Abstract: The invention relates to a multi-spindle machine system having a control arrangement for selectively slowing down the speed of a stock feeder mechanism. The machine is operable at a low speed or a high speed. A braking arrangement for slowing the advance of stock is operative responsive to a machine controller. The feeder mechanism is slowed prior to engagement of feed stock with a stock stop device. The operation of the system of the present invention enables slowing the feed stock during its feeding into the machine to reduce stock bounce back to ensure more accurate initial positioning of the stock in the machine. The braking arrangement may comprise a machine brake clutch and/or a snubbing clutch.

Abstract: A machining apparatus for machining a workpiece by rotating and revolving either the workpiece or a tool 1 to contact with each other. The machining apparatus comprises rotation/revolution ratio setting motors M1 and M3 for setting a ratio of a number of rotations to a number of revolutions of the workpiece or the tool 1, to a numerical value having a fraction below a decimal point, by changing the number of revolutions. The workpiece is machined by setting the number of revolutions and the number of rotations at the ratio.

Abstract: A method of processing a piece of bar stock material having spaced ends and a predetermined diameter and including the steps of: attaching an adaptor to one end of the piece; directing the piece into a feeder sleeve bounding an internal passageway; moving the piece in the internal passageway from an upstream end toward a downstream end so as to expose a part of the piece for processing; performing at least one processing step on the exposed part of the piece; engaging a retrieval assembly with the adaptor; extending at least a part of the retrieval assembly into the internal passageway from a downstream end of the at least part of the retrieval assembly to a predetermined distance in an upstream direction; and with the retrieval assembly engaged with the adaptor, repositioning the retrieval assembly to thereby reposition the piece within the internal passageway.

Abstract: An aspheric-surface processing method according to the present invention, uses a cutting apparatus including at least one turning tool movable in the same direction as the rotating axis of the work and is also movable in a direction perpendicular to the rotating axis of the work. This method includes moving the turning tool at a predetermined feed pitch in a fixed direction over at least a part of the work region extending from the center of the rotating axis of the work to a peripheral portion of the work and also moving the turning tool in another direction perpendicular to the rotating axis of the work in order to process the work for forming an axis-asymmetric aspheric surface.

Abstract: A disc component 2 for a gas turbine engine is produced from a workpiece 4 by a sequence of machining operations. During the machining operations, the workpiece 4 is supported by a fixture 36 engaging support surfaces 32, 34. The workpiece 4 remains secured to the fixture 36 throughout the sequence of machining operations so that these operations can be conducted on both faces 26, 28 of a disc portion 8 of the workpiece 4 without removing the workpiece 4 from the fixture 36. The machining operations are conducted alternately on the opposite faces 26, 28 in order to allow residual stresses in the workpiece 4 to dissipate in a controlled manner.

Abstract: A non-rotary cutting tool which is to be moved relative to a workpiece in a predetermined direction for cutting the workpiece, with its rake face being held substantially perpendicular to the predetermined direction. The cutting tool includes (a) a generally cylindrical shank portion, and (b) a generally semi-cylindrical body portion which has an outer circumferential surface constituted by the rake face and a semi-cylindrical surface. The semi-cylindrical body portion has a cutting edge which is defined by an edge of the rake face and which is covered with a diamond coating. Also disclosed is a process of machining a scroll member of a scroll compressor by using this non-rotary cutting tool.

Abstract: A processing apparatus is provided with a diamond tool. When a first edge portion is made as X axis, a tip end peak point of a rake face is made as an intercept (0, y) on Y axis, and the rake face is projected in the first quadrant on an X-Y plane, a shape between an end portion of a first edge portion and an end portion of a second edge portion is asymmetric around a straight line which passes at the intercept and is parallel to X axis and the shape is shaped to be not a straight line such that Y value of a point on the shape increases as X value of the point increases.

Abstract: A mounting arrangement 1 is provided in which clamping pairs comprising a clamping pad 2 and seating pads 3 are arranged about a mounting end of a component 4. Thus, the component 4 is appropriately presented to a machining device but the component 4 can slip relative to the pads 2, 3 in order to relieve residual stresses in the component due to initial forging processes. A damper 8 is provided in order to augment vibration control in association with the contact abutments between the pads 2, 3. In such circumstances accurate machining of a component 4 to a final profile 6 from an initial rough profile 5 can be achieved more efficiently without periodic release of the component 4 so that distortions are avoided in the final component as a result of retained residual stresses by previous clamping.

Abstract: It is one object of a hale-machining method and apparatus thereof according to the present invention to achieve an easy preparation of an NC machining program and perform a high geometrical accuracy in the predetermined three-dimensional free curved surface.

Abstract: A rotatable seat for an insert of a machine tool that has a clamp for holding the insert securely in place during the machining operations. The seat has a substantially cylindrical body that includes a longitudinally extending throughbore, and a first end and a second end. The first end has a v-shaped trough that is sized to receive the v-shaped back end of an indexable (or other type) of insert. The second end of the rotatable seat is sized and shaped for seating flush against a back end of the clamp of the cutting tool. A press fit, or other fastener, extends through the throughbore of the seat body into a bore in the back end of the clamp and the seat is able to rotate about the fastener. The seat is positioned at and angular orientation and the insert is then fitted in the v-shaped trough in the seat in a corresponding angular orientation. These two components as assembled together and held in place by tightening the clamp fastener.

Abstract: A machine tool and method provides integral cooling to the tool, by employing exhaust air from the drive motor. The exhaust air is suitably allowed to expand within the body of the tool, advantageously cooling the tool.

Abstract: A cutting tool assembly for machining a turbine component includes a substantially solid toolblock body, a blade sub-assembly, a cutting insert, and a lead screw. The toolblock body includes a centerline axis. The blade sub-assembly is slidably retained adjacent said toolblock body and a cutting insert is attached to the blade sub-assembly. The lead screw coupled adjacent to the toolblock body such that the lead screw is substantially perpendicular to the centerline axis. The lead screw is rotatably coupled to the blade sub-assembly such that rotation of the lead screw extends the blade sub-assembly from the toolblock body.

Abstract: An elliptical vibratory cutting apparatus includes a control mechanism which applies a sinusoidal voltage having a predetermined phase difference to piezoelectric elements. Flexure vibrations are accordingly generated in X and Y directions. The vibrations in the X direction cause interference with the vibrations in the Y direction and vice versa. An amount of interference, caused by vibrations in one direction, with vibrations in another direction, is correctively eliminated by the control mechanism (interference eliminating unit. A workpiece is thus cut by means of a cutting tool through elliptical vibrations with high precision.

Abstract: A method and an apparatus or machining a workpiece include the use of a cryogenically cooled oxide containing ceramic cutting tool. The method involves cryogenic cooling of the cutting tool during a cutting operation, which cooling results in enhanced wear resistance and fracture resistance of the cutting tool. A preferred embodiment involves jetting a cryogenic fluid directly at the cutting tool.

Abstract: A method of controlling a relative movement of a cutting blade and a workpiece which are moved relative to each other by a movement device in an operation with a machine tool. The method includes a step of bringing the cutting blade and an object into contact with each other, by moving at least one of the cutting blade and the object toward each other by the movement device, and a step of controlling the relative movement on the basis of a relative position of the cutting blade and the object which is detected by the movement device upon the contact of the cutting blade and the object with each other.

Abstract: A method for cuffing or hard turning the surface of a workpiece comprising using a cutting tool in which a cooling fluid is supplied to the cutting area by means of at least one jet nozzle. The cooling fluid is supplied as a jet with high pressure leaving the jet nozzle with a pressure above 60 bar.

Abstract: A cutting tool piece is provided including a rear portion and a lead portion, the lead portion including a front section having an upper side angled downwardly and forwardly and a lower side angled upwardly and forwardly to form a transverse lead cutting edge. The rear portion includes a hole to secure the tool piece to a cutting tool and transverse cutting edges extending outwardly from side walls of the front section. A system is also described for cutting a bowl by coring out an interior portion of a wood block by applying the cutting tool which is curved and rotatably mounted to a post. Its lead end with the tool piece attached creates a circular groove. The cutting tool is advanced on a path which curves toward the central axis of the lathe.

Abstract: In a method for producing workpieces having inner and/or outer contours deviating from a circular shape, at least one workpiece is clamped on a machine and the workpiece is driven in rotation about a rotational axis of the workpiece at a first constant velocity. At least one tool is arranged on a carriage that is moveable radially to the rotational axis of the workpiece as well as axially in the longitudinal direction of the rotational axis of the workpiece. The tool is rotatably driven about a rotational axis of the tool that deviates from the rotational axis of the workpiece such that an active cutting surface of the tool moves on a circular path at a second constant velocity. The second constant velocity is selected such that its revolutions per minute deviate from the revolutions per minute of the first constant velocity with respect to size and/or rotational direction.

Abstract: A method of generating holes in fiber-reinforced metal laminate material is provided, including creating a first bore 18 by passing a cutting element 16 from a first side 24 of the fiber-reinforced metal laminate material 10 to a second side 26, the first bore 18 including first bore sidewalls 19 at least a portion of which includes a taper 28 having a taper diameter 33 and a taper depth 32; passing the cutting element 16 through the first bore 18; moving the cutting element 16 outward of the taper diameter 33; and retracting the cutting element 16 through the first bore 18 to create a second bore 34 having straight second bore sidewalls 36.

Abstract: A method of controlling a relative movement of a cutting blade and a workpiece which are moved relative to each other by a movement device in an operation with a machine tool. The method includes a step of bringing the cutting blade and an object into contact with each other, by moving at least one of the cutting blade and the object toward each other by the movement device, and a step of controlling the relative movement on the basis of a relative position of the cutting blade and the object which is detected by the movement device upon the contact of the cutting blade and the object with each other.

Abstract: The invention comprises a method for manufacturing a shaft-hub connection. This connection includes a brake disk having a hub and a drive shaft having a bell, wherein the drive shaft comprises a catching portion having a polygonal outer contour. This portion extends into an aperture in the brake disk having a corresponding inner polygonal contour. The method comprises the procedural steps of green machining via turning of the brake disk and the drive shaft, hardening of the drive shaft, final finishing via turning of the brake disk and final finishing via turning of the drive shaft to obtain the final products with only one chucking action.

Abstract: Cutting tool (1) with a cutting insert (3), on the front edge (14) of which there is a first major cutting edge (15) and an approximately U-shaped indentation (18) that interrupts said first major cutting edge (15), whereby each side leg (19, 20) of the indentation (18) forms a minor cutting edge, and the base (21) of the indentation (18) forms a second major cutting edge (22) which is recessed in the feed direction (V) behind the first major cutting edge (15), and whereby the cutting insert (3) is formed by at least two separate sections (4a, 4b), each of which carries a portion of the indentation (18).

Abstract: A customized prosthesis, or instrument, for medical/dental applications is provided which replicates the desired bone-graft, tooth, or tool, being replaced. The dimensions of the prosthesis, or instrument, are determined by mathematically interpolating key-points that characterize a specific part. A computer controlled machine then cuts the desired part out of a pre-fabricated blank, directly at the site of operation. Methods of the invention relate to selecting the type of part being replaced, identifying and measuring the coordinates of key-points for that part, and initializing the automated machining process. Also, special supporting devices that include pre-fabricated features common between certain parts, are used in order to facilitate the machining process. The identification of key-points is done by comparing a schematic drawing of the type of part being replaced to the actual part. A grid is then used to measure the coordinates for those key-points.

Abstract: The present invention includes a cutter assembly and a method of using a cutter assembly. The cutter assembly comprises a fixed knife support shaft with a top end and a bottom end, a fixed knife mounted adjacent the top of the fixed knife support shaft, a moving knife support shaft with a top end and a bottom end and a moving knife mounted adjacent the top of the fixed knife support shaft, wherein the moving knife has a non-cutting position and a cutting position and the moving knife support is adapted to be rotated about an axis perpendicular to the axis of the moving knife support shaft to put the moving knife into the cutting position.

Abstract: A method for preparing a contact surface of an implantable bone, joint or similar prosthetic component subject to contact or motion includes the steps of mounting the prosthetic component on a turning or cutting machine and cutting the face of the prosthetic component with a diamond cutting tool using computerized control of tool position along a cross direction to machine cut a super finished surface. The variations of contour and the surface roughness are both under about 0.5 micrometers, and preferably under about 0.2 micrometers or less. The super finished surface generates wear particles at an asymptotically low or residual level during wear-in which may enhance wear characteristics and reduce local reaction or systemic rejection effects. The component is preferably formed by a strong hard polymer, such as UHMWPE.

Abstract: There is provided a numerically controlled lathe capable of simultaneously performing various kinds of machining to a plurality of workpieces. An NC lathe according to the present invention has a first main shaft 121 and a second main shaft, a first tool rest 160 to which a tool T1 and/or a tool T2 used to machine workpieces W1 and W2 grasped by these main shafts are attached, and a second tool rest 180 to which a tool T3 and/or a tool T4 used to machine the workpieces W1 and W2 are attached. The first tool rest 160, the second tool rest 180 and the second head stock 130 can move in the direction of a Z axis and the direction of an X axis without restraint. A numerical control device 191 controls movement of the first tool rest 160, the second tool rest 180 and the second head stock 130 in the direction of the X axis and movement of the same in the direction of the Z axis.

Abstract: A structure and method of manufacturing an outer surface of a shaft avoids the creation of a preferential lead and thereby minimizes leakage through an annular seal assembly when such shaft is rotated or otherwise moved relative thereto during use. The outer circumferential surface of the shaft is formed having a plurality of relatively small irregularities that are evenly distributed thereabout. Such irregularities may be defined by relatively higher portions and relatively lower portions that are formed in an intersecting, cross hatched pattern or in a circumferentially extending undulating or oscillating pattern. To form the cross hatched pattern, an apparatus can be operated to engage the outer circumferential surface of the shaft in two sequential passes in opposite axial directions while the shaft is being rotated. To form the undulating pattern, an apparatus can be operated to engage the outer circumferential surface of the shaft in an axially reciprocating manner while the shaft is being rotated.

Abstract: In a method for machining an electrically conductive workpiece with a cutting tool, an electric circuit is applied between the cutting tool and the workpiece which is positioned electrically insulated from the cutting tool, when the workpiece is subjected to a machining operation. At least one electric variable is determined and evaluated in the electric circuit during the machining operation. The advance of the workpiece is adjusted after each machining step of an entire surface of the workpiece, and the machining operation is terminated, when the at least one variable remains substantially constant during a machining step.

Abstract: A tool including a working portion with a working member, a side surface and an end surface. The working portion includes a passage passing through the side surface and the end surface. At least one seal is adapted to restrict fluid flow through the side surface and the end surface and at least partially defines a pressure chamber. The working member is adapted to be selectively pivotally positioned by selectively pressurizing the pressure chamber. The tool similarly enables unique methods of working workpieces.

Abstract: Disclosed is an apparatus for cutting a paper pipe, wherein a paper pipe is cut while rotating both a cutting blade and the long paper pipe in opposite directions to each other, in such a manner that rotational linear velocities of a cutting portion of the cutting blade and a central portion in a thicknesswise direction of the paper pipe are controlled to be within certain range. Cutting is performed while controlling the degree of vertical incision of the cutting portion.

Abstract: The invention relates to a method for finishing the ball cup of a homocinitic joint, especially for motor vehicles, having a ball ring-shaped bearing surface for the ball cage and a plurality of essentially axial running guideways which interrupt said ball ring-shaped bearing surface. The guideways are provided for the balls which are arranged in the ball recesses of the ball cage and which transmit torque between the ball cup and the ball star. In order to be able to finish such ball shells quickly, economically and as fully automatic as possible, the invention provides that both the ball ring-shaped bearing surface for the ball cage as well as the guideways for the balls are produced by means of a turning machining.

Abstract: The novel turning method on a lathe or a machining apparatus uses a tool head which is traversable for the machining and can be rotated mechanically in a receiver with a rotary axis D in the course of the machining. The rotary axis D of the tool head lies within an angular range &agr; of 45° to 90° to the X-axis and perpendicularly to the Z-axis of the machining apparatus. In addition, a tool head is used whose cutting inserts are arranged in such a way that each cutting insert has a tool reference plane Pr through in each case identical selected cutting-edge points perpendicularly to the assumed cutting direction in accordance with DIN 6581, this tool reference plane Pr running within an angular range &bgr; of 90° to 135° to the rotary axis D of the tool head.

Abstract: A brake lathe alignment system is provided for mounting a brake lathe upon an adapter attached to a wheel hub. A first structure is adapted to be attached to the wheel hub. A second structure is adapted to be attached to the brake lathe. A plurality of hydraulic pistons are carried by the second structure and engage the first structure, so that alignment of the second structure relative to the first structure is adjustable by extending and retracing the hydraulic pistons. The adjustment of position of the hydraulic pistons can be manually controlled on-the-fly by operation of manually actuated hydraulic pumps.

Abstract: In order to eliminate errors in roundness and the occurrence of helical waves, a skiving head is provided with at least three skiving blades arranged in a radially displaceable manner in the skiving head. With this skiving head, both the requirement for self-centering of the skiving blade set as well as the requirement for circular skiving geometry with consistent cutting depth are fulfilled.

Abstract: A procedure to machine openings in work pieces which provides two cutting blades (11, 12), defining a cutting blade axis, adjacent to a work piece in which an opening is to be machined, the opening defining a distance between two oppositely positioned opening edges and defining an opening axis. The opening axis and the cutting blade axis are inclined at an acute angle (&agr;) to one another in a way that the distance between the cutting blades parallel to the opening axis (9) is equal to the required distance between the opening edges. With the increasing wear of the cutting blades, the inclination angle is reduced so that the cutting blade distance parallel to the opening axis continues to correspond to the required distance of the opening edges.

Abstract: A method for forming a brake assembly for a motor vehicle includes a wheel hub, a knuckle, and a brake rotor. The wheel hub includes a neck portion and a flange portion having a flange face. The flange face has a plurality of bolt receiving holes formed therein. The wheel hub is placed in rotational communication with the knuckle. The flange face of the wheel hub has a brake rotor secured thereto. The brake rotor has an inner surface, which is subjected to final finishing in order to reduce lateral run-out of the brake rotor.

Abstract: A turning lathe for interior cutting of hollow work pieces using a boring rod onto which a tool holder device is fitted and on which there is a mechanism for holding a work piece in such a way that it encloses at least part of the boring rod characterized by the fact that the boring rod is gripped and held in place at both ends and by the fact that the tool holder device is fitted onto the boring rod in such a way that it is movable.

Abstract: Method and apparatus for adjusting the position of a cutting tool. In one embodiment, a boring tool includes a coupling member which is driven by a CNC boring machine, and a sliding tool holder which is slidably coupled to the coupling member. A frictional force resists sliding movement of the cutting tool holder. The frictional force is sufficient to retain the position of the cutting tool during machining operations. However, the frictional force is insufficient to resist a lateral force applied parallel to the direction of sliding, as used during adjustment of the tool position. In another embodiment, either a surface of the sliding tool holder or a surface of a frictional member are contoured with a shape that corresponds to a desired contour of a sidewall of a hole. During machining, a follower in contact with the contoured surface causes the cutting tool holder to slide laterally during machining, thus contouring the sidewall of the hole.

Abstract: The chip removing machining of a workpiece is performed by a cutting tool which includes a cutting insert. In order to cool the cutting insert, one or more over-cooling nozzles is arranged for directing a jet of cooling liquid downwardly toward a contact area between the workpiece and a chip surface of the cutting insert. A sub-cooling nozzle is arranged for directing a jet of cooling liquid upwardly toward a contact area between the workpiece and a flank surface of the cutting insert. A jet of cooling liquid can be emitted from only the over-cooling nozzle, or from only the sub-cooling nozzle, or from both of those nozzles simultaneously.

Abstract: An automotive hub assembly, which carries a brake disk, has a hub provided with a spindle which rotates in a housing on a double row antifriction bearing having its raceways oriented obliquely to the axis of rotation so that the bearing accommodates both radial and axial loads. The bearing is set to a condition of preload so no free motion exists in it. The hub also has a flange at one end of its spindle, and the flange is machined on its face that is presented away from the housing to provide a machined mounting surface against which the brake disk is installed. The machining occurs after the hub assembly is assembled. To this end, the housing of the hub assembly is held fast while the hub is rotated on the bearing. With the hub rotating, a cutting tool is moved across the face of the flange, and it produces the machined mounting surface which is perpendicular to the axis of the bearing. The machined mounting surface has essentially no runout, so that the brake disk acquires no runout from the hub assembly.

Abstract: A high bandwidth rotary fast tool servo provides tool motion in a direction nominally parallel to the surface-normal of a workpiece at the point of contact between the cutting tool and workpiece. Three or more flexure blades having all ends fixed are used to form an axis of rotation for a swing arm that carries a cutting tool at a set radius from the axis of rotation. An actuator rotates a swing arm assembly such that a cutting tool is moved in and away from the lathe-mounted, rotating workpiece in a rapid and controlled manner in order to machine the workpiece. A pair of position sensors provides rotation and position information for a swing arm to a control system. A control system commands and coordinates motion of the fast tool servo with the motion of a spindle, rotating table, cross-feed slide, and in-feed slide of a precision lathe.

Abstract: A tool for shaping sculpted surfaces where at least one portion of the silhouette of the cutting edge is curved and has a radius of curvature larger than the radius of the tool itself. The profile, or silhouette of the cutting tool may have a constant radius of curvature, or a changing radius of curvature. This invention could be used either for insert-type cutters, or standard, solid cutters. It could potentially also be used for grinding or polishing. In addition, mathematical definitions which can be used for the implementation of these cutters are also presented.

Abstract: A method of determining expected fatigue life of machined bearing races or other components wherein a hardened surface of each bearing race is machined to provide a machined surface including the steps of determining hardness distribution and residual stress distribution along a depth into the machined surface as a function of cutting parameters, determining a relationship of expected fatigue life of the machined bearing races as a function of the hardness distribution and the residual stress distribution using a fracture mechanics model, and determining expected fatigue life from the relationship using actual cutting parameters employed in machining the hardened surface of the bearing races. Cutting conditions to optimize fatigue life can be selected based on the expected fatigue life.

Abstract: A method of processing a workpiece including the steps of: placing a first preform element in a first operative position on a first holder so that a first portion of the first preform element is exposed; performing a processing operation on the first portion of the first preform element with the first preform element in the first operative position; transferring the first preform element into a second operative position on a second holder; with the first preform element in the second operative position exposing a second portion of the first preform element that is not exposed for processing with the first preform element in the first operative position; and with the first preform element in the second operative position and the second portion of the first preform exposed, performing a processing operation on the second portion of the first preform element.

Abstract: A method and control system for forming workpiece surfaces with at least a portion being non-rotationally symmetric (i.e., axis asymmetric) is provided. In one aspect, a slow tool servo system is provided to fabricate a surface having at least an axis asymmetric portion, and optionally, a superimposed axis symmetric asphere or spherical portion. A workpiece is mounted on a spindle and a tool is mounted to a translatable tabletop surface. The z position of the contact point of the workpiece and working tool is determined as a function of the x position of the same contact point and as a function of the angle of rotation of the spindle about the spindle axis. By making the z position of the contact point a function of both the angle of spindle rotation and the x position, the lateral and longitudinal position of the working tool can be moved at designated spindle rotation angles to form a surface having both axis asymmetric and axis symmetric asphere or spherical portions.

Abstract: A single point turning tool has a tip including a cutting edge with a tip radius and a linear portion added on one side of and slightly behind the point to form a cutting edge with a linear portion and a protruding portion. The protruding extends beyond the plane of the linear portion which, in turn, extends normal to a longitudinal axis on which the tip radius is centered. During manufacture of a piston, the turning tool is positioned with the linear portion aligned generally with the plane of the finished outer surface. The piston is turned while the tool cuts a helical path or turn around the skirt surface by advancing the tool each turn a desired dimension or lead that is greater than the width of the protruding portion but not greater than the combined widths of the linear and protruding portions.

Abstract: The invention relates to a method for finishing the ball star of a homocinetic joint, especially for automobiles. The ball star has a ball ring-shaped bearing surface for mounting in a ball cage, and has a plurality of essentially axial running guideways provided for the balls. Said balls are arranged in the ball recesses of the ball cage and transmit torque between the ball cup and the ball star. In order to be able to finish such ball stars quickly, economically and as fully automatic as possible, the invention provides that both the ring-shaped bearing surface provided for mounting in the ball cage as well as guideways provided for the balls are produced by a hard-rotary turning operation.

Abstract: A method of optimizing the functioning of a machining center for machining, at least one piece, by removal of material by means of at least one cutting tool. The machining center includes a certain number of different components including at least a structure, such as a frame, and at least one motor elements for producing actions of driving and displacement of at least the cutting tool and the piece. Further, the method includes an installation for lubricating and cooling the tool and the piece by means of a fluid, (i.e., lubricant) by determining at least one temperature value for the lubricant, at least empirically, referred to as the reference value, at which the machining center functions in a stable way, (e.g.

Abstract: A centering apparatus for centering a disk about a center member such as a shaft or hub includes a plurality of pairs of actuator units. The actuator units of each of the pairs faces each other through the disk. Each of the actuator units has a member which moves linearly and can come into contact with the disk.

Abstract: A turret (11) is clamped to a tool rest main body (10) by a pair of coupling members (27). During indexing rotation for selecting a tool, the tool rest main body (10) and the turret (11) are moved relatively in a Z-axis direction, and the pair of coupling members (27) are unclamped. At this time, the tool rest main body (10) is moved in the Z-axis direction relative to a lathe main body (100) in synchronization with the relative movement in the Z-axis direction between the tool rest main body (10) and the turret (11). This movement of the tool rest main body (10) is adjusted in direction and moving distance so that the relative movement between the turret (11) and a spindle table (1) is eliminated. As a result of this movement control, the turret (11) and the tool fitted to the former do not have relative displacement to the spindle table (1) and to a work, so that the danger of mutual interference among these constituent elements and the work can be eliminated.