The present disclosure provides a spindle structure including a base, a spindle, a sliding member, a restoring mechanism, and a restriction member. The spindle is rotatably received in the base and forms a receiving room. An end of the receiving room is a blind end communicating exterior via a gas channel. The sliding member is slidably received in the receiving room, and two ends thereof are a piston and a driving portion respectively. A gas cavity is defined between the piston and the blind end. The sliding member tends to move toward the blind end due to the restoring mechanism. The restriction member is connected to the driving portion and radially deforms when the sliding member slides so as to fix or to release the tool-holder. The sliding member slides outward when the gas cavity is injected with gas via the gas channel.

A rotating tool is held in a tool holder. The tool holder includes a male tapered portion. The tool holder is rotated by a rotating-tool main shaft. The rotating-tool main shaft includes a hollow main shaft. The hollow main shaft includes a circular conical hole formed in a tip and corresponding to the male tapered portion. The hollow main shaft includes a fluid passage to detect that the male tapered portion is properly attached to the circular conical hole, and an opening to blow out a fluid. The opening is provided in a portion offset from the circular conical hole.

A clamping device for releasably holding a tool holder shank includes a housing, a drawbar axially moveable in a bore in the housing, engagement members moveable under the effect of the drawbar into locking engagement with the tool holder shank, and an actuating member rotatably arranged in the bore. Upon rotation of the actuating member, a contact surface on a motion transferring element fixedly connected to the actuating member achieves an axial movement of the drawbar by pressing against a contact surface on another motion transferring element fixedly connected to the drawbar. At least one of the contact surfaces includes two sections with mutually different pitch, such that the same angular displacement of the actuating member, when rotated in a first rotary direction, results in a longer axial movement of the drawbar in a first phase of the rotary movement than in a final phase thereof.

In order to configure a multi-spindle machine tool comprising a machine frame, a spindle drum arranged on the machine frame to be rotatable about a spindle drum axis and having a plurality of workpiece spindles, each of which is provided with a workpiece receptacle for a workpiece that is to be machined in a working area, a plurality of tool carriers arranged in the working area, in particular associated with individual spindle stations, and each having a tool holder receptacle into which a tool holder is insertable, as well as a machine control system for controlling the machine tool to be more efficient, it is proposed that a handling apparatus is arranged on the machine frame, that with the handling device, also controlled by the machine control system, at least one tool holder is insertable into at least one of the tool holder receptacles and/or removable therefrom.

A flexible coupling for attaching a collet to a draw bar includes a draw bar having a first longitudinal axis and a first coupling portion. The first coupling portion includes two or more legs spaced apart from one another with each of the legs having first coupling surface formed thereon. The flexible coupling includes a collet having a second longitudinal axis and a clamping portion proximate one end of the collet. The collet includes a second coupling portion proximate a second end of the collet. The second coupling portion has a second coupling surface formed thereon and configured in a shape complementary to the first coupling surface so that the first coupling surfaces moveably engage the second coupling surface such that the first longitudinal axis and the second longitudinal axis are coaxial when an axial force is applied to the draw bar and the collet.

A clamping device for releasably holding a tool holder shank is formed with an engagement bore in a rear end, and includes a housing having a bore in a forward end for receiving the tool holder shank, a drawbar reciprocally movable inside the housing and which in a forward end is provided with engagement means arranged to engage with an engagement formation inside the engagement bore of the tool holder shank, and which is formed with a drawbar aperture extending through the drawbar in a transverse direction of the same, and a cam shaft extending through the drawbar aperture. The cam shaft includes three cam formations and more precisely first and second spaced apart cam formations, which are journalled in seating apertures in the housing on opposite sides of the drawbar, and an intermediate third cam formation located between the first and second cam formations and positioned within the aperture of the drawbar. The drawbar is insertable into the bore from the forward end.

A clamping device for releasably holding a tool holder shank is formed with an engagement bore in a rear end. The clamping device includes a housing having a mounting bore for receiving the tool holder shank; a drawbar being mounted reciprocally movable inside the housing and which in a forward end is provided with an engagement segment which is arranged to engage with an engagement formation inside the engagement bore of the tool holder shank, wherein the drawbar is in a rear portion formed with a drawbar aperture extending through the drawbar, and a cam shaft extending through the drawbar aperture and comprising a cam formation. The cam shaft is rotatably journalled in the housing and arranged to impart an axial displacement to the drawbar in relation to the housing by the cam formation when rotating the cam shaft. The cam shaft includes two identical cam formations, which are spaced apart by a recess, and the drawbar is on the inside of the aperture formed with a ridge on each side of the aperture which each fits in the recess of the cam shaft when rotating the same.

A method of monitoring a tool clamping device mounted on a machine spindle, the clamping force of which tool clamping device is generated by a spring assembly which exerts a force in the direction of the clamping position on an actuating element actuating the clamping or the release of a tool or tool holder. In the method, the spring force and the displacement of the actuating element are continuously measured during the release and/or clamping of a tool or tool holder and recorded as functions of the time. These recorded functions are used to identify at least one parameter characteristic for the status of the tool clamping device. Based on the spring force and the displacement over time, a spring characteristic curve is plotted in the form of the spring force as a function of displacement, the analysis of which spring characteristic curve provides information about a number of characteristic parameters.

A tool spindle having a spindle shaft rotationally-drivable about a spindle axis, a clamping system for the automatic chucking and unchucking of a tool, wherein the clamping system comprises a movement device enabling at least one movable and/or deformable clamping body of the clamping system to be transferred from a first position into a second position by execution of a movement of a part of the movement device in relation to the spindle shaft, wherein the tool is chucked on the tool spindle in the first position and the tool can be removed from the tool spindle in the second position, wherein it comprises a balancing system, which is integrated into the tool spindle so that it rotates jointly with the rotationally-drivable spindle shaft, which is arranged coaxially in relation to the spindle axis, and which is mounted so it is axially movable.

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).