Sheathed composite blind rivet

Claim 1

A blind plastic rivet for acceptance in an aperture in a workpiece, said rivet comprising: a tubular body portion, a head forming portion, a mandrel extending centrally of the body portion of said rivet and having a stem portion at one end an anvil at the other end overlying the head forming portion of said rivet, said mandrel being movable axially relative to the body and head forming portions of said rivet to form a radially expanded blind head on the head forming portion of said rivet, said body and head forming portions comprising a plurality of substantially continuous carbon fibres encapsulated in a resin matrix, the head forming portion of said rivet being radially deformable upon heating thereof, and a tubular, ductile, elastically expandable plastic sheath separate from said body portion but fully covering the blind head on said rivet, said sheath having one end portion initially engaged with said workpiece and movable to a position partially underlying the head forming portion of said rivet at the radially outer extremity thereof after deformation of said head forming portion, an opposite end portion of said sheath being initially disposed in close proximate relation to and about the stem portion of said mandrel and movable to a position partially underlying the anvil on said mandrel at the radially outer extremity thereof so as to be mechanically retained by said anvil, the head on said rivet having radially inner portions in direct engagement with both the anvil on said mandrel and the workpiece.