Blind fastener

Claim 1

AS AN ARTICLE OF COMMERCE A STRUCTURAL TYPE BLIND FASTENER OF THE BOLT OR SCREW TYPE ADAPTED TO BE DRIVEN TO A PREDETERMINED TORQUE IN SECURING TOGETHER A PLURALITY OF STRUCTURES HAVING ALIGNED APERTURES THEREIN FORMING A PASSAGE THERETHROUGH ACCESSIBLE FROM ONLY ONE SIDE: A FIRST MEMBER COMPRISING A CYLINDRICAL BODY HAVING AN EXTERNAL THREAD AND A CIRCULAR HEAD AT ONE END PROVIDED WITH A BEARING FACE INCLINED OUTWARDLY AWAY FROM SAID BODY, A DRIVING CONNECTION AT THE END OF SAID BODY OPPOSITE SAID HEAD, AND A WEAKENED SECTION BETWEEN SAID BODY AND SAID DRIVING CONNECTION ADAPTED TO BREAK WHEN SUBJECTED TO A PREDETERMINED TORQUE; A SECOND MEMBER COMPRISING AN INTERNALLY THREADED CYLINDRICAL TUBULAR-LIKE BODY PORTION HAVING AN OUTSIDE DIAMETER SUBSTANTIALLY EQUAL TO THE DIAMETER OF SAID HEAD OF SAID FIRST MEMBER THREADED ONTO SAID CYLINDRICAL BODY OF SAID FIRST MEMBER AND AN INTEGRAL HEAD AT THE END OF SAID TUBULAR-LIKE BODY REMOTE FROM SAID HEAD OF SAID FIRST MEMBER, SAID HEAD OF SAID FIRST MEMBER BEING LOCATED WITHOUT THE ADJACENT END OF SAID SECOND MEMBER AND ADAPTED TO BE DRAWN THEREIN TO EXPAND SAID ADJACENT END OF SAID SECOND MEMBER UPON RELATIVE AXIAL MOVEMENT BETWEEN SAID MEMBERS INCIDENT OF SETTING OR DRIVING THE FASTENER; THE MAJOR POR TION OF SAID EXTERIOR AND INTERIOR THREADS OF SAID FIRST AND SECOND MEMBERS INTERENGAGING WITH CLEARANCE FIT, AS DEFINED IN HANDBOOK H28 (1957), NAFTIONAL BUREAU OF STANDARDS; A FORMED ANNULAR GROOVE IN SAID TUBULAR-LIKE BODY PORTION OF SAID SECOND MEMBER PRODUCED WITH SAID FIRST AND SECOND MEMBERS ASSEMBLED WITH ONE ANOTHER AS AFORESAID; AND AT LEAST ONE UNITERRPTED ANNULAR PORTION OF LIMITED AXIAL LENGTH OF SAID EXTERIOR AND INTERIOR THREADS OF SAID FIRST AND SECOND MEMBERS FORMED BY THE INWARD DEFORMATION OF THE METAL OF SAID TUBULAR-LIKE BODY PORTION OF SAID SECOND MEMBER BY THE FOMATION OF SAID GROOVE THEREIN, INTEREGAGING WITH AN INTERFERENCE FIT, AS DEFINED BY SAID HANDBOOK, FORMING A FRICTION-TYPE THREAD INTERFERENCE LOCK BETWEEN SAID FIRST AND SECOND MEMBERS.