| 摘要 |
PROBLEM TO BE SOLVED: To reliably hold a wedge bar by forcedly inserting a position adjusting pin into a recessed part of the wedge bar when a chuck is put in an actuating state. SOLUTION: A lock device 21 is composed of a position adjusting pin 23 respectively incorporated into radial directional holes 22 of a chuck body 2. In an actuating state, respective wedge bars 8 have a slit-like recessed part 41 on the side opposed to the position adjusting pin 23 for fixing the wedge bars 8 not only by a cam 24 installed on the position adjusting pin 23 but also by the position adjusting pin 23, and the recessed part 41 extends over the whole length corresponding to an actuating area of a chuck 1. When the chuck 1 is put in an actuating state, the position adjusting pin 23 is forcedly inserted into the recessed part 41 of the wedge bars 8 by an adjusting member 42 to thus fix the wedge bars 8 by the position adjusting pin 23. |
