Abstract: A device for clamping a workpiece has a receiving head in a housing connected to a rotary drive with a rigid drive connection between a drive motor and the receiving head, radially adjustable clamping jaws connected to a clamping drive externally clamping the workpiece, and linear drives displacing the clamping jaws and forming the clamping drive driven jointly by a gear transmission with a central gear coaxial to the drive shaft of the receiving head by a separate drive motor. The central gear can be driven synchronously with the receiving head in the clamping position of the clamping jaws, and the rotary drive for the central gear comprises a rigid drive connection between its drive motor and the central gear or a superimposed gear comprising two input shafts drive-connected to the drive motor for the rotary drive of the receiving head and to the drive motor for the central gear.

Abstract: A chuck device in which a rotary sleeve provided to a main body is rotated, and by rotation of an annular rotary body which rotates together with the rotary sleeve, jaws screwed together with the rotary body are expanded, contracted, advanced, and retracted, and a tool is gripped by the jaws; the chuck device comprising a retaining engaging body for engaging with the rotary body and preventing the rotary sleeve from coming out of the rotary body; wherein the retaining engaging body is provided to be fixed to a proximal end side of the rotary sleeve; a rotation transmission part for directly or indirectly transmitting the rotation of the rotary sleeve to the rotary body is provided to the retaining engaging body; and the rotation of the rotary sleeve is transmitted to the rotary body via the retaining engaging body, and the rotary body rotates together with the rotary sleeve.

Abstract: A clamping device for machine tools, the device provided with a power-operated chuck, an electrical drive motor, and a movement converter, with force accumulator. An output element is rotatably mounted on the output shaft of the drive motor, and is in driving connection with the movement converter. The output element is adapted to be connected to the output shaft by a servo device, and the movement converter can be interlocked with the spindle of the machine tool by a second servo device. It is thus possible to clamp or unclamp a workpiece. During working procedures, the drive motor is stopped. There is no need for elaborate control functions, rather the servo devices are actuated to make a driving connection between the drive motor and the movement converter, or to release this connection, and to block the movement converter during working procedures by means of its connection to the spindle of the machine tool.

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

Abstract: A hand tool machine includes a tool receiving device configured to receive an application tool. The tool receiving device is allocated a mechanically actuated locking element in order to lock the application tool in the tool receiving device. The hand tool machine also includes an electric actuator system configured to mechanically actuate the locking element.

Abstract: A clamping device for machine tools with a power-operated chuck, the clamping jaws of which are actuatable by the clamping device via a movement converter and draw rod. A drive motor is provided with a switching element which is adjustable by axial control in a middle and two limit positions, wherein the switching element is connectable to the clamping device in one limit position and, in the other limit position, to an adjustment element connectable to an auxiliary device. The switching element is lockable in the limit positions with a machine spindle. The clamping device is thereby provided with an increased range of applications, without functions being impaired, with little structural complexity, because the switching element makes possible a clamping element integrated in the power-operated chuck to be operated using the drive motor, such that further procedures can be undertaken without changing the clamping device.

Abstract: A bit retaining system for a rotary tool or device such as a router is disclosed. The bit retaining system may include a collet assembly and a control assembly. The collet assembly may include a spindle, a collet adapted to receive the bit, and a collet nut. The collet assembly may further include a collet gear mounted on the collet nut and/or a spindle gear mounted on the spindle. The control assembly selectively engages the collet assembly to drive the collet nut and/or secure the spindle in a fixed position, preventing its rotation. In operation, a hand tool is utilized to engage the control assembly. This configuration enables a user to capture and release the rotary tool bit using one hand.

Abstract: A rotary actuator comprises a rotatable chuck assembly and an actuating mechanism. The chuck assembly may include a chuck housing movable between retracted and deployed positions. The chuck assembly may further include a pair of jaws pivotable between open and closed positions in correspondence to the retracted and deployed positions of the chuck housing. The actuating mechanism may be coupled to the chuck assembly for rotation between “Off”, “Neutral”, and/or “On” positions.

Abstract: A chuck has a chuck body rotatable about an axis, a plurality of jaws radially displaceable on the body for gripping a workpiece, a chuck drive for rotating the chuck about the axis, and a center point axially shiftable in the body and axially engageable with the workpiece gripped by the jaws. An electric drive is coupled to the center point for axially shifting same.

Abstract: A chuck for clamping workpieces or tools in a clamping space with a clamping force (F). The chuck includes at least two chuck jaws movable in translation along one clamping plane (E) in the direction of and a gear train located at least largely within the chuck for transfer of a driving torque of a drive motor, which can be coupled to the gear train by coupling means of the gear train, to the chuck jaws for movement of the chuck jaws. The coupling means able to be coupled to a corresponding coupling connection of the drive motor. The movement from the maximum size of the clamping space to the minimum size of the clamping space is executed via the gear train from the drive motor.

Abstract: In a clamping device for machine tools, the device is provided with a power-operated chuck and clamping jaws actuated by a draw rod, the clamping device having an electrical servomotor with a changeover function, a movement converter, and a force accumulator for maintaining clamping force, the movement converter and the force accumulator being integrated in a tube-shaped jacket piece inserted in a housing of the clamping device and divided into two parts connected together. A spindle nut of the movement converter is rotatably supported between the two parts by a projection, and spring packs of the force accumulator are clamped between stop rings and a cover on the jacket piece. The jacket piece is mounted within the housing as to be moved axially by the draw rod via the movement converter. It is possible to determine the clamping force prevailing in the power-operated chuck using only one measuring point.

Abstract: The invention refers to a machine tool for the machining of one or more work pieces, wherein the work piece is held indirectly or directly by a clamping device in the machine tool on or at a non-rotary work piece table or a work piece table rotating around at least one axis. The invention is characterized in that the clamping device comprises at least one clamping element interacting indirectly or directly with the work piece, and an electric motor is provided for generating the clamping power that is in operative connection with the clamping element.

Abstract: In a power driver, a power take off (PTO) arrangement (to open/close a chuck) includes: a chuck actuating shaft and a coaxial PTO actuator shaft axially displaceable along, yet rotationally locked together about, a first axis of the power driver; an input shaft, supporting jaws of the chuck, and concentric to at least a portion of the chuck actuating shaft and a portion of the PTO actuator shaft; relative rotation between the chuck actuating shaft and the input shaft selectively being prevented and being caused by first and second configurations of the chuck actuating shaft and the PTO actuator shaft, respectively; and a PTO-control member, displaceable between first and second positions along a second axis parallel to the first axis, and coupled to adjust at least one of the chuck actuating shaft and the PTO actuator to achieve the first and second configurations, respectively.

Abstract: The invention relates to a method for operating an actuation device (20), which is used to clamp and loosen a clamping device which comprises a tie bolt which can be adjusted in an axial manner in a machine spindle (3), for actuating a clamping head (6) which co-operates with clamping claws (5). Initially, force is exerted upon the tie bolt (4) by means of an actuation device (20) which is used to clamp in an axial clamping direction, until the axial length thereof is fixed in relation to the machine spindle (3) by means of self-locking. According to the invention, after self-locking is obtained, the effect of the force in the direction of clamping of the actuation element (20) on the tie bolt is stopped and remains blocked while the clamping device is being used, and to release clamping, the tie bolt (4) is displaced by the actuation device (20) in the direction of release which is counter to the clamping direction. The invention relates to a device for carrying out said method.

Abstract: In a robotic tool coupler, a rotating cam member having a plurality of surfaces formed therein urges a plurality of ball members in one tool coupling unit radially to contact an angled surface in the other tool coupling unit. Further rotation of the cam member exerts a radial force through the ball members onto the angled surface. A component of that force is directed by the angled surface toward the opposite tool coupling unit, locking the two units together. The cam member may include a failsafe surface and/or a failsafe lobe to maintain the two units locked together in the event of a loss of power to positively actuate the cam member.

Abstract: A detection circuit is provided for a power supply for an electrostatic chuck generating a trapezoidal waveform with approximately flat tops and minimal dead-time between phase reversals. The detection circuit includes an amplifying circuit which receives inputs from a secondary winding of a transformer of the power supply and produces an amplified buffered signal. A chucking detect circuit receives the signal from the amplifying circuit and is configured to produce a first signal indicative of a substrate on the electrostatic chuck and a second signal indicative of an electrostatic chuck without a substrate. A chucking quality circuit receives the signal from the amplifying circuit and produces a signal indicative of a quality of the chucking of the substrate. A movement detection circuit receives the signal from the amplifying circuit and produces a signal indicative of movement of the substrate on the electrostatic chuck.

Abstract: A power tool having a housing, an electric motor disposed in the housing, and a spindle drivingly attached to the electric motor. The spindle includes a cavity adapted for receiving a bit therein and a window extending through the spindle in communication with the cavity. The power tool further has a retention device including a bit engaging member disposed within the housing and operable to extend through the window and retain a bit within the cavity. The power tool still further has an actuator operable by a user externally of the housing to disengage the bit engaging member from a bit received in the cavity and, finally, a mechanical interconnection system operably coupled between the actuator and the retention device to actuate the retention device in response to the actuator, wherein the mechanical interconnection is disposed within the housing.

Abstract: A robotic tool changer comprises first and second units, operative to be separately attached to a robot and a robotic tool, and further operative to be selectively coupled together and decoupled. The first and second units are coupled and decoupled by an electric motor. Power from the electric motor may be applied to couple and decouple the first and second units in a variety of ways.

Abstract: A pair of gripping sections performs opening and closing operations along a base member through displacement of a piston by means of a pressure fluid supplied to a chuck body. A pair of fingers, which constitute the gripping sections, is openable and closable in directions perpendicular to opening/closing directions of the gripping sections, by means of a driving force supplied from a driving section. The gripping sections are positioned with respect to a workpiece by actuating the pair of fingers to perform the opening/closing operation. Thereafter, by supplying the pressure fluid, the workpiece is gripped at a desired gripping position by means of the gripping sections.

Abstract: A tool chuck may include a chuck body defining a longitudinal axis. A sleeve may be mounted on the chuck body for movement between a first axial position and a second axial position. A clutch part provided on the sleeve. The clutch part may engage with a cooperating clutch part when the sleeve is in the second axial position. The clutch part may have a working surface that faces in a direction perpendicular to the longitudinal axis.

Abstract: A work holder assembly for use in clamping a workpiece being machined. A chuck includes a fixed sleeve about which is mounted a rotatable collet. A plurality of individual clamps extend from circumferential spaced locations associated with the collet. The clamps each include a first spring biased and linear traveling component actuating a second radially traveling and adjustable component into engagement with annular disposed locations of the workpiece. Each the clamps exhibits a wedge shape at an interface between the linear and radial components, both in order to minimize clamping forces and to prevent backdriving of the clamps by the tooling. A fluid pressure extends through a location in the chuck, the collet further having a fluid delivery component in communication with the fluid supply and which is in contact with workpiece engaging locations, to overcome the spring bias of said pin in a fluid actuated release condition.

Abstract: A clamping device for machine tools is provided with a chuck, the clamping jaws of which are actuated by a draw rod, the clamping device having of a servomotor, a movement converter and a force accumulator, the servomotor is connectable to the movement converter for triggering clamping movements. The movement converter and the force accumulator are disposed in a housing connectable to the machine spindle, and in clamping position of the clamping device, the sliding sleeve can be decoupled from the servomotor, and the housing can be connected to the movement converter by means of the sliding sleeve. The servomotor is operated only to clamp and unclamp a workpiece, and is in a driving connection with the clamping device in operating conditions. All components of the clamping device involved in power transmission are in driving connection with the machine spindle during the machining of the workpiece.

Abstract: A rotary actuator comprises a rotatable chuck assembly and an actuating mechanism. The chuck assembly may include a chuck housing movable between retracted and deployed positions. The chuck assembly may further include a pair of jaws pivotable between open and closed positions in correspondence to the retracted and deployed positions of the chuck housing. The actuating mechanism may be coupled to the chuck assembly for rotation between “Off”, “Neutral”, and/or “On” positions.

Abstract: A power supply is provided for an electrostatic chuck. A signal generating circuit of the power supply is configured to generate a square wave signal. An amplifying circuit is electrically connected to the square wave circuit and configured to amplify the square wave signal. A transformer has a primary and a secondary winding. The primary winding is electrically connected to the amplifying circuit and the secondary winding is configured to be electrically connected to the electrostatic chuck. The secondary winding produces a signal for the electrostatic chuck. A voltage divider circuit is electrically connected to the secondary winding and to the amplifying circuit. The voltage divider circuit is configured to reduce the voltage of the signal for the electrostatic chuck and feed back the reduced voltage signal to the amplifying circuit. The signal from the secondary winding is a trapezoidal waveform with approximately flat tops and minimal dead-time between phase reversals.

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

Abstract: A rotatable chuck for securing a workpiece in a machine includes a base element having a center and a plurality of jaw elements movable relative to the center. The jaw elements are movable to clamp the workpiece. The jaw elements exert a measurable clamping force on the workpiece. The clamping force exerted on the workpiece is measured and the jaw elements are moved relative to the center to vary the clamping force exerted on the workpiece. A comparator compares the measured clamping force to a predetermined clamping force and the jaw elements are moved, as the chuck is rotating, to adjust the clamping force on the workpiece relative to the predetermined clamping force.

Abstract: A power tool, which includes a handle portion and a housing; a chuck disposed in front of the housing, and the chuck that is selectively operated in one of a working mode and a chucking mode. The power tool further includes a driving device which drives the chuck to axially move between a first position and a second position.

Abstract: Substrate support apparatus and methods are disclosed. Motion of a substrate chuck relative to a stage mirror may be dynamically compensated by sensing a displacement of the substrate chuck relative to the stage mirror and coupling a signal proportional to the displacement in one or more feedback loops with Z stage actuators and/or XY stage actuators coupled to the stage mirror. Alternatively, a substrate support apparatus may include a Z stage plate a stage mirror, one or more actuators attached to the Z stage plate, and a substrate chuck mounted to the stage mirror with constraints on six degrees of freedom of movement of the substrate chuck. The actuators impart movement to the Z stage in a Z direction as the Z stage plate is scanned in a plane perpendicular to the Z direction. The actuators may include force flexures having a base portion attached to the Z stage plate and a cantilever portion extending in a lateral direction from the base portion.

Abstract: A clamping device comprising clamping jaws actuated by means of an axially adjustable draw rod, the clamping device comprising a servomotor with a changeover function, a driveline arranged between the servomotor and the draw rod as well as a bell in a rotating mounting that is coupled to the servomotor, the driveline configured as a two-piece gear train, the first piece arranged in a housing permanently connected to a rotor shaft of the servomotor. An input element and output element of the gear train being connected to the bell by the second gear train. A starter of the servomotor can be arranged in a fixed position and the rotor of the servomotor held stationary when a workpiece is clamped. The servomotor maintains a selected clamping force if the electrical power fails, and the clamping device is automatically secured.

Abstract: A bit retaining system for a rotary tool or device such as a router is disclosed. The bit retaining system may include a collet assembly and a control assembly. The collet assembly may include a spindle, a collet adapted to receive the bit, and a collet nut. The collet assembly may further include a collet gear mounted on the collet nut and/or a spindle gear mounted on the spindle. The control assembly selectively engages the collet assembly to drive the collet nut and/or secure the spindle in a fixed position, preventing its rotation. In operation, a hand tool is utilized to engage the control assembly. This configuration enables a user to capture and release the rotary tool bit using one hand.

Abstract: A tool chuck may include a shaft supporting chuck jaws. The shaft may provide a first transmission power path for rotationally driving the chuck jaws. The shaft may have a through hole. A chuck actuating mechanism may be provided in the through hole. The chuck actuating mechanism may provide a second transmission power path for opening and closing the chuck jaws.

Abstract: An electrically-operated chuck opening-closing device includes a chuck that grasps workpiece, a conversion device with a control gear provided to the outer circumference, a drawbar that couples the conversion device and the chuck, a transmission gear provided to a main spindle, a second rotary shaft rotatably pivoted to be parallel to the main spindle, a first gear and a second gear rotatably provided on the second rotary shaft, an auxiliary motor that drives the first gear, a first clutch that can couple and decouple the auxiliary motor and the second rotary shaft, and a second clutch that can couple and decouple the second rotary shaft and the second gear.

Abstract: A tool chuck may include a chuck body defining a longitudinal axis. A sleeve may be mounted on the chuck body and axially fixed relative to the chuck body. A clutch part may be provided on the sleeve. The clutch part may interact with a cooperating clutch part mounted on the power driver housing. The cooperating clutch part may be mounted on the power driver housing for movement between a first axial position in which the chuck body is rotatable together with the sleeve, and a second axial position in which the chuck body is rotatable relative to the sleeve to actuate the tool chuck. The chuck body may be rotatable in a first direction to actuate the tool chuck up to a first torque threshold, and rotatable in a second direction to actuate the tool chuck up to a second, different torque threshold.

Abstract: A drill is provided with a chuck that has an actuator device that is mounted to the housing of the drill and is spaced from the chuck so that a user can activate the chuck between a “chuck mode” and a “drill mode” from a switch mechanism that is mounted remotely from the chuck.

Abstract: A automated chuck is provided with at least three user selectable operating modes, thereby enabling different functions to be performed during tightening and loosening of the chuck. In one exemplary implementation, the different user selectable operating modes of the chuck may be used to actuate a motor direction switch of the drill.

Abstract: A chuck is provided with a body, a plurality of jaws and an adjustment ring. The adjustment ring is threadably engaged with the jaws. When the adjustment ring is rotated in one direction, the jaws tighten by moving closer to each other. When the adjustment ring is rotated in the opposite direction, the jaws loosen by moving away from each other. An impact member is also provided for engagement with the adjustment ring. When the drive shaft of the power tool is rotated, the adjustment ring impacts against the impact member. As a result, the adjustment ring and the body of the chuck rotate relative to each other causing the jaws of the chuck to loosen or tighten depending on the direction the drive shaft is rotating.

Abstract: A chuck is provided with a body, a plurality of jaws and an adjustment ring. The adjustment ring is threadably engaged with the jaws. When the adjustment ring is rotated in one direction, the jaws tighten by moving closer to each other. When the adjustment ring is rotated in the opposite direction, the jaws loosen by moving away from each other. An impact member is also provided for engagement with the adjustment ring. When the drive shaft of the power tool is rotated, the adjustment ring impacts against the impact member. As a result, the adjustment ring and the body of the chuck rotate relative to each other causing the jaws of the chuck to loosen or tighten depending on the direction the drive shaft is rotating.

Abstract: An electrically-operated chuck opening-closing device includes a chuck that grasps workpiece, a conversion device with a control gear provided to the outer circumference, a drawbar that couples the conversion device and the chuck, a transmission gear provided to a main spindle, a second rotary shaft rotatably pivoted to be parallel to the main spindle, a first gear and a second gear rotatably provided on the second rotary shaft, an auxiliary motor that drives the first gear, a first clutch that can couple and decouple the auxiliary motor and the second rotary shaft, and a second clutch that can couple and decouple the second rotary shaft and the second gear.

Abstract: A chuck actuator has a hollow housing having a chamber and having a front end and a rear end. A ring in the chamber forms with the front end thereof a front compartment and a piston in the chamber between the ring and the rear end forms an intermediate compartment with the ring and a rear compartment with the rear end. A stem on the piston projecting forward through the ring and through the intermediate and front compartments is adapted to engage and open a chuck and is formed with a region of enlarged diameter. The piston is shiftable between a rear position with the enlarged-diameter region offset rearward from the ring and with the stem forming with the ring an axially extending passage between the front and intermediate compartments and a front position with the enlarged-diameter portion fitting snugly in the ring and substantially closing the passage.

Abstract: A spindle of a machining center is equipped with a clutch, which is fitted to a main spindle housing, and directly connected to a power source for separable engagement with a shaft coupling sleeve, and which is guided by sloping guiding trenches of a clutch disk such that a pull rod of the spindle is actuated for a tool shank housing to be changed between a clamped position and a released one; thus, power of the power source can be usually provided to the spindle to effect rotation of the spindle for machining a work piece, and the clutch can be operated for allowing the pull rod to be directly actuated with power of the power source without hydraulic mechanisms.

Abstract: A force limiting workpiece holding device for holding a workpiece in a workpiece processing assembly having a spindle and a closer that applies a force, comprises a workpiece holder slidably mounted to the spindle. The workpiece holder includes a plurality of circumferentially-spaced gripping segments that are movable between expanded and contracted positions to grip and release a workpiece. A force limiting coupling structure includes a biasing structure having a spring force. The coupling structure is operatively mountable between the workpiece holder and the closer such that a force applied by the closer to move the gripping segments of the workpiece holder between the expanded and contracted positions is transferred to the workpiece holder through the coupling structure and the biasing structure thereof, whereby a resultant force being applied to the workpiece holder by the closer is limited to the spring force of the biasing structure.

Abstract: An electrically operated chucking apparatus including (a) an electrically operated chuck including at least two movable members movable toward and away from each other, and at least two drive devices which include respective electrically operated actuators operable to move the at least two movable members, respectively, toward and away from each other, and (b) a control device operable to control the at least two drive devices, and wherein the control device includes: a drive control portion operable to control the at least two drive devices such that each of at least one of an actual position and an actual speed of movement of the at least two movable members changes toward a predetermined target value; and a load detecting portion operable to detect a load acting on the at least two movable members during operation of the drive control portion to control the at least two drive device.

Abstract: A rotary assembly for use in processing a tubular member wherein the assembly comprises a gripping mechanism, that is moveable from an open position to a closed position. In the closed position the gripping mechanism engages at least a portion of the tubular member. The gripping mechanism is operatively engaged to a piston that is fluid actuatable from a first position to a second position by a fluid acting upon the piston, such that when the piston is in the first position the gripping mechanism is in the closed position and when the piston is in the second position the gripping mechanism is in the open position. The assembly defines a circuit through which the fluid is transmitted to the piston.

Abstract: A chuck apparatus including a chuck, and a power-driven device which selectively places the chuck in an object-hold state thereof in which the chuck holds an object, and an object-release state thereof in which the chuck releases the object, the power-driven device including, as a power source thereof, an electric motor.

Abstract: A chuck unit for automatic machine tools perform both power tasks and high speed finishing of pieces with lubricant/coolant fluid flowing through a chuck shaft. The chuck unit includes a support on which a first chuck for a tool is mounted and driven by a motor. A second chuck is mounted inside the first chuck and is driven by the same or a second independent motor. A set of springs acts against a shaft with an attached gripper, to close the gripper in order to clamp the tool. The unit can therefore receive different types of tools and perform different tasks, eliminating the need to use different machines for different tasks. The pull of the power tool on upstream mechanical parts is discharged against the support structure of the first chuck.

Abstract: An electrostatic chuck having a bonded structure comprising a ceramic electrostatic chuck member, a metal member and a bonding layer; the bonding layer having at least a first most outer bonding layer being joined to the ceramic electrostatic chuck member, a second most outer bonding layer being joined to the metal member, and a polyimide layer as an intermediate layer disposed between the first and second most outer bonding layers, and each of the most outer bonding layers being made of a silicone layer or an acrylic layer, and a method for manufacturing the same are provided: the bonding layer being excellent in airtightness, bonding strength, and corrosion resistance, free from bleeding of a bonding material even under high pressures at time of joining, and the junction body being good in heat conductivity, and having a good flatness of its adsorption surface, with a small deformation due to temperature change.

Abstract: A drilling or milling head, especially for printed circuit board milling machines and/or engraving machines, having a collet chuck (11) which can be actuated by a rapid change mechanism and which is driven by a transmission. The collet chuck is opened by an axial displacement relative to a clamping sleeve (50), with the force necessary for the displacement being transmitted via a friction clutch. The transmission includes a ball bearing (9) whose balls (12) are moved around a common axis in a concentric manner by a driving part (6) fixed on a motor drive shaft (5). In addition, the balls are mounted between two bearing surfaces (13, 14) which are aligned in a concentric manner with regard to the axis and which have a circular cross-section. The balls are at least partially engaged with the bearing surfaces in a positive manner.

Abstract: This invention relates to a chuck unit for automatic machine tools, designed to perform both power tasks and high-speed finishing of pieces, with lubricant/coolant fluid flowing through the chuck shaft, which includes:

Abstract: A drill or milling head (1), especially for printed circuit milling machines and engraving machines, including a collet chuck (27) which can be actuated by a rapid change mechanism. The drill or milling head includes a drive shaft which can be connected to a motor (3a). The collet chuck (27) is opened by axial displacement opposite a clamping sleeve (29), and the force necessary for the axial displacement is transmitted via a friction clutch (19, 23). As a result the drill or milling head cannot be damaged, and there is no danger of injury when changing the tool if the user fails to turn the motor (3a) off beforehand.

Abstract: A rotary power tool is provided having a remotely actuated chuck device. The chuck is mounted onto the end of a drive spindle that extends from the casing of the power tool. The chuck includes an outer sleeve member that is axially movable relative to the drive spindle between a gripping and release position. A chuck actuating device is provided having a first member engaged with the outer sleeve member and which extends generally radially outward from the drive spindle or chuck. The first member is movable in a direction so as to move the outer sleeve member between the gripping position and release position. A solenoid and a biasing mechanism engage the first member so that the chuck device is movable between the gripping and release positions.