| 摘要 |
The present invention provides a chuck for clamping a plate. The chuck comprises a cylindrical main body, an electro-motive member and a movable piece. In the main body, a hollow space penetrating the center thereof and an opening connected to the hollow space are formed, and the opening narrows as it approaches the hollow space. For insertion into the hollow space and opening and vertical movement in the axial direction, the electromotive member includes an electromotive shaft and a pressing unit in which one lateral end of the electromotive shaft is tapered. A primary elastic member supports and allows the electromotive shaft to move down the main body by an external force and, when the external force is terminated, to move up the main body and back to the original position. In the main body positioned in the circumference of the opening, plural guide slots are radially formed. The movable piece is supported by a secondary elastic member and is inserted in the guide slot to protrude toward the circumference of the main body by the pressing unit and return when the electro-motive member moves back to the original position. Accordingly, when the electro-motive member moves down the main body, the movable piece protrudes toward the circumference of the main body and then moves down. |
