Patent ID: 8029220

Claim:
A blind rivet assembly comprising: a tubular shell having an enlarged shell head and a blind head section, said tubular shell being formed with a through bore extending towards said enlarged shell head and with a head bore through said enlarged shell head of a diameter smaller than said through bore, wherein a stop shoulder is located at a juncture of said through bore and said head bore; a stem disposed in said through bore and said head bore, said stem having an elongated shank with a stem head at a blind end of said shank and having gripping means at an end, opposite to said blind end, adapted to be gripped by an installation tool, wherein proximate to said stem head is a ring receiving portion of said elongated shank and proximate to said ring receiving portion on said elongated shank is a locking portion and proximate to said locking portion on said elongated shank is a break-groove; and a placement ring having an near end and a far end, said placement ring being initially disposed around said ring receiving portion of said elongated shank, wherein said blind rivet assembly is adapted for securing workpieces having aligned bores with the workpieces having an open surface at an open side and a blind surface at a blind side, and said enlarged shell head is adapted to be in engagement with the open surface of the workpieces, said shell being adapted to extend through the workpiece bores and said blind head section being located at the blind surface of the workpieces, and said stem being adapted for being axially pulled towards the open side of the workpieces with an axial pulling force when said gripping means is pulled by the installation tool, said placement ring being adapted to be forced into said through bore and said shell being adapted to deform outwards and form a blind head when said axial pulling force is applied, said placement ring and said stem being adapted to move due to said axial pulling force until the near end of said placement ring is located at a position proximate to the blind side of the workpieces and said placement ring cannot progress any further due to said shell deforming outwards and forming a blind shoulder that abuts against the blind side of the workpieces near the near end of said placement ring, said placement ring remaining one continuous piece, and wherein upon continued axial pulling of said stem, said stem is adapted to progressively move into said shell until said stem encounters said stop shoulder, whereupon material of said stop shoulder is adapted to move into said locking portion to arrest further movement of said stem, and wherein a portion of said stem on the open side at said break-groove is adapted for breaking by increased axial pulling upon completing setting of said rivet assembly.