is exposed via the apertured portion  13   a  thereby enabling a preselected amount of airflow to be diverted out of the side of the wall to alter the airflow which is discharged from the blower port  12   a . An airflow guide mechanism  9  is disposed between the vacuum nozzle  11  and blower nozzle  12 . The airflow guide mechanism  9  comprises a pair of side plates  9   b  which is disposed beneath the vacuum nozzle  11  and on top of the aperture  8  of the blower nozzle  12 . The distance between the two side plates  9   b  is slight larger than the aperture  8 . A top plate  9   a  formed by the wall of the vacuum nozzle  11  and a back plate  9   c  located behind the airflow adjustment  16  are shown in  FIG. 3 . 
   Under the normal operating conditions of the blower mode, the airflow discharged from the blower port  12   a  is directed at debris such as grass or leaves which are mostly propelled forwardly. Some light debris is blown upwardly or backwards towards the user when the airflow guide mechanism  9  is closed. When the airflow adjustment  16  is opened, communication of the airflow between the aperture  8  and the apertured portion  13   a  of the collar  13  causes at least partial air overflow from the blower nozzle  12  through the aperture  8 . The partial airflow will be guided by the airflow guide mechanism  9  and help to blow forwardly from the rear of the blower nozzle  12   a  to avoid blowing the user. Thus the user can face and blow the debris to a distant location for removal. 
   Referring to  FIG. 5 , a switch  7  is located in the main body  2 . The safety interlock  20  comprises an actuating member  21  slidably mounted on the front end of the first grip section  5   a . The actuating member  21  is movable between a forward “on” position and a rearward “off” position. A locking member  24  is movably disposed in the main body  2 . A sliding unit  22  is disposed between the locking member  24  and the actuating member  21  for selectively engaging the actuating member  21 . The actuating member  21  comprises a key point  21   a  for actuating the switch  7 , a stop portion  21   b  and a stop portion  21   c . In order to activate the motor  3 , the switch  7  is depressed by the key point  21   a  of the actuating member  21  by moving the actuating member  21  forward along the direction indicated as the arrow. The locking member  24  comprises a press portion  24   a  which extends over the surface of the grip section  5   a . A hook  24   b  engaged with a recess  19  is disposed at a rear end of the second grip section  5   b . The locking member  24  is biased by a spring  25  which is located in the main body  2  for supporting the locking member  24  to move upwardly and downwardly. The sliding unit  22  has a protruding shoulder  22   a  disposed in the intermediate portion and a stop portion  22   b  disposed at its upper end. The sliding unit  22  is biased by a spring  23  which is disposed under the sliding unit  22 . In addition, an extending block  18  is disposed on the second grip section  5   b  of the nozzle attachment  10  (shown in  FIG. 2 ) for selectively engaging the protruding shoulder  22   a  of the sliding unit  22 . 
   Referring to  FIG. 5A , when the elongate nozzle attachment  10  disengages the main body  2 , the sliding unit  22  biased by the spring  23  is located at its first position. The stop portion  22   b  of the sliding unit  22  engages the stop portion  21   b  of the actuating member  21  for preventing the movement of the actuating member  21 . The locking member  24  is located at its first position biased by the spring  25 . 
   Referring to  FIG. 5B , when the elongate nozzle attachment  10  is attached to the main body  2 , it drives the sliding unit  22  to slide downwards to its second position against the action of the spring  23  by engaging the extending block  18  with the protruding shoulder  22   a  of the sliding unit  22 . Thus the stop portion  22   b  of the sliding unit  22  disengages the stop portion  21   b  of the actuating member  21  and the actuating member  21  can move forward along the direction indicated by the arrow to actuate the switch  7 . 
   Referring to  FIG. 5C , the actuating member  21  has moved forward to its “on” position and activated the switch  7  through the key point  21   a  of the actuating member  21 . At the same time, the end portion  21   b  and stop portion  21   c  are located between the sliding unit  22  and the locking member  24 . The end portion  21   b  is engaged with the stop portion  22   b . The end portion  21   b  prevents the press portion  24   a  moving downwardly by depressing the press portion  24   a . Thus the elongate nozzle attachment  10  is held securely to the main body  2  by the hook  24   b  and the recess  19  of the second grip section  5   b.    
   Only when the actuating member  21  is moved backwards to its “off” position can the press portion  24   a  be depressed to release the elongate nozzle attachment  10  from the main body  2 . The user holds the first grip section  5   a  with one hand and the second grip section  5   b  with the other hand to depress the press portion  24   a  with his thumb. The hook  24   b  disengages the recess  19  of the second grip section  5   b . When the elongate nozzle attachment  10  is detached from the main body  2 , the sliding unit  22  is urged into its first position ( FIG. 5A ) by the spring  23  to prevent the actuating member  21  from movement. Thus the motor  3  cannot be actuated by the switch  7  and the safety of the operator is ensured. Only when the elongate nozzle attachment  10  is attached to the main body  2  can the motor  3  be actuated by the switch  7  through movement of the actuating member  21 . The volute housing  2   b  and the fan  4  can be maintained only through removing the elongate nozzle attachment  10  from the main body  2 . The detachable connection between the nozzle attachment  10  and main body  2  makes the packaging convenient. 
   Referring to  FIG. 6A , the blower-vacuum device  1  is in vacuum mode. The vacuum port  11   a  and blower port  12   a  are close to the ground and terminate substantially in the same plane parallel to the ground. The height H of the blower nozzle  12  and vacuum nozzle  11  along the perpendicular direction is substantially equivalent. The construction of the elongate nozzle attachment  10  makes the centre of gravity of the blower-vacuum device  1  lower. Because of the elongate configuration of the first grip section  5   a , the user can adjust to different positions according to requirements. The user can operate the blower-vacuum device  1  with one hand only and a comfortable operating position can be obtained easily. 
   Referring to  FIG. 6B , the blower-vacuum device  1  is in blower mode. The user holds the first grip section  5   a  with one hand but the holding position has changed with respect to the vacuum mode. The blower-vacuum device  1  is elevated to make the operating position more comfortable.

Summary:
The present invention relates to a portable blower-vacuum device which comprises a motor ( 3 ) operated by a switch ( 7 ) and located in a main body ( 2 ) and a fan ( 4 ) drivable by the motor. A vacuum nozzle ( 11 ) and a blower nozzle ( 12 ) are associated with the main body and the vacuum nozzle comprises a main portion ( 14   a ) extending in a direction of an axis (Z 1 ) of the main portion and a terminal portion ( 14   b ) with an axis (Z 2 ) angularly disposed with respect to the axis (Z 1 ) of the main portion.