Patent Publication Number: US-6216563-B1

Title: Reversible ratchet wheel positioning arrangement for a reversible ratchet socket wrench

Description:
BACKGROUND AND SUMMARY OF THE INVENTION 
     The present invention relates to a reversible ratchet socket wrench, and more specifically to a reversible ratchet wheel positioning arrangement for a reversible ratchet socket wrench, which can be used with different ratchet wheels. 
     A variety of wrenches, including combination wrenches, hex wrenches, ratchet socket wrenches, etc. have been disclosed, and have appeared on the market. Early designed wrenches are not efficient in use, because the user must release the wrench from the workpiece after each turning through a limited angle, and then repeat the operation again and again. Recently reversible wrenches have become popular. FIGS. 1 and 2 illustrates two different designs of ratchet wheel direction control arrangement for reversible ratchet socket wrench according to the prior art. According to these two designs, a C-shaped retainer ring is mounted in the body end of the wrench to hold a ratchet wheel in the box in the box end, a cylindrical stop rod is mounted in a transverse through hole on the box end body of the wrench, and a steel ball is mounted in a recessed hole on the periphery of the transverse through hole and forced by a spring element into engagement with the cylindrical stop rod. The cylindrical stop rod has toothed portions for engagement with the ratchet wheel. These two designs do not allow the user to replace the ratchet wheel conveniently. Further, the cylindrical stop rod can not stop outside dust or water from passing to the inside of the transverse through hole. FIG. 3 shows another reversible ratchet socket wrench according to the prior art. This design comprises a box end body having a transverse blind hole and a sliding slot perpendiculary disposed in communication with the transverse blind hole, a C-shaped retainer ring fastened to the box end body to hold a ratchet wheel in the box in the box end body, a cylindrical stop rod mounted in the transverse blind hole and moved between two positions to limit the direction of rotation of the ratchet wheel being installed in the box end wrench, a knob fastened to the cylindrical stop rod and extended out of the sliding slot for moving by hand to shift the cylindrical stop rod between the two positions, and a steel ball supported on a spring element inside the box end body and forced by the spring element into engagement with one recessed portion at the cylindrical stop rod, and an end cap covered on the transverse blind hole to stop dust and rain from passing to the inside of the transverse blind hole. This design still can not allow the user to replace the ratchet wheel conveniently. 
     The present invention eliminates the aforesaid problem. According to the present invention, a screw cap is threaded into an inner thread in the box in the box end of the wrench body to hold a ratchet wheel in the box, and a stop rod is mounted in a transverse hole on the box end body for controlling the direction of rotation of the ratchet wheel in the box in the box end body. The screw cap can be conveniently disconnected from the box end body, enabling the user to replace the ratchet wheel. The stop rod can be rotated in the transverse hole between a first position and a second position subject to the type of teeth of the ratchet wheel being installed in the box end body. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a sectional plain view of a reversible ratchet socket wrench according to the prior art. 
     FIG. 2 is a sectional view of another structure of reversible ratchet socket wrench according to the prior art. 
     FIG. 3 is an exploded view of still another structure of reversible ratchet socket wrench according to the prior art. 
     FIG. 4 is an exploded view of the present invention. 
     FIG. 5 is a sectional assembly view of the present invention, showing the stop rod shifted to the left position, the corresponding first toothed portion meshed with the ratchet wheel. 
     FIG. 6 is similar to FIG. 5 but showing the stop rod shifted to the right position, the corresponding second toothed portion meshed with the ratchet wheel. 
     FIG. 7 is a side view in section of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to Figures from  4  through  7 , the present invention comprises a body  1 , a ratchet wheel  2 , a stop rod  3 , a screw cap  4 , a spring member  5 , and a steel ball  6 . 
     The body  1  comprises a box end  11  defining a box  111 , which receives the ratchet wheel  2 , an inner thread  112  in the box  111  at a top side, a transverse hole  12  cut through the periphery of the box  111 , which receives the stop rod  3 . The ratchet wheel  2  is mounted within the box  111  in the box end  11  of the body  1 . The stop rod  3  comprises two pairs of recessed positioning portions  31  spaced at a backside. The stell ball  6  is supported on the spring element  5  in the body  1 , and forced by the spring element  5  into engagement with one recessed positioning portion  31  of the stop rod  3 . The stop rod  3  can be shifted in the transverse hole  12  between two positons to limit the direction of rotation of the ratchet  2  in the box  111 . 
     The screw cap  4  is a hollow member having an outer thread  41  threaded into the inner thread  112  to hold the ratchet wheel  2  in the box  111 . After removal of the screw cap  4  from the box end  11  of the body  1 , the ratchet wheel  2  can then be replaced with another one having a different design of teeth  21  or  22 . The stop rod  3  comprises two toothed units bilaterally disposed at a front side thereof, each toothed unit comprised of a first toothed portion  32  and a second toothed portion  33  disposed at different angles. 
     The stop rod  3  can be shifted in the transverse hole  12  between the left position (see FIG. 5) and right position (see FIG. 6) to limit the direction of rotation of the ratchet wheel  2 . After removal of the screw cap  4  from the box end  11  of the body  1 , the user can put the ratchet wheel having coarse teeth  21  or ratchet wheel having fine teeth  22  in teh box  111  inside the box end  11  of the body  1 . When the ratchet wheel having coarse teeth  21  is put in the box  111  inside the box end  11  of the body  1 , the stop rod  3  is rotated in teh transverse hole  12  to force the first toothed portion  32  of one toothed unit into engagement with the teeth of the ratchet wheel having coarse teeth  21  and one recessed positioning portion  31  into engagement with the steel ball  6 . When the ratchet wheel having fine teeth  22  is put in the box  111  inside the box end  11  of the body  1 , the stop rod  3  is rotated in the transverse hole  12  to force the second toothed portion  33  of one toothed unit into engagement with the teeth of the ratchet wheel having fine teeth  22 , and one recessed positioning portion  31  into engagement with the steel ball  6 . Because the first toothed portion  32  fits the coarse teeth of the ratchet wheel having coarse teeth  21  and the second toothed portion  33  fits the fine teeth of the ratchet wheel having fine teeth  22 , the two different designs of ratchet wheels  21  and  22  can be alternatively installed in the box end  11  and positively secured in position by the stop rod  3 . 
     Further, because the periphery of the two distal ends of the stop rod  3  fits the inner diameter of the transverse hole  1 , the stop rod  3  prohibits dust from entering the transverse hole  12 . 
     While only one embodiment of the present invention has been shown and described, it will be understood that various modifications and changes could be made thereunto without departing from the spirit and scope of the invention disclosed.