Patent ID: 6233802
Filing Date: 2001-05-22
Classification: B21J,F16B,Y10T

Abstract:
In a fastening system including a two piece fastener for securing a plurality of workpieces together and an installation tool for installing the fastener and with the fastener including a pin member and a tubular collar and with said collar having a generally straight collar shank adapted to be swaged into lock grooves on said pin member in response to a relative axial force or swage load applied between said pin member and said collar by said installation tool and providing a desired magnitude of clamp load on the workpieces in response to a predetermined magnitude of swage load,said pin member having an elongated pin shank adapted to be located in aligned openings in the workpieces and terminating at one end in an enlarged head adapted to engage a surface on one side of the workpieces and at its opposite end in a grooved portion adapted to extend past an opposite surface on the opposite side of the workpieces, said grooved portion comprising a locking portion having a plurality of said lock grooves defined by circumferentially extending pin grooves and associated pin shoulders terminating in pin crests, said pin grooves being wide and having an effective width Wg relative to the effective width Wc of the crests with a ratio of Wc/Wg of no greater than around 0.30, said pin grooves having an elongated root with a generally smooth contour, said collar shank adapted to be swaged into said lock grooves whereby the workpieces are fastened together to define the fastened joint, said collar when swaged having collar grooves and shoulders interlocking said pin grooves and shoulders,said installation tool having an anvil member with a swage cavity having an effective throat swage portion adapted to overengage said collar shank to thereby swage it radially inwardly into said lock grooves,said collar shank having a predetermined volume of material which is generally greater than the available volume defined by said effective throat swage portion and the confronting portion of said lock grooves into which said collar shank is swaged and with the material of said collar shank not fully engaging said root during swage and thus not completely filling said lock grooves after swage, said collar shank being of sufficient length to provide a predetermined number of said collar shoulders engaged with a corresponding number of said pin crests,said collar shank having a through bore having a bore diameter relative to the crest diameter of said pin crests for providing a minimal clearance prior to swage whereby the relative axial force for swage is minimized.