A workholding apparatus (10) wherein a draw bar (22) effects chucking and de-chucking of a workpiece (W) and wherein un-seating of the workholding apparatus is effected by piston-like mechanisms (30) located in a machine spindle (2).

A blade attachment-detachment assisting apparatus includes a nut rotating part having an engagement pin that engages with an engagement hole of a nut, a nut grip part that grips an annular groove of the nut, a housing that supports the nut rotating part rotatably by a predetermined angle, and a lock mechanism. The nut rotating part is capable of advancing and retreating, relative to the housing, to a protrusion position and a fixing position at which engagement between the nut grip part and the nut is kept, and is fixed to the housing with the intermediary of a spring. The lock mechanism includes an inside surface by which advancing and retreating of the nut rotating part are restricted through engagement of the nut rotating part with the housing when the housing is rotated in one direction at the fixing position to which the nut rotating part has been pushed.

A blade attachment-detachment assisting apparatus includes a nut rotating part having an engagement pin that engages with an engagement hole of a nut, a nut grip part that grips an annular groove of the nut, a housing that supports the nut rotating part rotatably by a predetermined angle, and a lock mechanism. The nut rotating part is capable of advancing and retreating, relative to the housing, to a protrusion position and a fixing position at which engagement between the nut grip part and the nut is kept, and is fixed to the housing with the intermediary of a spring. The lock mechanism includes an inside surface by which advancing and retreating of the nut rotating part are restricted through engagement of the nut rotating part with the housing when the housing is rotated in one direction at the fixing position to which the nut rotating part has been pushed.

The present disclosure provides a gripper module, including a base, an adapter holder, a collet holder, and an actuator. The base is adapted for an adapter to be detachably disposed thereon. The adapter holder is able to engage and to buckle the adapter. The collet holder is able to engage and to buckle a collet which is installed in the adapter. The actuator is connected to the collet holder. The actuator can pull the collet holder and the collet to move, causing pressing and retraction of the collet by the conical surface between the collet and the adapter. Therefore, sizes of collets may apply to the gripper module with the adapter. By sheathing the adapter, replacement and size alternation of the collets are made easier, and precisions of allocations of the collet and the gripped workpiece are improved.

A tooling exchange mechanism and a machine tool having the tooling exchange mechanism, in which a load applied to a turret is reduced when exchanging a tooling in the machine tool, are provided with a pressing member 210 of a tooling detachment unit 200 that presses the rear end of a tooling holding unit 100 to be able to release the retracted state of a tool holder Th of a tooling T by a tool holder holding portion 150 of the tooling holding unit 100, and a locking lever 220 of the tooling detachment unit 200 engageable with an engaging projection 112a formed on the rear end side of the tooling holding unit 100.

A tooling exchange mechanism and a machine tool having the tooling exchange mechanism, in which a load applied to a turret is reduced when exchanging a tooling in the machine tool, are provided with a pressing member 210 of a tooling detachment unit 200 that presses the rear end of a tooling holding unit 100 to be able to release the retracted state of a tool holder Th of a tooling T by a tool holder holding portion 150 of the tooling holding unit 100, and a locking lever 220 of the tooling detachment unit 200 engageable with an engaging projection 112a formed on the rear end side of the tooling holding unit 100.

A tool holder for a machine tool, in particular for a core drilling machine, having a hollow shaft which has, at one end for coupling to the drive of the machine tool, a connector and, at the other end, a receiving opening with a plurality of openings in which locking elements are accommodated which are radially adjustable between a clamping position and an release position for securing a tool accommodated in the receiving opening. A switching sleeve is provided, which is adjustably mounted on the hollow shaft between a first switching position and a second switching position, a first subset of the locking elements being provided in the first switching position for locking the tool in the receiving opening, and a second subset of the locking elements being provided in the second switching position for locking the tool in the receiving opening, while the adjustment of the respective remaining locking elements is deactivated.

A tool holder for a machine tool, in particular for a core drilling machine, having a hollow shaft which has, at one end for coupling to the drive of the machine tool, a connector and, at the other end, a receiving opening with a plurality of openings in which locking elements are accommodated which are radially adjustable between a clamping position and an release position for securing a tool accommodated in the receiving opening. A switching sleeve is provided, which is adjustably mounted on the hollow shaft between a first switching position and a second switching position, a first subset of the locking elements being provided in the first switching position for locking the tool in the receiving opening, and a second subset of the locking elements being provided in the second switching position for locking the tool in the receiving opening, while the adjustment of the respective remaining locking elements is deactivated.

A method for releasing a screw connection between a core drilling device and a drill bit, wherein the screw connection is released by application of torque spikes to the drive shaft of the core drilling device, these torque spikes coming into effect when the drive shaft is driven counter to the actual drilling direction of the core drilling device. A core drilling device with which the proposed method can be carried out is also provided. To this end, the core drilling device includes a drive shaft to which torque spikes can be applied, wherein the drive shaft can be driven in a drilling direction and a second direction of rotation which is opposite to the drilling direction. A core drilling device, in which the reversal of a direction of rotation of a drive shaft of the core drilling device and application of torque spikes to the drive shaft are combined with one another such that, as a result of the combination of the reversal of the direction of rotation and torque spikes, a screw connection between the core drilling device and a drill bit can be released.

A method for releasing a screw connection between a core drilling device and a drill bit, wherein the screw connection is released by application of torque spikes to the drive shaft of the core drilling device, these torque spikes coming into effect when the drive shaft is driven counter to the actual drilling direction of the core drilling device. A core drilling device with which the proposed method can be carried out is also provided. To this end, the core drilling device includes a drive shaft to which torque spikes can be applied, wherein the drive shaft can be driven in a drilling direction and a second direction of rotation which is opposite to the drilling direction. A core drilling device, in which the reversal of a direction of rotation of a drive shaft of the core drilling device and application of torque spikes to the drive shaft are combined with one another such that, as a result of the combination of the reversal of the direction of rotation and torque spikes, a screw connection between the core drilling device and a drill bit can be released.