Pull-type blind fastener construction

摘要

An improved pull-type blind fastener is disclosed comprising a tubular sleeve having a mandrel longitudinally movable within the sleeve for forming a head on one end thereof and a locking collar adapted to be moved into engagement with a lock pocket provided on the mandrel as the fastener is set whereby the mandrel is locked within the sleeve. The locking collar is generally cylindrical in shape having a bore extending therethrough which bore is defined by an inner portion of a first predetermined diameter and an outer portion of a diameter greater than the first predetermined diameter. The enlarged diameter outer portion operates to provide a relieved area at the outer end of the locking collar and immediately adjacent the nose assembly of an installation tool so as to prevent flow or wiping of collar material axially outwardly between the mandrel and the nose assembly of the installation tool during setting of the fastener.