| 摘要 |
PURPOSE:To make the degree of high indexing accuracy maintainable over a long period of time, by installing both roughed and corrected rotation systems of a chuck jaw, while constituting the corrected rotation system with a pair of wedge rods capable of engaging or disengaging to or from a cam and its working surface. CONSTITUTION:A chuck jaw 1 is driven in an arrow direction by a hydraulic cylinder 5. On the other hand, a chuck jaw 2 at the side given index rotation is driven by both of a roughed rotation system 6 and a corrected rotation system 7. And, the roughed rotation system 6 is to turn round a pinion 9 on a shaft 8 of the chuck jaw 2 by means of racks 10 and 11. In addition, the corrected rotation system 7 is to comprise a pair of wedge rods 12 and 13 operating on hydraulic pressure and a cam 14 to or from which these rods 12 and 13 are engaged or disengaged. In this case, the cam 14 is given each indexing rotation, for example, in an angle: a positive sense of 90 deg.+theta, a negative sense of theta, a negative sense of 180 deg.+theta and a positive sense of theta respectively, and working surfaces A-E commensurate to these index angles are installed. |
