Captive fastener apparatus for chain guide or tensioner arm

摘要

A fixed or adjustable chain guide includes a captured shoulder bolt fastener. An adjustable chain guide such as a chain tensioner arm assembly includes a tensioner arm with a pivot bore defined about a pivot axis. The pivot bore includes an inner end opening through a rear face of the tensioner arm and an outer end opening through a front face of the tensioner arm. The tensioner arm further includes at least one resilient fastener retaining tab located adjacent the pivot bore. The shoulder bolt extends through the pivot bore and is engaged by the at least one resilient fastener retaining tab, and the at least one fastener retaining tab inhibits separation of the fastener from the tensioner arm. The fastener preferably includes an annular groove or other recess to be engaged by the one or more fastener retaining tabs in order to permit the tensioner arm to rotate relative to the fastener. New shoulder bolt fasteners are also defined, each including a shoulder region having at least one retaining feature such as an annular groove adapted to be engaged by a projecting portion of an associated component for axially capturing the fastener to the associated component while permitting rotation of the associated component relative to the fastener.