Abstract: A tool adapter with a collar and a plurality of socket adapters is provided. The device includes an elongated shaft having an attaching end and a working end. A spring partially encircles the elongated shaft and is coupled to a collar. The spring biases the collar towards the working end of the elongated shaft. The collar is slidable along the elongated shaft. The collar partially encases a pivoting connector. The plurality of socket adapters is disposed on the pivoting connector. One or more removable locking pins secures the collar in position over the pivoting connector. A pair of parallel arms are disposed on opposing sides of the working end. The pivoting connector may freely rotate between a pair of parallel arms at a connecting point when the collar is slid towards the attaching end.

Abstract: A clamping device has a main body with a bore that extends from a back to a front end thereof. The bore has a fastening area proximate the back end, a front-end axial abutment surface and a central axial abutment surface. A centering sleeve is disposed in the bore and extends axially between a centering sleeve first and second axial end. A guide sleeve is disposed in the bore and partially in the centering sleeve. The guide sleeve extends axially between a guide sleeve first and second axial end. A locking member is removably disposed in the fastening area, has a tapered abutment surface and faces the front end. The centering sleeve is axially retained by and between the tapered abutment surface and the central axial abutment surface. The guide sleeve is axially retained by the tapered abutment surface and the central axial abutment surface.

Abstract: A cutter holder has a body and a retention knob connected to the body by threading. The body has a connecting hole having an internal threaded segment and a straight segment. The retention knob has a head, an abutting portion, and an external threaded portion. The abutting portion has a flange and an extending portion. The extending portion and the straight segment are in a clearance fit, and a sealing member seals the clearance between the extending portion and the straight segment. The external threaded portion is engaged with the internal threaded segment by threading, and has a first threaded segment and a second threaded segment. The first threaded segment is away from the head of the retention knob, and a tolerance class of the second threaded segment is higher than a tolerance class of the first threaded segment.

Abstract: A machine tool system includes a machine tool main body for machining a workpiece supported on a table by using a tool detachably attached to a spindle, and an information processing apparatus. The machine tool main body includes a rotary tool magazine in which multiple grips each capable of holding the tool to be attached to the spindle are provided along the circumferential direction, and an image pickup device that is arranged in the tool magazine and configured to take an image of multiple members in a machining area of the machine tool main body. The information processing apparatus includes a geometric feature calculating unit configured to calculate the shapes and the arrangement state of the multiple members in the machining area, based on image data of the image taken by the image pickup device.

Abstract: There are provided a cylindrical portion in which a passage for feeding/discharging working fluid to/from a fluid pressure chamber is formed and which is disposed inside a driven-side rotary body, a bolt member that connects the driven-side rotary body to a cam shaft, a valve body body for regulating a flow direction of the working fluid relative to the fluid pressure chamber and a valve accommodating body that accommodates the valve body, the valve body and the valve accommodating body being disposed inside the cylindrical portion, and an urging portion provided on at least one of an upstream side and a downstream side of the valve accommodating body and configured to generate a repulsive force between an other object that regulates a position of the valve accommodating body and the valve accommodating body.

Abstract: A drill guide for drilling bone comprising a housing having a bore running through the housing is disclosed. In one embodiment, the drill guide may comprise a locking member coupled to the housing that is adapted to engage with a locking portion of a drill bit to lock the drill bit axially within the housing. The locking member may also be adapted to disengage with the drill bit to allow the drill bit to move within the bore of the housing and be inserted into bone. A movable guide may also be provided with the drill guide, such movable guide including a bore for receiving a portion of the drill bit and allowing the same to move axially within the housing. Methods of using the aforementioned drill guide are also disclosed.

Abstract: A retention knob for use with a tool holder that is less prone to distorting a tapered tool holder surface, especially if it is over-tightened. The retention knob includes a knob head, a flange engageable with an end of a tool holder shank, a pilot segment receivable by the counter bore defined by said tool holder shank and a threaded segment spaced from said flange by an undercut segment. The threaded segment is configured so that it has a length that is substantially the minimum length required to achieve maximum thread holding strength. The undercut segment is configured to space the threaded segment from its head so that a distal end of the threaded segment is substantially near the bottom of the tapered bore forming part of the tool holder.

Abstract: A hand-held tool protection device includes a handle sized and configured to be grasped by an operator. A neck portion extends outwardly from the handle in a direction of a elongated axis of the handle. A swivel assembly is connected to the neck portion. The swivel assembly includes a body having a top, a bottom and a sidewall. The body is connected to the neck portion at the sidewall of the body. An opening extends through the body and intersects the top and the bottom of the body. A pivotable rod member is slidably and pivotably received in the opening extending through the body to provide a pivot axis. A tool element holding assembly is connected to the pivotable rod member such that the tool element holding assembly pivots therewith about the pivot axis. The tool element holding assembly includes a support assembly configured for receiving a tool such that the tool may be rotated about a tool rotation axis.

Abstract: Device for deployment of alternate tool heads having a tool bar, bias element, tool bar case, tool bar case removable cap, and tool bar locking pin.

Abstract: A fastener installation tool including a guide that guides a fastener into a side of a work piece at an angle, while optionally restraining the fastener from wobbling due to rotation, even upon initial entry into the work piece. The guide can define an angled bore including a fastener entrance opening and a fastener exit opening which is adapted to be positioned immediately adjacent the work piece. The guide can include a material ejection port between the openings, through which material bored from the work piece can be evacuated from the angled bore to prevent binding of the material with the fastener. The tool can include a clamp assembly that clamps opposing sides of the work piece to precisely align and steadily hold the angled bore as a fastener is being installed in a side surface. Related methods of using the tool to install fasteners also are provided.

Abstract: Apparatus and methods are provided to remove biopsy specimens from a bone and/or associated bone marrow using a powered drive and an intraosseous (IO) needle set. The powered driver may rotate the IO needle set at an optimum speed to obtain a biopsy sample of bone and/or bone marrow. Apparatus and methods may also be provided for aspiration of bone marrow and/or stem cell transplant procedures. The apparatus may include a powered driver, a coupler assembly, a containment bag or sterile sleeve and various IO needles and IO needle sets with associated hubs and/or hub assemblies. Each IO needle set may include a cannula or catheter and an associated trocar stylet with respective tips operable to penetrate a bone and/or bone marrow with minimum trauma to a patient. Each hub assembly may be used to releasably dispose a respective stylet within an associated generally hollow cannula. Some coupler assemblies and/or hub assemblies may also be used with manual drivers.

Abstract: In a machine tool, a support member to which a headstock is mounted movably in an upward-downward direction is movable so as to change a position thereof in a horizontal direction relative to that of a bed. A guide member is provided on the bed and configured to guide the support member. An engageable portion at which the support member is supported by the guide member is located in the support member at a level within a range of upward-downward movement of the headstock along the support member.

Abstract: Composite compositions and machine and contact tools, for example, metal boring tools and face mills that are manufactured from them. The tools are provided with composite structure to lighten the tools and yet retain the strength and durability of the tool. The novelty resides in the use of additives to certain composites that make up a portion of the tool, especially tool bars.

Abstract: The invention relates to a tool holder with a tool holding fixture, in particular a clamping chuck such as a contracting chuck, a draw-in collect chuck, a hydraulic expanding chuck and a high-precision chuck, and a shank of a tool, in particular a rotary tool, accommodated in it, wherein the tool holder contains a means for preventing the tool from being pulled out, locking it against axial displacement. This pull-out preventing unit comprises at least one locking element and at least one locking groove, which corresponds to the said locking element, receives it and interacts with it in a positively locking manner. In this case, both the locking element and the locking groove are formed at least partly in the manner of a ball head. Preferably, the tool has the locking grooves.

Abstract: A fixture is used to mount an angled machine head on a machine tool. The fixture includes a base adapted to be mounted on the machine tool, and a collar for holding the angled machine head. The collar is mounted for rotation on the base and allows the angled machine head to be rotated to any of a plurality of rotational positions. The collar may be selectively locked to the base to fix the position of the angled machine head.

Abstract: For balancing a tool coupling, the compensating measures (removal of material, use of other material) are carried out in two planes an axial distance apart. Tool couplings are provided with recesses for imbalance compensation in two planes an axial distance apart.

Abstract: A mechanical assembly for a power tool, and a power tool incorporating the mechanical assembly are provided. The mechanical assembly includes (i) a first member having a first axis and a first engagement portion inclined relative to the first axis, (ii) a second member having a second axis and a second engagement portion inclined relative to the second axis, wherein the first and second engagement portions engage each other by movement of the first and second members relative to each other in the direction of at least one of the axes; and wherein the first member is a ring gear and the second member is a central gear and the first and second engagement portions engage and disengage each other by movement of the second member within a space defined within the first member.

Abstract: A cutting tool has at least one cutting tool support pad. The cutting tool support pad includes two opposing primary surfaces, each primary surface includes an abutment surface and at least one convex contact surface. For each primary surface, the at least one contact surface extends outwardly further than the abutment surface.

Abstract: A tool adapter includes a holder structured to be attached to a machine tool and a tool receiver structured to receive a portion of a rotary cutting tool therein. The tool receiver being mounted in the holder so as to be rotatable to a limited extent. The tool receiver being mounted in the holder so as to be elastically resilient in the axial direction.

Abstract: A multi-functional cutting tool has a first cutting head, a second cutting head positioned opposite to the first cutting head, a shank formed between the first cutting head and the second cutting head, and a chip discharge portion extending from the first cutting head to the second cutting head by way of the shank. The first cutting head has 180 degrees rotational symmetry with the second cutting head about an axis, which passes through the longitudinal center of the cutting tool and is perpendicular to the central axis of the cutting tool. The chip discharge portion comprises a helical portion formed helically with respect to the central axis of the cutting tool such that the chip discharge portion is not positioned on the portion, where a tool holder clamps the cutting tool and a cutting load is concentrated during the cutting process.

Abstract: Drill stand (1) including a base plate (2), a carriage (3) arranged to be able to carry a drill motor and a drill column (4) which is pivotally mounted to a front part (5) of the base plate. The drill column is supported by a back support (7) located in a longitudinal direction rear of the drill column and is pivotally mounted to a back part (8) of the base plate, and a back side of the drill column facing the back support (7) is arranged as a track (10) having lateral wings (11, 11?), a right side wing (11) and a left side wing (11?). A clamping arrangement fastened to both of the back support and the track (10) enabling them to be fixed to each other in different positions along the track by clamping.

Abstract: It is an object of the invention to provide a tap holder in which even when an error is brought about in synchronizing spindle feeding and rotation of a tapper body and a tap collet of a tap holder in correspondence with a machine tool spindle, the synchronization can be established by absorbing the error by a simple constitution. As means therefor, the tap holder is characterized in that a tapper body and a tap collet are inserted by a locking member at portions of the tapper body and the tap collet overlapping each other, and the tap collet is fixed to the tapper body by engaging the locking member with at least one of the tap collet and the tapper body in a state of being interposed with an elastic member on both sides thereof in an axial direction X.

Abstract: Material removal tool (100), such as for forming surfaces of valve seats, includes an integral or separable reduced diameter circumferential insert housing (106) including a plurality of inserts (120) bonded thereto. The plurality of inserts (120) include cutting surfaces (122) at different axial and radial positions relative to the axis (112) of the material removal tool (100). Cutting surfaces (122) at different axial and radial positions are arranged at different angles to the axis (112), and at least one cutting surface (122) on at least one insert is at an angle of about 45 degrees relative to the axis (112). Cutting surfaces (122) can be located on one insert-type or different insert-types and can have different combinations of cutting surfaces (122). When arranged circumferentially on the insert housing (106), a N-effective material removal tool (100) is formed. Methods of machining using the N-effective material removal tool (100) is also disclosed.

Abstract: An adapter for operating a keyhole saw (10) on a driving machine includes a driving section (17; 117) for absorbing torque and a threaded section (18; 118) screwed into a threaded hole (20) in the keyhole saw (10). A driving segment (16; 116) is offset radially relative to the adapter axis and is inserted in a form-fit manner into a receiving hole (21) present in the keyhole saw (10). The driving segment (16; 116) is located in an axially extending manner on the end of a driving element (12; 112) which includes the driving element section (17; 117). The threaded section (17; 117) is formed on a threaded mandrel (13; 113) which is situated in the driving element (12; 112) and is non-detachably connected thereto. The threaded mandrel (13; 113) is held in the driving element (12; 112) in a rotatable manner to be axially displaceable to a limited extent.

Abstract: A holder for a cutting tool includes a body having a first channel for receiving a stem portion of the cutting tool. The body has a second channel intersecting with the first channel. The holder further includes a plunger to be inserted in the second channel, the plunger having a third channel the cross section of which at least partly overlaps with the cross section of the first channel when the plunger is inserted into the body so as to enable the stem of the cutting tool to extend into the third channel when the stem is inserted in the first channel. The holder further includes a mechanism for locking the stem against movement relative to the body by means of the plunger. A cutting tool for use in such a holder and a cutting insert are also provided.

Abstract: A power tool combination includes a power driving device having a chuck device attached to a barrel for engaging with a driven tool member, a control ferrule engaged onto the barrel, and a non-circular member, and a tool device includes a housing having a bore for receiving the driven tool member, and having a compartment for receiving the barrel, and having a non-circular engaging member for engaging with the non-circular member and for allowing the housing to be rotated by the power driving device. The tool device includes a tool element attached to the housing, and a securing device for detachably attaching the tool element to the housing.

Abstract: A universal drill stand for supporting a hand-held drill in an elevated and inverted position for drilling holes or inserting fasteners into a concrete ceiling or other overhead surface. The universal drill stand is extendable for use with varying ceiling heights. It eliminates the need for a worker to construct scaffolding or ascend a ladder or other elevating device to drill each hole, allowing the worker to remain safely on the floor and away from dust and debris associated with the drilling.

Abstract: Described is a quick-change arbor for a tool, in particular a hole saw (2), the arbor comprising a longitudinal body (3) having a drive end and a tool end, means (6) for attaching the tool which are provided with a central hole allowing a sliding of the attachment means (6) over the longitudinal body (3), and means for rotationally and axially locking the attachment means (6) to the longitudinal body (3). The attachment means (6) are slidably releasable from the longitudinal body (3), and can after applying a latch (9-1) in the attachment means (6) simply be slid over the body in order to push a plug of the sawn material out of the hole saw (2).

Abstract: A cutting insert for a drill of the present invention comprises an upper face having a first side and a second side respectively disposed on both sides of a first corner portion, a bottom face corresponding to the upper face, and a side face located between the upper face and the bottom face. The insert has a first cutting edge formed along the first side, and a second cutting edge formed along the second side. The side face has a first region corresponding to the first cutting edge, a second region corresponding to the second cutting edge, and a third region corresponding to the first corner portion. The third region has an upper region which is adjacent to the first corner portion and disposed toward the upper face, and a lower region located below the upper region. An inclination angle ?3 of the lower region to the bottom face is larger than each of an inclination angle ?1 of the first region to the bottom face and an inclination angle ?2 of the second region to the bottom face.

Abstract: A detachable operating handle for an elongated handheld portable power tool with a nose portion having an output shaft and a slidable operating switch having an outer recess and being configured to slide between on and off positions, the handle comprising a housing configured to cooperatively mate with the power tool housing and be attached at least to the nose portion of the power tool, the housing having an elongated handle portion, a trigger located in the bottom of the handle portion positioned to be moved between depressed and rest positions by a user's finger while holding the handle portion, a linkage mechanism for interconnecting the trigger and the switch, and the linkage mechanism having a lockout mechanism for preventing the trigger from moving the switch when the lockout mechanism is in a locked position and permitting the trigger to move the switch when in a release position.

Abstract: An exemplary embodiment of a material removal tool has a housing at a mating end, an extension longitudinally extending from the housing to a distal end, a plurality of spacers arranged along the extension, and a nut at the distal end of the extension, wherein the plurality of spacers are formed from a material having a Young's modulus of greater than about 1.5 times that of steel. The spacers along the extension of the tool place the stiffer material of the spacer at a location of greatest resistance to bending moments (i.e. highest sectional modulus). Optionally preloading and “built-in” relief points contribute to improved performance of the material removal tool. A method of manufacturing a material removal tool and a method of machining a workpiece are also disclosed.

Abstract: Disclosed is a tap driver for rigid tapping, which includes predetermined tension and compression factors to self-synchronize the tap driver. In the preferred embodiment, the tap driver includes helical coils imparted in the tap driver body which allow the attachment body to synchronize axially in response to a force of a predetermined magnitude imparted on the tap. An additional embodiment of this invention provides such a tap driver body wherein the body allows for lateral flexure and movement to compensate for feed error and location error.

Abstract: A smart tool holder is for use with a machine tool platform. The smart tool holder includes a body having a first end and an opposite second end, a processor disposed with the body, and a transceiver disposed with the body and in communication with the processor. The transceiver is structured to communicate with an external receiving device. The first end of the body is structured to be coupled to the machine tool platform and the opposite second end is structured to be selectively coupled to a cutting assembly having a number of sensors. The processor is structured to communicate with the number of sensors when the cutting assembly is coupled to the body. The processor may perform data analysis tasks using model based data analysis, digital filtering, and other techniques. The smart tool holder may suggest changes to the machining process based on two-way communication with a machine tool controller through a receiver or interface device.

Abstract: This invention relates to a tooling system comprising a plurality of elements (22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64) having tessellating sides arranged in an array. The elements of the array being movable between a closed position in which the elements contact one another, and an open position in which the elements of the array are spaced apart. In the open position the elements are capable of vertical movement relative to one another. Drive means for opening and closing the array are provided and the elements are mounted on supporting rails (2, 4, 6, 8, 10, 12, 14) and are driven by the drive means between the open position and the closed position along a drive axis which is at angle to the longitudinal axis of the supporting rails.

Abstract: Tool bars that are manufactured as a composite, that is, layered devices. The tool bars can have a solid core, covered with a wrapped composite material, and then optionally covered with a metal sleeve. The tool bars are provided with high strength, improved stiffness over prior art tool bars, high density, low coefficient of thermal expansion, high damping capacity, improved rigidity, improved damping, less chatter and vibration, improved work piece tolerance, improved surface finish, increased speed/fee rates, and low production cost.

Abstract: A drive motor for driving a tool such as a grinding tool through a right angle drive has a rotatable head mounted on the housing and having a detent on the rotatable head for engaging a fixed component of the angled drive coupling so as to hold the axis of the angled drive coupling at a required angle around the axis of the housing and for adjusting the angle without removal of the right angle drive from the motor. The rotatable head includes an annular disk which surrounds the axis of the motor and has a central hole through which the driven member extends into the chuck. The disk is driven by an adjustment motor having a sprocket which engages gear teeth on the exterior of the disk and has a series of holes through the disk member at angularly spaced locations around the axis so that a locking pin driven by a locking pin motor engages into a selected one of the holes to lock the head at the required angle when rotated to the required angle by the adjustment motor.

Abstract: A tool holder (1) has a shaft (2) intended to be arranged in a tool holder in a manufacturing machine, a head (3) on which a cutter is intended to be arranged and a viscoelastic materials (4) arranged so that the cutter is in contact with the manufacturing machine solely via the viscoelastic material (4), in which at least those parts on the surface (5) of the shaft (2) that are intended to be in contact with the manufacturing machine are provided with the viscoelastic material (4). The viscoelastic material (4) is attached on a bearer material that is attached to the surface (5) of the shaft (2).

Abstract: The present invention relates to a replaceable cutting tip and, more particularly, to such cutting tips attachable to the cutting tip holders by a threaded connection. The cutting tip for a cutting tool includes a working end portion disposed along an axis of the cutting tip and including one or more cutting edges for machining a workpiece, and a mounting portion disposed along the axis of the cutting tip. The mounting portion includes a frustoconical supporting surface tip portion and a frustoconical threaded portion. The present invention also relates to a cutting tool per se.

Abstract: A hand power tool has a striking element via which a tool (10) in a tool holder (12) can be driven in striking fashion, which the tool holder can be detachably secured—via its body (14)—to a drive part (16) via at least one locking element (18), which the locking element, in its engaged position, is capable of being fixed in position radially by a retaining element (20), which the retaining element is capable of being automatically guided by means of an operating element (22) out of its locked position into a release position that radially releases the locking element (18) in order to release the tool holder (12), whereby the retaining element (20) is capable of being moved by a corresponding component (14) into its release position against a spring force of a spring element (24) when the tool holder (12) is pushed onto the drive part (18), wherein the retaining element (20) is captively held on the drive part (16) and is capable of being guided into its release position by the operating element (22) in the p

Abstract: The present invention relates to a tool and a male part for chip removing machining. The tool includes a male part and a holder for the male part. The male part includes a radial and axial supporting and positioning portion and a threaded portion. A largest diameter of the externally threaded portion is smaller than a smallest diameter of the radially and axially supporting and positioning portion. A transition portion is disposed along the axis of the male part between a radially largest portion of the radially and axially supporting and positioning portion and the externally threaded portion.

Abstract: A boring tool for use in a tool holder, such as a boring head, that is driven about a drive axis and includes a pair of parallel bores for mounting boring tools generally includes a body including a cutting edge and a pair of mounting shanks for mounting in the bores of the tool holder. Preferably, the mounting shanks can be mounted in either bore and the cutting edge is disposed on the body so as to be different distances from the driven axis depending upon in which bores the mounting shanks are mounted.

Abstract: A flightless rock auger is used for drilling postholes through rock with the use of hydraulic pressure and at slow revolution per minute. The rock auger is used in combination with a conventional flighted auger used for drilling postholes in dirt and clay. During a posthole drilling operation, the rock auger is substituted for a conventional flighted auger as needed for drilling through and removing rock or other hard material such as concrete from the posthole. The rock auger is designed for use at very low revolutions per minute and can function utilizing only the weight of the auger; however, the rock auger is designed for use with pressure drilling units as well for cutting a circular hole through the rock and forming a plug which is to be lodged in the cavity of the rock auger cylinder to be removed from the posthole.

Abstract: A tool employs a connect-disconnect coupling for a power drill to hold a multi-functional bit having at its one end a drill element adapted to form a hole and a countersink and at its other end a driver element to drive a screw or other type of fastener.

Abstract: A portable boring and welding machine includes a tool shaft adapted to mount tools for boring and welding workpieces. The shaft extends along an axis and is driven by an electric motor. The motor and the shaft are connected by a helical gearwheel and worm pair, the helical gearwheel being connectable to the tool shaft, and the worm being connected to a drive shaft of the motor itself.

Abstract: The invention relates to a spindle (9) for a machine tool, having a housing (12) to accommodate an electric motor (11) and a shaft (13) driven by the latter and having a tool holder for a tool (10) for machining workpieces, at least one data acquisition element (2) being provided to record operating and/or state data of the spindle (9), and at least one spindle-integrated data storage element (1) being provided to store the recorded data from the data acquisition element (2).

Abstract: The present invention is to provide a machining tool bar in which mechanical machining properties are improved by using high stiffness composite material. According to the present invention, the tool bar includes an adaptor constructed to be coupled to a driving device, a body constructed to be mounted with cutting tools and a tip constructed to be supported by a workpiece, said body is constructed to be mounted with one or more cutting tools, wherein the adaptor and tip are made of metal material, the body is made of composite material having high stiffness, the composite material constructing the body is formed to surround at least a portion of the adaptor and at least a portion of the tip, and the metal material constructing the adaptor and tip and the composite material constructing the body are securely joined to each other in an interface therebetween.

Abstract: A hand power tool has a tool, a hammer tube, a striking mechanism with a striker and an anvil with an integrated receptacle for the tool which is strikingly drivable in the receptacle, a blocking element connecting the tool and the anvil in an axial direction, and a toothing that connects the anvil with the hammer tube displaceably in an axial direction.

Abstract: The tensioning mechanism (18) comprises a clamp bolt (28), arranged in a displaceable manner in a transverse bore (26) in the fitting plug (12) and two diametrically opposed retainers (34, 36) in the second component (14) which engage with an axially facing internal or external cone against a complementary internal or external cone on the clamp bolt (28) and, during tensioning, are tensioned with the same in a wedge fashion. According to the invention, the clamp bolt (28) comprises a frustum-shaped external cone (40), the base diameter of which is smaller than the diameter of the guide surface (62) thereof in the transverse bore (26).

Abstract: A reversible drill/driver tool includes an elongated socket having a bifurcated part defining a tool-receiving space to receive a two-ended tool that includes first and second driving bits and a rod having two opposite ends connected respectively to the first and second driving bits, and pivoted to the bifurcated part so as to be rotatable relative to the socket and so as to dispose a selected one of the first and second driving bits outwardly of the space. A positioning member is slidable on the socket to position the rod at a desired position.

Abstract: A tool, attachable to a spindle of a machine tool and capable of changing independently a rotational speed of a cutting tool from that of the spindle, provided with a cutting tool for machining a workpiece, an electric motor for driving the machining tool, a generator for generating electric power to drive the electric motor by the rotation of the spindle, a tool holding part for rotatably holding the cutting tool, a casing for holding the electric motor, the generator, the tool attachment part, and the tool holding part, and a locking part for preventing rotation of the casing by engagement with a non-rotating part of the machine tool. A tool includes an AC generator, an AC motor and a case holding the generator and motor such that the generator and the motor are arranged in the case along a center axis and a longitudinal direction of a rotatable portion of the generator.