Chuck for hammer action drill has the adjusting ring supported by a thrust ring located under a lipped profile of the chuck core

摘要

A chuck for a hammer action drill has the chuck grips moving in inwards sloping grooves (8) in the chuck core (2) to grip the tool bit between shaped jaws (6). The chuck grips have an outer thread which meshes with an adjusting ring (10) operated by twisting the outer sleeve of the chuck. The adjusting ring is braced by a sprung thrust ring (12) secured by a lipped profile (13) in the chuck core, covering up to half the area of the thrust ring. The front end of the outer sleeve is secured by a front stepped profile (29) in the chuck core.