Abstract: A milling method includes moving a milling tool having at least two axially spaced apart sets of cutting inserts to an axial position within a bore in a material and rotating the milling tool about a longitudinal axis. The method further includes initiating contact between the milling tool and a wall of the bore in a region of the wall having a least amount of material at the axial position. The method further includes moving the milling tool around a perimeter of the bore.

Abstract: A positioning of a spindle with micrometric forwarding control and tilting of its rotation axis includes a spindle shaft rotatingly supported inside rotatable supports, wherein the rotatable supports include two spherical elements having housings which are eccentric with respect to the rotation axis that join the centers of the spheres, and wherein the two spherical elements are positioned in a cylindrical housing having at least two parts, and wherein two rotation elements are connected to the two spherical elements and cause their independent rotation.

Abstract: A machine tool for machining gear teeth into an inner side of an annular workpiece, the tool comprising a circular substructure having an upper side, a rotary bearing on which is disposed an annular machining table adapted to support a workpiece, a chassis for supporting a tool head, and a plurality of exchangeable machining rings, an adaption ring supporting the machining ring and supporting concentric cones, and a braking device adapted to act on the adaption ring.

Abstract: A ram guiding apparatus 1 of a machine tool is incorporated in a portal type machine tool 2 and provided with a cross saddle 5 that is cross-like in shape, as seen in a side view of the machine tool 2, provided so as to be freely movable in the horizontal direction along a horizontal cross beam 4. The cross saddle 5 has a box 18, both upper and lower faces thereof being open, in a front side of a horizontal part, wherein a first linear guide 21, a second linear guide 22, and a third linear guide 23, respectively serving as linear guides in the box 18 for a ram vertical movement, guide the ram 9 so as to be freely movable only in the vertical direction.

Abstract: An apparatus for making variable diameter and shape holes through metal plates in a sheet plate machining gantry machine comprises two parallel cross members and two horizontal parallel guides integral with the cross members and supporting a horizontal cross arm which is controllably driven on the guides, the horizontal arm supporting horizontal parallel guides therealong is controllably driven an apparatus including a milling tool which can controllably driven in a vertical plane. The method comprises the step of controllably simultaneously driving a two-fluted mill both in a vertical plane (Z), and in a horizontal plane (U).

Abstract: Provided is a horizontal machine tool with a base frame including a base part and a saddle supporting part vertically standing on the base part; an X-axis saddle mounted on the back face of the saddle supporting part and capable of sliding in the left-right direction via an X-axis translation mechanism; a Y-axis saddle mounted on the X-axis saddle and capable of sliding in the up-down direction via a Y-axis translation mechanism; and a spindle device mounted on the Y-axis saddle and capable of sliding in the front-rear direction via a Z-axis translation mechanism. The horizontal machine tool is adapted such that a workpiece supporting member is installed on the base part in front of the saddle supporting part. This configuration can reduce the size and weight of the entire construction.

Abstract: A horizontal machine tool (1) includes a base frame (10) where workpiece support faces (11c) for supporting a workpiece are formed at front portions; an X-axis saddle (20) attached to a back-face portion (12b) of the base frame (10) through an X-axis movement mechanism (50) universally slidably in a left-right direction; a Y-axis saddle (30) attached to the X-axis saddle (20) through a Y-axis movement mechanism (60) universally slidably in an up-down direction; and a spindle device (40) attached to the Y-axis saddle (30) through a Z-axis movement mechanism (70) universally slidably in a front-rear direction. According to this configuration, it is possible to make a whole of the horizontal machine tool a small size and lightweight and to enhance machining accuracy of the workpiece.

Abstract: An engraving machine includes a base with two side panels extending upward from two sides of the base, and a top board is driven horizontally by a motor in the base. A horizontal frame is movably mounted on two rods connected between the two side panels by a motor. A vertical frame is located on a front side of the horizontal frame and is movable along two rods in vertical direction by another motor. The horizontal frame, the vertical frame and the top board are movable along X, Y and Z directions by three independent motors. A chuck is connected to the vertical frame and secures an engraving tool which is driven by a main motor connected between the two side panels. The object to be engraved is secured on the top board and engraved by the engraving tool in X, Y and Z directions.

Abstract: An orbital drilling tool unit configured to be detachably mounted to a rotatable spindle of a stationary machine tool. The tool unit comprises an outer eccentric body having an eccentric, longitudinally extending cylindrical hole, an inner eccentric body rotatably supported in the eccentric hole of the outer eccentric body and having likewise an eccentric, longitudinally extending cylindrical hole, a spindle motor for detachably supporting a cutting tool and rotatably supported in the eccentric hole of the inner eccentric body. The machine tool end of the outer eccentric body is configured to be concentrically mounted to a tool holder attached to the machine tool spindle for rotating the outer eccentric body.

Abstract: A rotary tool-equipped tool rest is provided, including a movable member made to move frontwardly when a turret is clamped with respect to a non-swiveling housing after swiveling and indexing. Then, a phase determining pin provided in the turret is made to project and engage with the non-swiveling housing. Further, a coupling mechanism to clamp the turret with respect to the non-swiveling housing has three coupling members.

Abstract: A modular slider feeder tube system comprising first and second feeder tubes having respective ends that are coupled by a tube coupling device. Each of the first and second feeder tubes is made of resilient material and comprises a respective channel having a profile that is asymmetric and substantially constant along the lengths of the channels. The tube coupling device also comprises a channel, via which channel the channel of the first feeder tube communicates with the channel of the second feeder tube. Each of the channels maintains the orientation of each slider passing therethrough so that the same end of the slider is always in the lead.

Abstract: A machine tool includes a table supported by a bed for forward and rearward movement along a path of movement, left and right transversely aligned upright columns on opposite sides of the path of movement, a cross rail supported in the columns for movement upwardly and downwardly along forward and rear guide rails on inwardly facing column surfaces, a spindle head supported by the cross rail for movement leftwardly and rightwardly. The cross rail, the left and right columns, the spindle head and the guide rails are symmetrically positioned from front to rear and vertically by vertical or horizontal symmetry defining planes so that heat generated creates balanced self-cancelling forces.

Abstract: Machine tool with: a bed furnished with a base and two side walls provided standing along respective left and right sides of the base; a first saddle composed of a rectangular frame, with vertical sides provided perpendicularly and transverse sides provided sideways, and both ends of the frame sideways being supported on rear faces of the side walls so as to be perpendicularly movable; a second saddle arranged within the first-saddle frame and provided to be movable sideways, and having a front-to-rear penetrating through-hole; a spindle head arranged in the second-saddle through-hole and provided to be movable back-and-forth; a tool-retaining spindle supported, by the spindle head, with its axis paralleling the front-to-rear orientation and rotatable about its axial center; and, arranged on the bed, a table on which workpieces are set.

Abstract: A plunge milling system (10) for effecting rapid removal of material from a workpiece during a rough and/or finishing cutting procedure. In this system, an axial cutting tool (12) is rotated about its axis and axially moved into engagement with the workpiece for cutting material from the workpiece. When the tool (12) is engaged with the workpiece, the tool is also moved transaxially and simultaneously with the axial movement whereby material is removed from the workpiece along a curved path.

Abstract: A fixation device for positioning a rotating machine tool onto a template, the template having at least one hole and at least one locating pin. The fixation device includes a housing with a housing tool end and a housing template end, a seat located on the housing tool end for coupling with the rotating machine tool, and a clamping mechanism disposed at least partially at the housing template end for coupling with at least one locating pin.

Abstract: A hole of a hole size is cut in a composite material workpiece by selecting a milling cutter having an effective cutter size less than the hole size, mounting the composite material workpiece in operable relation to the milling cutter, rotating the milling cutter about an axis of rotation, and advancing the milling cutter longitudinally into the composite material workpiece parallel to the axis of rotation at a rate of longitudinal advance, while laterally moving the milling cutter perpendicular to the axis of rotation to interpolate the hole. The rate of longitudinal advance is controlled such that the hole remains substantially a flat-bottomed hole as it is cut. The composite material workpiece is desirably affixed to a backing fixture with an adhesive material during the cutting of the hole.

Abstract: A milling method is provided for the manufacture of components composed of difficult-to-cut materials for turbomachines, aircraft and spacecraft by producing recesses with one or more side walls. An end milling cutter which cuts at the circumference and at the tip and has a tip contour which is rounded towards the circumference is used as the rotating milling tool. In addition to rotation about its axis, the milling tool performs an eccentric orbiting motion about an orbital axis spaced apart from its axis. The opposite senses of rotation lead to downcut milling, and the orbital axis performs a translational advance motion on a straight and/or curved path transversely to its longitudinal direction, with or without a swivelling motion.

Abstract: A machine tool capable of performing an accurate machining by preventing a second saddle 6 from displacing aslant to suppress the vibrations of a spindle head 8, wherein a column 2 is fixedly installed on bed 1, a first saddle 4 is movably guided by the column 2 in vertical direction f1, a second saddle 6 is movably guided by the first saddle 4 in lateral direction f2, a spindle head 8 is movably guided by the second saddle 6 in longitudinal direction 18, and interfitted guide route devices 5A, 5B, 5C for guiding the second saddle 6 in lateral direction f2 are formed at the rear lower position of the first saddle 4 as well as at the front upper and lower positions of the first saddle 4.

Abstract: The tool comprises firstly a cutter support for being driven in rotation about a first axis of rotation that is to coincide with the axis of the orifice, and a cutter rotatably mounted on the cutter support to rotate about a second axis of rotation parallel to the first axis of rotation and spaced apart therefrom by a non-zero offset distance. A front segment of the cutter support has maximum radial extent relative to the first axis of rotation that is less than or equal to the radius of the orifice to enable the front segment to penetrate into the orifice during drilling. The tool is particularly applicable to drilling machines used in the aviation industry.

Abstract: The structure for symmetrically disposed linear motor operated tool machine comprises two parallelly erected sustaining walls, a movable gantry, a sliding saddle, a tool spindle, and a weight compensation device. At both sides of the movable gantry between the sustaining walls, between the gantry and the sliding saddle, and between the tool spindle and the sliding saddle, a pair of linear motors is symmetrically disposed such that the armature reaction between the winding and magnet is compensated each other by the opposite one therefore any possible deformation force to the tool machine structure is eliminated.

Abstract: A method and cutting tool for producing a hole or a recess in a workpiece which includes flat or curved sheets of fiber-reinforced composite material, metal or combinations thereof. The cutting tool has a shaft with a longitudinal axis and an axial cutting surface and at least one cutting edge disposed on the axial cutting surface and extending radially from the longitudinal axis with a gap between the radial inner extent of the cutting edge and the longitudinal axis. The method of use includes rotating the cutting tool about its longitudinal axis and also translating the cutting tool during rotation.

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 hand tool apparatus uses a cutting tool with a first width and a tool axis to machine a hole in an object. The hole has a second width at least as large as the first width of the cutting tool. The apparatus includes a housing, a spindle unit in the housing for rotating the cutting tool and an orbital drive for rotating the spindle unit. An axial feed mechanism moves the orbital drive and the spindle unit jointly either toward or away from the object being machined.

Abstract: A semi-contact guide apparatus includes a bed as a first member, a column as a second member, a plural number of oil-hold portions and an oil-supply device. The column is movably guided on the bed. A sliding surface is formed on the column. The plural number of oil-hold portions is formed on the sliding surface. Dimensions of the oil-hold portions are defined according to load distribution of the weight of the column. The oil-supply device supplies lubricant oil to the oil-hold portions. The amount of lubricant oil supplied to the oil-hold portion is defined according to each of dimensions of the oil-hold portions. Since the dimensions such as areas of the oil-hold portions and the amount of the lubricant oil supplied to the oil-hold portion are defined as above, inclination of the column on the bed is prevented, and the column can be smoothly moved on the bed.

Abstract: A plunge milling system (10) for effecting rapid removal of material from a workpiece blank during a rough and/or finishing cutting procedure. In this system, an axial cutting tool (12) is rotated about its axis and axially moved into engagement with the workpiece blank for cutting material from the workpiece. When the tool (12) is engaged with the workpiece, the tool is also moved transaxially and simultaneously with the axial movement whereby material is removed from the workpiece blank along a curved path.

Abstract: A hand tool apparatus uses a cutting tool with a first width and a tool axis to machine a hole in an object. The hole has a second width at least as large as the first width of the cutting tool. The apparatus includes a housing, a spindle unit in the housing for rotating the cutting tool and an orbital drive for rotating the spindle unit. An axial feed mechanism moves the orbital drive and the spindle unit jointly either toward or away from the object being machined.

Abstract: A hand tool apparatus uses a cutting tool with a first width and a tool axis to machine a hole in an object. The hole has a second width at least as large as the first width of the cutting tool. The tool axis passes through a predetermined point on a surface of the object. The apparatus includes an actuating assembly including a housing. The housing contains an axial feed mechanism configured for moving the cutting tool in an axial direction, a spindle motor configured for rotating the cutting tool about the tool axis, and a radial offset mechanism. The radial offset mechanism is configured for moving the cutting tool such that the tool axis is offset from a principal axis. A motor is configured for rotating the axial feed mechanism and the cutting tool about the principal axis.

Abstract: A machine tool comprises a rack, a horizontally displaceable x skid and a y skid that is vertically displaceable thereon. The skids are drivable by linear motors which are arranged on the front side of the rack and the face side of the x skid, respectively, and on the rear side of the x skid and the rear side of the y skid, respectively. The same may apply to the x guides and the y guides. The air gaps of the linear motors of each skid are arranged in one plane.

Abstract: In a machine tool of the type comprising a spindle mounting slide which is driven by a linear electric motor and which runs in a vertical direction in a slideway, the slide comprises two runners designed to engage with corresponding fixed sliding guides integral with the slideway, and two roller pads that slide on corresponding longitudinal sliding surfaces which are also integral with the slideway.

Abstract: For an orbit boring to be performed by a tool (10) in an orbital motion along an orbit (A), a permissible range of an acceleration (a) of the orbital motion is provided to meet a criterion of a machining precision of the orbit boring, and the acceleration (a) is controlled to be suppressed within the permissible range.

Abstract: A machine tool capable of performing an accurate machining by preventing a second saddle 6 from displacing aslant to suppress the vibrations of a spindle head 8, wherein a column 2 is fixedly installed on a bed 1, a first saddle 4 is movably guided by the column 2 in vertical direction f1, a second saddle 6 is movably guided by the first saddle 4 in lateral direction f2, a spindle head 8 is movably guided by the second saddle 6 in longitudinal direction f3, and guide route means 5A, 5B, 5C for guiding the second saddle 6 in lateral direction f2 are formed at the rear lower position of the first saddle 4 as well as at the front upper and lower positions of the first saddle 4.

Abstract: In a machine tool (2), in particular for cutting treatment of workpieces (9) comprising a machine frame, a workpiece table (15) borne on the machine frame and an approximately horizontally disposed processing unit (8) which is mounted to the machine frame, the processing unit (8) is mounted also to a support (6) of the machine frame overlapping the workpiece table (15). This upper mounting prevents displacement of the processing unit relative to the workpiece due to the forces acting thereon during processing, in particular in the Z-direction. These forces are accommodated by the machine frame which is self-contained through the support.

Abstract: A machine (1) (42) wherein a frame (2) supports at least one operating head (34) (34a, 34b) via the interposition of an actuating device (4) for enabling the operating head (34) (34a, 34b) to move in relation to the frame (2) within a predetermined volume; and wherein the actuating device (4) is defined by two electric motors (14,24), the respective axes (6,21) of which are parallel to each other; and wherein a rotor (15) of one (14) of the two motors (14,24) is supported by the frame (2) and eccentrically supports a stator (23) of the other motor (24), a rotor (25) of which supports a straight guide member (31) in turn supporting a powered slide member (33) in turn supporting the operating head (34) (34a, 34b).

Abstract: A machine tool and a cover device for the machine tool capable of preventing work cutting chips and coolant from falling on the rear part of a spindle head (8) and the operating positions of a first saddle (4) and a second saddle (6) without expanding the lateral width of the machine tool, wherein a column (2) is fixedly installed on a bed (1), the first saddle (4) is guided on the front surface of the column (2) movably in vertical direction (f1), the second saddle (6) is guided on the front surface of the first saddle (4) movably in lateral direction (f2), and the spindle device (8) is guided on the second saddle (6) movably in longitudinal direction (f3) and, in addition, a first cover plate (31) is fixed to the second saddle (6), a side cover plate (33) is installed continuously with each of the right and left side edges of the cover plate (31) bendably in longitudinal direction (f3), a second cover plate (39) is fixed integrally with the first saddle (4), and a third cover plate (41) is installed fixedly

Abstract: A fixation device for positioning a rotating machine tool onto a template, the template having at least one hole and at least one locating pin. The fixation device includes a housing with a housing tool end and a housing template end, a seat located on the housing tool end for coupling with the rotating machine tool, and a clamping mechanism disposed at least partially at the housing template end for coupling with at least one locating pin.

Abstract: The process contemplates material removal from the surface of rotating bodies (11) by moving at least one milling cutter (5) along an arched trajectory (21) in a plane transverse to the axis of the bodies, so as to remove the material in the circumferential direction of the body surface and parallel to the axis of the milling cutter (5). This working can be carried out in addition to a vectorial milling. The trajectory (21) is obtained by composing two linear translations perpendicular to the milling cutter (5) by adjustment of the speed and the rotation direction of the motors producing such translations.

Abstract: A machine tool comprises a rack, a horizontally displaceable x skid and a y skid that is vertically displaceable thereon. The skids are drivable by linear motors which are arranged on the front side of the rack and the face side of the x skid, respectively, and on the rear side of the x skid and the rear side of the y skid, respectively. The same may apply to the x guides and the y guides. The air gaps of the linear motors of each skid are arranged in one plane.

Abstract: A machine tool includes a spindle-headstock structure with a horizontal axis which is displaceable along three mutually orthogonal axes. The headstock structure is mounted so that it slides along an axis Z parallel to the axis of the spindle on a slide. The slide is mounted so that it slides according to a horizontal direction X orthogonal to the axis of the spindle beneath a cross member. The cross member moves vertically between the two uprights of a fixed portal frame.

Abstract: A hand tool apparatus uses a cutting tool with a first width and a tool axis to machine a hole in an object. The hole has a second width at least as large as the first width of the cutting tool. The apparatus includes a housing, a spindle unit in the housing for rotating the cutting tool and an orbital drive for rotating the spindle unit. An axial feed mechanism moves the orbital drive and the spindle unit jointly either toward or away from the object being machined.

Abstract: A portable multi-axis drilling machine includes a drill mounted between a pair of 2-axis positioning devices each of which translates along X and Y axes. The positioning devices are spaced apart along a Z axis of the machine and are mounted in a frame that has a workpiece-engaging side provided with a pair of index cylinders that receive spherical tool balls mounted on the workpiece surface so as to fix the position and orientation of the machine relative to the workpiece. The frame also has swiveling feet on the workpiece-engaging side that pivot as needed to accommodate complex contoured workpiece surfaces. Rotational movement of the drill is effected by differentially translating the two positioners, and translational X and Y movements are effected by synchronously translating the positioners.

Abstract: A hand tool apparatus uses a cutting tool with a first width and a tool axis to machine a hole in an object. The hole has a second width at least as large as the first width of the cutting tool. The tool axis passes through a predetermined point on a surface of the object. The apparatus includes an actuating assembly including a housing. The housing contains an axial feed mechanism configured for moving the cutting tool in an axial direction, a spindle motor configured for rotating the cutting tool about the tool axis, and a radial offset mechanism. The radial offset mechanism is configured for moving the axial feed mechanism in a radial direction such that the tool axis is offset from a principal axis. A motor is configured for rotating said axial feed mechanism and the cutting tool about the principal axis.

Abstract: A method for lengthening the machining travel of a machine-tool operating at a very high speed, including a tool-carrying ram mobile on three axes. The method combines with the machining movements of the tool-carrying ram along one or several axes, one or several rectilinear movements of the part to be machined by parametering and digitising the relative travels and speeds of the part to be machined with respect to the tool-carrying ram. The invention also concerns the device for implementing this method and the machine-tool using such a device.

Abstract: An apparatus for working on both sides of a flat workpiece includes a first support surface having a first axial line thereacross, a second support surface juxtaposed to and associated with the first support surface and having a second axial line thereacross which lies in a common plane with the first axial line, and a first carrying assembly operably connected to the first support surface in a manner to movably reciprocate along the first axial line and having a first extending arm which is laterally displaced from one side of the common plane and a second extending arm which is laterally displaced from another side of the common plane. A second carrying assembly is operably connected to the second support surface in a manner to movably reciprocate along the second axial line, wherein the second carrying assembly includes a workpiece removably mounted in a manner to position the workpiece in the common plane between the arms such that the arms extend about the workpiece.

Abstract: A machine tool for the cutting process of work pieces and having at least one horizontally lodged work spindle, preferably for high speed and/or high precision processing. The work spindle displaces on and/or inside a frame-like tool carrier vertically placed on a machine support having slides moving along x-, y- and z-axes. According to the invention, the frame-like tool carrier (3) has an associated frame-like work piece holder (2), which is also placed vertically on the machine support (1). The work piece holder (2) and the tool carrier (3) are interconnected as one single stable unit by one or several connecting elements (8) in the area of their upper horizontal traverse (4, 6).

Abstract: A machine tool is structured enhance rigidity of a slide member opposing to a cutting force acting on a tool spindle with no extra increase in weight, thereby intending to lighten the slide member. The machine tool comprises a tool spindle rotating around an axis extending along an Z-axis, a slide member slidable in at least one of the X-axis, Y-axis and Z-axis directions and a guide apparatus having a straight rail and movably supporting the slide member on the guide rail and disposed such that three supporting points for supporting the slide member form vertexes of a triangle as seen from the X-axis direction. Further, in another construction, two sets of linear guide mechanism and a linear motor for guiding each of an upper portion and a lower portion of a gantry are respectively disposed between a lower surface of the gantry and a base, and between a front surface of a cross beam and an upper back surface of the gantry, so that the cross beam does not lap over the upper surface of the gantry.

Abstract: A profile processing method and a processing machine therefor which can obtain a good finish surface accuracy in all the carving surfaces and curb the decrease in tool's life are provided.More specifically, an end mill is first moved along an outermost side of an annular groove in carving the annular groove to a work. Consequently, the end mill is gradually moved to inside to be moved and carve along the annular groove. When the outermost side of the annular groove is carved, the movement path of the end mill is selected so that the outermost side is down-cut (counterclockwise in FIG. 5). When further inner side is carved, the movement path of the end mill is selected so that the direction of the relative movement path is opposite to the direction of the relative movement path when the outermost side is carved, in other words, the carved surfaces are down-cut by the end mill.

Abstract: A surface finishing method and a machine therefor, in which good finish accuracy can be obtained in all carving surfaces and deterioration of tool's life can be prevented. When a surface of a concave portion formed on a workpiece is carved, an end mill is first revolved along an outermost side of a slope, and is moved toward inside and revolved along a circumferential direction. When a surface of the slope is carved, a movement path of the end mill is selected so that the surface of the slope is down-cut. When a bottom is carved, the end mill is moved from inside to outside, in other words, the movement path is selected so that a surface of the bottom is down-cut.

Abstract: A logical structure of a frame of a machine tool enables displacements of a movable mechanism, such as a slide, along three axes X, Y, and Z. A first pair of parallel transverse horizontal guide rails is disposed in a vertical plane and enables horizontal displacements of the slide along the X axis. A second pair of parallel lateral vertical guide rails is disposed in the same vertical plane and enables vertical displacements of the slide along the Y axis which is perpendicular to the X axis. A third pair of parallel longitudinal horizontal guide rails is disposed in a horizontal plane and enables horizontal displacements of the slide along the Z axis which is perpendicular to both the X and Y axes. A front portion of the slide is unencumbered by drive mechanisms and passes through a telescopic cowling which follows movements of the slide and separates a drive station from a machining station.

Abstract: A spindle supporting box structure, wherein longitudinal parts forming both ends of lateral parts at each of right and left longitudinal side faces facing, with a spindle therebetween, in a direction almost perpendicular to longitudinal side faces facing in a front-back direction are formed by longitudinal tubular members having suitable flexural rigidity. A damping structure wherein required frameworks of structures are formed by tubular members and wherein concrete is filled in the tubular members and then solidified. As an alternative, a powdery damping material or a jelly damping material is airtightly sealed in the tubular members. An inner space of one or more of the tubular members is made into a gas pressurized tank wherein a balance cylinder is connected to the gas pressurized tank and wherein the gas in the gas pressurized tank directly acts on a cylinder chamber of the balance cylinder.

Abstract: There is provided a method of three-dimensionally cutting a mold including the steps, in sequence, of (a) rotating a single ball end mill at a rate in the range of 50,000 rpm to 200,000 rpm, the ball end mill being made of material having high thermal resistance, (b) driving the ball end mill in horizontal, reciprocating movement at a rate in the range of 10 m/min to 100 m/min, and driving the ball end mill in transverse movement at a predetermined depth of cut in a direction perpendicular to a direction in which the ball end mill is reciprocated, at opposite ends of the reciprocating movement to cut a workpiece in a surface thereof at a common depth of cut, and (c) vertically feeding the ball end mill at a predetermined depth of cut. This method makes it possible to significantly increase a rotation speed and a feeding speed of a cutting tool to thereby remarkably reduce time necessary for cutting a mold.