Quick-change jaw assembly

摘要

A rotary chuck having a plurality of quick change jaw assemblies each including a master jaw carried by the chuck body and a top jaw releasably secured to the master jaw by a single retaining fastener having a shank including a frustoconical portion. A resilient roll pin carried by the top jaw bears upon and is compressed by the frustoconical portion. The compressed roll pin exerts a resilient biasing force which acts upon the top jaw to continuously urge an arcuate reference surface on the top jaw into coengagement with a complementary reference surface on the master jaw. A hardened locking pin carried by the jaw assembly bears against a frustoconical head on a locking fastener threadably engaged with the master jaw to prevent relaxation of the resilient biasing force provided by the roll pin when the jaws clampingly engage the I.D. of a tubular workpiece.