A clamping device is arranged for releasably holding a tool holder shank. The clamping device includes a housing, a drawbar mounted reciprocally movable inside a bore in the housing, and an actuator. An aperture extends along an actuator axis and is delimited by an aperture housing surface and a drawbar groove. A first locking pressure applying surface on the actuator acts upon a first locking pressure receiving surface in the drawbar groove to effectuate a displacement of the drawbar when the actuator is moved along the actuator axis in a first direction, resulting in clamping of the tool holder shank.

This invention concerns a clamping device for firmly holding a part to be clamped at a clamping recess in which the clamping device is arranged. The clamping device comprises a collet with a first external protrusion for engagement with an internal recess in an inner peripheral area of the part that is to be clamped and with a second external protrusion for engagement with an internal recess in an inner peripheral area of the clamping recess. At least one of the first external protrusion or the second external protrusion comprises a first external taper or a second external taper for pulling the part to be clamped axially into the clamping recess by a radial outward movement of the collet or a section of the collet and an operation stud including an external tapered section for effecting the radial outward movement of the collet. The connection between the operation stud and the collet is self-locked and pre-loaded after a clamping movement of the operation stud in axial direction that locks and pre-loads the external taper of the operation stud and the collet or a part between the collet and the operation stud with each other. The invention includes a method for a part to be clamped in a clamping recess.

A clamping assembly includes a base member having an internal bore, a lock rod within the internal bore of the base member and moveable in a forward direction and rearward direction between an unlocked position and a locked position, a crank wheel having an axis of rotation, and a linkage coupled to the lock rod and coupled to the crank wheel at a position radially offset from the axis of rotation of the crank wheel.

An ultrasonic spindle device with automatic tool changer is disclosed. The ultrasonic spindle device includes a housing member having an inner space along a longitudinal direction, a shaft member rotatably disposed in the inner space and having a hollow portion, an ultrasonic oscillation member disposed in the hollow portion and having a through hole, a drawbar member disposed in the hollow portion to move in a front-rear direction, a portion of the drawbar member being inserted into the through hole and passing through the ultrasonic oscillation member, a clamping member connected to a front end of the drawbar member and clamping a tool, a portion of the clamping member being disposed outside the housing member, a rotation means rotating the shaft member, and a cylinder member moving the drawbar member forward or backward along a longitudinal direction of the shaft member.

A connection device for connecting a tool holder (4) to a drive unit (2), which are provided on adjacently opposite contact surfaces with a serration (124, 56) each, which can be brought into engagement with each other and having a retraction device (90, 118), which reduces an axial distance between the serrations (124, 56) until they are in contact with each other.

A connection device for connecting a tool holder (4) to a drive unit (2), which are provided on adjacently opposite contact surfaces with a serration (124, 56) each, which can be brought into engagement with each other and having a retraction device (90, 118), which reduces an axial distance between the serrations (124, 56) until they are in contact with each other.

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 clamping device includes a first clamping segment which has a first mounting flange and a tubular member extending axially away therefrom. A first bore extends through the first mounting flange and the tubular member. The first mounting flange is configured for attachment to a rotatable spindle of a machine tool. The clamping device includes a draw bar assembly which has an axially extending elongate shaft. The elongate shaft extends through the first bore of the first clamping segment. A biasing unit is mounted on or in the tubular member. A locking member is removably secured to the elongate shaft such that the biasing unit is compressed between the locking member and a portion of the first clamping segment. The biasing member remains compressed when the first clamping segment is separated from the spindle of the machine tool.

A chuck operating apparatus includes a claw, a shifter, and a shifter drive unit. The rotatable claw has a first posture to bring the chuck into the opened state and a second posture to bring the chuck into the closed state. The rotatable shifter is brought in a first position to bring the claw into the first posture and in a second position to bring the claw into the second posture. The shifter drive unit has a shifter lever having an insertion part provided with a shifter bearing capable of being brought into contact with a side surface of an outward groove of the shifter. A roller is provided on one of the claw and the shifter in a contact position with the other to roll in a spindle axis direction and a groove is formed on the other to receive the roller when the chuck is in the opened state.

A chuck operating apparatus includes a claw, a shifter, and a shifter drive unit. The rotatable claw has a first posture to bring the chuck into the opened state and a second posture to bring the chuck into the closed state. The rotatable shifter is brought in a first position to bring the claw into the first posture and in a second position to bring the claw into the second posture. The shifter drive unit has a shifter lever having an insertion part provided with a shifter bearing capable of being brought into contact with a side surface of an outward groove of the shifter. A roller is provided on one of the claw and the shifter in a contact position with the other to roll in a spindle axis direction and a groove is formed on the other to receive the roller when the chuck is in the opened state.