A substrate supporting apparatus includes a rotatable chuck, a first mass flow controller, a second mass flow controller, a plurality of locating pins and guiding pillars, and a motor in which the rotatable chuck defines a plurality of first injecting ports and second injecting ports, the first injecting ports are connected with a first gas passage for supplying gas to the substrate and sucking the substrate by Bernoulli effect, the second injecting ports are connected with a second gas passage for supplying gas to the substrate and lifting the substrate, the first and the second mass flow controllers are respectively installed on the first and the second gas passages, the plurality of locating pins and guiding pillars are disposed at the top surface of the rotatable chuck and every guiding pillar protrudes to form a holding portion, and the motor is used for rotating the rotatable chuck.

A collet (230) for holding a contact lens mold half (240) during machining of a surface of the mold half (240) having a disc (235) having a face and defining: a central structure (250a), at the center of the face, for receiving a head portion (240a) of the mold half (240), and an elongate recess (250b), in the face, for receiving a tail portion (240b) of the mold half (240), the elongate recess (250b) extending from the central structure (250a) along a radius of the disc (235).

A spindle apparatus for use at a machine tool, having: an assembly including a workpiece spindle to receive an elongated workpiece and a motor for driving spindle rotation of the workpiece spindle about a spindle axis; a rotary guide-bush assembly being axially arranged with the workpiece spindle with respect to the spindle axis, the rotary guide-bush assembly receiving the elongated workpiece supported at the rotary guide-bush assembly to rotate about the spindle axis enabling movement of the elongated workpiece; wherein the rotary guide-bush assembly includes a portion to clamp the elongated workpiece, received in the rotary guide-bush and in the workpiece spindle, to transfer driving torque applied from the spindle motor during a driven acceleration of the rotation through the clamped elongated workpiece for rotation of the rotary guide-bush synchronized with the driven acceleration of the rotation of the workpiece spindle.

A clamping chuck is provided for clamping palettes having a clamping spigot. The clamping chuck includes a receiving opening for the clamping spigot and a clamping device that includes an actuating piston displaceable between an initial position and a locking position for actuating clamping members for clamping the clamping spigot in the receiving opening. The clamping chuck includes a monitoring line that is acted upon pneumatically and leads from an inlet to an outlet. The receiving opening includes a conical insertion region, into which at least one control hole connected to the monitoring line emerges, the control hole being closed by the clamping spigot. A valve device is arranged between the inlet and the outlet of the monitoring line to vary the flow of a fluid through the monitoring line depending on the position of the actuating piston.

A clamping chuck is provided for clamping palettes having a clamping spigot. The clamping chuck includes a receiving opening for the clamping spigot and a clamping device that includes an actuating piston displaceable between an initial position and a locking position for actuating clamping members for clamping the clamping spigot in the receiving opening. The clamping chuck includes a monitoring line that is acted upon pneumatically and leads from an inlet to an outlet. The receiving opening includes a conical insertion region, into which at least one control hole connected to the monitoring line emerges, the control hole being closed by the clamping spigot. A valve device is arranged between the inlet and the outlet of the monitoring line to vary the flow of a fluid through the monitoring line depending on the position of the actuating piston.

A clamping device for clamping a workpiece to a machine spindle includes at least one clamping bush which extends around a central axis and has at least one clamping surface for the workpiece and at least one clamping body. The clamping bush on a side remote from the clamping surface at least one support surface which extends about the central axis along a helical line. On a side facing, the clamping bush comprises at least one support surface which extends about the central axis along a helical line with a predefined pitch and is inclined at an angle of inclination to a direction axial to the central axis. The clamping body includes a hydraulic chamber in the interior of the clamping body. The clamping device also includes a displacement element, and at least one pressure generator. A clamping force is generatable between the clamping bush and workpiece.

This invention provides a machine tool capable of easily and quickly attaching/detaching a tool holder while reliably holding the tool holder, including at least two clamp holes (211) that receive pins (203) extending through at least two through holes (202) provided in a tool holder (134), at least two tubular clamp sleeves (302) fitted in the at least two clamp holes (211), respectively, and each including a flexible trunk portion (321), a fluid encapsulating chamber that encapsulates a fluid, a channel extended from the fluid encapsulating chamber to an outer peripheral surface of the flexible trunk portion, and a pressure adjusting portion that adjusts a pressure of the fluid in the fluid encapsulating chamber, wherein a clamp fastening force is made to act on the pins (203) in synchronism with an increase or a decrease in the fluid pressure in the fluid encapsulating chamber.

In one aspect, expansion sleeves for pressure-activated tool holder apparatus are described herein. An expansion sleeve, for example, comprises a first end, a second end and a longitudinal axis extending between the first end and the second end. A first set of fluid chambers are proximate the first end of the sleeve and a second set of fluid chambers are proximate the second end, wherein fluid channels extend along the longitudinal axis to connect radially offset fluid chambers of the first and second sets.

A clamping chuck is provided for clamping palettes having a clamping spigot. The clamping chuck includes a receiving opening for the clamping spigot and a clamping device that includes an actuating piston displaceable between an initial position and a locking position for actuating clamping members for clamping the clamping spigot in the receiving opening. The clamping chuck includes a monitoring line that is acted upon pneumatically and leads from an inlet to an outlet. the receiving opening includes a conical insertion region, into which at least one control hole connected to the monitoring line emerges, the control hole being closed by the clamping spigot. A valve device is arranged between the inlet and the outlet of the monitoring line to vary the flow of a fluid through the monitoring line depending on the position of the actuating piston.

A clamping chuck is provided for clamping palettes having a clamping spigot. The clamping chuck includes a receiving opening for the clamping spigot and a clamping device that includes an actuating piston displaceable between an initial position and a locking position for actuating clamping members for clamping the clamping spigot in the receiving opening. The clamping chuck includes a monitoring line that is acted upon pneumatically and leads from an inlet to an outlet. the receiving opening includes a conical insertion region, into which at least one control hole connected to the monitoring line emerges, the control hole being closed by the clamping spigot. A valve device is arranged between the inlet and the outlet of the monitoring line to vary the flow of a fluid through the monitoring line depending on the position of the actuating piston.