Abstract: The invention concerns a multi-spindle automatic lathe intended for machining bars of material. Such lathe comprises: a spindle carrier (2) adapted to be displaced in rotation and translation and on which spindles (3) intended for holding bars (M) are assembled together, and bar (M) shaping means including tool bearing carriages (14) which are arranged and adapted in order to receive machining tools (12) and which are directed by control cams (16, 18) supported and driven in rotation, such lathe being characterized in that the shaping means are mounted around a central body (50) which assures the interior guidance of the spindle carrier (2) while the shaping means and the spindles (3) assembled on the spindle carrier (2) are actuated from the exterior by peripheral driving means.

Abstract: The invention concerns an arrangement for clamping a bar of material. Such arrangement includes: clamping jaws (MS, MS') guided in a radial direction relative to the bar and adapted to take up two distinctive radial positions referred to as closed and open in order to clamp and to release the bar (B), a jaw closing mechanism (MF, MF') adapted so as to provide the jaws with a grasping force intended to assure clamping of the bar (B), return means (MR) for urging the jaws towards their open position and to assure release of said bar (B), and control means (MP) capable of controlling the operation of the closing mechanism (MF, MF') and the operation of the return means (MR) by a motion of translation substantially coaxial to the bar (B) in order to control respectively the closing and opening of the jaws, such control means (MP) being freely mounted for rotation relative to the closing mechanism (MF, MF'), while such mechanism (ME, MF') is entirely subjected to the rotational motion of said jaws (MS).

Abstract: A guide bush is described, having a bush-holder and a quill integral with the bush support. The device has a clamp capable of rotating a workpiece, means for opening and closing the clamp and regulating means adapted to monitor the opening and closing means in order to compensate for changes in the dimensional tolerances of the workpiece, wherein the bush regulating means are adapted to operate the opening and closing means of the clamping means very quickly as a direct result of variations in the dimensional tolerances of the workpiece in order to provide a substantially constant pressure of the clamp on the workpiece. The bush is for use with a machine tool such as a travelling headstock automatic lathe.

Abstract: The automatic machine works on coiled stock to produce a series of workpieces. It comprises a spindle arranged to turn around its axis, but only somewhat more than through an angle of 360.degree., between two fixed angular limits. The tools consist of shaped milling cutters or grinding wheels which machine surfaces of revolutions on the workpieces.

Abstract: A numerically controlled automatic lathe comprises radial tools fanning out around that part of a bar of stock emerging from a guidance bush. Each of the tools is fastened to the end of a cylindrical slider guided by a bore of a fixed support. Each slider can be displaced within its bore by a gear which is fixed in the axial direction, engages a slider thread and meshes with a pinion gear of a stepping motor subject to numerical control and fastened to the support parallel to the slider. A sleeve permits centering the cutting edge of the tool by means of an offset screw, of which the tip transversely displaces a shoe constrained within a longitudinal groove of the slider.

Abstract: A thread-rolling head comprises three identical support pieces rotatingly and non-displaceably mounted in a bearing member. Each support piece has at its outer end a supporting journal on which a thread roller is rotatingly disposed between an annular shoulder of the support piece and a circlip which matingly engages a V-shaped annular groove; the side of the groove nearest the thread-roller is a flat shoulder and the other conical side has an outer diameter equal to that of the journal, the outer end face of which is flush with the outer face of the circlip.

Abstract: A thread-rolling head comprises three crank-like support pieces, each bearing a thread roller, protruding from a support member in which they are mounted. A control member is held unrotatably on the support member while a bearing member held in front of the support member is rotatable and stop means are operative between the bearing and the support member to transmit to the latter a torque received from the workpiece through the thread rollers; the stop means is rendered inoperative when the bearing means is caused by the workpiece to move forwardly, whereby the torque will aid a spring in rotating the bearing member to pivot the support pieces in order to remove the thread rollers from the workpiece.