Patent Publication Number: US-7717016-B2

Title: Tool handle for an exchangeable screwdriver

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a tool handle, and more particularly to a tool handle for an exchangeable screwdriver. 
   2. Description of Related Art 
   A conventional exchangeable screwdriver in accordance with the prior art comprises a tool handle and a tool shank. The tool handle has an open cavity for receiving one end of the tool shank. The other end of the tool shank is an actuating portion for actuating a screw. The middle of the tool shank has two projections symmetrically extending therefrom. The tool handle has two slots symmetrically extending from the cavity for engaging the middle of the tool shank. Therefore the tool shank is retained to prevent rotation relative to the tool handle. The tool shank is free to be detached from the tool handle to change the different tool shank. The conventional tool handle does not avoid the axial movement of the tool shank. When operating the conventional exchangeable screwdriver, the tool shank is possible to slide out. It is inconvenient for usage and maybe dangerous for the user. 
   The present invention has arisen to mitigate and/or obviate the disadvantages of the conventional tool handle. 
   SUMMARY OF THE INVENTION 
   The main objective of the present invention is to provide an improved tool handle for an exchangeable screwdriver, which prevents the tool shank from axial movement and permits the tool shank detaching from the tool handle easily and quickly. 
   To achieve the objective, the tool handle includes a handle, a retaining unit connected to the handle and a control unit connected to the retaining unit. The handle has a mounting portion formed in one end thereof. The retaining unit is mounted in the mounting portion. The retaining unit has a retaining hole defined therein and extending therethrough. The retaining unit has a recess defined in a lateral thereof and communicated with the retaining hole. The retaining unit has at least one connecting portion disposed between the recess and the retaining hole. The control unit is received in the recess. The control unit has at least one resilient arm extending therefrom. The at least one resilient arm passes the recess and is abutted against the at least one connecting portion to selectively extend to the retaining hole. 
   Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an exploded perspective view of a tool handle for an exchangeable screwdriver in accordance with the present invention; 
       FIG. 2  is another exploded perspective view of the tool handle for an exchangeable screwdriver in accordance with the present invention; 
       FIG. 3  is a cross-sectional view of the tool handle taken along line A-A in  FIG. 2 ; 
       FIG. 4  is an assembly perspective view of the tool handle for an exchangeable screwdriver in  FIG. 1 ; 
       FIG. 5  is a cross-sectional view of the tool handle for an exchangeable screwdriver taken along line B-B in  FIG. 4 ; and 
       FIG. 6  shows the operation of the control unit of the tool handle for an exchangeable screwdriver in accordance with the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring to the drawings and initially to  FIGS. 1-4 , a tool handle for an exchangeable screwdriver in accordance with the present invention comprises a handle  1 , a retaining unit  2  connected to the handle  1 , and a control unit  3  connected to the retaining unit  2 . 
   The handle  1  has a mounting portion  11  formed in one end thereof. The other end of the handle  1  is provided to be gripped by user&#39;s hand. The mounting portion  11  is open and hollow. The mounting portion  11  has at least one rib  111  extending from an inner peripheral thereof. In the preferred embodiment, the mounting portion  11  has two ribs  111  symmetrical to each other. The mounting portion  11  has at least one aperture  112  defined in an outer peripheral thereof and extending therethrough. In the preferred embodiment, the mounting portion  11  has two apertures  112  symmetrical to each other. 
   The retaining unit  2  has a cap  21  formed in one end thereof and a cylinder  22  extending from the cap  21 . The cylinder  22  has at least one slot  222  defined in an outer peripheral thereof and at least one hook  221  extending from the outer peripheral thereof. In the preferred embodiment, the cylinder  22  has two slots  222  symmetrical to each other and two hooks  221  symmetrical to each other. The cylinder  22  is inserted in the mounting portion  11 . The at least one rib  111  of the mounting portion  11  engages with the at least one slot  222  in the cylinder  22  and the at least one hook  221  of the cylinder  22  engages with the at least one aperture  112  in the mounting portion  11  to prevent the retaining unit  2  from rotating and moving along an axial direction. The retaining unit  2  has a retaining hole  223  defined in a center of the cylinder  22  and extending through the cylinder  22  and the cap  21  to complementarily receive a tool shank  4 . The retaining hole  223  has a noncircular section. In the preferred embodiment, the retaining hole  223  has a hexagonal section and the tool shank  4  has a hexagonal section. The tool shank  4  is complementarily received in the retaining hole  223  to prevent from rotation. The cap  21  has a recess  224  defined in a lateral thereof and communicated with the retaining hole  223 . The retaining unit  2  has at least one connecting portion  225  disposed between the recess  224  and the retaining hole  223  to connect the cap  21  and the cylinder  22 . In the preferred embodiment, the retaining unit  2  has two connecting portions  225 .
         The control unit  3  has a press surface  31  formed in one end thereof. The press surface  31  is in a shape of camber. The control unit  3  has at least one resilient arm  32  curvilinearly extending from the other end thereof. In the preferred embodiment, the control unit  3  has two resilient arms  32  to form a semicircle. Each resilient arm  32  has an extending catch  321  extending from a free end thereof. The control unit  3  is received in the recess  224 . The press surface  31  fits the cap  21  to conceal the control unit  3 . The two resilient arms  32  passes the recess  224  and respectively abuts against the two connecting portions  225 . Each extending catch  321  extends into the retaining hole  223  as shown in  FIG. 5 . The tool shank  4  has an annular groove  41  defined in an outer peripheral thereof. When inserting the tool shank  4  into the retaining hole  223 , the two extending catches  321  engage with the annular groove  41  to prevent the tool shank  4  from axial movement. When pressing the press surface  31 , the two resilient arms  32  respectively pivot on the two connecting portions  225  to retract the extending catches  321  as shown in  FIG. 6 . Therefore, each extending catch  321  disengages with the annular groove  41  such that the tool shank  4  is free to be detached from the handle  1 .       

   The tool handle in accordance with the present invention further comprises a sleeve  5  disposed in an outer peripheral of the mounting portion  11  to avoid disengaging the at least one hook  221  unconsciously and prevent the retaining unit  2  from dust and moisture. 
   Although the invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.