A blind fastener of the type wherein a cylindrical stem or mandrel pulled within a tubular sleeve or rivet body to cause legs formed in the latter to collapse outwardly into engagement with the blind side of a work piece. Such legs are formed in the rivet body by providing longitudinal cuts or slots,...http://www.google.es/patents/US4696610?utm_source=gb-gplus-sharePatente US4696610 - Blind fastener
