Patent ID: 6551040
Filing Date: 2003-04-22
Classification: F16B

Abstract:
A blind type fastener for securing a plurality of workpieces including an outer workpiece having an outer side surface and an inner workpiece having an inner side surface comprising:a hollow sleeve having a through bore, said sleeve having a sleeve shank portion and an enlarged sleeve head at one end, a pin, said pin having a pin shank portion and a pin head segment, said pin shank portion adapted to be located within said bore of said sleeve with said pin head segment located at the end of said sleeve shank portion opposite said sleeve head, said pin shank portion having a pull section opposite from said pin head segment and adapted to be gripped by an installation tool whereby a relative axial force can be applied between said pin and said sleeve for installing said fastener, said through bore of said sleeve having an enlarged bore portion in said sleeve shank portion and a reduced diameter bore portion proximate thereto and defining a radially inwardly extending sleeve stop shoulder at the juncture of said enlarged and reduced bore portions, said pin having a pin shoulder portion adjacent said pin shank portion and being of a diameter larger than that of said pin shank portion, a pin stop shoulder defined by the juncture of said pin shoulder portion and said pin shank portion, a lock groove located proximate said pin stop shoulder, said pin head segment adapted to engage said sleeve shank portion and to deform the same to form a blind head opposite said sleeve head in response to a relative axial force applied between said pin and said sleeve, said pin stop shoulder adapted to engage said sleeve stop shoulder, said pin head segment having an enlarged shear ring adapted to engage the outer end of said sleeve shank portion, said pin head segment having a reduced diameter retention portion connected to the end of said shear ring opposite from said outer end of said sleeve shank portion, said retention portion comprising a plurality of grooves and crests, said shear ring adapted to be moved into said sleeve shank portion through said outer end to form a tulip shaped blind head with a clamp and lock section at the inner side surface of the workpieces at a preselected magnitude of relative axial force and to be at a position substantially blocked from further movement at the inner side surface, said shear ring adapted to be sheared from said pin head segment at a larger magnitude of relative axial force whereby said pin shank portion will be moved through said sleeve shank portion until said pin stop shoulder engages said sleeve stop shoulder to form said lock, said shear ring being sheared across a shear plane whereby an opening is formed in said shear ring having a preselected diameter less than the diameter of said crests, as said pin shank portion is moved with movement of said shear ring blocked said retention portion is moved more or less through said shear ring with said crests engaging said shear ring to form a lock at said blind head, said pin stop shoulder and said sleeve stop shoulder having engaging surface means for directing the material of said sleeve stop shoulder substantially radially inwardly into said lock groove to lock said pin and said sleeve together and to finally form a stop surface on said sleeve for stopping axial movement of said pin through said sleeve.