Patent Publication Number: US-8109182-B2

Title: Ratchet tool

Description:
CROSS-REFERENCE TO RELATED U.S. APPLICATIONS 
     Not applicable. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     NAMES OF PARTIES TO A JOINT RESEARCH AGREEMENT 
     Not applicable. 
     REFERENCE TO AN APPENDIX SUBMITTED ON COMPACT DISC 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to a handheld tool, and more particularly to an innovative tool which is a ratchet. 
     2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98 
     With the elastic support of the elastic parts and position switching of the switching parts, the conventional ratchet tool enables the unidirectional latched block or snap gauge to be snapped (or articulated) along the preset rotational direction, or otherwise rotated reversely in an idle state. Yet, there are shortcomings for the typical ratchet tool are observed during actual application. 
     Thus, to overcome the aforementioned problems of the prior art, it would be an advancement in the art to provide an improved structure that can significantly improve efficacy. 
     Therefore, the inventor has provided the present invention of practicability after deliberate design and evaluation based on years of experience in the production, development and design of related products. 
     BRIEF SUMMARY OF THE INVENTION 
     Based on the unique structure of the present invention that a first braking slot, a second braking slot and an arched control slot are triangularly configured onto the internal surface of the tool driving seat, two braking slots are separately fitted with the first and second braking swing blocks. A moveable control gear is placed into the control slot, and an elastic resetter is additionally provided to make the first and second braking swing blocks swing inwards in a normal state. The frictional resistance of the ratchet tool of the present invention can be minimized under an idle state, thus preventing interlocking of the bolts and nuts, and improving substantially the working efficiency with better convenience and applicability. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIG. 1  shows an assembled perspective view of the preferred embodiment of the ratchet tool of the present invention. 
         FIG. 2  shows an exploded perspective view of the preferred embodiment of the ratchet tool of the present invention. 
         FIG. 3  shows a schematic view of the ratchet tool of the present invention actuating. 
         FIG. 4  shows a partially enlarged schematic view of  FIG. 3 . 
         FIG. 5  shows another schematic view of the ratchet tool of the present invention actuating. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1-3  depict preferred embodiments of a ratchet tool of the present invention, which, however, are provided for only explanatory objectives with respect to the patent claims. The ratchet tool of the preferred embodiment refers to a ratchet spanner. There is a main body  10 , including a handle  11  and an actuating end  12  (a quadrangular rod). The actuating end  12  is provided with a round groove  13 . A circular tooth row  14  is arranged on the inner periphery of the round groove  13 . 
     There is a tool driving seat  20 , assembled rotatably onto one side of the round groove  13  of the main body  10 . A tool driving portion  21  is placed at external end of the tool driving seat  20 , and the internal end of the tool driving seat  20  faces the round groove  13 . 
     A first braking slot  22 , a second braking slot  23  and a control slot  24  are triangularly configured onto the internal surface  211  of the tool driving seat. The first and second braking slots  22 ,  23  are arranged at intervals, with external openings connected with the circular tooth row  14 . The control slot  24  is an arced space in tune with the circular tooth row  14 . A through-hole  25  at both ends of the control slot  24  is separately connected to the first and second braking slot  22 ,  23 . The exterior of the control slot  24  is open-ended and connected with the circular tooth row  14 . 
     A first braking swing block  40  is placed into the first braking slot  22 . An outer tip edge  411  and an inner tip edge  412  are arranged laterally onto the first braking swing block  40 . The outer tip edge  411  faces the external opening of the first braking slot  22  corresponding to the circular tooth row  14 . The inner tip edge  412  faces the through-hole  25  corresponding to the control slot  24 . Moreover, the first braking swing block  40  is provided with a first pivoted portion  42 , so that the first braking swing block  40  can swing by taking the first pivoted portion  42  as a pivot. 
     A second braking swing block  41  is placed into the second braking slot  23 . An outer tip edge  413  and an inner tip edge  414  are arranged laterally onto the second braking swing block  41 . The outer tip edge  413  faces the external opening of the second braking slot  23  corresponding to the circular tooth row  14 . The inner tip edge  414  faces the through-hole  25  corresponding to the control slot  24 . Moreover, the second braking swing block  23  is provided with a second pivoted portion  43 , so that the second braking swing block  23  can swing by taking the second pivoted portion  43  as a pivot. 
     An elastic resetter  60  is assembled between the first braking swing block  40  and second braking swing block  41 , and used to drive the ends of the first/second braking swing blocks  40 ,  41  with inner tip edges  412 ,  414  to swing inwards in a normal state. The elastic resetter  60  of the preferred embodiment is a U-shaped torsional spring, which comprises a first elastic pin  61 , a second elastic pin  62  and a locating collar  63  at the central section. At the spacing between the first braking slot  22  and second braking slot  23 , a locating column  221  is protruded for sleeving of the locating collar of the elastic resetter  60 . At the ends of the first/second braking swing blocks  40 ,  41  with inner tip edges  412 ,  414 , the first and second insertion holes are arranged separately for embedding and positioning of the first/second elastic pins  61 ,  62  of the elastic resetter  60 . 
     A moveable control gear  70  is placed into the control slot  24  in a moveable state. One side of the moveable control gear  70  is normally mated with the circular tooth row  14 . When the moveable control gear  70  shifts to the through-hole  25  at both ends of the control slot  24 , it is mated simultaneously with the inner tip edges  412 ,  414  of the first braking swing block  40  or the second braking swing block  41 . Moreover, the moveable control gear  70  is fitted with a brake rod  71  protruding out of the control slot  24 . 
     The invention includes a cover  50 , covered onto one side of the round groove  13  of the tool driving seat  20  so as to conceal the parts within the aforementioned round groove  13 . The cover  50  is provided with an arched hole  53  for the penetration of the brake rod  71  of the moveable control gear  70 . 
     The first pivoted portion  42  of the first braking swing block  40  and the second pivoted portion  43  of the second braking swing block  41  can be arranged in an offset state nearby the outer tip edges  411 ,  413 . 
     The first pivoted portion  42  of the first braking swing block  40  and the second pivoted portion  43  of the second braking swing block  41  can be designed into a flanged shaft. The cover  50  is provided with a first axle hole  51  for insertion and limitation of the first pivoted portion  42  of the first braking swing block  40 , or provided with a second axle hole  52  for insertion and limitation of the second pivoted portion  43  of the second braking swing block  41 . 
     The first and second axle holes  51 ,  52  of the cover  50  can be designed into elongated holes, which are extended linearly through the first/second axle holes  51 ,  52  from the central point of the cover  50 , so that the first and second braking swing blocks  40 ,  41  can also generate slight offset for more tight mating of the outer tip edges  411 ,  413  with the circular tooth row  14 . 
     A rotary table  80  is mounted at the exterior of the cover  50 . The center of the rotary table  80  is assembled onto the cover  50  via a supported spindle  81 . The protruding end of the brake rod  71  of the moveable control gear  70  is connected eccentrically to the rotary table  80 , so that the brake rod  71  can shift under the drive of the rotary table  80 . Furthermore, an elastic bead  90  and two spaced snapping edges  91 ,  92  are arranged on the assembly surface of the rotary table  80  and the cover  50 , so that the positive and reverse rotation angles of the rotary table  80  can be positioned by snapping the elastic bead  90  into either of the snapping edge  91  or  92 . 
     Based upon above-specified structures, the present invention is operated as follows: 
     Referring to  FIG. 2 , the ratchet tool of the preferred embodiment can be used in such a way that the rotary table  80  is rotated positively or reversely to drive the brake rod  71 , so as to switch the shift direction of the moveable control gear  70  on the control slot  24 , and further control the driving direction of the main body  10  for the tool driving seat  20  (i.e. positive or reverse driving mode). 
     Referring to  FIGS. 3 and 4 , when the moveable control gear  70  is located at a left-hand through-hole  25  of the control slot  24 , the present invention is under a reverse driving mode. Namely, when the main body  10  is reversely turned (shown by arrow L 1  in  FIG. 3 ), the moveable control gear  70  is mated with the circular tooth row  14  (e.g. position A) in a reverse rotation state, and then mated with the inner tip edge  412  (e.g. position B) to drive the first braking swing block  40  to swing positively by taking the first pivoted portion  42  as a pivot (shown by arrow L 2  in  FIG. 4 ). Furthermore, the outer tip edge  411  of the first braking swing block  40  is mated with the circular tooth row  14  (e.g. position C). Owing to the mating state of positions A, B, C, the circular tooth row  14  and the moveable control gear  70  cannot rotate continuously, but are connected permanently so that the tool driving seat  20  will be rotated along with the circular tooth row  14  of the main body  10 . 
     Referring also to  FIG. 5 , when the main body  10  is positively turned (shown by arrow L 3 ), the circular tooth row  14  and the moveable control gear  70  are rotated simultaneously, and the inner tip edge  412  is mated to drive the first braking swing block  40  to rotate by taking the first pivoted portion  42  as a pivot (shown by arrow L 4 ), so the outer tip edge  411  of the first braking swing block  40  is disengaged from the circular tooth row  14 . Since the circular tooth row  14  is only mated with the moveable control gear  70  and able of rotating continuously, the tool driving seat  20  is under an idle state while it cannot be driven by the circular tooth row  14  of the main body  10 . In such a state, the inner tip edge  412  of the first braking swing block  40  can be elastically reset inwards with the assembly of the elastic resetter  60 , so when the moveable control gear  70  is positively rotated to continuously mate with the inner tip edge  412  and bring about the reverse swinging of the first braking swing block  40 , the snapping effect will be yielded from the elastic resetting action. 
     When the ratchet tool of the present invention is under an idle state, the frictional resistance is generated only through the elastic snapping position between the moveable control gear  70  and the inner tip edges  412  of the first braking swing block  40 , so the tiny resistance permits to realize excellent idle state. 
     When the ratchet tool of the present invention is under a positive driving state, the moveable control gear  70  is switched to the right-hand through-hole  25  of the control slot  24  in the same manner.