Blind two-piece fastener

Claim 1

A FASTENER FOR JOINING TOGETHER A PLURALITY OF WORKPIECES HAVING ALIGNED OPENINGS COMPRISING: A PIN AND A TUBULAR SLEEVE MEMBER, SAID SLEEVE MEMBER HAVING A THROUGH BORE AND HAVING AN ENLARGED HEAD FOR ENGAGING THE FORWARD ONE OF THE WORKPIECES AND HAVING A CYLINDRICAL PORTION FOR EXTENDING REARWARLY FROM SAID ENLARGED HEAD THROUGH THE ALIGNED OPENINGS AND TERMINATING BEYOND THE REARWARD ONE OF THE WORKPIECES, SAID BORE HAVING A FORWARD BORE PORTION EXTENDING GENERALLLY FORWARDLY FROM A POINT PROXIMATE SAID ENLARGED HEAD AND A REARWARD BORE PORTION EXTENDING GENERALLY REARWARDLY FROM SAID POINT WITH SAID FORWARD BORE PORTION BEING OF A SMALLER DIAMETER THAN SAID REARWARD BORE PORTION, A RADIALLY INWARDLY EXTENDING SHOULDER PORTION LOCATED ADJACENT SAID ENLARGED HEAD AND AT THE JUNCTURE OF SAID FORWARD AND REARWARD BORE PORTIONS, SAID PIN COMPRISING A SHANK EXTENDING THROUGH SAID BORE AND HEAD MEANS AT ONE END OF SAID SHANK ENGAGEABLE WITH THE END OF SAID CYLINDRICAL PORTION OPPOSITE SAID ENLARGED HEAD FOR FORMING A DEFORMED, ENLARGED HEAD IN THAT PORTION OF SAID SLEEVE EXTENING BEYOND THE REARWARD ONE OF THE WORKPIECES AS SAID PIN IS MOVED AXIALLY FORWARDLY RELATIVELY TO SAID SLEEVE, MEANS ON THE END OF SAID SHANK OPPOSITE SAID HEAD MEANS FOR BEING GRIPPED BY A TOOL WHEREBY A RELATIVE AXIAL FORCE CAN BE APPLIED BETWEEM SAID PIN AND SAID SLEEVE FOR SETTING THE FASTENER, SAID SHANK HAVING AN ANNULAR LOCKING GROOVE LOCATED INTERMEDIATE ITS ENDS, SAID LOCKING GROOVE HAVING A FIRST ANNULAR SHOULDER AT ITS REARWARD END ON SAID SHANK AND BEING OF A DIAMETER LESS THAN SAID REARWARD BORE PORTION AND GREATER THAN SAID SHOULDER PORTION AND BEING ENGAGEABLE WITH A FIRST PORTION OF SAID SHOULDER PORTION FOR DEFORMING MATERIAL FROM SAID SHOULDER PORTION INTO SAID LOCKING GROOVE AS SAID PIN IS MOVED RELATIVELY FROM ITS INITIAL UNSET POSITION TO A PRESELECTED POSITION AFTER THE FASTENER HAS BEEN SET WHEREBY SAID PIN AND SAID SLEEVE ARE LOCKED TOGETHER, AN ANNULAR PORTION LOCATED AT THE FORWARD END OF SAID LOCKING GROOVE AND BEING OF A DIAMETER PROXIMATE TO THE DIAMETER OF SAID FORWARD BORE PORTION, SAID ANNULAR PORTION HAVING AN AXIAL LENGTH LESS THAN THAT OF SAID FORWARD BORE PORTION, A SECOND ANNULAR SHOULDER ON SAID SHANK INTERMEDIATE SAID FIRST ANNULAR SHOULDER AND SAID HEAD MEANS AND BEING OF A DIAMETER GREATER THAN SAID FIRST ANNULAR SHOULDER AND BEING ENGAGEABLE WITH A SECOND PORTION OF SAID SHOULDER PORTION FOR STOPPING THE AXIALLY FORWARD MOVEMENT OF SAID PIN AT SAID PRESELECTED POSITION SAID SECOND ANNULAR SHOULDER EXTENDING GENERALLY TRANSVERSELY TO THE AXIS OF SAID PIN AND BEING AXIALLY SPACED FROM SAID FIRST ANNULAR SHOULDER A DISTANCE LESS THAN THE AXIAL LENGTH OF SAID FORWARD BORE PORTION.