A chuck device includes a connecting mechanism and a locking mechanism, where the locking mechanism includes a driving portion, a first locking portion and a second locking portion, where the first locking portion at least partially extends into a first receiving portion; and the second locking portion is rotatably connected to the first receiving portion through a second shaft. When the locking mechanism is in a first state, the second locking portion rotates along a first direction to drive a sleeve to bias against a biasing element and release a limitation on the first locking portion.

A chuck apparatus grips a workpiece by a gripping section having a pair of chuck members. The chuck apparatus is equipped with a cover member and pressing members. The cover member includes insertion holes through which fingers of the chuck members are inserted, and seal members that surround the insertion holes and abut against the fingers. The cover member is attached to a body so as to cover base portions of the chuck members, and is elastically deformable so as to follow displacement of the chuck members. The pressing members press the seal members against the fingers.

What is shown and described is a clamping device (1) with hub centering for attachment of an automobile wheel to the shaft of a balancing machine, with a contact flange (2) with several centering elements (3) guided in a radially moveable manner on the contact flange (2) for centering engagement in a centering hole of the rim, and with a clamping sleeve (4) guided in a moveable manner axially to the contact flange (2), wherein the clamping sleeve (4) and the centering elements (3) are kinematically coupled such that an axial movement of the clamping sleeve (4) leads to a radial movement of the centering elements (3). According to the invention, a provision is made that at least one tension lever (16) connected in an articulated manner to the clamping sleeve (4) and a centering element (3) is provided for the kinematic coupling of clamping sleeve (4) and centering element (3).

A clamping device for machine tools with a power-operated chuck, the clamping jaws of which are actuatable by the clamping device via a movement converter and draw rod. A drive motor is provided with a switching element which is adjustable by axial control in a middle and two limit positions, wherein the switching element is connectable to the clamping device in one limit position and, in the other limit position, to an adjustment element connectable to an auxiliary device. The switching element is lockable in the limit positions with a machine spindle. The clamping device is thereby provided with an increased range of applications, without functions being impaired, with little structural complexity, because the switching element makes possible a clamping element integrated in the power operated chuck to be operated using the drive motor, such that further procedures can be undertaken without changing the clamping device.

A drive system for driving a chuck device including a piston and a pair of fingers to be opened and closed according to the displacement of the piston, includes a controller, a detection sensor to detect an axial position of the piston, and three-port servo valves to switch a state of supply of the fluid to the chuck device. A degree of valve opening is controllable based on a control signal input from the controller, and an amount of displacement of the piston and an amount of opening and closing of the fingers are controlled by changing the degree of valve opening. One of the 3-port servo valves is connected to a first cylinder chamber of the chuck device, and another of the 3-port servo valves is connected to a second cylinder chamber of the chuck device.

A control method of controlling a chuck device in a drive system for driving the chuck device, comprising opening or closing fingers by opening a switching valve at a first degree of valve opening to supply the fluid to a first cylinder chamber of the chuck device and to discharge the fluid from a second cylinder chamber of the chuck device so that a piston moves in one direction, and stopping the fingers in an intermediate position between a fully open position and a fully closed position by opening the switching valve at a second degree of valve opening to stop supplying the fluid to the first cylinder chamber and to stop discharging the fluid from the second cylinder chamber when the axial position of the piston reaches a target position set in advance while the fingers are being opened or closed.