Abstract: A cutting tool chuck comprises a spindle provided with a tapered bore having the shape of a regular hexagonal prismoid for receiving a shank of a tool holder or a cutting tool, a retainer placed in the tapered bore of the spindle, and a plurality of rollers held in place by the retainer so as to be in rolling contact with the surfaces defining the tapered bore and the surfaces of the shank. The retainer has a plurality of retaining ribs extending along ridge sections of the tapered bore, an upper connecting ring to which the upper ends of the retaining ribs are joined, and a lower connecting ring to which the lower ends of the retaining ribs are joined. Each roller has a pair of projections at its opposite ends, and the rollers are supported for rotation at their projections on the retaining ribs.

Abstract: A cutting tool chuck holds a collet so as to be easily changed. In the cutting tool chuck, a fastening collar (12) is screwed on a chuck sleeve (14). The fastening collar (12) is provided with an internal guide groove (24), deep recesses (24a) formed in a side surface of the guide groove (24), and shallow recesses (24b) formed in the same side surface. A drive shaft (16) is axially slidably fitted in the chuck sleeve (14) with end portions (26a) of a drive shaft control member (26) laterally projecting from the drive shaft (16) and fitted in the guide groove (24). A collet (20) is detachably mounted on the front end of the drive shaft (16). The fastening collar (12) is turned so as to position the end portions (26a) of the drive shaft control member (26) at positions on the side surface of the guide groove (24) other than the deep recesses (24a) to hold the collet (20) on the drive shaft (16).

Abstract: A chucking barrel is connected to a holder capable of being fitted into a rotation spindle of a machine tool. A plurality of axially extending projections are disposed in equally spaced relationship as viewed in the circumferential direction on the connection surface side of the holder, and a plurality of opening portions are formed between adjacent projections. A plurality of teeth-like projections, capable of being fitted in the opening portions, are radially formed on a driving annular member, and a plurality of male threads are formed on the outer surface of the tooth-like projections so as to allow the driving annular member to be displaced in the axial direction. A tightening ring has a plurality of female threads threadably engageable with a plurality of male threads on the driving annular member formed on an inner hole surface thereof, and the tightening ring is rotatably held on the outer peripheral surface of the chucking barrel.