Abstract:
The present invention is directed to a fiber cleaving tool that cleaves a fiber optic cable flush with the ferrule&#39;s end face. The fiber cleaving tool has a tool body with a tensioning mechanism and a cleaving mechanism. A handle extends from one end of the tool body and a lever is pivotally connected to the opposite end of the tool body. The lever has a trigger blade that activates the cleaving mechanism to cleave the fiber optic cable extending from a connector positioned in the tool body.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to U.S. Provisional Application No. 61/700,440, filed Sep. 13, 2012, the subject matter of which is herein incorporated by reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to a fiber cleaving tool, and more particularly to a fiber cleaving tool that engages a ferrule end face while cleaving the fiber optic cable extending from the ferrule in a connector. 
       BACKGROUND OF THE INVENTION 
       [0003]    It is well known to cleave a fiber extending from a ferrule in a connector. Prior fiber cleaving tools, however, have not achieved cleaving a fiber flush or recessed within 100 microns of the ferrule&#39;s end face. 
         [0004]      FIG. 1  illustrates a prior tool  20  where the ferrule  22  of a connector is inserted into a hole in a ferrule holder. The front face of the connector body  24  is pressed against the connector plate  26  and the end face  23  of the ferrule  22  protrudes through the connector plate  26 . The cleaving blade  28  moves in a direction perpendicular to the fiber  30  and a direction axial to the fiber  30  when the tool is actuated. The cleaving blade  28  may move too far in the direction axial to the fiber thereby missing the end face of the ferrule  22 . Also, the ferrule  22  often pitches or tilts causing the cleaving blade  28  to contact the side of the ferrule  22 . 
         [0005]    U.S. Pat. No. 6,695,191 discloses another prior art fiber cleaving tool where the ferrule is installed in an opening in a housing. The end face of the ferrule abuts a stop shelf or a shoulder and a blade is positioned below the edge of the shoulder. The blade propagates a crack in the fiber below the shoulder. Once the blade cracks the fiber, the tool bends the fiber to continue to propagate the crack in the fiber at a distance from the ferrule&#39;s end face. 
         [0006]    Although the prior art tools cleave the fiber extending from the connector, the tools fail to ensure a flush cutoff. It is important that the fiber optic cable is cleaved flush or recessed within 100 microns of the ferrule end face for an acceptable transmission. As such, it is desirable to provide a fiber cleaving tool that assures that the cleaving blade scores the fiber optic cable flush with the ferrule&#39;s end face. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention is directed to a fiber cleaving tool that scores a fiber optic cable flush with the ferrule&#39;s end face. The tool has a body with a pocket that receives a connector and connector snaps that extend over the pocket to retain the connector in the tool body. A handle extends from a first end of the tool body. A lever is pivotally connected to a second end of the tool body. The tool also includes a tensioning mechanism and a cleaving mechanism. The lever has a blade trigger that activates the cleaving mechanism to cleave the fiber optic cable extending from the connector positioned in the tool. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a cross-sectional view of a prior art fiber cleaving tool. 
           [0009]      FIG. 2  is a perspective view of the fiber cleaving tool of the present invention. 
           [0010]      FIG. 3  is a perspective view of a connector with fiber extending out of the ferrule prior to installation in the fiber cleaving tool of  FIG. 2 . 
           [0011]      FIG. 4  is a bottom front perspective view of the fiber cleaving tool of  FIG. 2  with the connector of  FIG. 3  positioned therein. 
           [0012]      FIG. 5  is a back perspective view of the fiber cleaving tool of  FIG. 4 . 
           [0013]      FIG. 6  is an exploded view of the fiber cleaving tool of  FIG. 2  with the connector of  FIG. 3 . 
           [0014]      FIG. 7  is a perspective view of the cleaving mechanism of the fiber cleaving tool of  FIG. 4 . 
           [0015]      FIG. 8  is a side view of the fiber cleaving tool of  FIG. 4  prior to the lever being activated. 
           [0016]      FIG. 9  is a top view of the fiber cleaving tool of  FIG. 8 . 
           [0017]      FIG. 10  is a cross-sectional view of the fiber cleaving tool of  FIG. 8  taken along line  10 - 10 . 
           [0018]      FIG. 10A  is an enlarged view of the cutting mechanism of the fiber cleaving tool of  FIG. 10 . 
           [0019]      FIG. 11  is a cross-sectional view of the fiber cleaving tool of  FIG. 9  taken along line  11 - 11 . 
           [0020]      FIG. 12  is a bottom perspective view of the fiber cleaving tool of  FIG. 4  with the lever activated. 
           [0021]      FIG. 13  is a top view of the fiber cleaving tool of  FIG. 12 . 
           [0022]      FIG. 14  is a cross-sectional view of the fiber cleaving tool of  FIG. 13  taken along line  14 - 14 . 
           [0023]      FIG. 15  is a cross-sectional view of the fiber cleaving tool of  FIG. 14  taken along the line  15 - 15 . 
           [0024]      FIG. 15A  is an enlarged view of the cutting mechanism of the fiber cleaving tool of  FIG. 15 . 
           [0025]      FIG. 16  is a cross-sectional view of the fiber cleaving tool of  FIG. 15  taken along line  16 - 16 . 
       
    
    
     DETAILED DESCRIPTION 
       [0026]    The present invention is directed to a tool that cleaves the plastic clad silica (PCS) fiber optic cable from a connector for industrial automation. 
         [0027]    As illustrated in FIGS.  2  and  4 - 6 , the fiber cleaving tool  50  includes a tool body  52  with a handle  54  on one end and a lever  56  pivotally connected at the opposite end. The tool body  52  includes a backbone  60 , gripper opener cams  62 , grippers  64 , a gripper carriage  66  and a spring  68 . The lever  56  includes a blade trigger  58  that engages the cleaving mechanism  80  when the lever  56  is activated (see  FIG. 7 ). 
         [0028]      FIG. 3  illustrates a connecter  120  with a connector body  122  and a fiber optic cable  128  extending from the ferrule  124  positioned within the connector body  122 . As illustrated in  FIG. 5 , the connector  120  is positioned in a pocket  70  in the backbone  60  of the fiber cleaving tool  50 . The connector snaps  72  engage the connector  120  to hold the connector  120  in place in the tool body  52 . 
         [0029]    As illustrated in  FIG. 7 , once the connector  120  is installed in the tool  50 , the ferrule  124  is positioned in the ferrule holder  74  and stops at the ferrule stop plate  76 . The end face  126  of the ferrule  124  abuts the ferrule stop plate  76  and the end face  126  is flush with the ferrule holder  74 . The placement of the connector  120  in the tool  50  assures that the ferrule end face  126  is secured at a known location. The blade holder  88  is adjusted in both the forward and reverse direction, however, reverse travel is controlled by the reverse travel set screw  96  (see  FIG. 7 ) such that the cleaving blade  92  never completely disengages the ferrule  124 . Once the connector  120  is inserted in the tool  50 , the cleaving blade  92  is on the ferrule end face  126  and ready to start cleaving. Thus, the cleaving blade  92  is in constant contact with the ferrule end face  126 . 
         [0030]      FIGS. 8-11  illustrate the fiber cleaving tool  50  prior to the lever  56  being activated.  FIGS. 12-16  illustrate the fiber cleaving tool  50  with the lever  56  activated. 
         [0031]    As discussed above, the connector  120  is positioned within pocket  70 . Prior to the lever  56  being activated, the gripper opener cams  62  maintain the open position of the grippers  64  so the fiber optic cable  128  extending from the ferrule  124  may be installed. As illustrated in  FIG. 9 , the fiber optic cable  128  is positioned between the gripper opener cams  62  and the grippers  64 . The grippers  64  include hard rubber pads  65  to prevent the fiber optic cable  128  from slipping under tension. 
         [0032]    To activate the tool  50 , the lever  56  is pressed toward the tool body  52 . As the lever  56  is pressed, it pivots thereby exerting a force on the spring  68  which pulls the gripper carriage  66  and attached grippers  64  linearly away from the backbone  60 . As illustrated in  FIG. 13 , when the gripper carriage  66  pulls away from the backbone  60 , the spring loaded grippers  64  close since they are no longer held open by the gripper cam openers  62 . The grippers  64  clamp the fiber optic cable  128 . As the gripper carriage  66  is pulled linearly away from the backbone  60 , the fiber optic cable  128  is tensioned. 
         [0033]      FIGS. 7 ,  10 , and  10 A illustrate the cleaving mechanism  80  of the fiber cleaving tool  50  prior to activation.  FIGS. 15 ,  15 A, and  16  illustrate the cleaving mechanism  80  of the fiber cleaving tool  50  after activation. As the lever  56  is completely depressed, the blade trigger  58  exerts a force on the plunger  82 , which is free to move linearly. A swivel plate  84  is connected to the plunger  82  via a pin  86  so that the swivel plate  84  is free to pivot. The force exerted by the blade trigger  58  is transmitted through the plunger  82  to a swivel plate  84  and then the force is transmitted to the blade holder  88 . The blade holder  88  is mounted such that it is free to pivot on the blade holder pivot pin  90 . As the blade holder  88  pivots, the cleaving blade  92  swipes across the fiber optic cable  128  and scores it. 
         [0034]    Since the fiber optic cable  128  is under tension, the score will propagate and the fiber optic cable  128  will break. As discussed above, the cleaving blade  92  is flush with the ferrule end face  126 . As a result, the cleaving blade  92  is able to score the fiber optic cable  128  at a distance of 100 microns, or less, from the end of the ferrule  124 . 
         [0035]    Once the force on the lever  56  is relieved, the return spring  94  returns the entire cleaving mechanism  80  back to the initial or home position. 
         [0036]    Thus to use the fiber cleaving tool  50  of the present invention, an operator inserts a connector  120  into the tool  50 . The ferrule  124  is positioned in the ferrule holder  74  and stops at the ferrule stop plate  76 . The connector snaps  72  engage the connector  120  to hold it in place in the tool body  52 . 
         [0037]    As illustrated in  FIGS. 12-16 , the operator presses the lever  56  which tensions the fiber optic cable  128  to a calibrated tension. The operator continues to press the lever  56  until the blade trigger  58  pushes the plunger  82  to advance the blade holder  88  with the cleaving blade  92 . The cleaving blade  92  scores the fiber optic cable  128  which creates a crack that propagates under tension thereby severing the fiber optic cable  128 . The gripper carriage  66  advances to the end of travel after the fiber optic cable  128  is severed. The connector  120  may now be removed from the tool  50 . The operator also removes the scrap fiber optic cable from the tool  50 . At this point the operator can release the lever  56  returning gripper carriage  66  to the home or original position. 
         [0038]    Furthermore, while the particular preferred embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the teaching of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as limitation. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective based on the prior art.