Patent Publication Number: US-7913589-B2

Title: Adjustable wrench that clamps a workpiece exactly and tightly

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a wrench and, more particularly, to a wrench for operating a workpiece, such as a bolt, nut and the like. 
     2. Description of the Related Art 
     A conventional wrench comprises a handle having a first end provided with an open drive head and a second end provided with a box drive head. Thus, the wrench can be used to operate a workpiece, such as a bolt, nut and the like. However, when the wrench is used in a narrower space, such as the inside of a car engine and the like, the wrench cannot be used to operate the workpiece easily and quickly, thereby causing inconvenience to a user when operating the wrench in the narrower space. 
     BRIEF SUMMARY OF THE INVENTION 
     In accordance with the present invention, there is provided a wrench, comprising a handle, and a driving unit pivotally mounted on and movable relative to the handle. The handle has an end portion provided with a support surface. The driving unit includes a first jaw pivotally connected with the handle and having a first end pivotally mounted on the end portion of the handle, and a second jaw pivotally connected with the first jaw and having a first end pivotally connected with a second end of the first jaw and a second end that is movable to abut the support surface of the handle and the first end of the first jaw. 
     The primary objective of the present invention is to provide an adjustable wrench that clamps a workpiece exactly and tightly. 
     Another objective of the present invention is to provide a wrench, wherein the second end of the second jaw abuts the support surface of the handle tightly and closely so that the force applied by a user is transmitted to the wrench directly and exactly so as to drive the wrench to operate the workpiece in an energy-saving manner. 
     A further objective of the present invention is to provide a wrench, wherein the reaction of the workpiece applied on the wrench is shared by and evenly distributed on the support surface of the handle, the first jaw of the driving unit and the second jaw of the driving unit to prevent from incurring a stress concentration, thereby prevent the wrench from being worn out or broken due to an excessive force. 
     A further objective of the present invention is to provide a wrench, wherein the second end of the second jaw abuts the support surface of the handle tightly and closely by the elastic force of the elastic member and the restoring member, so that the workpiece is clamped by the first jaw and the second jaw of the driving unit exactly to prevent the workpiece from being detached from the wrench. 
     A further objective of the present invention is to provide a wrench, wherein the second end of the second jaw abuts the support surface of the handle tightly and closely by the magnetically attractive force of the first magnet and the second magnet, so that the workpiece is clamped by the first jaw and the second jaw of the driving unit exactly to prevent the workpiece from being detached from the wrench. 
     A further objective of the present invention is to provide a wrench, wherein the second end of the second jaw has a periphery fully encompassed by the mounting groove of the support surface, so that the second end of the second jaw is combined with the support surface of the handle exactly and closely to facilitate the user operating the wrench. 
     Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
         FIG. 1  is a perspective view of a wrench in accordance with the preferred embodiment of the present invention. 
         FIG. 2  is an exploded perspective view of the wrench as shown in  FIG. 1 . 
         FIG. 3  is a front operational view of the wrench as shown in  FIG. 1 . 
         FIG. 4  is a front view of a wrench in accordance with another preferred embodiment of the present invention. 
         FIG. 5  is a schematic operational view of the wrench as shown in  FIG. 4 . 
         FIG. 6  is a schematic operational view of the wrench as shown in  FIG. 4 . 
         FIG. 7  is a front view of a wrench in accordance with another preferred embodiment of the present invention. 
         FIG. 8  is a schematic operational view of the wrench as shown in  FIG. 7 . 
         FIG. 9  is a perspective view of a wrench in accordance with another preferred embodiment of the present invention. 
         FIG. 10  is a front view of the wrench as shown in  FIG. 9 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to the drawings and initially to  FIGS. 1-3 , a wrench in accordance with the preferred embodiment of the present invention comprises a handle  1 , and a driving unit  2  pivotally mounted on and movable relative to the handle  1 . 
     The handle  1  has an end portion  11  provided with a support surface  14 . The end portion  11  of the handle  1  has a forked shape and has two opposite sidewalls  10  protruding outwardly and each having a first side provided with a pivot ear  16  and a second side provided with the support surface  14 . The pivot ear  16  of the end portion  11  of the handle  1  is provided with a fixing hole  13 . The end portion  11  of the handle  1  is provided with a receiving chamber  12  located between the two opposite sidewalls  10 . The support surface  14  of the handle  1  has a substantially concave shape and has an opening directed toward the driving unit  2 . 
     The driving unit  2  includes a first jaw  21  pivotally connected with the handle  1  and having a first end  210  pivotally mounted on the end portion  11  of the handle  1 , and a second jaw  22  pivotally connected with the first jaw  21  and having a first end  220  pivotally connected with a second end  214  of the first jaw  21  and a second end  223  that is movable to abut the support surface  14  of the handle  1  and the first end  210  of the first jaw  21 . 
     The first jaw  21  of the driving unit  2  has an inner side provided with a first clamping face  211  located between the first end  210  and the second end  214  of the first jaw  21 . The first end  210  of the first jaw  21  is pivotally mounted in the receiving chamber  12  of the handle  1  and is located between the two opposite sidewalls  10  of the handle  1 . The first end  210  of the first jaw  21  is provided with a pivot hole  213 . The second end  214  of the first jaw  21  has a forked shape and has two opposite sidewalls each provided with a fixing bore  215 . The second end  214  of the first jaw  21  is provided with a mounting recess  212  located between the two opposite sidewalls of the first jaw  21 . 
     The second jaw  22  of the driving unit  2  has an inner side provided with a second clamping face  221  located between the first end  220  and the second end  223  of the second jaw  22  and facing the first clamping face  211  of the first jaw  21 . The second clamping face  221  of the second jaw  22  is movable to combine with the first clamping face  211  of the first jaw  21 , so that the second clamping face  221  of the second jaw  22  co-operates with the first clamping face  211  of the first jaw  21  to form a substantially polygonal driving face as shown in  FIG. 1 . The first end  220  of the second jaw  22  is pivotally mounted in the mounting recess  212  of the first jaw  21 . The first end  220  of the second jaw  22  is provided with a pivot bore  222 . The second end  223  of the second jaw  22  has a substantially convex shape. 
     The driving unit  2  further includes a pivot pin  23  extending through the fixing hole  13  of the handle  1  and the pivot hole  213  of the first jaw  21  so that the first end  210  of the first jaw  21  is pivotally mounted on the end portion  11  of the handle  1 , and a pivot shaft  25  extending through the fixing bore  215  of the first jaw  21  and the pivot bore  222  of the second jaw  22  so that the first end  220  of the second jaw  22  is pivotally connected with a second end  214  of the first jaw  21 . 
     In operation, again referring to  FIGS. 1-3 , the first jaw  21  of the driving unit  2  is pivotally mounted on the end portion  11  of the handle  1 , and the second jaw  22  of the driving unit  2  is pivotally connected with the first jaw  21  of the driving unit  2 , so that the first jaw  21  of the driving unit  2  is pivotable relative to the end portion  11  of the handle  1 , and the second jaw  22  of the driving unit  2  is movable relative to the first jaw  21  of the driving unit  2  as shown in  FIG. 3 . In such a manner, when the second clamping face  221  of the second jaw  22  is moved to combine with the first clamping face  211  of the first jaw  21 , the second clamping face  221  of the second jaw  22  co-operates with the first clamping face  211  of the first jaw  21  to form a substantially hexagonal driving face as shown in  FIG. 1  to clamp a workpiece  4  (see  FIG. 6 ), such as a bolt, nut and the like. Then, the end portion  11  of the handle  1  is pivoted relative to the driving unit  2  until the second end  223  of the second jaw  22  is moved to abut the support surface  14  of the handle  1  as shown in  FIG. 1 . Thus, the first jaw  21  of the driving unit  2  is positioned on the end portion  11  of the handle  1  by the pivot pin  23 , and the second end  223  of the second jaw  22  is locked by the support surface  14  of the handle  1 , so that the end portion  11  of the handle  1  is combined with the first jaw  21  and the second jaw  22  of the driving unit  2  to operate the workpiece  4 . 
     Referring to  FIGS. 4-6 , the driving unit  2  further includes an elastic member  24  mounted on the pivot pin  23  and biased between the end portion  11  of the handle  1  and the first end  210  of the first jaw  21  to push the first jaw  21  of the driving unit  2  toward the support surface  14  of the handle  1 , and a restoring member  26  mounted on the pivot shaft  25  and biased between the second end  214  of the first jaw  21  and the first end  220  of the second jaw  22  to push the second jaw  22  of the driving unit  2  toward the support surface  14  of the handle  1  and the first jaw  21  of the driving unit  2 . The elastic member  24  is received in the receiving chamber  12  of the handle  1 , and the restoring member  26  is received in the mounting recess  212  of the first jaw  21 . 
     Referring to  FIGS. 7 and 8 , the wrench further comprises a first magnet  3  mounted in the support surface  14  of the handle  1 , and a second magnet  30  mounted in the second end  223  of the second jaw  22  and movable to abut the first magnet  3  so that the second end  223  of the second jaw  22  is combined with the support surface  14  of the handle  1  exactly and closely. 
     Referring to  FIGS. 9 and 10 , the support surface  14  of the handle  1  is provided with a mounting groove  15  to receive the second end  223  of the second jaw  22 . The mounting groove  15  of the support surface  14  of the handle  1  has a substantially U-shaped cross-sectional profile, and the second end  223  of the second jaw  22  has a periphery fully encompassed by the mounting groove  15  of the support surface  14 , so that the second end  223  of the second jaw  22  is combined with the support surface  14  of the handle  1  exactly and closely. 
     Accordingly, the second end  223  of the second jaw  22  abuts the support surface  14  of the handle  1  tightly and closely so that the force applied by a user is transmitted to the wrench directly and exactly so as to drive the wrench to operate the workpiece  4  in an energy-saving manner. In addition, the reaction of the workpiece  4  applied on the wrench is shared by and evenly distributed on the support surface  14  of the handle  1 , the first jaw  21  of the driving unit  2  and the second jaw  22  of the driving unit  2  to prevent from incurring a stress concentration, thereby prevent the wrench from being worn out or broken due to an excessive force. Further, the second end  223  of the second jaw  22  abuts the support surface  14  of the handle  1  tightly and closely by the elastic force of the elastic member  24  and the restoring member  26 , so that the workpiece  4  is clamped by the first jaw  21  and the second jaw  22  of the driving unit  2  exactly to prevent the workpiece  4  from being detached from the wrench. Further, the second end  223  of the second jaw  22  abuts the support surface  14  of the handle  1  tightly and closely by the magnetically attractive force of the first magnet  3  and the second magnet  30 , so that the workpiece  4  is clamped by the first jaw  21  and the second jaw  22  of the driving unit  2  exactly to prevent the workpiece  4  from being detached from the wrench. Further, the second end  223  of the second jaw  22  has a periphery fully encompassed by the mounting groove  15  of the support surface  14 , so that the second end  223  of the second jaw  22  is combined with the support surface  14  of the handle  1  exactly and closely to facilitate the user operating the wrench. 
     Although the invention has been explained in relation to its preferred embodiment(s) as mentioned above, it is to be understood that many other possible modifications and variations can be made without departing from the scope of the present invention. It is, therefore, contemplated that the appended claim or claims will cover such modifications and variations that fall within the true scope of the invention.