Patent ID: 7922180

Claim:
A screwdriver bit holder structure comprising: a holder body that sets a polygon hole along the shaft axis, a cylinder cavity sharing the same axis of center as the polygon hole, an inner spring and a sliding tube inside the cylinder cavity, and front ball holes and front balls in one end; a fixing cap with an inner hole is capped around said polygon hole on said holder body and an outer spring is set inside said fixing cap; the features comprising: the said holder body is clipped by a c-clamp, on one side of which said outer spring is against, and on the other side of which set middle and back ball holes on said holder body with middle and back balls nesting inside the said holes; a front and a back groove are set on said sliding tube to contain said middle and back balls; at the front end of said inner hole of said fixing cap set a front and a back recess for said front balls to stay against, and at the back end sets a limiting ring to limit its movement up to the said c-clamp.