Patent Publication Number: US-2007119057-A1

Title: High-branch shears

Description:
BACKGROUND OF THE INVENTION  
      The present invention is related to an improved high-branch shears in which an adjustment unit is fixed on the branch-shearing mechanism or the connecting rod. The high-branch shears includes a locating member for adjusting a distance between a movable member and a fixed seat. The high-branch shears can be operated to shear branches with less strength.  
       FIG. 10  shows a conventional high-branch shears having a connecting rod  61  and a shear seat  62  connected with one end of the connecting rod  61 . The shear seat  62  has a shear opening  621 . A shear board  63  is pivotally mounted on the shear seat  62 . The shear board  63  has a blade section  631  corresponding to the shear opening  621  of the shear seat  62 . A rocking arm  64  is pivotally connected with the shear seat  62 . One end of the shear board  63  distal from the. blade section  631  is pivotally connected with the rocking arm  64 . A restoring spring  65  is connected between the rocking arm  64  and the shear seat  62 . A movable pulley  66  is pivotally connected with one end of the rocking arm  64  distal from the shear seat  62 . An adjustment unit  67  is pivotally disposed at one end of the shear seat  62  distal from the rocking arm  64 . A cord  68  is passed through the movable pulley  66  and the adjustment unit  67 . By means of pulling the cord  68 , the rocking arm  64  is swung to drive the shear board  63 . The shear board  63  is pivoted, whereby the blade section  631  is moved relative to the shear opening  621  for shearing branches.  
      The adjustment unit  67  is pivotally disposed at the end of the shear seat  62  distal from the rocking arm  64 . When the rocking arm  64  is swung to shear the branches, the angle θ contained between the cord  68  between the fixed pulley  67  and the movable pulley  66  and the vertical line is several times enlarged as shown in  FIG. 11 . Under such circumstance, the component force Fa for downward pulling the pulley  66  is minified. In other words, the larger the amplitude of the downward swinging rocking arm  64  is, the larger the angle θ is and the less the component force for downward pulling the pulley  66  is. As a result, it is necessary to apply a greater downward pulling force to the cord  68 . This makes it laborious to shear the branches.  
     SUMMARY OF THE INVENTION  
      It is therefore a primary object of the present invention to provide a high-branch shears in which a locating member is disposed between a movable member and a fixed seat of an adjustment unit for adjustably fixing a distance between the movable member and the fixed seat. The movable member is slidably fitted on the connecting rod. The fixed seat is fixed on the branch-shearing mechanism or the connecting rod. When it is necessary to adjust the shears for shearing branches with different diameters, by means of the locating member, the distance between the movable member and the fixed seat can be quickly and conveniently adjusted.  
      According to the above object, the high-branch shears of the present invention includes:  
      a branch-shearing mechanism connected with one end of a connecting rod for shearing branches; and  
      a pulley device composed of an adjustment unit, a movable pulley and a cord passed through and wound on the adjustment unit and the movable pulley, the movable pulley being pivotally mounted on a pulley rack which is pivotally connected with the branch-shearing mechanism, the adjustment unit including a first fixed pulley, a movable member, a fixed seat and a locating member, the movable member being slidably fitted on the connecting rod, the first fixed pulley being pivotally mounted on the movable member, the movable member being movable relative to the fixed seat, the fixed seat being fixed on the branch-shearing mechanism or the connecting rod, the locating member being disposed between the movable member and the fixed seat for adjustably fixing a distance between the movable member and the fixed seat, one end of the cord being fixed on the pulley rack, the cord being sequentially passed through and wound on the first fixed pulley and the movable pulley, the other end of the cord being a force application end for a user to pull to drive the branch-shearing mechanism for shearing branches.  
      The present invention can be best understood through the following description and accompanying drawings wherein:  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a side view of the present invention;  
       FIG. 2  is a perspective view of the adjustment unit of the present invention;  
       FIG. 3  is a plane sectional view of the adjustment unit of the present invention;  
       FIG. 4  is a sectional view taken along line  3 - 3  of  FIG. 3 ;  
       FIG. 5  shows the use of the present invention;  
       FIG. 6-1  shows that the locating bolt of the present invention is-pressed with a finger;  
       FIG. 6-2  shows that the locating bar of the present invention is moved upward;  
       FIG. 6-3  shows that the locating bolt of the present invention is released;  
       FIG. 7  is a perspective view of the locating member of a second embodiment of the present invention;  
       FIG. 8-1  shows that the locating bar of the second embodiment of the present invention is not biased;  
       FIG. 8-2  shows that the locating bar of the second embodiment of the present invention is outward biased to make the locating bolt move out of the notch;  
       FIG. 8-3  shows that the locating bar of the second embodiment of the present invention is shifted to make the locating bolt move into another notch;  
       FIG. 9  is a side view of a third embodiment of the present invention;  
       FIG. 10  is a side view of a conventional high-branch shears; and  
       FIG. 11  shows the use of the conventional high-branch shears. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Please refer to FIGS.  1  to  7 . The high-branch shears of the present invention includes a branch-shearing mechanism  1  connected with one end of a connecting rod  2 . The branch-shearing mechanism  1  is drivable by a pulley device  3  for shearing branches. The branch-shearing mechanism  1  includes a shear seat  11  connected with the connecting rod  2 . The shear seat  11  has a shear opening  111  facing downward.  
      The branch-shearing mechanism  1  further includes a shear board  12  pivotally disposed on the shear seat  11 . The shear board  12  has a blade section  121  corresponding to the shear opening  111  of the shear seat  11 .  
      The branch-shearing mechanism  1  further includes a rocking arm  13  pivotally disposed on the shear seat  11 . One end of the shear board  12  distal from the blade section  121  is pivotally connected with the rocking arm  13 . A restoring spring  14  is connected between the rocking arm  13  and the shear seat  11 . The pulley device  3  is pivotally connected with one end of the rocking arm  13  distal from the shear seat  11 . When the pulley device  3  drives the rocking arm  13  to swing, the shear board  12  is driven and pivoted, whereby the blade section  121  is moved relative to the shear opening  111  for shearing branches.  
      The pulley device  3  is composed of an adjustment unit  31 , a movable pulley  32  and a cord  33  passed through and wound on the adjustment unit  31  and the movable pulley  32 . The movable pulley  32  is pivotally mounted on a pulley rack  34  which is pivotally connected with one end of the rocking arm  13  distal from the shear seat  11 . The adjustment unit  31  includes a first fixed pulley  311 , a second fixed pulley  312 , a movable member  313 , a fixed seat  314  and a locating member  315 . The movable member  313  is slidably fitted on the connecting rod  2 . The first fixed pulley  311  is pivotally mounted on the movable member  313 . The movable member  313  is movable relative to the fixed seat  314 . The fixed seat  314  is fixed on the shear seat  11  of the branch-shearing mechanism  1  or the connecting rod  2 .  
      In this embodiment, the fixed seat  314  is fixed on the connecting rod  2  distal from the branch-shearing mechanism  1 . One end of the cord  33  is fixed on the pulley rack  34 . The cord  33  is sequentially passed through and wound on the first fixed pulley  311 , the second fixed pulley  312  and the movable pulley  32 . The other end of the cord  33  is a force application end  331  for a user to pull to drive the branch-shearing mechanism  1  for shearing branches.  
      The movable member  313  is a substantially ring-shaped member fitted around the connecting rod  2 . The movable member  313  has two first lugs  3131 . A pin member  316  is connected between the first lugs  3131 . The first fixed pulley  311  is pivoted on the pin member  316 . One end of the locating member  315  is fixed with the pin member  316 . The fixed seat  314  is a substantially ring-shaped member fixedly fitted around the connecting rod  2  near the branch-shearing mechanism  1 . The fixed seat  314  has two second lugs  3141 . The second fixed pulley  312  is pivotally disposed between the second lugs  3141 . The other end of the locating member  315  is positioned between the second lugs  3141 .  
      The locating member  315  includes a locating bolt  3151  and a locating bar  3152 . The locating bolt  3151  has a small diameter section d and a large diameter section D. The locating bolt  3151  is-fitted through the second lugs  3141 . A first end of the locating bolt  3151  outward protrudes from one of the second lugs  3141 . A resilient member  317  is disposed between the first end of the locating bolt and the second lug  3141  adjacent to the first end of the locating bolt. In this embodiment, the resilient member is a compression spring. The small diameter section d of the locating bolt  3151  extends from the first end of the locating bolt  3151  to one side of the locating bar  3152  proximal to the compression spring. The large diameter section D extends from the small diameter section d to a second end of the locating bolt  3151 . The locating bar  3152  is formed with a slot  3153  for the small diameter section d of the locating bolt  3151  to extend through. The slot  3153  has several locating holes  3154  for the large diameter section D of the locating bolt  3151  to pass therethrough. The large diameter section D can extend through any of the locating holes  3154  of the locating bar  3152 . A fixing pin  318  is radially passed through the fixed seat  314  and the connecting rod  2  to fix the fixed seat  314  on the connecting rod  2 .  
      Referring to  FIG. 5 , the second fixed pulley  312  is pivotally mounted on the fixed seat  314  and the first fixed pulley  311  is pivotally mounted on the movable member  313 . The locating member  315  is arranged between the movable member  313  and the fixed seat  314 . When a user pulls the force application end  331  of the cord  33  downward to drive and pivot the rocking arm  13  downward, the angle α contained between the cord  33  between the first fixed pulley  311  and the movable pulley  32  and the vertical line is enlarged to a less extent. That is, the component force for downward pulling the movable pulley  32  is minified to a less extent. Therefore, the force applied to the cord  33  is increased to a less extent. Accordingly, the shears can be operated with less strength.  
      Referring to  FIGS. 6-1  to  6 - 3 , when it is necessary to adjust the shears for shearing branches with different diameters, a user can press the protruding first end of the locating bolt with a finger to compress the compression spring. At this time, the large diameter section D of the locating bolt  3151  is extracted from the locating hole  3154  and the small diameter section d of the locating bolt is longitudinally movably positioned in the slot  3153 . The movable member  313  is moved along with the locating bar  3152 . When moved through a certain distance, the locating bolt is released. At this time, the compression spring is restored to make the large diameter section D extend into a new locating hole  3154 . Under such circumstance, the movable member  313  is spaced from the fixed seat  314  by a new distance and located. According to the above arrangement, by means of the locating bolt  3151  and the locating bar  3152  of the adjustment unit  31 , the distance between the movable member  313  and the fixed seat  314  can be quickly and conveniently adjusted for shearing branches with different diameters.  
       FIG. 7  shows a second embodiment of the present invention, in which the locating member  315  includes a locating bolt  3155  and a locating bar  3156 . One side of the locating bar  3156  is formed with several substantially L-shaped notches  3157  facing the connecting rod  2 . The locating bolt  3155  can be inlaid and located in any of the notches  3157 . When the cord  33  is free from any application force, the locating bar  3156  will move downward due to gravity. Under such circumstance, the locating bolt  3155  will abut against top wall of the notch  3157 . When a force is applied to the cord  33  for shearing branches, the locating bar  3156  is driven to move upward. At this time, the locating bolt  3155  abuts against bottom wall of the notch  3157  and is inlaid and located in the notch  3157 .  
      When it is necessary to adjust the shears for shearing branches with different diameters, as shown in  FIGS. 8-1  to  8 - 3 , a user can bias the locating bar  3156  with a finger to make the locating bolt  3155  move out of the notch  3157  and separate from the locating bar  3156 . At this time, the user can move the locating bar  3156  through a certain distance and then push the locating bar  3156  to make the locating bolt  3155  move into a new notch  3157 . Such operation can be also quickly and conveniently performed.  
       FIG. 9  shows a third embodiment of the present invention, in which the fixed seat  4  has a fitting section  41 . The branch shearing mechanism  1  is fitted in one end of the fitting section  41 , while the connecting rod  2  is fitted in the other end of the fitting section  41 . The fixed seat  4  further has two third lugs  42  protruding from the fitting section  41 . A third fixed pulley  43  is pivotally mounted between the third lugs  42 . One end of the locating member  5  is positioned between the third lugs  42 .  
      The above embodiments are only used to illustrate the present invention, not intended to limit the scope thereof. Many modifications of the above embodiments can be made without departing from the spirit of the present invention.