Abstract: A turning machine has a spindle box, a workpiece spindle rotatably supported in the spindle box and having at its on end a clamping device for clamping rod-shaped workpieces, a tool holder arranged displaceably transversely to an axis of the workpiece spindle, a guiding bushing support, and a workpiece guiding bushing rotatably supported in the guiding bushing support so that the guiding bushing is oriented coaxially with the axis of the workpiece spindle and exchangeably mounted in the guiding bushing support. The workpiece spindle displaces the guiding bushing in the direction of the axis of the workpiece spindle. The workpiece spindle is sleeve-shaped and extends out of the spindle box over at least a length of the relative movement. The workpiece guiding bushing is exchangeable by the workpiece spindle guiding bushing for receiving the sleeve-shaped workpiece spindle.

Abstract: In order to improve a machine tool with a motor spindle, including a main motor integrated into a work spindle coaxially with the spindle axis, the main motor, for its part, comprising a rotor and a stator, and with a cooling device for supplying cooling surfaces of the main motor with a gaseous coolant, so that simple and effective cooling of the main motors of the motor spindles is possible, it is proposed that the stator be comprised of stator plates which, for their part, form cooling surfaces, and that the gaseous coolant be conducted directly along the cooling surfaces of the stator plates.

Abstract: A pipe machining apparatus includes a tool carrier, with a frame attachable to a pipe for rotatably mounting the tool carrier. The tool carrier is circumferentially rotatable about the pipe and carries a tool for performing cutting or machining operations on the pipe. A plurality of rotatable bearings are provided between the frame and the tool carrier, and the bearings are individually adjustable in a radial direction to compensate for wear of the bearings during use of the apparatus.

Abstract: A mechanism for detachably mounting any selected one of several attachments to a hollow spindlehead ram within which a spindle is rotatably supported by a hollow shaft, the latter being capable of both rotary and axial displacement relative to the ram. Both the hollow shaft and the selected attachment are coupled with the ram via Curvic coupling teeth. Further, in order to retain the attachment in positive engagement with the ram via the Curvic coupling teeth, a series of external locking teeth are formed on the hollow shaft at constant circumferential spacings for engagement with a series of internal locking teeth formed on the attachment. The hollow shaft forces the attachment against the ram via the interengaged locking teeth under hydraulic pressure.

Abstract: A hydrostatic spindle device has a housing, a hydrostatic radial bearing at each end of the housing, a spindle rotatably and translatably supported by the hydrostatic radial bearings, and extending through the bearings. A hydraulic motor is attached to one end of the spindle and a cutting tool or workpiece is attached to the other end. The interior of the housing comprises a cylinder in which a piston, fashioned integral with the spindle travels. Pressurized hydraulic fluid suitably introduced by an electrohydraulic servo control system precisely controls the translational position, velocity, and acceleration of the spindle. Hydrostatic thrust bearings at each end of the cylinder prevent the piston, when rotating, from wearing either end surface of the cylinder.

Abstract: A machine tool has a housing normally rotated about a housing axis and a part that is axially movable relative to the housing to adjust the tool. An adjustment apparatus for the tool has a drive having a rotary drive output, a differential transmission having a rotary input connected to the drive output and a pair of transmission outputs. This transmission includes a reverser for rotation of one of the transmission outputs opposite that of the other transmission output. Respective wheels coupled to the transmission outputs are rotatable coaxially on the tool housing and respective screws are rotationally coupled to the wheels, axially fixed on the tool housing, and both threaded in the movable part of the machine tool. According to this invention one of the screws is of opposite hand to the other screw.

Abstract: The workpiece-carrier spindle assembly comprises a stator (10) mounted on a slide (202), a spindle (50) supported by active magnetic bearings and rotated by an external electric motor (2) connected to the stator via a coupling (3) which filters the mechanical disturbances due to the excentricity of the motor, and a chuck (5) fixed to the spindle (50). Additional means for detecting movements of the spindle assembly slide (202) include, in the servo-control plane of each of the radial beraings, two position detectors (216, 218: 215, 217) fixed to the stator (10) and facing two plane reference surfaces (211, 212) disposed parallel to the direction of slide displacement and delivering signals which are applied to means for selectively modifying the electric reference voltages applied to the servo-control loops of the magnetic bearings. The spindle assembly is applicable to machine tools for providing optical-quality machining.

Abstract: To center optic lenses in a mechanical mounting, in particular during edge cutting and bevelling, the invention includes a device with a housing (10), in which a motor drive (M, R) acts through a torque part (50), drive shafts (14, 14') and drive elements (16, 16') onto aligned centering spindles (18, 18'). These are arranged in guide bearings (22, 22') on projecting parts of the C-shaped housing (10) and are constructed as air bearings. In this manner, it is possible to hold the clamping angle (.alpha.) on the lens (L) in the range below 2.times.8.degree., preferably below 2.times.6.degree.. In particular the lower centering spindle (18) is smoothly axially adjustable in the air bearing (22), for which purpose axially parallel and/or partial-ring-shaped grooves (90) are provided at the ends of a thin-wall guide sleeve (76), between which ends peripheral air-cushion fields build up when pressurized air is being supplied.

Abstract: A lathe and a method of using the lathe are disclosed for forming an aspheric surface on a workpiece, in which the workpiece is mounted to a holder that is rotatably carried by the spindle, headstock and bed of a lathe, with that spindle and workpiece being rotated about the axis of the spindle with the workpiece being engaged by a forming tool which forming tool is moved through an arcuate path about an axis that is generally transverse to the spindle axis. The method and apparatus provide further for determining the time-varying angular position of the forming tool along the arcuate path, for determining the time-varying angular position of a point on the workpiece about the spindle axis and for reciprocating the workpiece holder and the workpiece held thereby relative to the lathe headstock and to the forming tool in synchronization with the movement of the forming tool and with the rotation of the workpiece about the spindle axis to form the desired contoured surface.

Abstract: For centering optic lenses in a mechanical mounting, in particular during edge cutting and bevelling, a device with a housing (10) is provided, in which housing a split drive shaft (14, 14') with a torque divider (50) is supported. Two centering spindles (18, 18') are aligned in an axial direction (A) and are in this manner driven by a motor. The ends of the mutually adjacent ends of the centering spindles carry clamping cups (20, 20') between which a lens (L) can be aligned and clamped. An air bearing is provided at least for the lower clamping spindle. The air bearing can be pressure loaded by paraxial and/or graduated-ring-shaped channels (90) with control openings (A, B). In particular, two diametrically opposed air-cushion fields can be loaded with pressure. The clamping spindle (18) can then be smoothly axially moved by a membrane piston (32) permitting thereby a very finely dosable feed movement (FIG. 3).

Abstract: According to the method of machining on ultra-precise surface of revolution (240) on a workpiece (204) held in position by means of a workpiece-carrier spindle assembly (1) whose spindle is mounted on a spindle slide (202) by means of active magnetic bearings, the natural frequencies of the bearing servo-control are adjusted to values which are less than about 80 Hz, and the speed of spindle rotation is adjusted to a value of about 20 Hz to about 75 Hz, the radial and axial positions of the spindle are selectively modified about a nominal position by applying variable reference voltages to the circuits controlling the magnetic bearings, said voltages being varied as a function of control signals which are delivered as a function of the position of the tool (207), and displacement of the spindle slide (202) is inhibited so long as the control signals are less than predetermined values lying within the dynamic range of the magnetic bearings.

Abstract: For centering optic lenses in a mechanical mounting, in particular during an edge cutting and bevelling, the invention includes a device having a housing (10), a drive (M, R, 14/14', 16/16') for a lower centering spindle 18 and an upper centering spindle 18' with an interpositioning of a torque divider (50). The centering spindles are held in axial alignment by guiding and clamping bearings (22, 22') and carry clamping cups (20, 20'), between which clamping cups the lens (L), which is to be machined, can be clamped. A clamping device (24) is for this purpose connected parallel to a membrane piston (32), which assures a precise stepped moving of the lower centering spindle 18 in an axial direction (A) to the upper centering spindle (18'). A short-stroke piston (38) exists in each pressure cylinder 28, which short-stroke piston (38) is followed by a long-stroke piston (40) having a bore (42) extending therethrough.

Abstract: Apparatus for use in cutting a workpiece on different centers. The workpiece is mounted in a chuck on a spindle top. The spindle top is mounted on the upper end of a rotatable, vertical spindle shaft adjacent to a cutting tool in different positions spaced apart laterally relative to the spindle shaft axis. When the spindle shaft is rotated with the spindle top in one position, the tool will cut the workpiece on one center. In another position of the spindle top, the tool will cut on a different center.

Abstract: A lathe and a method of using the lathe are disclosed for forming an aspheric surface on a workpiece, in which the workpiece is mounted to a holder that is rotatably carried by the spindle, headstock and bed of a lathe, with that spindle and workpiece being rotated about the axis of the spindle with the workpiece being engaged by a forming tool which forming tool is moved through an arcuate path about an axis that is generally transverse to the spindle axis. The method and apparatus provide further for determining the time-varying angular position of the forming tool along the arcuate path, for determining the time-varying angular position of a point on the workpiece about the spindle axis and for reciprocating the workpiece holder and the workpiece held thereby relative to the lathe headstock and to the forming tool in synchronization with the movement of the forming tool and with the rotation of the workpiece about the spindle axis to form the desired contoured surface.

Abstract: A high speed spindle has a motor and tool adjustment mechanism which aligns spaced bearing means to rigidly support the spindle shaft at high speed operation and to prevent excessive lateral loading of a bearing unit of the tool adjustment mechanism. The unitary motor and tool adjustment mechanism are joined together as a single unitary assembly which is mountable on a machine tool base without requiring alignment and pre-assembly of the motor and tool adjustment mechanism at field locations.

Abstract: A machine tool having a work spindle with an electrically actuated clamping unit including a three-phase motor with a stationary stator. The motor is supplied with electricity from a control unit operating with frequency conversion, and the control unit is alternatingly also used for triggering a spindle drive motor. A sensor detects clamping force applied to a workpiece, and produces a signal used to reduce motor speed of the three-phase motor until a predetermined clamping force is achieved.

Abstract: This invention pertains to a head stock assembly for a chucker and bar machine which includes a special bearing system comprising three forward bearings and two rearward bearings for providing five point contacts to the spindle for maintaining stiffness and rigidity and improved accuracy in machining. It also includes cooling fin means for dissipating the heat about the bearings which would normally build up in a headstock after long periods of operation. The heat dissipation reduces growth of the headstock and therefore improves accuracy. In addition, the headstock assembly has mounted directly thereon a spindle encoder, a brake disc, a collet closer mechanism, a balancing disc, as well as a low pressure means for preventing cutting fluids and dust and dirt from entering into the bearing mechanism.

Abstract: A method of machining short-length workpieces provides a hollow spindle adapted to be driven in rotation around a longitudinal axis thereof, the spindle having first and second chucks at one and the other longitudinal ends thereof, respectively. A short-length workpiece is gripped by the first chuck and the spindle and workpiece gripped by the first chuck are rotated for performing a primary operation of machining on one end of the workpiece. The first chuck is then loosened to release the workpiece and the workpiece conveyed within the first chuck through the hollow interior of the spindle into the second chuck, which is in a loosened state, by pushing the workpiece from one longitudinal end of the spindle to other. The second chuck is then tightened to grip the workpiece so as to rotate the workpiece together with the spindle for performing a secondary operation of machining on the opposite end of the workpiece. Finally, the second chuck is loosened to release the workpiece.

Abstract: A method and apparatus for rotatably supporting a workpiece WP includes a bearing ring 300 which extends around a center support member 204. The bearing ring is deflectable inwardly at a plurality of spaced apart locations 310 to engage the center support member at these locations during machining of a workpiece. At each of the locations where the bearing ring is deflected inwardly into engagement with the center support member, the bearing ring has a reduced thickness to thereby reduce the resistance of the bearing ring to deformation at these locations. Fluid pressure applied against the outside of the bearing ring deflects the bearing ring inwardly at the locations of reduced thickness. The deflected portions of the bearing ring engage the center support member to securely hold it during machining of a workpiece.