Patent ID: 6901826

Claim:
A screwdriver comprising: a handle having a polygonal hole defined in a first end thereof for allowing an operate shaft extending into the handle; a locking device mounted in the handle for selective holding the operate shaft in place, the locking device including a stopper secured in the handle and having a hole defined therein and extending therethrough, the hole co-axially corresponding to the polygonal hole in the handle, the hole in the stopper including a tapered section facing the first end of the handle and having a diameter gradually enlarged relative to the first end of the handle, a slider extending through the stopper and partially received in the hole in the stopper, the slider being movable relative to the stopper, the slider having a polygonal hole defined therein and extending therethrough for allowing the operate shaft extending through the slider, multiple steel balls buried in the slider and radially extending through the slider, each steel ball selectively abutting an inner periphery of the tapered section of the hole in the stopper and the outer periphery of the operate shaft to selectively hold the operate shaft in place, a resilient member mounted around the slider after extending through the stopper for providing a restitution force to make the multiple steel balls engaged to the operate shaft; and a controlling device is mounted to the handle and corresponding to the locking device for forward moving the slider and making the multiple steel balls disengaged from the operate shaft.