Abstract:
A joint is disclosed for connecting a handle with various bits. The joint includes an insert fit in the handle, a socket connected with the insert for receiving the bits, a first locking device installed on the socket for locking long bits to the socket and a second locking device installed on the socket for locking short bits to the socket.

Description:
BACKGROUND OF INVENTION 
   1. Field of Invention 
   The present invention relates to a tool and, more particularly, to a tool joint for connecting a handle with various bits. 
   2. Related Prior Art 
   In Taiwanese Patent M2403 11, a conventional screwdriver is disclosed. This conventional screwdriver includes a handle  1 , a bit  3  inserted in the handle  1 , a locking device  2  installed in the handle  1  in order to lock the bit  3  and a controlling device  4  installed on the handle  1  in order to control the locking device  2 . The locking device  2  includes a socket  22  with an axial passage  221  for receiving the bit  3  and two apertures communicated with the axial passage  221 . An annular flange is formed on the socket  22 . Two balls  222  are put in the apertures of the socket  22 . A ring  21  is installed on the socket  22 . The ring includes a tapered internal side  211  for pushing the balls  222 . A spring  24  is installed on the socket  22 . A C-clip is engaged with the socket  22  opposite to the annular flange. Thus, the spring  24  is compressed between the C-clip and the ring  21 . Thus, the tapered internal side of the ring  21  pushes the balls  222  into contact with the bit  3 . The controlling device  4  includes two wedges  42  provided between the ring  21  and the annular flange of the socket  22 . Each wedge  42  is connected with a button  41 . When the buttons  41  are pushed, the wedges  42  push the ring  21  from the annular flange of the socket  22 . Thus, the tapered internal side of the ring  21  allows the balls  22  to leave the bit  3 . However, a few problems are encountered in use of this conventional screwdriver. Firstly, short bits cannot be used, because the locking device  2  is located deep into the handle  1 . Secondly, the bit  3  might accidentally be released, because the buttons  42  are pushed by mistake since the buttons  42  are located-close to an area of the handle  1  that is held. 
   The present invention is therefore intended to obviate or at least alleviate the problems encountered in prior art. 
   SUMMARY OF THE INVENTION 
   According to the present invention, a joint can connect a handle with various bits. The joint includes an insert fit in the handle, a socket connected with the insert for receiving the bits, a first locking device installed on the socket for locking long bits to the socket and a second locking device installed on the socket for locking short bits to the socket. 
   An advantage of the joint of the present invention is that it can connect the handle with long and short bits. Another advantage of the joint of the present invention is that it can connect the handle with some bits with two locking devices. Other advantages and novel features of the invention will become more apparent from the following detailed description in conjunction with the attached drawings. 

   
     BRIEF DESCRIPTION OF DRAWINGS 
     The present invention will be described via detailed illustration of embodiments referring to the drawings. 
       FIG. 1  is a perspective view of a tool joint according to a first embodiment of the present invention. 
       FIG. 2  is an exploded view of the tool joint shown in  FIG. 1 . 
       FIG. 3  is a cross-sectional view of the tool joint shown in  FIG. 1 . 
       FIG. 4  is a cross-sectional view taken along a line  4 — 4  in  FIG. 3 . 
       FIG. 5  is a cross-sectional view taken along a line  5 — 5  in  FIG. 3 . 
       FIG. 6  is similar to  FIG. 3  but shows the tool joint in a different position. 
       FIG. 7  is a cross-sectional view taken along a line  7 — 7  in  FIG. 6 . 
       FIG. 8  is a cross-sectional view taken along a line  8 — 8  in  FIG. 6 . 
       FIG. 9  is similar to  FIG. 3  but shows the tool joint connected with a longer bit. 
       FIG. 10  is similar to  FIG. 3  but shows the tool joint connected with a shorter bit. 
       FIG. 11  is a cross-sectional view taken along a line  11 — 11  in  FIG. 10 . 
       FIG. 12  is a perspective view of a tool joint according to a second embodiment of the present invention. 
       FIG. 13  is an exploded view of the shown in  FIG. 12 . 
       FIG. 14  is a cross-sectional view of the shown in  FIG. 12 . 
       FIG. 15  is a cross-sectional view of a tool joint according to a third embodiment of the present invention. 
       FIG. 16  is a cross-sectional view of a tool joint according to a fourth embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF EMBODIMENTS 
   Referring to  FIG. 1 , according to a first embodiment of the present invention, a joint is shown to include a core  10 , a locking device  30  and a locking device  20 . 
   Referring to  FIG. 2 , the core  10  includes an insert  13  to be inserted in a handle (not shown) and a selective one-way socket  12  connected with the insert  13 . An axial passage  11  extends through the insert  13  and the selective one-way socket  12 . 
   The selective one-way socket  12  includes an annular groove  15  defined in the periphery, three apertures  14  communicated with the axial passage  11 , three apertures  18  communicated with the axial passage  11  and an annular groove  17  defined in the periphery. 
   The locking device  30  includes three balls  32  put in the apertures  14  and a collar  31  for controlling the balls  32 . 
   The locking device  20  includes three balls  22  put in the apertures  18  and a ring  21  for controlling the balls  22 . 
   Referring to  FIG. 3 , the collar  31  includes an internal side that is divided into a cylindrical section  33 , a frustum-shaped section  34  and an annular shoulder  35  formed between the cylindrical section  33  and the frustum-shaped section  34 . The frustum is defined by rotation of a curve instead of a straight line. 
   A C-clip  16  is put in the annular groove  15 . A spring  40  is installed on the socket  12  and against the C-clip  16 . The collar  31  is installed on the socket  12 . The spring  40  is compressed between the annular shoulder  35  and the C-clip  16 . Referring to  FIGS. 3 and 5 , the annular shoulder  35  pushes the balls  32  into the axial passage  11 . The balls  32  enter an annular groove  52  defined in a shank  51  of a bit  50 . The ring  21  is installed on the socket  12  in a rotational manner. A C-clip  19  is put in the annular groove  17  in order to keep the ring  21  on the socket  12 . 
   Referring to  FIG. 4 , the ring  21  includes an internal side on which three slopes  23  are formed for pushing the balls  22  into the axial passage  11 . The slopes  23  extend along a curve instead of a straight line. 
   Referring to  FIGS. 6 and 8 , the collar  31  is moved rectilinearly on the socket  12  in order to move the frustum-shaped section  34  from the balls  32 . Thus, the balls  32  are allowed to leave the annular groove  52 . 
   Referring to  FIG. 7 , the ring  21  is rotated on the socket  12  in order to move the slopes  23  from the balls  22 . Thus, the balls  22  are allowed to leave the shank  51  of the bit  50 . 
   As the collar  31  is in the position shown in  FIGS. 6 and 8  and the ring  21  is in the position shown in  FIG. 7 , the shank  51  of the bit  50  can be disengaged from the joint. 
   Referring to  FIG. 9 , the tool joint is connected with a bit  60 . The bit  60  is longer than the bit  50 . The bit  60  does not include annular groove like the annular groove  52  of the bit  50 . The balls  32  contact the bit  60 . 
   Referring to  FIG. 10 , the tool joint is connected with a bit  70 . The bit  70  is shorter than the bit  50 . The balls  32  abut an end of the bit  70  in order to prevent the bit  70  from completely entering the axial passage  11 . The bit  70  does not include an annular groove like the annular groove  52  of the bit  50 . The bit  70  includes three recesses  72  that are, however, too small for the balls  22 . The balls  22  contact the bit  70 . 
   Referring to  FIGS. 12 through 14 , a tool joint according to a second embodiment of the present invention is shown. The second embodiment is identical to the first embodiment except for not including the first locking device  20 . 
   Referring to  FIG. 15 , a tool joint according to a third embodiment of the present invention is shown. The third embodiment is identical to the first embodiment except for including socket  80  instead of the selective one-way socket  12 . 
   Referring to  FIG. 16 , a tool joint according to a fourth embodiment of the present invention is shown. The fourth embodiment is identical to the first embodiment except for not including the first locking device  20  and for including socket  80  instead of the selective one-way socket  12 . 
   An advantage of the joint of the present invention is that it can connect the handle with long and short bits. Another advantage of the joint of the present invention is that it can connect the handle with some bits with two locking devices. 
   The present invention has been described via detailed illustration of the embodiments. Those skilled in the art can derive variations 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.