Abstract: An automatic lathe having two workpiece spindles each provided with a workpiece clamping device and arranged with coaxial spindle axes. At least one of the workpiece spindles is arranged on a slide guided for displacement in the direction of the spindle axis and displaceable in the direction of the spindle axis by a drive element and a coupling device between the drive element and the slide. In order to compensate for axial movement component of the clamping device during clamping, the coupling device is designed such that in a first condition thereof, the slide is freely displaceable relative to the drive element in the direction of the spindle axis and opposite to the axial movement component of the clamping device. In a second condition of the coupling device, the slide is not displaceable relative to the drive element in the direction of the spindle axis.

Abstract: In order to so improve a bar stock feeding means for machine tools comprising a longitudinal guide means on which several holders which each receive the bar stock in a guide means are held for movement in the longitudinal direction of the longitudinal guide means, and a drive means with which the holders are displaceable from an initial position in which they exhibit a maximum spacing from one another in the longitudinal direction into an end position on the machine tool side in which they exhibit a minimum spacing from one another in the longitudinal direction, that it can be sturdily and structurally simply made, it is proposed that the longitudinal guide means comprise a guide element having a longitudinal thread, that the holders be held in parallel alignment with one another by threaded rings engaging the longitudinal thread, and that the holders be movable in the longitudinal direction between the initial position and the end position by a relatively rotation between the guide element and the threaded r

Abstract: In order to improve a multiple-spindle automatic lathe comprising a working area, a spindle drum having several spindles in different spindle positions, the spindles being adapted to be brought into different spindle stations on a machine frame by rotation of the spindle drum about a spindle drum axis, a bar stock feed means associated with at least one spindle, and a stop arranged in the working area and having a stop surface for bar stock, such that the stop can be arranged so as to save more space, it is proposed that the stop be mounted for rotation concentrically with the spindle drum axis, and that the stop be fixable relative to the spindle drum during bar stock feed in an initial position in which the stop surface intersects a feed direction of the bar stock located in the spindle position associated with this initial position.

Abstract: In a method and a multiple-spindle automatic lathe for machining both sides of workpieces, in order to increase the number of spindle positions available for machining the workpieces, it is suggested that the spindle drum be indexed in single steps, that the feeding of raw workpieces, the removal of finished workpieces and the changeover of half-finished workpieces be carried out in a single spindle position of the spindle drum and that the feeding of raw workpieces and the removal of finished workpieces occur alternately after each drum indexing.

Abstract: In order to improve a spindle drive for machine tools, comprising a housing, a spindle mounted in the housing, a drive motor arranged on the housing and a gear arranged in the housing and comprising an intermediate shaft driven by the drive motor and mounted in the housing via two shaft bearings spaced from one another as well as a first gear wheel seated on the intermediate shaft, wherein for driving the spindle as C-axis the first gear wheel engages in a first position with a second gear wheel driving the spindle so as to mesh with the second gear wheel without clearance, such that it is more simple in construction it is suggested that the first shaft bearing fix the intermediate shaft immovably on the housing in a direction transverse to its axis and that the intermediate shaft be adapted to be moved back and forth by the second shaft bearing relative to the second gear wheel in an adjusting direction between the first position and a second position, the gear wheels meshing with one another in the second p

Abstract: A method of machining a workpiece, which is rotatable about a first axis, by a tool pivotable about a second axis parallel to the first axis and drivable about a third axis perpendicular to the second axis. To allow the circumference of the workpiece to be machined off-center without the necessity of moving the first or the second axis transversely to the plane defined by these two axes, the workpiece and the tool are rotated or pivoted about the first .[.or.]. .Iadd.and .Iaddend.second .[.axis.]. .Iadd.axes.Iaddend., respectively, at the same time, in the same direction and at the same angular velocity and, simultaneously, the second axis is displaced transversely to the first axis at such a velocity that the equation X.sup.2 =Y.sup.2 +A.sup.

Abstract: .[.A method of.]. .Iadd.Apparatus for .Iaddend.machining a workpiece, which is rotatable about a first axis, by a tool pivotable about a second axis parallel to the first axis and drivable about a third axis perpendicular to the second axis. To allow the circumference of the workpiece to be machined off-center without the necessity of moving the first or the second axis transversely to the plane defined by these two axes, the workpiece and the tool are rotated or pivoted about the first .[.or.]. .Iadd.and .Iaddend.second .[.axis.]. .Iadd.axes.Iaddend., respectively, at the same time, in the same direction and at the same angular velocity and, simultaneously the second axis is displaced transversely to the first axis at such a velocity that the equation X.sup.2 =Y.sup.2 +A.sup.