Abstract: A method of forming an integral tubular projection in a disk-shaped work by spinning is provided. In the method, h=0.1 to 0.5t, d=0.25 to 0.94D, T=0.5 to 7h, and V=0.029 to 0.234&pgr;D2h where h is a depth by which a forming roller cuts into the work, t is a thickness of the work, d is an outer diameter of the tubular projection, D is a diameter of a circle including a point where the spinning by the forming roller starts, T is a thickness of a wall of the tubular projection, and V is a volume of the tubular projection. A product produced by the above method is also provided.

Abstract: A device and a method are disclosed for attenuating a chatter oscillation in a processing machine, for example a cutting machine, such as a lathe. The machine includes at least one feed system with a primary section and a secondary section driven by a linear motor which can be powered via a converter. The device has a magnetic field control to control an in-phase component (d-component) of the magnetic field which produces the attractive force between of the primary section and the secondary section. An actual signal that is proportional to the chatter oscillation is generated and compared with a predetermined setpoint for a chatter oscillation. The comparison produces a control variable which is applied as a current setpoint to a field control that controls the current of the linear motor. This sufficiently attenuates chatter oscillations so that a reduction of the cutting depth is no longer required.

Abstract: A method of processing a piece of bar stock material having spaced ends and a predetermined diameter.

Abstract: A tool presetter and a tool offset amount calculation method are provided which ensure easy and accurate determination of reference tool offset amounts in a machine tool having a pivotal tool spindle stock. The tool presetter is mounted in a composite lathe having a pivotal tool spindle stock 17. The tool presetter calculates tool offset amounts Oz (=A−Zm), Ox (=B−Xm) on the basis of machine coordinate values Zm, Xm of the tool spindle stock detected when a nose of a tool T is in contact with Z-axis and X-axis detection points of a presetter sensor 18 with the tool spindle stock 17 pivoted by a pivot angle &agr;, and machine coordinate values A, B of the Z-axis and X-axis detection points of the presetter sensor 18, and calculates reference tool offset amounts Lz, Lx from predetermined expressions on the basis of the tool offset amounts Ox, Oz and the pivot angle &agr; of the tool spindle stock 17.

Abstract: A machining system having a first machine tool assembly with a first workpiece holder and a first machining unit for performing a processing operation on a workpiece held by the first workpiece holder, and a second machine tool assembly having a second workpiece holder and a second machining unit for performing a processing operation on a workpiece held by the second workpiece holder. The machining system further includes a base assembly on which the first and second machine tool assemblies are supported in an operative position. At least a part of the first machine tool assembly is repositionable by movement along a first line. At least a part of the second machine tool assembly is repositionable by movement along a second line that is non-parallel to the first line. The parts of the first and second machine tool assemblies are relatively repositionable along the first and second lines to facilitate transfer of a workpiece between the first and second machine tool assemblies.

Abstract: A system for processing elongate workpieces. The system consists of a first machining unit for performing a first processing operation on an elongate workpiece that is situated at a first location and a second machining unit for performing a second processing operation on an elongate workpiece that is situated at a second location that is vertically spaced from the first location. The system further consists of a first supply unit on which a plurality of elongate workpieces can be placed in a stored position. A transfer assembly engages an elongate workpiece in a stored position and selectively delivers an elongate workpiece engaged by the transfer assembly to one of the first and second locations.

Abstract: A production method of a thin plate includes preparing a thin plate support with a receptacle cavity having a bottom surface formed with a complementary three-dimensional pattern with a three-dimensional pattern of one side surface of a machining object, setting the machining object within the receptacle cavity with mating the complementary three-dimensional pattern with the three-dimensional pattern on the one surface of the machining object, chucking the thin plate support carrying the machining object set in the receptacle cavity on a machine tool, driving the thin plate support together with the machining object to rotate, and machining the machining object as being driven to rotate on the machine tool from the other side of the machining object by means of a cutting tool.

Abstract: The present invention provides a method and article involving a one-piece, unibody spindle liner having a tubular shape with an outside diameter and inside diameter that may be sized to fit virtually any spindle of a turning machine and to readily allow for the feeding therethrough of any size or shape of bar or tube stock. This invention provides that the axial centerline of the workpiece is maintained in concentric axial alignment with the working centerline of the turning machine to reduce wobble or “whip” of the stock during the machining process. The liner's inner bore and diameter is molded to match and allow for feeding of virtually any size and shape stock being turned, including but not limited to round, hex, square, and extruded. The inner bore is molded into the spindle liner along its entire length providing absolute support of the workpiece. The spindle liner also has a flanged mounting end to allow for the proper orientation and attachment to the spindle.

Abstract: A dual machining clutch apparatus (10) for a multiple spindle machine has at least two stations (20) for holding work pieces (22, 23). A first machining tool (24) is guided on a first slide (26). A controller (34) is notified that the earlier of the first or second machining tool has reached its selected position for completion of its machining operation. The respective machining clutch is de-energized, allowing its shaft to free-wheel. The later machining tool continues to perform its machining operation. As the later machining tool reaches its selected position for completion, the threading clutch for the earlier machining tool is engaged and the high speed clutch is engaged. The machining tools are then backed off the work piece to return to their original positions. The machining operation is complete and the main drum may index.

Abstract: A headstock 10 having a chuck 12 and a tailstock 20 having a shaft 21 are mounted on a bed 1 and can move with respect to each other in the direction of the Z-axis, A carriage 50 is slidably mounted on the bad 1 and can move in the Z-axis direction with respect to the rotational axis of a spindle 11. A turning device (lathe tool) 30 is provided to perform a turning operation on a workpiece and a gear cutting device 40 is provided to perform a gear cutting on the workpiece. The turning device 30 and the gear cutting device are preferably slidably mounted on the carriage 50 in a side-by-side relationship. The turning device 30 and the gear cutting device 40 may have respective traverse slide bases 31 and 41. The traverse slide bases 31 and 41 are mounted on the carriage 50 and can move independently in the direction of the X-axis perpendicular to the axis of the spindle 11, i.e. in a traverse sliding direction.

Abstract: Spiral electrodes and similar structures are manufactured using a high-pressure fluid stream. Specifically, spiral electrodes are made from tubular structures by using a high-pressure water stream to precisely cut, or etch spirals of predetermined geometries to conform to a particular current distribution and conduction requirements. In an embodiment, the high-pressure water stream is tangentially and rotatably oriented against a rotating and translating tubular element. The tangential orientation enables limited cutting or etching of the tubular surface that is only in direct contact with the high pressure stream. Various geometries and spiral structures could be formed by managing the pressure and rotation of the high-pressure water stream source and the rotation and translation of the tubular element.

Abstract: A turning assembly for turning a workpiece includes a holder and plurality of turning bits mounted next to one another in a parallel relationship for simultaneously engaging a the workpiece. The turning bits are mounted in respective holding elements which are individually adjustably mounted in the holder. Spacers can be provided to space the turning bits apart. Safety devices are provided, each including an elastic element for frictionally retaining a respective turning bit and/or spacer within the holder to enable the holder to be manipulated without the turning bits and/or spacers falling out.

Abstract: In a complex machining machine tool, a tool rest capable of attachably and detachably installing tool installing inserts thereon is provided, a plural number of virtual tools is set and registered concerning a predetermined at least one tool together with its indexing positional data in tool file, the tool data of the corresponding virtual tool is read out from the tool file on the basis of the machining instruction by the virtual tool stored in machining program, and the corresponding virtual tool is indexed on the tool rest on the basis of the indexing positional data, and then machining with the virtual tool is executed. At the time of machining, it is possible to continue machining with the same tool by only positional indexing without changing the tool. The work for changing tools can be extremely decreased even if machining contents are changed or it is necessary to change tools by tool exhaustion.

Abstract: A lathe-cutting apparatus and a method with a structure of a chuck being simple, which are capable of lathe-cutting an eccentric part of a crankshaft with high accuracy are provided. For this purpose, the apparatus includes a supporting device (21) for supporting both end portions of a crankshaft (1), a rotational drive device (20) for rotating the crankshaft from at least one end side of the supporting device with a main journal (3) of the crankshaft as a center, and rotationally driving an eccentric part (2), a tool (31) for performing lathe-cutting of the eccentric part, and a cutting tool drive unit (30) for making a cutting edge position of the tool perform crank rotation synchronously with the rotation of the eccentric part which is rotationally driven by the rotational drive device, and performing lathe-cutting of the eccentric part.

Abstract: An apparatus and a method are disclosed for reducing a thickness of a thermomechanically-affected layer on an as-machined surface of a hard metal workpiece being machined by a hard cutting tool exerting a thermomechanical load on a surface of the workpiece. The method involves reducing the thermomechanical load on the surface of the workpiece, and the apparatus includes a means for reducing the thermomechanical load on the surface of the workpiece.

Abstract: A cutting tool for a machine tool is provided in order to cut an inside corner of a workpiece. The cutting tool has at least one cutting edge formed on its bottom. In operation, the cutting tool is rotated by the machine tool. Further, both cutting tool and workpiece move relatively to each other in accordance with the rotating angle of the cutting tool so that the cutting tool has its outer end describing a moving track in agreement with the contour of an inside corner of the workpiece. The cutting tool further moves along the direction of a rotating axis of the cutting tool in rotation.

Abstract: A cutting tip has a cutting face and a flank face. A compression face for plastically deforming a workpiece is provided between the cutting face and the flank face. The cutting tip allows work-hardening to be easily performed by plastic deformation of the cut-finished surface during cutting, without adding a separate process step.

Abstract: A device for removing the filter medium from the spool of an oil filter, includes a spindle assembly having (1) a spindle which is shaped and dimensioned to receive the hole in the first end of the spool, (2) a plurality of bearings, and (3) a cutter. A holder/crank having a rotational rim is attached to the spool of the oil filter and locked in place. The holder/crank and spool are then installed in the spindle assembly so that the spindle engages the hole in the spool and rim engages the plurality of bearings. The holder/crank is then rotated as the cutter is brought to bear against the filter medium so that a circumferential cut is made through the filter medium.

Abstract: An inside diameter machining method for machining inside a workpiece uses a turning tool utilized within a main body in the shape of a bar with a hook-shaped top end portion which has a cutting portion. When the machining diameter of the portion to be machined inside the workpiece is bigger than the workpiece's tool insertion hole, the workpiece interferes with the tool when the turning tool's top end portion is moved linearly. To overcome the interference, moving the turning tool's top end portion in two axial directions orthogonal to each other and in a rotational direction with a third axial direction orthogonal to the other two axial directions as its center permits the top end portion to be inserted into the tool insertion hole. The turning tool's cutting portion is then positioned at the portion to be machined inside the workpiece. Turning machining subsequently can be commenced.

Abstract: An improved hydrodynamic bearing design and method for fabricating a hydrodynamic bearing is disclosed, which incorporates a filling groove so that oil or other lubricating fluid can be efficiently inserted into the bearing gap without risking the loss of fluid during operation; the method provides for fabricating the hydrodynamic bearing and its oil filling groove so that the efficiency of the manufacturing process is not compromised. The same grooving tool which forms the hydrodynamic bearing is scraped across an abutment on the sleeve which supports the counterplate to form a shallow filling groove under the counterplate.

Abstract: A method of milling a large thread length with a thread milling cutter having a shank and a milling section having a plurality of rows of teeth arranged in each row one after another with at least two adjacent teeth in each row being separated, in an axial direction by a missing tooth space, with the method including positioning the cutter in a bore of a workpiece, with the cutter being adjusted in an axial direction and fed outwardly, forming a portion of the thread by imparting to the cutter rotational, axial feeding, and circular movements, and forming a further portion of the thread by imparting to the cutter a further circular movement corresponding to the tooth missing space, while continuing to impart to the cutter rotational and axial feeding movement.

Abstract: In a complex machining machine tool, a tool rest capable of attachably and detachably installing tool installing inserts thereon is provided, a plural number of virtual tools is set and registered concerning a predetermined at least one tool together with its indexing positional data in tool file, the tool data of the corresponding virtual tool is read out from the tool file on the basis of the machining instruction by the virtual tool stored in machining program, and the corresponding virtual tool is indexed on the tool rest on the basis of the indexing positional data, and then machining with the virtual tool is executed. At the time of machining, it is possible to continue machining with the same tool by only positional indexing without changing the tool. The work for changing tools can be extremely decreased even if machining contents are changed or it is necessary to change tools by tool exhaustion.

Abstract: A process for cutting machining of rotating rotationally symmetrical workpieces with a defined cutting edge, wherein the resulting rotationally symmetrical surface has either no twist or a twist which is only insignificant in terms of transport effect and abrasive action and/or when machining the hardened workpiece surfaces a particularly high material removal rate can be achieved, wherein a cutting edge which is askew with respect to the axis of rotation of the workpiece is guided in contacting relationship along the rotating workpiece in a linear feed movement transversely with respect to the axis of rotation, wherein the machining parameters, in particular the broaching feed and the inclined positioning of the cutting edge are so selected that the twist occurring at the machined surface becomes a minimum in respect of twist pitch and/or twist depth and in particular the twist depth becomes a minimum.

Abstract: A device for removing the filter medium from the spool of an oil filter, includes a spindle assembly having (1) a spindle which is shaped and dimensioned to receive the hole in the first end of the spool, (2) a plurality of bearings, and (3) a cutter. A holder/crank having a rotational rim is attached to the spool of the oil filter and locked in place. The holder/crank and spool are then installed in the spindle assembly so that the spindle engages the hole in the spool and rim engages the plurality of bearings. The holder/crank is then rotated as the cutter is brought to bear against the filter medium so that a circumferential cut is made through the filter medium.

Abstract: A method of reducing hard machining time, and correspondingly increasing hard machining tooling life, of a non plunging type constant velocity joint for use in reduced angle applications. The method comprises forming a recess having a larger formed radius in a portion of the ball track and cage track areas that is non-functional in low angle operations prior to heat treat hardening. The new process results in a significant reduction of approximately forty-five percent in the hard machining of the ball and cage track surfaces.

Abstract: A bar stock feeder and support mechanism for an automated machining center having a control system and a method for operation thereof. A work positioning structure is removably mounted to a work support and positioning table of an automated machining center and has a bar feeder top plate. Mechanized machine controlled pneumatic bar stock chucks on the bar feeder top plate have bar stock gripping collets which are closed and opened by the control system of the automated machining center for selectively gripping the bar stock during machining and selectively releasing the bar stock to permit its movement by a bar puller which raises the bar stock to a programmed height. A control umbilical cable is connected with the control system of the automated machining center and has controlling connection with each of the bar stock chucks. During operation of the machining center machining is performed serially on each bar stock, thus enhancing the productivity of the machining center.

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 chamfering the cam plate of a swash plate compressor comprising a cylinder block provided with cylinder bores, pistons inserted into the cylinder bores to be slidable, a driving shaft, a cam plate slantedly fixed to the driving shaft and shoes inserted between the cam plate and pistons, wherein the circumferential surface of the cam plate forms a cylindrical surface extending coaxially with the driving shaft, comprises the steps of rotating the cam plate around an axis inclined relative to the driving shaft, disposing the blade of a cutting tool to extend parallel to the axis, and abutting the blade of the cutting tool against edges of the circumferential surface of the cam plate.

Abstract: A cutting method in which a solution is sprayed or jetted to a machining portion when machining by use of a water-insoluble cutting oil, wherein recovered liquid is collected and stored in one recovery tank, and separated into the water-insoluble cutting oil and another solution on the basis of the specific gravity difference, and are re-used. Stable machining is enabled by using the water-insoluble cutting oil, and measures against disaster are fully taken.

Abstract: The invention relates to a process for the finishing of ball cages (1) destined for constant-velocity joints which are provided with spherical annular inner and outer bearing surfaces (3, 2) and ball pockets (4) for the accommodation of torque-transmitting balls. In order that the finishing of such ball cages (1) can be carried out rapidly, at low cost and in as fully automated a manner as possible it is proposed according to the invention that the finishing both of the inner and outer spherical annular bearing surfaces (3, 2) as well as the contact surfaces (5) of the ball pockets (4) located opposite one another in the axial direction and each for one ball ensues by means of lathe machining.

Abstract: A locking assembly for a toolholder to releasably secure the toolholder with a tool support member.

Abstract: A method for making a cutting insert for use in an ID rotary cutter includes obtaining the profile of a convex surface portion of a finished part to be milled with the cutter, translating the profile a minimum distance away from a reference axis for the convex surface portion, and generating a reference contour by rotating the translated profile about the reference axis. A reference profile for a cutting edge of the cutting insert is obtained as the intersection of the reference contour with a reference plane that is disposed at a predetermined helix angle relative to the reference axis.

Abstract: A device for catching cut off workpieces from a C. N. C. lathe, the lathe having a toolholding turret and a turret back wall. The device attaches to the turret. A basket for catching cut off workpieces is attached to a bracket. The bracket is shaped to be attachable to the turret, to permit the basket to fit underneath the workpiece and to permit the basket to clear the turret back wall when the turret is rotated about its axis into any position. Preferably, an L-shaped bracket is used for octagon type turrets and an oblique angled bracket is used for VDI turrets. One version of the invention comprises a lathe to which a C. N. C. parts catcher is attached. Another version of the invention is a method for catching workpieces cut off from the spindle of a C. N. C. lathe.

Abstract: A method and apparatus for removing chips from a workpiece on a lathe including a spindle with a through hole formed therein, a chuck having a through hole formed therein and affixed adjacent a forward end of the spindle, a cutting mechanism cooperative with the chuck so as to remove metal chips from a workpiece mounted on the chuck, and a coolant line connected to the cutting mechanism and directed generally toward the through hole of the chuck so as to drive metal chips through the through hole of the spindle and outwardly of a rear end of the spindle. A guide sleeve is positioned within the through hole of the spindle so as to be fixed and nonrotatable therewithin. The coolant line includes a high pressure coolant line and a low pressure coolant line. The cutting system includes a turret with a cutting tool affixed to a station of the turret. The coolant line is connected to the turret and extends so as to have an outlet adjacent to the cutting 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: A method for making a cutting insert for use in an ID rotary cutter includes obtaining the profile of a convex surface portion of a finished part to be milled with the cutter, translating the profile a minimum distance away from a reference axis for the convex surface portion, and generating a reference contour by rotating the translated profile about the reference axis. A reference profile for a cutting edge of the cutting insert is obtained as the intersection of the reference contour with a reference plane that is disposed at a predetermined helix angle relative to the reference axis.

Abstract: A compound machining center is provided which includes at least one work driving unit, including a chuck, mounted on a bed and adapted to rotate a work to be worked in a state in which the chuck grasps a first end of the work. At least one tail stock center is mounted on the bed and adapted to support a second end of the work so as to support the work on a working axial line between the tail stock center and the chuck of the work driving unit. At least one working unit is disposed on the bed to be movable in an X-axis direction parallel to the working axis line and a Y-axis direction normal to the X-axis direction. And at least one tool is mountable to the working unit to be linearly movable in a tangential direction of the work.

Abstract: An improved method for producing a brake drum which balances a brake drum defining an inner surface and an axis. Balancing specifications are determined which correct an imbalance of the brake drum about the axis. Material is removed from the inner surface, which forms a cylindrical surface preferably defining a braking surface of the brake drum, to balance the brake drum according to the balancing specifications. It is a further feature of the invention to remove material surrounding a pilot hole initially formed in the brake drum, wherein the removal of the material also correlates to the balancing specifications.

Abstract: A machining device (6) for machining a workpiece by relatively rotating the workpiece and a tool (1) which comprises a revolving shaft (8) held for rotation on its own axis that is parallel with the center axis, a main shaft (4) that is eccentric with respect to the center axis of the revolving shaft (8) and that rotates on its own axis that is parallel with the center axis of the revolving shaft (8), the main shaft having either the workpiece or the tool (1) mounted on the front end thereof, and rotation drive mechanisms (M1, M3) for rotating the revolving shaft (8) and main shaft (4) at different rpm's.

Abstract: A headstock 10 having a chuck 12 and a tailstock 20 having a shaft 21 are mounted on a bed 1 and can move with respect to each other in the direction of the Z-axis, A carriage 50 is slidably mounted on the bad 1 and can move in the Z-axis direction with respect to the rotational axis of a spindle 11. A turning device (lathe tool) 30 is provided to perform a turning operation on a workpiece and a gear cutting device 40 is provided to perform a gear cutting on the workpiece. The turning device 30 and the gear cutting device are preferably slidably mounted on the carriage 50 in a side-by-side relationship. The turning device 30 and the gear cutting device 40 may have respective traverse slide bases 31 and 41. The traverse slide bases 31 and 41 are mounted on the carriage 50 and can move independently in the direction of the X-axis perpendicular to the axis of the spindle 11, i.e. in a traverse sliding direction.

Abstract: A reversible cutting tip for a cutting tool has a cutting wedge defined by a first face and a first flank. The cutting wedge has a clearance angle of 0° to 3°. The first flank is produced by applying a first coating to the cutting tip and the first face is produced by applying a second coating to the cutting tip. The tool is employed for removing cuttings from a workpiece by the cutting tips and for subsequently smoothing the crack surface of the workpiece, created by removing the cuttings, by employing the first flanks.

Abstract: A method of machining seats of a compressor piston having an approximately hemispherical recess. A surface of a piston extending perpendicular to an axis of the piston is machined by annularly moving a cutting element while the cutting element is rotated with respect to the piston to form an annularly cut portion. The surface is further machined by moving the same cutting element in a direction toward the surface while the cutting element and the piston are relatively rotated to form a hemispherical recess in the surface. The firstly formed annularly cut portion becomes an annular chamfered portion on the periphery of the hemispherical recess. In this way, it is possible to form the hemispherical recess, and the annular chamfered portion on the periphery thereof, with the common cutting tool.

Abstract: A method of machining a workpiece uses a complex tool having a number of inserts. The tool is installed on a tool holder of a machine tool and used for a turning machining operation on a workpiece, including rotating the workpiece, and selectively using one or more of the inserts on the complex tool, with the complex tool being fixed and held. A milling machining operation is performed on a workpiece using one or more of the inserts, with the complex tool being rotated and driven. Both turning machining and milling machining operations can be performed without changing tools. Extremely efficient machining is possible.

Abstract: A method for producing steel rolling bearing rings, starting from a hot-rolled tube, the structure of which is similar to a spheroidized structure and from which rings of the same continuous length are hot-cut while supplying a lubricant and, after cooling, are further processed. The hot-cutting takes place at a temperature below the transformation temperature of the rolling bearing steel used but above 720° C., with subsequent cooling in static air. From the blank ring a green or soft ring of a rolling bearing ring is produced with narrow tolerances of its shaped elements by an optimally timed multistage machining type of cold further processing operation, the main element of the cold further processing being a turning operation.

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 and an apparatus for 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: An used PCB milling cutter reclamation method includes the step of processing the cutting tip and a part of the handle of the damaged PCB milling cutter to form a new cutting tip, the step of processing the end of the handle remote from the new cutting tip to form a round rod, and the step of fastening an end cap to the round rod, keeping the end cap in line as well as in flush with the periphery of the handle.

Abstract: A method for machining a pair of shoe pockets for piston in a swash plate type compressor is disclosed. In this method, the shoe pockets are respectively formed on the opposed walls of the slot in the piston of the compressor while conforming to a single imaginary sphere. The method comprises the step of moving a cutter provided with an arc-shaped cutter blade that has a rotation diameter less than the width of the slot. Thereafter, there is performed the step of relatively revolving the cutter with regard to the piston by allowing the central axis of a revolved part to move along a circular orbit within the slot while rotating the cutter, so as to cut the shoe pockets to conform to the single imaginary sphere. Finally, the step of retreating the cutter out of the slot when the cutter completes one round revolution and is returned to its initial position is performed.

Abstract: In cutting a high-accuracy thread, a control unit (CPU) uses a first position data calculation program to determine the moving positions of a workpiece and tool every predetermined rotational angle of a spindle rotating motor. The control unit stores the determined moving positions of the workpiece and tool in a first position data table memory, and outputs the determined moving positions as a workpiece position instruction signal and tool position instruction signal to a workpiece feed control circuit and tool feed control circuit every predetermined rotation. In cutting a low-accuracy thread, the control unit uses a second position data calculation program to determine the moving positions of the workpiece and tool every predetermined time interval.

Abstract: An insert for turning of titanium is provided. By using inserts with a reduced length of primary land compared to prior art an unexpected increase in tool life and productivity has been obtained. Said positive results are further improved by subjecting the inserts to an additional heat treatment after grinding to final shape and dimension.