Patent Publication Number: US-2003221522-A1

Title: Reversible ratchet wrench

Description:
FIELD OF THE INVENTION  
       [0001] The present invention related to a hand tool, and more particularly to a reversible ratchet wrench.  
       BACKGROUND OF THE INVENTION  
       [0002] U.S. Pat. No. 6,282,992 disclosed a reversible ratchet wrench, please refer to FIG. 14, which comprises a handle  90  having a head portion  91  at an end thereof. The head portion  91  is provided with a through hole  911 , a first chamber  912  and a second chamber  913 . An engaging member  92  is installed in the through hole  911  for free rotating and is locked by a C-ring  96 . A pawl  93  is installed in the first chamber  912  and is detachably meshed with a teeth portion  921  of the engaging member  92 . A switching device  94  is installed in the second chamber  913  which has a spring  95  installed in a recess  941  at front side thereof. The distal end of spring  95  rests against the pawl  93  to make it can be driven to shift by turning the switching device  94 . A positioning device  97 , which is composed of a spring and a ball, is installed in a slot  914  at the rear sidewall of the second chamber  913  to rest against the switching device  94 .  
       [0003] To assemble aforesaid reversible ratchet wrench, operator must install the positioning device  97  via the first chamber  912  first, and then insert the switching device  94  via the opening end of the second chamber  913 , install the spring  95  to the switching device  94  via the first chamber  912 , at least, install the pawl  93  and the engaging member  92  into the first chamber  912  and the through hole  911  in sequence.  
       [0004] It is a hard job to assemble aforesaid ratchet wrench, and more particularly to a ratchet wrench of smaller size.  
       SUMMARY OF THE INVENTION  
       [0005] The primary objective of the present invention is to provide a reversible ratchet wrench, which has an easy way to assemble the elements.  
       [0006] According to the objective of the present invention, a reversible ratchet wrench comprises a handle having a head portion at an end thereof. The head portion has a through hole, a first chamber and a second chamber, wherein the first chamber is communicating with the through hole and the second chamber respectively. An engaging member is received in the through hole of the handle for free rotating. A pawl is received in the first chamber detachably meshed with the engaging member. A switching device comprises an axle member having an axial direction and a radial direction and a turning member at an end of the axle member along the axial direction thereof, and a driving device has a coupling portion and an elastic arm, wherein the coupling portion is received in the second chamber and the elastic arm is projected out along the radial direction of the axle member to rest against the pawl at the driven portion thereof. The axle member of the switching is installed in the second chamber to be coupled with the axle member of the turning member along the axial direction thereof. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0007]FIG. 1 is an exploded view of a first prefer embodiment of the present invention;  
     [0008]FIG. 2 is a top view of the first prefer embodiment of the present invention in combination;  
     [0009]FIG. 3 is a sectional view along the  3 - 3  line in FIG. 2;  
     [0010]FIG. 4 is a perspective view of a switching device of the first prefer embodiment of the present invention;  
     [0011]FIG. 5 is a perspective view of a driving device of the first prefer embodiment of the present invention;  
     [0012]FIG. 6 is a top view of the driving device of the first prefer embodiment of the present invention;  
     [0013]FIG. 7 is a sectional view along the  7 - 7  line in FIG. 6;  
     [0014]FIG. 8 is a sectional view of the first prefer embodiment of the present invention, showing a pawl being moved to left side and the handle being turned counterclockwise;  
     [0015]FIG. 9 is a sectional view following FIG. 8, showing the handle being turned clockwise;  
     [0016]FIG. 10 is a sectional view of the first prefer embodiment of the present invention, showing a pawl being moved to right side and the handle being turned clockwise;  
     [0017]FIG. 11 is a sectional view following FIG. 10, showing the handle being turned counterclockwise;  
     [0018]FIG. 12 is an exploded view of a second prefer embodiment of the present invention;  
     [0019]FIG. 13 is a sectional view of a second prefer embodiment of the present invention, and  
     [0020]FIG. 14 is an exploded view of a conventional reversible ratchet wrench. 
    
    
     DETAIL DESCRIPTION OF THE INVENTION  
     [0021] Please refer to FIGS. from FIG. 1 to FIG. 3, a reversible ratchet wrench  1  of the first prefer embodiment of the present invention comprises a handle  10 , an engaging member  20 , a pawl  30 , a switching device  40  and a driving device  50 , wherein  
     [0022] The handle  10  has a head portion  11  at an end thereof at which is provided with a through hole  12 , a first chamber  13  and a second chamber  13 . The first chamber  13  is located between the through hole  12  and the second chamber  14  and is communicated with both of them. The through hole  11  is opening at both sides of the head portion  11  of the handle  10 , the first chamber  13  is closed at both sides thereof and the second chamber  14  is opening at a side thereof and is closed at the opposite side thereof. An annular slot  121  is disposed at the sidewall of the through hole  12  and a recess  141  is disposed at the bottom of the second chamber  14 .  
     [0023] The engaging member  20  has a dodecahedral hole  21  (or a hexagonal hole) at central for engaging a nut or a bolt (not shown). The engaging member  20  further has a teeth portion  22  at out surface and an annular slot  23  beside the teeth portion  22 . The engaging member  20  is received in the through hole  12  of the handle  10  with a retaining ring  24  installed in the annular slots  121  and  23  to lock the engaging member  20  and making it can free rotate.  
     [0024] The pawl  30  has a teeth portion  32  at a side thereof, a driven portion  34  at opposite side thereof and two against portions  36  beside the driven portion  34  respectively. The driven portion  34  is a curved cavity in this embodiment having two lug portions  341  and two recesses  342  at two sides thereof, wherein the recesses  342  are located at outsides of the lug portions  341  respectively. The pawl  30  is installed in the first chamber  13  of the handle  10  to be driven to the left side, as shown in FIG. 8, and to the right side, as shown in FIG. 10, of the first chamber  13 .  
     [0025] The switching device  40  has an axle member  41  and a turning member  42  at an end of the axle member  41 . The axle member  41  is a column in this prefer embodiment having an axial direction La and a radial direction Lr. Please refer to FIG. 4, the axle member  41  has an indentation  411  at the end opposite from the turning member  42  and a locking portion  412  which is an annular recess in this prefer embodiment. Two inclined portions  413  are disposed at the distal end of the axle member  41  at two sides of the indentation  411  respectively. The axle member  41  of the switching device  40  is inserted into the second chamber  14  of the handle  10  via the opening end of the second chamber  14  for the distal end thereof received in the recess  141  and the turning member  42  is left outside to be exerted thereon for driving the axle member  41  to turn.  
     [0026] The driving device  50  has a coupling portion  51  and an elastic arm  52 . Please refer to FIGS. from FIG. 5 to FIG. 7, the driving device  50  is made from a flexible wire, such as spring wire, so that the coupling portion  51  is a spiral column (like a spring) and the elastic arm  52  is a curved wire projected from an end of the coupling portion  51  along the radial direction thereof. Please refer to FIG. 5, the coupling portion  51  has a locking device  511  which is a smaller diameter section closing to the elastic arm  52 , a connecting portion  512  which is a wire section connecting the elastic arm  52  with the coupling portion  51  and crosses the diameter at the end of the coupling portion  51  and a stop portion  513  which is a small wire section projected from the end opposite from the elastic arm  52  along the radial direction.  
     [0027] The coupling portion  51  of the driving device  50  is received in the second chamber  14  of the handle  10  for the stop portion  513  resting against the inner sidewall of the first chamber  13  beside the opening end of the second chamber  14  to prevent the coupling portion  51  from escaping from the second chamber  14  via the opening end thereof. The elastic arm  52  is extended in the first chamber  13  and against the pawl  30  at the driven portion  34 . The axle member  41  of the switching device  40  is inserted into the coupling portion  51  of the driving device  50  via the opening end of the second chamber  14 , such that the connecting portion  512  of the coupling portion  51  is received in the indentation  411  of the axle member  41  and the locking device  511  of the coupling portion  51  is received in the locking portion  412  of the axle member  41  to lock the coupling member  51  with the axle member  41 . Thus, user can turn the turning member  42  of the switching device  40  to drive the elastic arm  52  of the driving member  50  to turn and the pawl  30  will be driven to shift by the elastic arm  52  to the right side and the left side of the first chamber  13 .  
     [0028] Please refer to FIG. 8, when turning the turning member  42  of the switching device  40  to right will drive the elastic arm  52  of the driving member  50  turning to left. The elastic arm  52  will cross the lug portion  341  at left side of the driven portion  34  of the pawl  30  first and then is received in the recess  342  behind the lug portion  341 , in the meantime, the pawl  30  will be driven to the left side of the first chamber  13  and the against portion  36  at left side thereof will rest against the left sidewall of the first chamber  13 .  
     [0029] If user turns the handle  10  counterclockwise, please refer to FIG. 8, the teeth portion  32  of the pawl  30  will be meshed with the teeth portion  22  of the engaging member  20  and make the engaging member  20  turning with the handle  10  for turning loose a nut or a bolt (not shown).  
     [0030] If user turns the handle  10  clockwise, please refer to FIG. 9, the pawl  30  will be detached from the engaging member  20  and the elastic arm  52  will be compressed so that the engaging member  20  will keep still.  
     [0031] On the contrary, please refer to FIG. 10, when turning the turning member  42  of the switching device  40  to left will drive the elastic arm  52  of the driving member  50  turning to right. The elastic arm  52  will cross the lug portion  341  at right side of the driven portion  34  of the pawl  30  first and then is received in the recess  342  behind the lug portion  341 , in the meantime, the pawl  30  will be driven to the right side of the first chamber  13  and the against portion  36  at right side will rest against the left sidewall of the first chamber  13 .  
     [0032] Please refer to FIG. 10 and FIG. 11, if user turns the handle  10  clockwise will drive a nut or a bolt (not shown) to turn tight but turns the handle  10  counterclockwise will keep the nut or the bolt still.  
     [0033] The operating way of the reversible ratchet wrench  10  of the present invention is as same as a conventional reversible ratchet wrench, so I will not describe the detail here.  
     [0034] One thing I had to mention here is that when the elastic arm  52  is driven to cross the lug portion  341  and be received in the recess  342 , there will be a feedback of resistance and sound to user that will make user understanding the elastic arm  52  is turned to the right position.  
     [0035] There will be an easy way to assemble the reversible ratchet wrench  1  of the present invention, first, install the coupling portion  51  of the driving device  50  into the second chamber  14  of the handle  10  via the first chamber  13 , and then insert the axle member  41  of the switching device  40  into the coupling portion  51  via the opening end of the second chamber  14 . The connecting portion  512  of the coupling portion  51  will be received in the indentation  411  of the axle member  41  and the locking device  511  of the coupling portion  51  will be received in the locking portion  412  of the axle member  41  automatically so that the driving device  50  is secured with the switching device  40  for turning the switching device  40  can drive the elastic arm  52  to turn. At least, install the pawl  30  and the engaging member  20  into the first chamber  13  and the through hole  12  respectively to complete the reversible ratchet wrench  1  of the present invention.  
     [0036] It is obvious to see that the coupling portion  51  of the driving device  50  is coupled with the axle member  41  of the switching device  40  along the axial direction La thereof and the elastic arm  52  is projected out along the radial direction Lr.  
     [0037] The inclined portions  413  on the opposite sides of the indentation  411  are to facilitate the connecting portion  512  of the coupling portion  51  sliding into the indentation  411  when inserting the axle member  41  of the switching device  40  into the coupling portion  51 .  
     [0038]FIG. 12 and FIG. 13 show a reversible ratchet wrench  2  of the second prefer embodiment of the present invention, it is similar to the first prefer embodiment, comprising a handle  70 , an engaging member  71 , a pawl  72 , a switching device  73  and a driving device  74 . The handle  70  has a through hole  711 , a first chamber  712  and a second chamber  713 , wherein the through hole  711  is opening at both sides of the handle  711  and the first and the second chambers  712  and  713  are opening at a side of the handle  70 . A cover  75  is installed on the handle  10  at the opening ends of the through hole  711  and the first chamber  712 . A retaining ring  76  is applied to lock the cover  75 . The switching device  73  has a lug  731  below the cover  75  to prevent it from escaping from the second chamber  713 . The driving device  74  has a coupling portion  741  and an elastic arm  742  but without aforesaid stop portion.