A clamping unit for a chuck of a machine tool spindle contains a threaded shaft for adjusting the clamping jaws of the chuck. The threaded shaft is axially adjustable in the clamping unit by means of a threaded nut connected to a rotor of a servomotor actuator. An electrically actuable, releasable clutch has a first clutch element, which is connected in a rotationally secure and axially displaceable manner to the threaded shaft, and a second clutch element, which cooperates with the first clutch element and is connected in a rotationally secure manner to the rotor. When the clutch is activated, the threaded shaft and the threaded nut are mutually connected in a rotationally secure manner and prevent axial displacement of the threaded shaft.

An additive repair device for internal threads is provided. The device includes a moving assembly, a rotating assembly, a speed regulation assembly, a gear assembly, an additive assembly, and a connecting assembly. The moving assembly includes a drive part and a linear movement mechanism. The additive assembly is connected to the linear movement mechanism through the connecting assembly. One end, which is far away from the drive part, of the linear movement mechanism is connected to an input end of the speed regulation assembly through the gear assembly. The rotating assembly includes a clutch mechanism and a clamping mechanism. The clutch mechanism includes a clutch outer gear and a clutch inner gear. The clutch outer gear is arranged at an output end of the speed regulation assembly. The clamping mechanism is fixed to one end, which is far away from the speed regulation assembly, of the clutch inner gear.

The clamping device is provided for tools and has a coupling piece that is provided with at least one actuating unit. The coupling piece acts to actuate a nut seated on a spindle journal that is receiving the tool. A torque coupling is provided for the nut. The coupling piece is fixedly connected with an output shaft that is in drive connection with a drive shaft by a transmission gear. As a result of the transmission gear, it is possible to rotate the drive shaft with minimal moment in order to apply the great clamping force required for axial clamping of the tool.

An apparatus is disclosed for holding the shaft of an object, wherein the shaft rotates in a first working direction. The apparatus includes a bore, a first ball slot in communication with the bore, a first ball disposed within the first ball slot, and a spring. The bore has a longitudinal axis, and the shaft is inserted into the bore in an insertion direction. The first ball slot is in communication with the bore and includes a ramp. The first ball slot has a first axis that is angularly offset from the longitudinal axis at an acute angle between the insertion direction and the first working direction. Upon insertion of the shaft into the bore, the shaft contacts the ball and causes it to move along the ramp within the ball slot, thereby compressing the spring by a first amount.

A tool with a transmission having a reduction gearset and a speed selector. The speed selector has a member, an actuator and a shifter assembly. The member is movable between a first position, in which the member is non-rotatable, and a second position in which the member is coupled to a planet carrier of the reduction gearset for common rotation. The actuator includes a pivoting yoke and a follower that is coupled to the yoke. The follower engages the member so as to be axially movable with the follower. The shifter assembly has a selector switch, a switch fork, and a pair of springs. The selector switch is slidable between a first switch position and a second switch position. The shift fork is slidably coupled to the selector switch and receives the yoke. The springs cooperate to bias the shift fork relative to the selector switch into a neutral position.

A drilling and tapping machine includes a power head assembly supported at a vertical orientation, a parallelogram arm structure including a head support and an arm base, and an arm positioning assembly coupled with the head support and the arm base support for guiding corresponding movements of the head support and the arm base support so as to ensure a vertical trajectory of the power head assembly. The machine further includes a counterweight configuration to vertically move the power head assembly via a lever. The machine further includes an operational control assembly to selectively shift the power head assembly between a drilling operation and tapping operation. Therefore, the machine is suitable to make a hole with a diameter of 0.5 to 3 mm.

A tool with a transmission assembly having a reduction gearset and a speed selector. The speed selector has a member, an actuator and a shifter assembly. The member is movable between a first position, in which the member is non-rotatable, and a second position in which the member is coupled to a planet carrier of the reduction gearset for common rotation. The actuator includes a pivoting yoke and a follower that is coupled to the yoke. The follower engages the member so as to be axially movable with the follower. The shifter assembly has a selector switch, a switch fork, and a pair of springs. The selector switch is slidable between a first switch position and a second switch position. The shift fork is slidably coupled to the selector switch and receives the yoke. The springs cooperate to bias the shift fork relative to the selector switch into a neutral position.

Disclosed is a machine tool ELECTRICAL DRIVING SYSTEM capable of selectively transmitting power of a motor for driving a spindle in a lathe which machines a workpiece to a rotation system including a drawbar and a spindle for driving a chuck, using a clutch mechanism. The machine tool ELECTRICAL DRIVING SYSTEM includes a housing, a hollow tubular spindle rotatably installed inside the housing, a drive pulley rotatably installed with respect to the spindle outside the spindle, a spindle motor, a drawbar installed to be linearly movable with respect to the spindle but non-rotatable relative to the spindle, a motion conversion unit configured to convert a rotary motion of the drive pulley into a forward-rearward linear motion of the drawbar, a clutch unit, a position detection unit configured to the drive pulley to detect an amount of rotation and a rotation position of the drive pulley, and a controller.

A tool with a transmission having a reduction gearset and a speed selector. The speed selector has a member, an actuator and a shifter assembly. The member is movable between a first position, in which the member is non-rotatable, and a second position in which the member is coupled to a planet carrier of the reduction gearset for common rotation. The actuator includes a pivoting yoke and a follower that is coupled to the yoke. The follower engages the member so as to be axially movable with the follower. The shifter assembly has a selector switch, a switch fork, and a pair of springs. The selector switch is slidable between a first switch position and a second switch position. The shift fork is slidably coupled to the selector switch and receives the yoke. The springs cooperate to bias the shift fork relative to the selector switch into a neutral position.

A machine tool electrical driving system includes a housing, a hollow tubular spindle rotatably installed inside the housing, a drive pulley rotatably installed with respect to the spindle outside the spindle, a spindle motor, a drawbar installed to be linearly movable with respect to the spindle but non-rotatable relative to the spindle, a motion conversion unit configured to convert a rotary motion of the drive pulley into a forward-rearward linear motion of the drawbar, a clutch unit, a position detection unit configured to the drive pulley to detect an amount of rotation and a rotation position of the drive pulley, and a controller.