INDEXING DEVICE

摘要

A turret tool post (14) is provided with a turret (24) which is movably supported by a base (22) and can mount a desired tool at a predetermined index angular position. Arranged between the base (22) and the turret (24) are a pair of coupling members (66, 68) capable of engaging with each other. These coupling members (66, 68) move between an engaged position where they engage with each other to fixedly hold the turret at each of a plurality of indexing positions on the base and a disengaged position where they disengage from each other to enable indexing rotation of the turret. Until relative engagement of the coupling members is completed while the coupling members (66, 68) move between the engaged position and the disengaged position, a spring plunger unit (78) suppresses free rotation of the turret (24) on the base (22). The spring plunger unit (78) comprises a plunger (84) retractably installed in the turret (24), a countersink (90) fixedly provided on the base (22) to engage with the plunger when the turret is positioned at an indexing position, and a coil spring (86) for biasing the plunger in a direction in which engagement of the plunger and the countersink is maintained.