Clamping device

A clamping device for machine tools, the device being provided with a power-operated chuck for holding a workpiece, and clamping jaws adapted to be actuated using the clamping device by means of a movement converter and an axially moveable draw rod, wherein the clamping device is provided with an electric drive motor having a changeover function connectable to the movement converter for triggering clamping movements, wherein the drive motor is provided with a switching element which is adjustable by axial control in a middle position and in one or both limit positions, and which is driven directly or by intermediate elements, the switching element being connectable in a positive or non-positive arrangement to components of the clamping device, in particular the power-operated chuck, in one limit position, and to an axially movable adjustment element in the other limit position, wherein the adjustment element is connected to an auxiliary device of the machine tool, or is connected to the power-operated chuck in order to rotate the power-operated chuck in a position-oriented manner, the rotationally fixed connection being effected by means of components of the clamping device, and the switching element is adapted to be locked and unlocked on a machine spindle of the machine tool in one or both limit positions;

• wherein the switching element is mounted so as to rotate in a housing as an intermediate piece connected to a spindle stock of the machine tool in a rotationally fixed arrangement whilst allowing controlled axial movement;
• wherein the housing is configured in two parts and is supported on guide pins arranged evenly around a circumference, and are disposed in a movable arrangement in locationally fixed carriers, or carriers that are attached to the spindle stock;
• wherein for controlled axial movement of the housing accommodating the switching element, a servo device is provided in the form of a piston inserted in a cylinder to which pressurised fluid can be applied from both sides, a piston rod of a piston being in a driveable connection with the switching element.

A clamping device for machine tools, the device being provided with a power-operated chuck for holding a workpiece, and clamping jaws adapted to be actuated using the clamping device by means of a movement converter and an axially moveable draw rod, wherein the clamping device is provided with an electric drive motor having a changeover function connectable to the movement converter for triggering clamping movements, wherein the drive motor is provided with a switching element which is adjustable by axial control in a middle position and in one or both limit positions, and which is driven directly or by intermediate elements, the switching element being connectable in a positive or non-positive arrangement to components of the clamping device, in particular the power-operated chuck, in one limit position, and to an axially movable adjustment element in the other limit position, wherein the adjustment element is connected to an auxiliary device of the machine tool, or is connected to the power-operated chuck in order to rotate the power-operated chuck in a position-oriented manner, the rotationally fixed connection being effected by means of components of the clamping device, and the switching element is adapted to be locked and unlocked on a machine spindle of the machine tool in one or both limit positions;

• wherein the switching element is mounted so as to rotate in a housing as an intermediate piece connected to a spindle stock of the machine tool in a rotationally fixed arrangement whilst allowing controlled axial movement;
• wherein the housing is configured in two parts and is supported on guide pins arranged evenly around a circumference, and are disposed in a movable arrangement in locationally fixed carriers, or carriers that are attached to the spindle stock;
• wherein the drive motor is supported in a fixed location on the housing, or on one of the carriers connected to the spindle stock, and a drive shaft of the drive motor is connectable to the switching element in a positive-locking arrangement;
• wherein in an operating position of the clamping device the clamping device is lockable and unlockable to lock onto and unlock from a bell housing and in a rotationally fixed connection with the machine spindle;
• wherein to achieve positive connection between the clamping device and the bell housing, spring detent means are inserted therein, or in an intermediate element, the spring detents being adapted to be released in limit positions of the switching element by means of stops formed on the switching element, or on the housing, or directly by means of the switching element;
• wherein in limit positions, the switching element is connectable to the clamping device, or the intermediate element configured as a nut, with a connection effected by helical gearing, or friction pads attached to sides of the switching element, in which case the intermediate element is in driving connection with an adjustment element by means of threads for converting rotational movements to axial adjustment movements.

A clamping device for machine tools, the device being provided with a power-operated chuck for holding a workpiece, and clamping jaws adapted to be actuated using the clamping device by means of a movement converter and an axially moveable draw rod, wherein the clamping device is provided with an electric drive motor having a changeover function connectable to the movement converter for triggering clamping movements, wherein the drive motor is provided with a switching element which is adjustable by axial control in a middle position and in one or both limit positions, and which is driven directly or by intermediate elements, the switching element being connectable in a positive or non-positive arrangement to components of the clamping device, in particular the power-operated chuck, in one limit position, and to an axially movable adjustment element in the other limit position, wherein the adjustment element is connected to an auxiliary device of the machine tool, or is connected to the power-operated chuck in order to rotate the power-operated chuck in a position-oriented manner, the rotationally fixed connection being effected by means of components of the clamping device, and the switching element is adapted to be locked and unlocked on a machine spindle of the machine tool in one or both limit positions;

• wherein the switching element is mounted so as to rotate in a housing as an intermediate piece connected to a spindle stock of the machine tool in a rotationally fixed arrangement whilst allowing controlled axial movement;
• wherein the housing is configured in two parts and is supported on guide pins arranged evenly around a circumference, and are disposed in a movable arrangement in locationally fixed carriers, or carriers that are attached to the spindle stock;
• wherein the drive motor is supported in a fixed location on the housing, or on one of the carriers connected to the spindle stock, and a drive shaft of the drive motor is connectable to the switching element in a positive-locking arrangement;
• wherein in an operating position of the clamping device the clamping device is lockable and unlockable to lock onto and unlock from a bell housing and in a rotationally fixed connection with the machine spindle;
• wherein to achieve positive connection between the clamping device and the bell housing, spring detent means are inserted therein, or in an intermediate element, the spring detents being adapted to be released in limit positions of the switching element by means of stops formed on the switching element, or on the housing, or directly by means of the switching element;
• wherein the switching element is connected to an input element of the clamping device, and/or the intermediate element, and/or to the bell housing by means of helical gearing.