Indexing devices

摘要

An indexing head has a plurality of co-axial discs rotatable relative to each other. A first disc carries an indexing pin receivable in a series of equi-angularly spaced recesses of a second disc. A third disc is angularly settable relative to the second disc by means of gauge blocks, and is lockable after setting by locking means. A tool shank can be releasably held in an axial bore of the first disc. When used in an oil bath of an erosion machine, the head is fitted with a bellows skirt to prevent the oil reaching the discs.