Abstract: A chuck device includes: a chuck body having a tapered hole at a front end portion and being fixed to a rotational spindle of the machine tool; a collet capable of being reduced in diameter and inserted into the tapered hole for holding the tool; and a nut that can be screwed to the chuck body for fastening the collet. A non-alignment prevention member is provided for suppressing relative movement by bringing the nut into radial contact with the chuck body even when the spindle of the machine tool is rotated and includes a first nut rear end side tapered surface at a farther rear end side than a screw portion, and a chuck body side tapered surface formed in the chuck body for coming into contact with the first nut rear end side tapered surface when the nut is screwed up.

Abstract: A joint unit comprises a lock mechanism in which a ball-like joint section provided at the base end of an arm is housed in a holder formed at an end of a cylindrical case. As the joint section is brought into pressed contact against an inner surface of the holder, the lock mechanism locks a pivotal angle. In the lock mechanism, in response to a manual operation of a knob, a bolt is caused to project into the case and this pressing force is transmitted to a roller-like first pressing body and then to a second pressing body placed in contact therewith. Further, the pressing force from the first pressing body is transmitted to a pressure block and then the pressing force from this pressure block brings the joint section into pressed contact against the holder inner surface.

Abstract: A joint unit comprises a lock mechanism in which a ball-like joint section provided at the base end of an arm is housed in a holder formed at an end of a cylindrical case. As the joint section is brought into pressed contact against an inner surface of the holder, the lock mechanism locks a pivotal angle. In the lock mechanism, in response to a manual operation of a knob, a bolt is caused to project into the case and this pressing force is transmitted to a roller-like first pressing body and then to a second pressing body placed in contact therewith. Further, the pressing force from the first pressing body is transmitted to a pressure block and then the pressing force from this pressure block brings the joint section into pressed contact against the holder inner surface.