| 摘要 |
PROBLEM TO BE SOLVED: To move a jaw portion in radial, axial and horizontal directions by methods independent of each other. SOLUTION: This chuck includes a plurality of jaw portions 8, each of them is fixed to the front end of a jaw portion holding arm 5, and the arm 5 is supported by a pivot joint 6 installed on a chuck main body 1. By the rotation of this pivot joint 6, substantially radial motion is provided to the jaw portion 8, the rotation being controlled by the radial displacement of a sliding element 4 for pushing a truncated conic ball 10, and the ball is housed between the sliding element 4 and a recessed portion formed in the arm 5 in the rear side of the pivot joint 6. The truncated conic ball 10 is slidable on a plane in contact with the sliding element 4, and thereby the jaw portion holding arm 5 is slid in the pivot joint 6 substantially in the axial direction while being pulled backward by a return spring 7. |
