Abstract: A workpiece adapter system to support a workpiece rotated by a rotary machine, the system including a first drive member having a proximal end configured to be secured in a chuck of a rotary machine, at least one workpiece adapter configured to secure at least a portion of an end of a workpiece in a central opening of the workpiece adapter, an adapter mount configured to be connected to the at least one workpiece adapter, and a universal joint assembly arranged between the first drive member and the adapter mount, the universal joint assembly comprising a first fork member coupled to the first drive member, and a second fork member coupled to the adapter mount. An adapter ring may be provided to rotatably support a workpiece being machined.

Abstract: This present disclosure relates to a device for rotary entrainment of a workpiece clamped between two tips, which is mounted on a machine table of a machine tool, consisting of a base body with a centrically arranged tip and a plurality of concentrically arranged, axially shiftable driver elements which for the rotary entrainment of the workpiece are pressed against or into an end-face surface, wherein an axial position of the driver elements can be defined by active fixation after a centering operation of the workpiece, and to a receptacle opposite the base body, for example a tip or hollow tip, which serves a guidance of an opposite side of the workpiece.

Abstract: A balancing device for a bar loading magazine for guiding material bars on a turning machine, includes at least one mass body that can be repeatedly positioned in relation to a guiding unit that allows a rotation of an introduced material bar about a rotary axis. The mass body is, after each completed positioning, in a connection with the guiding unit and/or the material bar, so that the mass body rotates, during the rotation of an introduced material bar, together with the material bar at the same angular speed about the rotary axis. At least one positioning unit is designed to bring the mass body into a starting position in relation to the guiding unit, to detect during rotation any required repositioning because of an imbalance, and to reposition in each case the mass body in response to the detection of any required repositioning in relation to the guiding unit.

Abstract: An inner cowl structure for circumscribing at least a portion of a jet engine extending from an aircraft includes an apron configured to mount directly to the engine independent of the pylon and overly an upper portion of the jet engine, and an inner body configured to circumscribe a portion of the jet engine not circumscribed by the apron.

Abstract: A mechanical device for the fast exchange of jaws in a lathe plate providing an intermediate jaw support attached to the jaw holder with a straight support face and providing with a guide wherein the jaw is positioned and fixed precisely and eliminating the clearances found in the conventional method.

Abstract: A clamping unit (1) for machine tools (2) with a housing (11) connected in a rotationally fixed arrangement with a machine spindle, (5) and a screw drive (13) that interacts with a draw rod (6) such that rotational movements are converted into translational movements, the housing (11) being provided with an output element by which rotational movements are transmitted to an actuator (21). The housing (11) has an input element in a rotating mounting, with the actuator (21) acting on the input element, and the input element (29) is in driving connection with a shaft (14) by means of intermediate elements (31), whereby to direct rotational movements of the machine spindle (5) via the clamping unit (1), and for adjustment movements of differently configured clamping devices, to be converted into axial adjustment movements and transmitted directly onto the draw rod (6).

Abstract: A face driver has a body rotatable about an axis and a head rotationally fixed on the body and formed with a plurality of guides open axially forwardly toward a workpiece and radially offset from the axis. A centering rod axially shiftable in the body on the axis has a front-end point engageable with the face of the workpiece. A compression spring in the body urging the rod axially forward toward the workpiece, a driver disk has a front face engageable with the workpiece and a back face formed with a plurality of rearwardly open and radially extending grooves aligned with the guides. Respective support pins axially shiftable in the guides have heads engaged in the respective grooves so as to rotationally couple the driver disk rotationally to the body while permitting the driverd disk to tip with axial displacement of the pins.

Abstract: A dual lock brake lathe chuck comprises of at least one primary drive gear with keyhole along with at least one secondary drive gear with keyhole. The keyhole is rotated through the side of the chuck whereas the secondary keyhole is rotated through the back of the chuck. Rotation of either the primary keyhole or the secondary keyhole extends a plurality of jaws to secure a brake rotor on a brake lathe. The secondary keyhole positioned on the back of the chuck allows easier access of the keyhole when a brake rotor is attached to the chuck allowing the user to ensure that the brake rotor is securely tightened onto the brake lathe chuck.

Abstract: An apparatus for adapting a workpiece holding device to a chuck of a machine tool includes a plurality of chuck locators configured for attachment to the chuck, such that the plurality of chuck locators includes at least three chuck locators. The apparatus further includes a mounting plate configured for attachment to the workpiece holding device. The mounting plate includes a body and a plurality of mounting plate locators corresponding to the plurality of chuck locators, such that the plurality of mounting plate locators are attached to the body and are configured to interface with the plurality of chuck locators.

Abstract: A pottery holding device and method for securely holding a workpiece during rotation and working of the workpiece on a wheelhead of a pottery wheel. The pottery holding device includes a wheelhead member and at least three holding members. The wheelhead member configured for attachment to the wheelhead of a pottery wheel. The at least three holding members and wheelhead member configured to allow selective locking of the at least three holding members in positions about the periphery of a workpiece. The device adapted to securely hold circular, non-circular symmetric and irregular, asymmetric or organic shaped workpieces. The device further adapted to securely hold workpieces in positions and orientations such that the center of the workpieces is aligned with the axis of rotation of the device, and positions and orientations such that the center of the workpieces is spaced from the axis of rotation of the device.

Abstract: A face driver has a body rotatable about an axis and a head rotationally fixed on the body and formed with a plurality of guides open axially forwardly toward a workpiece and radially offset from the axis. A centering rod axially shiftable in the body on the axis has a front-end point engageable with the face of the workpiece. A compression spring in the body urging the rod axially forward toward the workpiece, a driver disk has a front face engageable with the workpiece and a back face formed with a plurality of rearwardly open and radially extending grooves aligned with the guides. Respective support pins axially shiftable in the guides have heads engaged in the respective grooves so as to rotationally couple the driver disk rotationally to the body while permitting the driverd disk to tip with axial displacement of the pins.

Abstract: A work head adapted to support at least one elongate work piece, said work head having a first drive shaft capable of rotation about a central axis, said work pieces being supported from the work head at a position spaced radially from the central axis such that the axis of each work piece is in the same plane as the central axis, the work pieces supported from the work head to be capable of rotation about their central axes, the drive shaft adapted to be caused to rotate by a first drive, the work pieces adapted to be caused to rotate by a second drive.

Abstract: The invention relates to an electrical stressing means having a housing (2) which can be attached to the drive spindle of a machine tool and in which a threaded rod (3) for adjustment of the clamping jaws of a chuck is mounted such that it can be moved axially, and having an electric actuating motor (4), whose rotor is connected for drive purposes to a drive wheel (6). The drive wheel (6) is connected to the shaft generator (7) of a harmonic drive, and the internal gearwheel (8) of the harmonic drive is connected to the housing (2), with the steel bush (9) (flexspline), which has an external tooth system, of the harmonic drive being provided as a drive for the spindle nut associated with the threaded rod (3).

Abstract: A machine and method for machining parts of partial revolution. The machine has a driving sheave rotatable about a first axis and a first driven sheave rotatable about a second axis fixed relative to the first axis. An eccentric link is rotatably connected to the first driven sheave at a pivotal connection that is spaced a predetermined distance from the second axis. A belt is wrapped around the driving sheave and the first driven sheave so that rotation of the driving sheave causes the first driven sheave to rotate. A second driven sheave is rotatable about a third axis fixed relative to the second axis. A second driven sheave contacts with the eccentric link. The eccentric link moves in a reciprocating motion when said first driven sheave is caused to rotate and causes reciprocating rotary motion in the second driven sheave, which is transferred to a part being machined.

Abstract: A cylindrical grinding apparatus grinding a side face of a cylindrical ingot, having a centering means of at least three rollers and an arm holding the rollers. The cylindrical ingot is placed on a table longitudinally, its end faces being held vertically with a pair of clamps. Afterward, the centering means moves backward and forward against the ingot horizontally to bring the rollers into pressure contact with the side face of the ingot while the ingot is rotated about a central axis with a rotation means, and thereafter the ingot is ground with the grinding wheel. The cylindrical grinding apparatus and the method for grinding enable improvement of grinding processing efficiency of the ingot.

Abstract: A chuck for a laser cutting/engraving rotary fixture comprises a chuck plate having a chuck plate axis of rotation and at least two mount brackets spaced symmetrically radially with respect to one another about the chuck plate axis of rotation. Each mount bracket comprises an inclined contact surface and each mount bracket is rotatably attached to the chuck plate about the mount bracket axis of rotation. The inclined contact surface can be selectively rotated between a first position with the inclined contact surface inclined toward the mount plate axis of rotation and a second position with the inclined contact surface inclined away from the mount plate axis of rotation. An effectively concave contact surface is defined with each of the inclined contact surfaces in the first position. An effectively convex contact surface is defined with each of the mount brackets in the second position for engaging an inner diameter of a work piece.

Abstract: A method of dialing a workpiece having an axis into a chuck includes providing a chuck assembly having a plurality of independent hydraulically controlled jaws distributed about a central axis, each jaw having first and second hydraulic chambers. The method further includes the steps of inserting a portion of the workpiece into the chuck assembly, pumping hydraulic fluid uniformly into each of the first chambers until the jaws are substantially touching the perimeter of the workpiece, and adjusting one or more of the jaws to align the axis of the workpiece with the central axis of the chuck assembly by pumping hydraulic fluid into at least one of the chambers of at least one of the jaws. The method also includes the step of pumping hydraulic fluid uniformly into each of the first chambers until the jaws are clamped around the perimeter of the workpiece at a predetermined pressure.

Abstract: An automatic lathe is capable of rapidly and easily switching between machining of a material with a guide bush and machining of the material without the guide bush. The automatic lathe has a guide bush support table, a support table fixing device for fixing the guide bush support table, a guide member rotatably installed on the guide bush support table so as not to move forward and backward, a guide bush detachably fitted to the tip of the guide member, a driving device for rotating the guide bush, a rotation transmission device for transmitting the rotation of the guide member to the spindle, and a spindle moving device for moving the spindle forward and backward within the guide member. A spindle fixing device positions and fixes the spindle at a specified position on the guide bush support table when the guide bush is removed from the guide member.

Abstract: An automatic lathe is provided which is capable of rapidly and easily switching between machining of a material with a guide bush and machining of the material without the guide bush. The automatic lathe has a head stock (6) and a guide bush support table (1). The head stock (6) is provided with a spindle drive motor (8). The guide bush support table (1) is provided with a guide bush rotating motor (11). There are provided: support table fixing means (15) for positioning and fixing the guide bush support table (1); a guide member (12) rotatably installed on the guide bush support table (1) and regulated so as not to move forward and backward and having a through-hole formed for a spindle (3) to be inserted therein; a guide bush (4) detachably fitted to the tip of the guide member (12); and spindle fixing means (37) for positioning and fixing the spindle (3) on the guide bush support table (1) at a specified position when the guide bush (4) is removed from the guide member (12).

Abstract: It is an object of the invention to provide an effective technique for avoiding the influence of reaction during tightening operation in the rotary fastening tool.

Abstract: A workpiece holder for a lathe includes a receptacle having a workpiece-receiving-cavity that has a polygonal cross-section when viewed along an axis of rotation. The receptacle is sized to receive workpiece stock having a polygonal cross-section.

Abstract: The device is constructed with a tensioning spindle (12), a counter-holder (14) and a carrier (30), at least the tensioning spindle (12) being mounted such that it is rotatable about the longitudinal axis, and the carrier (14) being fixed to the tensioning spindle (12) and, when the workpiece (50) is clamped between the tensioning spindle (12) and the counter-holder (14), being capable of being brought into engagement with the workpiece (50) in such a way that it transmits a rotary movement of the tensioning spindle (12) to the workpiece (50). The device furthermore provides for the carrier to have a spring element (30) which can be coupled to the workpiece (50) under prestress to transmit a torque.

Abstract: A C-axis driving device of a computer numerical controlled (CNC) lathing and milling machine includes a spindle, an encoder, a spindle motor, and a servo motor. The spindle has a clamping device and a transmission portion. This encoder connects with the transmission portion via an auxiliary timing belt. The spindle motor and the servo motor connect with the transmission portion via at least one driving timing belt. Only at most one of the spindle motor and the servo motor is to drive this transmission portion at any time during operation. So, it has a simple structure to achieve the clutching change function. It can save more space. And, it can significantly reduce the manufacturing cost.

Abstract: A lathe 1 comprises a bed 5, a headstock 10 having a housing 13 and a support base 14, a main spindle 11, a first tool rest 44, and a second tool rest 50. The support base 14 is formed so as to have a concave portion 14a on the upper portion thereof and so that the upper portion protrudes toward the second tool rest 50. The tool rest body 51 of the second tool rest 50 is configured so as to be movable into and out of a space formed downward from the upper portion of the support base 14. The housing 13 has a holding hole 13a for rotatably holding the main spindle 11, and installation portions 13b. The installation portions 13b are supported on the support base 14 in a state wherein a predetermined clearance is provided between the housing 13 and the concave portion 14a.

Abstract: A material stock advancing apparatus for use with a turning and milling machine having a computerized numeric controller or lacking programmable capabilities. The material stock advancing apparatus generally comprising an elongate body of cylindrical form having first and second ends and an interior chamber for housing therein a plunger assembly operably working therewithin. The second end comprising means for attaching the elongate body to an external holding device such as a collet or chuck adapter seated in a headstock spindle assembly. The first end comprising an end plug having a threaded section situated in between external and internal ends thereof, with the threaded section being threadably attached to the first end to permit the internal end to substantially engage a portion of the plunger assembly and ensure proper axial positioning of the plunger assembly during cyclic operation.

Abstract: A power chucking system 10 comprises a chuck mounted on a headstock, the chuck with its jaws being caused to rotate by rotation or the machine spindle 6. The spindle 6 may be engaged with the pulley 1 in order to rotate a work piece retained within the chuck jaws. A clutch 2 may be used to disengage the spindle 6 from the pulley 1 and to lock the spindle 6 to the head stock. In this configuration, rotation of the pulley 1 will cause an actuator jack 7 to screw or unscrew, into or out of spindle 6, in order to open or close the chuck jaws to grip release the workpiece.

Abstract: A tire uniformity machine having a framework for receiving a tire to be tested, a rotatable chuck located within the framework and having a spindle driven by a motor directly coupled to the spindle to selectively cause rotation thereof, whereby the tire is chucked within the chuck assembly and caused to rotate by the motor. The motor is disposed in axial alignment with the spindle.

Abstract: A workpiece seat for the machining of bar-shaped workpieces by milling and turning. The workpiece seat has an elongated housing, a spindle rotatably supported in the housing, and an electric direct drive for the spindle. The drive rotor is fixed on the spindle and the drive stator is fixed in the housing. Clamping means are provided at the working end in the spindle for fixing a bar-shaped workpiece in the spindle. A connection unit is provided at the rear part of the housing for power supply. A fixing means is provided for fixing the spindle in the housing. To achieve high machining accuracy of thick bars and high clamping forces at reduced longitudinal dimensions, as well as relatively simple design, the fixing means is formed as a compact part and is arranged at the working end of the housing.

Abstract: A facedriver for holding a miniature workpiece along the axis of a rotary-drive machining device, including a base member, a forwardly-biased centerpoint member, drivepins supported rearwardly by fluid in a fluid-containing chamber in the base member, a grip member contacting the centerpoint member, and a grip portion of the fluid chamber adjacent to the grip member for fluid contact therewith such that varying fluid pressure caused by loading force on the drivepins causes application of varying radial gripping force on the centerpoint member through the grip member.

Abstract: The device serves for the end face, angularly true driving of a pre-toothed workpiece (21) clamped between work centers by the rotating work spindle (3) of a tooth flank grinding machine. It takes place by means of a wobble plate (10) connected without play to the work spindle by way of the work arbor (1), the intermediate disc (17) and the cylindrical steel rollers (13, 18), the surface of which said wobble plate which contacts the workpiece end face (29) being according to the invention coated with galvanically bonded hard material grains (24).

Abstract: A collet chuck assembly for an axially fixed collet head. The collet head is fixedly and removably mounted in a threaded bushing to prevent axial motion, and is keyed into place to prevent rotation. A sleeve assembly has cam surfaces adapted to engage the cam surfaces of the collet head to open and close the collet head, and slides between collet head open and collet head closed positions within a spindle adapter body. The sleeve assembly has projections that extend from a rearward portion and pass through appropriately sized passages in the axially-fixed bushing. Motion from a spindle drawbar is transmitted by a drawbar link-up through the projections of the sleeve assembly. Using this arrangement, no physical connection is required between the drawbar link-up and the sleeve assembly. Additionally, no cap assembly is required.

Abstract: In order to machine a workpiece on a machine-tool successively between centers and with the workpiece clamped in a chuck, the workpiece is held during at least one machining operation—and if necessary between different kinds of machining—through the axial pressure of a center pin clamped in a chuck of the machine-tool. To this end the chuck comprises an axial center pin hydraulically movable in axial direction, which can be extended for enough towards the workpiece to be gripped by the jaws of the chuck, and which is journalled in at least one expanded sleeve bearing.

Abstract: A part clamping fixture assembly for locating and holding a wheel hub assembly for final finishing a flange face of the wheel hub includes a top portion having a bore formed therethrough. The fixture assembly includes a puller member having an upper end for communicating with a drive mechanism and a lower end opposite the upper end. The puller member has an encasing disposed therearound. The encasing has a lower portion for engaging a bearing of the wheel hub assembly and an upper portion in communication with the top portion. The fixture assembly also includes a lift mechanism for lifting the wheel hub assembly generally upward such that a surface of the bearing engages the lower end of the puller member. The lift mechanism is engageable with the lower end of the puller member such that the drive mechanism will rotate the puller member and the lift mechanism together to accomplish the final finishing of the flange face.

Abstract: A brake rotor refinishing system provides simultaneously refinishing of two workpieces that are clamped at opposite ends of a duplex chuck, when the chuck is installed on a machine spindel. The duplex chuck has respectives sets of jaws that are independently driven by separate pinion elements. In the case of disk brake rotors, opposite sides of both workpieces are finished simultaneously. The system also includes a refinishing machine that incorporates the spindle and a machining mechanism having cutting elements for simultaneously refinishing opposite sides of a pair of disk rotors.

Abstract: A tire uniformity machine having a framework for receiving a tire to be tested, a rotatable chuck located within the framework and having a spindle driven by a motor directly coupled to the spindle to selectively cause rotation thereof, whereby the tire is chucked within the chuck assembly and caused to rotate by the motor. The motor is disposed in axial alignment with the spindle.

Abstract: A holding chuck has a clamping device for firmly holding the tire-wheel in the position aligned with a center axis of a holding chuck. Chatter-suppressing dampers are disposed on an intermediate plate fitted around the chuck. The dampers are disposed on circles concentric with the center axis of the holding chuck. Each of the dampers has a damping rod extending in the direction parallel to the center axis and abutting a rim of the wheel. A damper cover is disposed between the rim of the wheel and the dampers and fastened to the holding chuck. The damper cover has slot holes disposed on a circle concentric with the center axis of the chuck which allow the damping rods of the dampers disposed on only one of the concentric circles to extend therethrough and abut the rim of the wheel.

Abstract: A brake rotor refinishing system provides simultaneously refinishing of two workpieces that are clamped at opposite ends of a duplex chuck, when the chuck is installed on a machine spindel. The duplex chuck has respectives sets of jaws that are independently driven by separate pinion elements. In the case of disk brake rotors, opposite pinion both workpieces are finished simultaneously. The system also includes a refinishing machine that incorporates the spindle and a machining mechanism having cutting elements for simultaneously refinishing opposite sides of a repair of disk rotors.

Abstract: A self-aligning arbor nut system is disclosed. The self-aligning arbor nut system, according to the present invention, includes a body formed with a duct substantially coincident with the longitudinal axis of the body. A substantially circular ring known as a swivel also is provided. The ring is engageable with either end of the duct. An o-ring is included. The o-ring is engageable with a groove in the wall of the ring, and with a slot formed on the inner surface of the duct at both ends of the duct to reverse engagement of the nut with an arbor. The swivel is engageable with at least one end of the body, and in fact is engageable with both ends of the body. When mounted on an arbor, the swivel aligns and helps prevent a bent or distorted arbor. A circumferential depression may be formed around the outside surface of the body. One or more bores is formed in the circumferential depression for manipulation with a key.

Abstract: A computer numerically controlled (CNC) machine has a chuck (2) rotatable about a first axis (A) and a V-block clamp (#) for clamping a workpiece (4) with its central longitudinal axis (C) extending parallel to the first axis (A). The offset (d) between the axes (A) and (C) is known or calculated and the CNC machine is programmed to compensate for the offset (d) during operation of a cutting tool (5) upon the workpiece (4). The V-block clamp (3) can accommodate workpieces of different diameters without having to align the central longitudinal axis (C) of each workpiece to coincide with the axis of rotation of the chuck (2), resulting in a reduction in set up time and an increased concentricity of a ground workpiece compared with conventional CNC grinding machines.

Abstract: A facedriver for holding a miniature workpiece along the axis of a rotary-drive machining device, including a base member, a forwardly-biased centerpoint member, drivepins supported rearwardly by fluid in a fluid-containing chamber in the base member, a grip member contacting the centerpoint member, and a grip portion of the fluid chamber adjacent to the grip member for fluid contact therewith such that varying fluid pressure caused by loading force on the drivepins causes application of varying radial gripping force on the centerpoint member through the grip member.

Abstract: A lathe chuck has a rotatable chuck body formed with jaw guides and with respective secantally extending rack guides crossing the jaw guides. Jaws are radially displaceable in the jaw guides between radial inner and outer end positions and have axially backwardly directed jaw teeth. Racks are secantally displaceable in the rack guides, and respective bolts in the racks each have teeth meshable with the respective jaw teeth and are each displaceable between a forward meshing position and a rear out-of-mesh position. A slide assembly in the body has respective cam surfaces engageable with the bolts and is displaceable angularly between a holding position retaining the bolts in the meshing position and a freeing position allowing the bolts to move into the out-of-mesh positions. Pins displaceable on the bolts have outer ends engageable with the respective jaws in both the meshing and out-of-mesh positions of the bolts.

Abstract: The “Barfield Non-Slip Spur” has the unique recessed chamber compartment that allows for stock to be inserted into the chamber for holding prior to the turning process. This feature does not allow slippage, boring, or splitting of the stock.

Abstract: The device serves for the end face, angularly true driving of a pre-toothed workpiece (21) clamped between work centers by the rotating work spindle (3) of a tooth flank grinding machine.

Abstract: A facedriver for holding a workpiece along the axis of a rotary-drive machining device, including a base member, a forwardly-biased centerpoint member, drivepins supported rearwardly by fluid in a fluid-containing chamber in the base member, a grip member contacting the centerpoint member, and a grip portion of the fluid chamber adjacent to the grip member for fluid contact therewith such that varying fluid pressure caused by loading force on the drivepins causes application of varying radial gripping force on the centerpoint member through the grip member.

Abstract: In order to machine a workpiece on a machine-tool successively between centres and with the workpiece clamped in a chuck, the workpiece is held during at least one machining operation—and if necessary between different kinds of machining—through the axial pressure of a centre pin clamped in a chuck of the machine-tool. To this end the chuck comprises an axial centre pin hydraulically movable in axial direction and which can be extended for enough towards the workpiece to be gripped by the jaws of the chuck.

Abstract: An air actuated finger pull back chuck device having a locating portion and a clamping portion. Locator slides and locator cams are air actuated to position the workpiece. The workpiece is located to the device with locator slides and air actuated clamp arms operate clamp fingers to pull back and hold a workpiece to the chuck device for the operation. The locator cams have a single connector to the locator actuator plate and the locator cams can be quickly reversed for locating on an inside diameter or an outside diameter. Various fingers can be attached to the clamp arm to fit various workpiece sizes. The quick change over times for different sized and shaped workpieces are facilitated by the simplicity of the invention.

Abstract: A controlled spindle drive is utilized for producing an axially acting clamping force for the purpose of clamping/releasing tools or workpieces on the work spindle of machine tools. A two-part spindle shaft is enclosed coaxially by a ring which can be displaced axially between two end positions. In one end position, the ring connects the two spindle-shaft parts to form a spindle shaft, which acts as a whole, for a normal operation as a machine spindle. In the other end position, the spindle-shaft part with the tool or workpiece mounting, is connected in a fixed manner to the non-rotating spindle housing. The non-secured spindle-shaft part then acts exclusively on the task-specific clamping/release mechanism. The controlled spindle drive, which acts on the non-secured spindle-shaft part, can actuate the clamping mechanism exclusively.

Abstract: A modular device for holding a workpiece or a bar of a material to be machined in a gripping chuck of a rotating spindle of a machine tool. A gripping chuck is actuated by a thrust tube coaxial with the spindle. To tighten the chuck, various forces are exerted including: a spring applying a first axial force on a thrust tube and applying a first air pressure force introduced through a duct into at least one tightening-pressure chamber. The tightening-pressure chamber is defined between at least a first wall fastened axially to the thrust tube and at least a second wall fastened axially to a regulating tube. Loosening of the chuck is obtained by a second air pressure introduced through another duct into at least one loosening-pressure chamber made between and on the other faces of the first walls fastened axially to the thrust tube and the other faces of the second walls fastened axially to a regulating tube.

Abstract: A method of repairing a drill pipe having first and second connector ends, each of the first and second connectors ends including a threaded portion and sealing portions, with a lathe having a chuck with longitudinally spaced first and second sets of jaws, the method comprising the steps of mounting the drill pipe in a lathe, gripping the first connector end of the drill pipe with each of the first and second sets of jaws, orienting the first connector end by manipulation of the first and second sets of jaws into a working position; and rotating the drilling pipe against a working tool to machine the threaded portion and sealing portion of the first connector end and produce a new threaded portion and sealing portion of the first connector end. A lathe with longitudinally spaced first and second sets of jaws is also disclosed. A device for positioning of subsequent workpieces without repeating alignment steps is also disclosed.

Abstract: A working machine for machining a workpiece includes a base having a first track and a second track mounted therein and arranged in parallel with each other, at least one clamping device slidably mounted in the first track for clamping the workpiece, and at least one cutter device slidably mounted in the second track to mate with the at least one clamping device for machining the workpiece. In such a manner, the at least one cutter device is movable relative to the at least one clamping, device to machine the two ends of the workpiece.