A machine tool includes: a hollow spindle including a hollow portion along an axial direction; a plurality of chuck claws openably mounted at a distal end portion of the hollow spindle, and configured to hold a workpiece; an operation rod inserted into the hollow portion of the hollow spindle in a movable manner, and configured to close the plurality of chuck claws with movement of the operation rod toward one side in the axial direction and open the plurality of chuck claws with movement of the operation rod toward the other side in the axial direction; and a measuring apparatus configured to measure an opening dimension of the plurality of chuck claws based on a movement amount of the operation rod.

A workpiece holding device includes: a chuck including a chuck body, and a plurality of chuck claws openably supported on the chuck body and configured to hold a workpiece; an operation rod configured to drive the plurality of chuck claws for opening and closing with movement of the operation rod; and a measuring apparatus configured to measure an opening dimension of the plurality of chuck claws based on a movement amount of the operation rod.

Provided is a retracting chuck that does not rattle even though a moving body can be operated axially, and that enables turning in which the grasp accuracy is increase and vibration and chatter are inhibited. The retracting chuck (100) is provided with: a body (1) comprising a rear body (2) disposed on the axial rear side and a moving body (3) disposed on the axial front side; a plunger (8) moving axially in the body (1); and a master jaw (6) which engages with the plunger (8) and which is caused by a wedge action to move in the radial direction by a slot (3a) provided to the moving body (3). The moving body (3) moves axially relative to the rear body (2). In the rear body (2), a plate spring (11) is disposed in a bridging manner between seats (2a) provided at a distance from each other, and the plate spring (11) is fastened by a bolt (13) to each of the seats (2a). Between the seats (2a), the plate spring (11) is fastened by a bolt (16) to a seat (3b) of the moving body (3)

A power chuck includes a housing in which there is arranged a drive unit having a traction guide means moveable in the direction of a clamping axis. There are arranged two pairs of mutually diametrically opposite base jaws. The base jaws are guided radially, in the housing substantially perpendicularly to the clamping axis, and the drive unit is adapted to convert the movement of the traction guide means into the movement of the base jaws. According to the invention, it is proposed that the drive unit for each base jaw has a slider which is in engagement with the base jaw and which is moveable with a movement component on a circular path about the clamping axis.

An automatic carving device for a wheel, including a rack, a chassis, a lifting cylinder, brackets, bearing blocks, linear bearings, mounting plates, guide shafts, a lifting shaft, a servo motor, a synchronous pulley, a connection plate, a synchronous belt, a synchronous pulley, a pedestal, a connection shaft, a servo motor, a shaft sleeve, a lower end cover, a connection shaft, a shaft sleeve, and an oil cylinder. The automatic carving device for the wheel can automatically carve characters on the wheel, meanwhile it also has the characteristics of simple structure, convenience for manufacturing, stable performance and high precision that can meet the machining requirement, and can also meet the requirement of automatic production.

A lathe includes a main shaft, a moving shaft, a cutter mounted on the moving shaft, and a clamping assembly. The cutter is capable of telescopic translation relative the moving shaft. The clamping assembly includes a cylinder mounted on the cutter, an assembly member mounted on the cylinder, a moving member, and at least two clamping members. The cylinder defines an inner cavity, and a first air intake and a second air intake communicated to the inner cavity. The moving member is movably mounted in the inner cavity and partially received in the assembly member, and capable of telescopic translation relative the assembly member. The clamping members are movably mounted on the assembly member and engaged with the moving member. The clamping members are translatably urged by the moving member in a direction relative the axis defined by the assembly member.

An apparatus for clamping a component on a rotating machine part, in particular a balancing machine, having a basic body, having a clamping mandrel, which is arranged in an axially displaceable manner within the basic body, and having a plurality of clamping devices, which can be moved between a release position and a clamping position by axial displacement of the clamping mandrel. In order to make it possible for components to be clamped centrally with repeated accuracy, the clamping devices are designed as clamping segments which can be displaced radially in relation to the center axis of the basic body above the latter.