Patent Publication Number: US-2010122608-A1

Title: Open-Ended Ratchet Wrench

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a ratchet wrench and, more particularly, to an open-ended ratchet wrench. 
     2. Description of the Related Art 
     A conventional open end wrench comprises a handle having two opposite ends each provided with a substantially C-shaped operation head. Thus, the operation head of the handle is mounted on a workpiece, such as a hexagonal nut, bolt and the like, so as to operate and rotate the workpiece by rotation of the handle. However, the operation head of the handle cannot rotate the workpiece successively, so that a user has to mount the operation head of the handle on the workpiece and to remove the operation head of the handle from the workpiece in an alternating manner, thereby greatly causing inconvenience to the user when operating the operation head of the handle to rotate the workpiece. 
     BRIEF SUMMARY OF THE INVENTION 
     In accordance with the present invention, there is provided an open-ended ratchet wrench, comprising a handle provided with an open driving head, an open ratchet wheel mounted in the driving head of the handle and having an outer wall provided with a plurality of oneway ratchet teeth, and a pawl member movably mounted in the driving head of the handle and having a first side provided with a plurality of oneway locking teeth detachably meshing with the ratchet teeth of the ratchet wheel. 
     The open-ended ratchet wrench further comprises a cover mounted on the driving head of the handle and abutting the pawl member and the elastic member to retain the pawl member and the elastic member in the driving head of the handle. 
     The open-ended ratchet wrench further comprises an elastic member mounted in the driving head of the handle and biased between the driving head of the handle and a second side of the pawl member to push the locking teeth of the pawl member toward the ratchet teeth of the ratchet wheel. 
     The open-ended ratchet wrench further comprises an open retaining ring located between the driving head of the handle and the ratchet wheel to retain the ratchet wheel in the driving head of the handle. 
     The primary objective of the present invention is to provide an open-ended ratchet wrench that is operated to drive a workpiece in an energy-saving manner. 
     Another objective of the present invention is to provide an open-ended ratchet wrench, wherein the ratchet wheel has a side provided with an opening to make the ratchet wheel flexible so that the ratchet wheel is mounted on and detached from the workpiece easily and quickly, thereby facilitating a user operating the ratchet wrench to rotate the workpiece. 
     A further objective of the present invention is to provide an open-ended ratchet wrench, wherein the ratchet wheel is fully encompassed by the stop flange of the driving head so that the ratchet wheel will not be exposed outwardly from the driving head of the handle to prevent the ratchet wheel from being worn out or broken due to an accidental hit. 
     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 an open-ended ratchet wrench in accordance with the preferred embodiment of the present invention. 
         FIG. 2  is an exploded perspective view of the open-ended ratchet wrench as shown in  FIG. 1 . 
         FIG. 3  is a top cross-sectional view of the open-ended ratchet wrench as shown in  FIG. 1 . 
         FIG. 4  is a cross-sectional view of the open-ended ratchet wrench taken along line  4 - 4  as shown in  FIG. 3 . 
         FIG. 5  is a schematic operational view of the open-ended ratchet wrench as shown in  FIG. 3 . 
         FIG. 6  is a perspective view of an open-ended ratchet wrench in accordance with another preferred embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to the drawings and initially to  FIGS. 1-4 , an open-ended ratchet wrench in accordance with the preferred embodiment of the present invention comprises a handle  1  provided with an open driving head  11 , an open ratchet wheel  21  mounted in the driving head  11  of the handle  1  and having an outer wall provided with a plurality of oneway ratchet teeth  212 , a pawl member  31  movably mounted in the driving head  11  of the handle  1  and having a first side provided with a plurality of oneway locking teeth  310  detachably meshing with the ratchet teeth  212  of the ratchet wheel  21 , an elastic member  32  mounted in the driving head  11  of the handle  1  and biased between the driving head  11  of the handle  1  and a second side of the pawl member  31  to push the locking teeth  310  of the pawl member  31  toward the ratchet teeth  212  of the ratchet wheel  21 , a cover  33  mounted on the driving head  11  of the handle  1  and abutting the pawl member  31  and the elastic member  32  to retain the pawl member  31  and the elastic member  32  in the driving head  11  of the handle  1 , and an open retaining ring  22  located between the driving head  11  of the handle  1  and the ratchet wheel  21  to retain the ratchet wheel  21  in the driving head  11  of the handle  1 . 
     The handle  1  has one end provided with the driving head  11 . The driving head  11  of the handle  1  has an inner wall provided with a receiving chamber  12  to receive the ratchet wheel  21 . The receiving chamber  12  of the driving head  11  has a side provided with a receiving space  13  to receive the pawl member  31  and the elastic member  32 . The receiving chamber  12  of the driving head  11  has a top provided with a radially and inwardly extending stop flange  120  abutting the ratchet wheel  21  and a bottom provided with a retaining slot  121  to retain the retaining ring  22 . The driving head  11  of the handle  1  has a substantially C-shaped profile and has a side provided with a first opening  110  connected to the receiving chamber  12  and located opposite to the receiving space  13 . The driving head  11  of the handle  1  has a top provided with a receiving depression  14  to receive the cover  33 . The receiving depression  14  of the driving head  11  is connected to the receiving space  13  and the receiving chamber  12 . The receiving depression  14  of the driving head  11  has a bottom wall provided with a plurality of screw bores  141 . 
     The ratchet wheel  21  has an inner wall provided with a plurality of radially and inwardly extending pressing bosses  213 . Each of the pressing bosses  213  of the ratchet wheel  21  has a substantially arc-shaped profile. The ratchet wheel  21  has a substantially C-shaped profile and has a side provided with a second opening  210  that is movable to align with the first opening  110  of the driving head  11 . The ratchet wheel  21  is fully encompassed by the stop flange  120  of the driving head  11 . The ratchet wheel  21  has a top provided with a stepped resting edge  214  abutting the stop flange  120  of the driving head  11  and the cover  33  and a bottom provided with a retaining groove  211  to retain the retaining ring  22 . The ratchet teeth  212  of the ratchet wheel  21  are located between the resting edge  214  and the retaining groove  211 . 
     The retaining ring  22  has a substantially C-shaped profile and has a side provided with a third opening  220  aligning with the first opening  110  of the driving head  11  and the second opening  210  of the ratchet wheel  21 . The retaining ring  22  has an inner wall retained in the retaining groove  211  of the ratchet wheel  21  and an outer wall retained in the retaining slot  121  of the driving head  11 . 
     The cover  33  has a size greater than that of the receiving space  13  of the driving head  11  and has a side  332  extending into the receiving chamber  12  of the driving head  11  and abutting the resting edge  214  of the ratchet wheel  21 . The cover  33  is provided with a plurality of fixing holes  331 , and the open-ended ratchet wrench further comprises a plurality of locking screws  34  extending through the fixing holes  331  and screwed into the screw bores  141  of the driving head  11  to lock the cover  33  onto the driving head  11  of the handle  1 . 
     The second side of the pawl member  31  has a first face provided with a smooth resting portion  312  that is movable to abut a periphery of the receiving depression  14  of the driving head  11  and a second face provided with a mounting recess  311  to receive the elastic member  32 . 
     In operation, referring to  FIGS. 3-5  with reference to  FIGS. 1 and 2 , the ratchet wheel  21  is mounted on a workpiece, such as a bolt, nut and the like, with the pressing bosses  213  of the ratchet wheel  21  pressing the periphery of the workpiece. In such a manner, when the driving head  11  of the handle  1  is rotated in the clockwise direction as shown in  FIG. 3 , the oneway locking teeth  310  of the pawl member  31  mesh with the ratchet teeth  212  of the ratchet wheel  21 , so that the ratchet wheel  21  is driven by the driving head  11  of the handle  1  to rotate the workpiece in the clockwise direction. On the contrary, when the driving head  11  of the handle  1  is rotated in the counterclockwise direction as shown in  FIG. 5 , the oneway locking teeth  310  of the pawl member  31  disengage the ratchet teeth  212  of the ratchet wheel  21 , so that the ratchet wheel  21  is not driven by the driving head  11  of the handle  1 , and the driving head  11  of the handle  1  idles in the clockwise direction. Thus, the workpiece is driven by the driving head  11  of the handle  1  to rotate in a oneway direction only. 
     As shown in  FIG. 6 , the handle  1  has two opposite ends each provided with the driving head  11 . 
     Accordingly, the ratchet wheel  21  has a side provided with an opening to make the ratchet wheel  21  flexible so that the ratchet wheel  21  is mounted on and detached from the workpiece easily and quickly, thereby facilitating a user operating the ratchet wrench to rotate the workpiece. In addition, the ratchet wheel  21  is fully encompassed by the stop flange  120  of the driving head  11  so that the ratchet wheel  21  will not be exposed outwardly from the driving head  11  of the handle  1  to prevent the ratchet wheel  21  from being worn out or broken due to an accidental hit. 
     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.