The invention concerns a keyless drill chuck with preferably three jaws (5). The aim of the invention is to enable a large enough clamping force to be exerted by hand to hold a tool inserted in the chuck. In order to do this, it is only necessary to modify slightly an ordinary chuck opened and closed with a key. Instead of a key, the chuck has a toothed wheel (17). A ring (10) designed as a spur gear is fitted with a grip sleeve (13) and has teeth (15) which mesh with the toothed wheel (17). The teeth (20) of a second grip sleeve (19) opposite the ring (10) also mesh with the toothed wheel (17). Rotation of the two large-area grip sleeves (13 and 19) in opposite directions enables a large clamping force to be exerted on the chuck jaws (5).
