Abstract:
A selective one-way wrench includes an annular head comprising a first space defined therein, a second space communicated with the first space and a third space communicated with the second space. A gear is put rotationally in the first space. A transmission is put in the second space for transmitting torque from the annular head to the gear in selective one of two opposite directions. A switch is put in the second space through the third space and connected with the transmission. The transmission prevents the switch from rotating and rocking on the annular head.

Description:
BACKGROUND OF INVENTION  
       [0001]     1. Field of Invention  
         [0002]     The present invention relates to a selective one-way wrench.  
         [0003]     2. Related Prior Art  
         [0004]     Referring to  FIGS. 10 and 11 , a conventional selective one-way wrench  70  includes an annular head  71  and a handle  76  extending from the annular head  71 . The annular head  71  includes a circular space  72 , a crescent space  73  communicated with the circular space  24  and an aperture  77  communicated with the crescent space  73 . A pawl  81  is put in the crescent space  73 . The pawl  81  includes a first side and a second side opposite to the first side. A toothed face  84  is formed on the first side of the pawl  81 . A recess  85  is defined in the second side. Two concave faces  86  and  87  are formed on the second side. The recess  85  is located between the concave faces  86  and  87 . A direction controller  82  is put in the crescent space  73  before the pawl  81 . The direction controller  82  includes a rod  88  and two wings  89  and  91  extending from the rod  88 . The rod  88  includes a recess  92  defined in the top and a recess  93  defined in a side. A spring  83  includes an end put in the recess  85  of the pawl  81  and an opposite end inserted in a recess  93  of the direction controller  82 . An annular gear  74  is put in the circular space  72 . The annular gear  74  includes a toothed external face  77  for engagement with the toothed face  84  of the pawl  81  and a toothed internal face  75  for engagement with a bolt or nut. An O-ring  78  is put rotationally on the annular gear  74 . The O-ring  79  is put in the circular space  72 . The O-ring  79  is secured to the annular head  71  by means of a C-ring  95 . A switch  90  is put in the aperture  77 . The switch  90  includes a tongue  95  defined therein. The tongue  95  is inserted into the recess through the aperture  77 . The switch  90  drives the direction controller  82  so that the wing  89  or  91  is engaged with the concave face  86  or  87  of the pawl  81 . The switch  90  is secured to the annular head  71  by means of a C-ring  94 .  
       SUMMARY OF INVENTION  
       [0005]     According to the present invention, a selective one-way wrench includes an annular head comprising a first space defined therein, a second space communicated with the first space and a third space communicated with the second space. A gear is put rotationally in the first space. A transmission is put in the second space for transmitting torque from the annular head to the gear in selective one of two opposite directions. A switch is put in the second space through the third space and connected with the transmission. The transmission prevents the switch from rotating and rocking on the annular head.  
         [0006]     The primary advantage of the selective one-way wrench of the present invention over the conventional selective one-way wrench discussed in Related Prior Art is that the transmission prevents the switch from rotating and rocking on the annular head.  
         [0007]     Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the attached drawings. 
     
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0008]     The present invention will be described through detailed illustration of embodiments referring to the attached drawings.  
         [0009]      FIG. 1  is a perspective view of a selective one-way wrench according to a first embodiment of the present invention.  
         [0010]      FIG. 2  is an exploded view of the selective one-way wrench of  FIG. 1 .  
         [0011]      FIG. 3  is a cross-sectional view of the selective one-way wrench of  FIG. 1  and shows the selective one-way wrench in a position for driving a bolt or nut clockwise.  
         [0012]      FIG. 4  is similar to  FIG. 3  but shows the selective one-way wrench in a neutral position.  
         [0013]      FIG. 5  is a cross-sectional view of the selective one-way wrench of  FIG. 1 .  
         [0014]      FIG. 6  is an exploded view of a selective one-way wrench according to a second embodiment of the present invention.  
         [0015]      FIG. 7  is an exploded view of a selective one-way wrench according to a third embodiment of the present invention.  
         [0016]      FIG. 8  is an exploded view of a selective one-way wrench according to a fourth embodiment of the present invention.  
         [0017]      FIG. 9  is an exploded view of a selective one-way wrench according to a fifth embodiment of the present invention.  
         [0018]      FIG. 10  is an exploded view of a conventional selective one-way wrench.  
         [0019]      FIG. 11  is a cross-sectional view of the conventional selective one-way wrench of  FIG. 10 . 
     
    
     DETAILED DESCRIPTION OF EMBODIMENTS  
       [0020]     Referring to  FIG. 1 , according to a first embodiment of the present invention, a selective one-way wrench  10  includes an annular head  11  and a handle  18  (only shown partially) extending from annular head  11 .  
         [0021]     Referring to  FIG. 2 , the annular head  11  defines a large circular space  12 , a crescent space  13  communicated with the large circular space  12 , a small circular space  15  and an aperture  17  through which the small circular space  15  is communicated with the crescent space  13 . An annular groove  14  is defined in a wall of the large circular space  12 . An annular groove  16  is defined in a wall of the small circular space  15 .  
         [0022]     A transmission  20  is put in the crescent space  13 . The transmission  20  includes a pawl  21 , a direction controller  22  and a spring  23  for connecting the direction controller  22  with the pawl  21 .  
         [0023]     The direction controller  22  includes two wings  26  and  27 , a groove  24  defined in the top, a recess  25  defined therein. The recess  25  is located between the wings  26  and  27 .  
         [0024]     The spring  23  includes a first end and a second end opposite to the first end. The first end of the spring  23  is inserted in the recess  25  of the direction controller  22 .  
         [0025]     The pawl  21  includes a first side and a second side opposite to the first side. Three concave faces  28 ,  29  and  38  are defined in the first side of the pawl  21 . The concave face  29  is located between the concave faces  28  and  38 . Two protrusions  39  and  44  are formed on the first side of the pawl  21 . The protrusion  39  is adjacent to the concave face  28 . The protrusion  44  is adjacent to the concave face  38 . The recess  29  receives the second end of the spring  23 . The protrusions  25  and  26  are used for restraining the wings  26  and  27  of the direction controller  22 . A toothed face  45  is formed on the second side of the pawl  21 .  
         [0026]     An annular gear  40  is put in the large circular space  12 . The annular gear  40  includes a toothed external face  41  for engagement with the toothed face of  45  of the pawl  21  and a toothed internal face  42  for engagement with a bolt or a nut.  
         [0027]     An O-ring  50  is rotationally put on the annular gear  40 . The O-ring  50  is put in the large circular space  12 . The O-ring  50  includes an annular groove  51  defined in external face thereof. A C-ring  52  includes an internal edge put in the annular groove  51  and an external edge-put in the annular groove  14 . Thus, the O-ring  50  is firmly attached to the annular head  11  by means of the C-ring  52 .  
         [0028]     A switch  30  includes a lever  31 , a shaft  32  extending from the lever  31 , a tongue  35  extending from the shaft  32  and an annular groove  36  defined in the shaft  32 . The tongue  35  is inserted into the groove  24  through the small circular space  15 . By means of maneuvering the switch  30 , the direction controller  22  is rotated so that the wing  26  of the direction controller  22  is engaged with the concave face  28  of the pawl  21  or that the wing  27  of the direction controller  22  is engaged with the concave face  38  of the pawl  21 .  
         [0029]     A C-ring  33  includes an internal edge put in the annular groove  36  and an external edge put in the annular groove  16 . Thus, the switch  30  is firmly attached to the annular head  11  by means of the C-ring  33 .  
         [0030]     Referring to  FIG. 3 , the selective one-way wrench  10  can be switched to a first working mode by means of the switch  30 . To this end, the switch  30  is rotated clockwise. The direction controller  22  is also rotated. The pawl  21  is moved into a first end of the crescent space  13  by means of the spring  23 . A first end of the pawl  21  abuts the wall of the crescent space  31 . The wing  27  of the direction controller  22  abuts the concave face  38  of the pawl  21 . In the first working mode, the annular head  11  can drive the annular gear  40  clockwise, but not vice versa.  
         [0031]     Referring to  FIG. 4 , the annular head  11  is rotated counterclockwise. In this case, the spring  23  allows the pawl  21  to disengage from the annular gear  40 . Thus, the annular head  11  does not drive the annular gear  40  counterclockwise. During the counterclockwise rotation of the annular head  11 , the wing  26  of the direction controller  22  abuts the wall of the crescent space  13 , and the wing  27  of the direction controller  22  abuts the concave face  38 . Thus, the direction controller  22  does not rotate on the annular head  11 . Accordingly, the switch  30  does not rotate on the annular head  11 . Referring to  FIG. 5 , the space  15  receives the shaft  32  so that the switch  30  does not rock. Therefore, the switch  30  remains still during the counterclockwise rotation of the annular head  11 .  
         [0032]     Although not shown, the selective one-way wrench  10  can be switched to a second working mode by means of the switch  30 . To this end, the switch  30  is rotated counterclockwise. The direction controller  22  is rotated accordingly. The pawl  21  is moved into a second end of the crescent space  13  by means of the spring  23 . A second end of the pawl  21  abuts the wall of the crescent space  31 . The wing  26  of the direction controller  22  abuts the concave face  28  of the pawl  21 . In the second working mode, the annular head  11  can drive the annular gear  40  counterclockwise, but not vice versa.  
         [0033]      FIG. 6  shows a selective one-way wrench  10  according to a second embodiment of the present invention. The second embodiment is identical to the first embodiment except for including a joint  60  instead of the annular gear  40 . The joint  60  includes a hollow insert  61 , a detent  62  movably put in the hollow insert  61  and a control element  63  movably put in the hollow insert  61  for pushing the detent  62  from the hollow insert  61 .  
         [0034]      FIG. 7  shows a selective one-way wrench  10  according to a third embodiment of the present invention. The third embodiment is identical to the first embodiment except for a few things. Firstly, a screw hole  46  is defined instead of the groove  24 . Secondly, a hole  47  is defined in the shaft  32 . The hole  47  is preferably a screw hole. Thirdly, a screw  48  is driven into the screw hole  46  through the screw hole  47 . The direction controller  22  can thus be rotated by means of the switch  30 . Fourthly, the tongue  35  is saved. Fifthly, the annular groove  36  is saved.  
         [0035]      FIG. 8  shows a selective one-way wrench  10  according to a fourth embodiment of the present invention. The fourth embodiment is identical to the first embodiment except for two things. Firstly, a hexagonal tongue  54  is formed instead of the tongue  35 . Secondly, instead of the slot  24 , a hexagonal recess  73  is defined for receiving the hexagonal tongue  54 .  
         [0036]      FIG. 9  shows a selective one-way wrench  10  according to a fifth embodiment of the present invention. The fifth embodiment is identical to the third embodiment except for a few things. Firstly, instead of the screw hole  46  defined in the top of the direction controller  22 , a rod  55  is formed on the top of the direction controller  22 . Secondly, passage  56  is defined in the rod  75 . Thirdly, instead of the screw hole  47 , a recess  57  is defined for receiving the rod  55 . Fourthly, the shaft  32  includes a passage  58  extending laterally through the shaft  32 . Fifthly, a pin  59  is inserted into the passage  56  through the passage  58 . The direction controller  22  can thus be rotated by means of the switch  30 .  
         [0037]     The present invention has been described through detailed illustration of the embodiments. Those skilled in the art can derive variation from the embodiments without departing from the scope of the present invention. Therefore, the embodiments shall not limit the scope of the present invention defined in the claims.