Abstract: For the attachment of a tool provided with a cylindrical or frusto-conical shank to a rotating machine spindle at one end of the machine spindle a complementary reception opening for the shank is provided. The shank contains a coaxial bore and a plurality of slots distributed in the circumferential direction and extending through radially to the bore, which divide the shank within the reception opening into segments. In the region of the slots the shank widens out under the influence of centrifugal forces more than does the region of the spindle surrounding the shank. Thus the radial guidance of the tool is not lost even at very high rotation rates of 10,000 r.p.m. and above. A support shoulder on an annular collar of the tool prevents axial reshifting of the shank by reason of the axial stress of a clamping device and improves the rigidity of the tool-spindle connection. The bore extends through the annular collar.

Abstract: A thread spooler includes a plurality of spool units, each of which includes a thread defect sensor of a defect classification device which reacts to defects of the thread to be wound up. A large number of sets of predetermined operational parameters of the spool units and/or the defect classification devices can be recorded by a central input device into a central memory which stores all these data simultaneously. Each of the spool units includes a decentralized memory, into which one of the centrally stored operational parameter sets can be loaded individually for each spool unit by a call-up switch. A central control determines for respective groups of spool units a predetermined sequence, in which the operational parameter sets can be called up by the spool units. The classification device determines the thread defect, preferably individually for each spool unit, and indeed respectively referred onto the last wound gauged length of the thread.

Abstract: In a draw-bar mechanism for moving the collet of a chuck or the like on a spindle of an automatic turning machine toward its axial clamping position and for thereafter closing the collet more slowly with greater force about a tool or workpiece to be clamped, motion is transmitted from an actuating sleeve to a draw bar or like control member by spherical thrust members movably confined between three faces obliquely inclined relative to each other. A first face is fixed relative to the spindle assembly and has one section parallel to the axis and another axially contiguous section obliquely inclined relative to the axis, the two sections merging in an exposed edge. A second face is fixed relative to the control member, and the third face is fixed relative to the actuating sleeve and has two axially consecutive sections obliquely inclined relative to each other.