Patent Publication Number: US-10306843-B2

Title: Backpack leaf blower

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of co-pending U.S. patent application Ser. No. 13/544,700, filed Jul. 9, 2012, the entire contents of which are incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to a leaf blower and, more particularly, to a backpack leaf blower. 
     A leaf blower is a gardening tool that propels air out of a nozzle to move yard debris, such as leaves, twigs, and the like. Typically, these devices include a power source, such as an internal combustion or electric motor, driving a blower that in turn exhausts air under pressure. In most leaf blower designs, the air exhausted from the blower must travel through some type of elbow or bend before it can be directed through the output, reducing efficiency of the device. Furthermore, existing leaf blower designs generally position the motor (usually the heaviest part of the leaf blower) far away from the user&#39;s back, increasing the strain on the user and making the device uncomfortable to wear. 
     SUMMARY OF THE INVENTION 
     In some embodiments, the invention includes a leaf blower to be worn by a user, the leaf blower including a frame having a back plate defining a back plate plane and a blower system coupled to the frame. The blower system includes a motor having a drive shaft, the drive shaft defining an axis, and wherein the axis forms an angle with respect to the back plate plane between about 5 degrees and about 35 degrees. 
     In other embodiments, the invention includes a leaf blower to be worn by a user, the leaf blower including a frame having a back plate and a base plate extending from the back plate, wherein an angle is formed between the back plate and the base plate. The leaf blower also includes a blower system coupled to the base plate of the frame. Further, the angle between the back plate and the base plate is between about 55 degrees and about 85 degrees. 
     In still other embodiments, the invention includes a leaf blower to be worn by a user, the leaf blower including a frame having a back plate defining a back plate plane and a blower system coupled to the frame. The blower system includes a housing defining a chamber and an impeller at least partially positioned within the chamber and having an axis of rotation. The housing defines a working plane substantially perpendicular the axis of rotation of the impeller, wherein the working plane of the housing forms an angle with respect to the plane of the back plate between about 55 degrees and about 85 degrees. 
     In still other embodiments, the invention includes a leaf blower to be worn by a user, the leaf blower including a frame and a blower system coupled to the frame. The blower system includes a housing defining a chamber and an impeller at least partially positioned within the chamber and having an axis of rotation. The housing defines a working plane substantially perpendicular the axis of rotation of the impeller. The leaf blower also includes an output tube defining an axis therethrough where the axis of the output tube is substantially aligned with the working plane 
     In still other embodiments, the invention includes a leaf blower to be worn by a user, the leaf blower including a frame having a back plate defining a back plate plane, and a blower system coupled to the frame. Where the blower system includes a motor having a center of gravity, and wherein a distance between the back plate plane and the center of gravity is less than half a length of the leaf blower when the distance and the length is measured perpendicularly from the back plate plane. 
     Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a first side view of a backpack leaf blower according to one embodiment of the invention, and being worn by a user. 
         FIG. 2  is a second side view of the leaf blower shown in  FIG. 1 . 
         FIG. 3  is a rear view of the leaf blower shown in  FIG. 1 . 
         FIG. 4  is a partial section view of a blower system of the backpack leaf blower shown in  FIG. 1 . 
     
    
    
     Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of embodiment and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. 
     DETAILED DESCRIPTION 
       FIGS. 1-4  illustrate a leaf blower  10  to be worn by a user like a backpack. The leaf blower  10  includes a frame  14 , a harness (not shown) for securing the frame  14  to the user, a blower system  18  coupled to the frame  14 , and an output hose  22  for directing the blower&#39;s exhaust. During use, the blower system  18  produces a high pressure air flow capable of clearing leaves, twigs, and other debris from a given area. In the illustrated embodiment, the orientation of the blower system  18  on the frame  14  allows the output hose  22  to be attached without the use of an elbow or other curved ducting. As such, the present invention has reduced air resistance, which increases the efficiency of the device. 
     Illustrated in  FIGS. 1 and 2 , the frame  14  of the leaf blower  10  provides a mounting point for the blower system  18  and is shaped to be worn comfortably by the user. In the illustrated embodiment, the frame  14  is substantially “L” shaped, having a back plate  26  defining a back plate plane  30 , and a base plate  34  extending from a bottom  38  of the back plate  26  and defining a base plate plane  42 . When the leaf blower  10  is worn, the back plate  26  of the frame  14  contacts the user&#39;s back and is generally aligned with the user&#39;s spine ( FIG. 1 ). In some embodiments, the back plate  26  may be contoured to better correspond to the curvature of a user&#39;s back. In other embodiments, the back plate  26  may include padding, such as foam or fabric, to increase comfort. 
     The base plate  34  of the frame  14  extends from the back plate  26  proximate the bottom  38 , and forming an angle A therewith. The angle A is preferably between about 55 degrees and about 85 degrees, and in the illustrated embodiment is about 65 degrees. 
     Illustrated in  FIGS. 1, 2 and 4 , the blower system  18  is coupled to the frame  14  and includes a motor  46 , an impeller  48  driven by the motor  46 , and a housing  50  at least partially encompassing the impeller  48  and having an air inlet  54  and an air outlet  58 . During use, the motor  46  drives (e.g., rotates) the impeller  48  causing it to draw air into the air inlet  54  to be exhausted through the outlet  58  under pressure. More specifically, the illustrated blower system  18  is a centrifugal type blower, having an impeller  48  that draws air axially through the inlet  54  to be centrifugally forced out the outlet  58 . 
     In the illustrated embodiment, the blower system  18  is coupled to the frame  14  by three vibration isolating members  62  (e.g., rubber gaskets, springs, and the like). In the illustrated embodiment, the vibration isolating members  62  extend between the blower system  18  and the frame  14  (e.g., the base plate  34 ). During use, the vibration isolating members  62  at least partially absorb and dissipate any vibrations formed by the blower system  18  during use. In other embodiments, fewer or more isolating members  62  may be used. 
     The motor  46  of the blower assembly includes a drive shaft  64  defining an axis  66  therethrough. When the blower assembly  18  is assembled, the axis  66  of the drive shaft  64  forms an angle B with respect to the back plate plane  30  ( FIG. 1 ). The angle B is preferably between about 5 degrees and about 35 degrees, and in the illustrated embodiment is about 25 degrees. In the illustrated embodiment, the motor  46  is an internal combustion type motor, however in other embodiments, an electric motor or other type of power source may be used. 
     The orientation of the motor  46  with respect to the frame  14  allows the motor&#39;s center of gravity CG to be placed closer to the user&#39;s back, thereby making the backpack leaf blower  10  more comfortable and easier to carry. More specifically, a distance  16  between the center of gravity CG and the back plate  26  (i.e., CG S ) is less than half the overall length L of the leaf blower  10 , when each distance is measured perpendicularly from the back plate  26  (i.e., CG D &lt;L/2). 
     Referring to  FIG. 4 , the housing  50  of the blower system  18  defines a chamber  68  defining the air inlet  54  and the air outlet  58 . During operation, the motor  26  rotates the impeller  48  within the housing  50 , causing air to be drawn in through the inlet  54  and exhausted, under pressure, through the outlet  58 . Although not illustrated, the housing  50  may include one or more channels or walls to direct air within the chamber  68 . The housing  50  also defines a working plane  70 , substantially perpendicular to the axis of rotation  66  of the impeller  48 . In the illustrated embodiment, the working plane  70  forms an angle C with respect to the back plate plane  30 . The angle C is between about 55 degrees and about 85 degrees, and in the illustrated embodiment is about 65 degrees. 
     The output tube  22  extends from the air outlet  58  of the housing  50  and directs the high pressure exhaust of the blower system  18 . In the illustrated embodiment, the output tube  22  includes a flexible portion  74  connected to the air outlet  58  and a rigid portion  78  extending from the flexible portion  74  to a tube outlet  76 . When assembled, the user may adjust the rigid portion  78 , using it as a nozzle to direct the high pressure air stream from the blower system  18 . When the flexible portion  74  is straight and aligned with the rigid portion  78  (e.g., a “straightened configuration”), the output tube  22  extends along a tube axis  82 . 
     In the illustrated embodiment, the tube axis  82  of the output tube  22  is alignable with and to lie in the working plane  70  of the housing  50  ( FIG. 1 ). Also, in the illustrated embodiment, when the rigid portion  78  of the output tube  22  is in a rested position (e.g., the flexible portion  74  is straight (the straightened configuration)), the axis  82  is substantially perpendicular to the axis of rotation of the impeller  48  (and to the axis  66  of the drive shaft  64 ). By being aligned with and lying in the working plane  70  of the housing  50 , the high pressure air flow produced by the blower system  18  exits directly from the outlet  58  and through the output tube  22  without encountering any unnecessary resistance (e.g., by traveling through an elbow tube and the like). 
     The output tube  22  also includes a control handle  86  coupled to the rigid portion  78  to help the user control the orientation of the output tube  22 . In the illustrated embodiment, the control handle  86  includes one or more controls  90 , such as a trigger or throttle, to set the motor speed, ignition, and the like. 
     Although the invention is described with regards to a leaf blower, in further embodiments the same geometry and orientations may be used in other designs, such as blower vacs and the like. 
     Although the invention has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of one or more independent aspects of the invention as described.