Patent ID: 7249770

Claim:
A locking drill chuck comprising a chuck body having a front portion, a back end and an outer circumference; a plurality of jaws having threads, a nut having threads, a nut jacket having a front end portion, an upper end portion, and an inner circumference wall, a front sleeve having an inner circumference wall, and a rear sleeve, wherein an axial bore engaged with a driving shaft of a driving means is provided at the back end of the chuck body, the rear sleeve is fixedly connected to the outer circumference of the chuck body, the plurality of jaws are respectively installed in angled bores uniformly distributed around the chuck body, the threads of the nut and the threads of the jaws installed in the angled bores of the chuck body are engaged and together form a thread driving mechanism, the nut jacket is fixedly connected to the nut, the locking drill chuck further comprises: a toothed member fixed to the front portion of the chuck body with respect to the nut, the toothed member having ratchets; a plurality of elastic elements formed at the front end portion of the nut jacket, each of the elastic elements has an elastic positioning pawl, an elastic locking positioning pawl, and a locking detent thereon; a plurality of grooves formed in the inner circumference wall of the front sleeve, wherein a positioning state of the elastic elements of the nut jacket can be controlled through the grooves of the front sleeve, and the locking detents and the ratchets of the toothed member engage to form a locking mechanism, and wherein a plurality of keyslots are formed on the upper end portion of the nut jacket in a radial direction, and the front sleeve has a plurality of keys extending downward to engage with the keyslots and to locate inside the inner circumference wall of the nut jacket respectively.