Abstract:
In a ratchet wrench structure, a fitting sleeve of a sleeve type ratchet wrench is provided with a retaining ball. An elastically movable drive ring is provided externally of the fitting sleeve to control movement of the retaining ball such that an extension sleeve can be quickly assembled to or disengaged from the fitting sleeve. The ratchet wrench thus can adapt to various working environments and can be operated single-handedly to assemble or disengage the extension sleeve and to lock and position the same.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    (a) Field of the Invention  
           [0002]    The invention relates to a ratchet spanner, and is particularly directed to improving parts of the ratchet wrench which concern assembly and disengagement of sleeves and the tightening and loosening of workpieces.  
           [0003]    (b) Description of the Prior Art  
           [0004]    Referring to FIG. 1, a unidirectional ratchet is connectedly provided with a fitting post having a retaining ball disposed thereon for retaining a sleeve. The rotating direction of the ratchet is controlled via a swing button. In order to match position and depth of workpieces, sleeves of different lengths and sizes are provided for selection by the operator, which increases costs and may not oftentimes meet actual needs.  
           [0005]    Referring to FIG. 2, a polygonal sleeve hole is provided at a working end of a ratchet spanner for receiving a sleeve. The sleeve is provided with a retaining ball at a polygonal coupling end thereof for retaining shallow grooves in the sleeve hole. In addition to the aforesaid drawback, this type of wrench is costly since each sleeve is provided with a retaining ball, and the depth of the groove cannot firmly retain the retaining ball and the sleeve cannot be firmly secured.  
           [0006]    Referring to FIG. 3, a ratchet at a working end of a wrench is insertably provided with a retaining ring for retaining and coupling a sleeve with an open top. This sleeve type ratchet wrench permits a workpiece to extend through the sleeve and the wrench to suit more workpiece positions and depths. However, during assembly or disengagement of the sleeve, the operator has to use both hands and apply a relatively large force. Besides, the retaining ring readily wears and becomes deformed. After prolonged use, the retaining ring will suffer from fatigue and result in slippage of the sleeve.  
         SUMMARY OF THE INVENTION  
         [0007]    The primary object of the invention is to provide a ratchet wrench structure which can be operated single-handedly to assemble and disengage sleeves, which can lock and position sleeves, which can flexible adapt to the position and depth of a workpiece.  
           [0008]    Another object of the invention of the invention is to provide a ratchet wrench structure which provides a quick operation function so that the operator can, under the condition that turning of the wrench is not desired, use his fingers to rotate a drive ring at an end portion to tighten or loosen a workpiece, thereby expediting operation.  
           [0009]    In order to achieve the aforementioned objects, a sleeve type ratchet wrench includes a fitting sleeve provided with a retaining ball. The fitting sleeve is externally provided with an elastically movable drive ring for controlling movement of the retaining ball such that an extension sleeve can be quickly assembled to or disengaged from the fitting sleeve. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    The foregoing and other features and advantages of the present invention will be more clearly understood from the following detailed description and the accompanying drawings, in which,  
         [0011]    [0011]FIG. 1 is an exploded perspective view of a conventional ratchet wrench and a sleeve;  
         [0012]    [0012]FIG. 2 is a perspective view of another conventional ratchet wrench;  
         [0013]    [0013]FIG. 3 is a perspective view of a further conventional ratchet wrench;  
         [0014]    [0014]FIG. 4 is an exploded perspective of a ratchet wrench and sleeve according to the invention;  
         [0015]    [0015]FIG. 5 is a perspective assembled view of the invention;  
         [0016]    [0016]FIG. 6A is a schematic sectional view illustrating coupling of the sleeve and the wrench according to the invention;  
         [0017]    [0017]FIG. 6B is another schematic sectional view illustrating coupling of the sleeve and the wrench according to the invention; and  
         [0018]    [0018]FIG. 7 is a sectional view of FIG. 6A, taken along line  7 - 7  and the arrows. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0019]    Referring to FIGS. 4 and 5, a ratchet wrench structure according to the invention includes a sleeve type ratchet wrench  20 , a drive ring  33 , an extension sleeve  40 , and a quick operating structure.  
         [0020]    The wrench  20  has a working end provided with an angular-hole ratchet device  25 , the direction action of which is controlled by a swing button  26 . The lower end of the ratchet device  25  is a fitting sleeve  21 . The center of the fitting sleeve  21  is a polygonal sleeve hole  22 , the wall surface of which is provided with at least one movable type retaining structure. The retaining structure is provided with at least one ball hole  24  in an end wall of the sleeve hole  22 . The ball hole  24  has a retaining ball  23  disposed therein.  
         [0021]    The drive ring  33  is provided externally of the fitting sleeve  21 . A spring  32  is disposed between the drive ring  33  and fitting sleeve  21 . A groove  31  is formed in an upper portion of the outer surface of the fitting sleeve  21  for retaining a C-clip  38  for the end portion of the spring  32  to abut against to be thereby positioned. The inner ring surface of the drive ring  33  has an inwardly projecting stop portion  34  for the other end of the spring  32  to abut against. The lower portion of the outer edge of the fitting sleeve  21  is provided with a recess  39  for retaining another C-clip  35  which is stopped at the bottom edge of the drive ring  33 . The drive ring  33  can elastically move up and down without slippage due to the spring  32 . The projecting vertical wall edge of the stop portion  34  also forms a wedge-shaped push surface  36  for pushing the retaining ball  23  so that a part of the edge surface thereof projects toward the inner wall of the sleeve hole  22 . The inner wall of the drive ring  33  that is adjacent to the lower edge of the push surface  36  is provided with an outwardly depressed annular ball surface  37 .  
         [0022]    The extension sleeve  40  includes a sleeve portion  41  and a coupling portion  42 . The coupling portion  42  has a hollow and cylindrical interior and a polygonal outer surface. A retaining groove  43  is provided at each angular corner of the outer surface such that when the extension sleeve  40  is disposed in the sleeve hole  22  of the fitting sleeve  21 , the retaining ball  23  projecting from the inner wall of sleeve hole can extend into the retaining groove  43  to thereby secure the extension sleeve  40 .  
         [0023]    The operating structure includes two planar milled surfaces  51  disposed at opposite positions on the outer surface of the fitting sleeve  21  near the bottom end. The inner edge of the bottom end of the drive ring  33  is provided with planar projecting blocks  52  to correspond to the milled surfaces  51 , respectively. The projecting blocks  52  are provided to abut against the milled surfaces  51  such that when the drive ring  33  is rotated by hand, the fitting sleeve  21  and ratchet device  25  can be brought to quickly rotate.  
         [0024]    Referring to FIGS. 6A and 6B, when assembling the extension sleeve  40 , the drive ring  33  is pushed in the direction of the ratchet wrench  20  so that the depressed annular ball surface  37  therein is aligned with the retaining ball  23  of the fitting sleeve  21 . When the extension sleeve  40  is inserted into the sleeve hole  22 , it will push the retaining ball  23  to cause it to withdraw and sink into the depressed annular ball surface  37 . After the extension sleeve  40  is disposed in the sleeve hole  22  of the fitting sleeve  21 , the drive ring  33  is released so that the drive ring  33  resumes its position due to the biasing action of the spring  32 . During that process, the wedge-shaped push surface  36  will slidably push the retaining ball  23  so that the retaining ball  23  projects from the wall surface of the sleeve hole  22  so that a part thereof is insertably retained in the retaining groove  43  of the extension sleeve  40 , thereby positioning the extension sleeve  40 .  
         [0025]    Generally speaking, the ratchet wrench is manipulated to move in the operating direction to bring the sleeve and workpiece to rotate, and reverse rotation thereof produces idle rotation to buffer the driving of the ratchet wrench. However, the interval of idle rotation may make the operator feel that the operation process is prolonged, and the operator may not need to use the idle rotation function of the wrench. The quick operating structure of the invention employs the milled surfaces  51  and the projecting blocks  52  to cause the drive ring  33  to bring the fitting sleeve  21  and the ratchet device  25  to quickly rotate, so that the operator can directly rotate the drive ring to tighten or loosen the workpiece without turning the wrench, thereby expediting the operation.  
         [0026]    In addition, the present invention has the following advantages:  
         [0027]    The ratchet device  25  and the fitting sleeve  21  combine with the extension sleeve  40  to form a sleeve type ratchet wrench to allow the workpiece to extend through the fitting sleeve  21  and the ratchet device  25 , thereby flexibly accommodating the position and depth of the workpiece.  
         [0028]    The fingers holding the wrench can be used to grip the drive ring  33 , and the straightening or bending of the fingers can rotate the drive ring  33  axially, thereby permitting mounting and dismantling of the extension sleeve  40  single handedly in a simple, convenient and quick manner.  
         [0029]    When the retaining ball  23  is retained in the retaining groove  43  of the extension sleeve, the extension sleeve  40  is in a locked and secured state. Even the application of an outward pulling force will not disengage the extension sleeve  40 . Hence, the extension sleeve  40  will not accidentally slip during operation.