Deformable tubular fastener with external tapping threads

Claim 1

A BLIND FASTENER COMPRISING A TUBULAR SLEEVE DEFINING AN AXIS AND HAVING FIRST AND SECOND ENDS, A HEAD AT SAID FIRST END, A FIRST ANNULAR PORTION HAVING A PREDETERMINED WALL THICKNESS AXIALLY SPACED FROM SAID HEAD AND HAVING AN INTERNAL SCREW THREAD, A SECOND ANNULAR PORTION HAVING A WALL THICKNESS SUBSTANTIALLY LESS THAN SAID PREDETERMINED WALL THICKNESS AXIALLY BETWEEN SAID HEAD AND SAID FIRST ANNULAR PORTION AND OUTWARDLY DEFORMABLE BY FORCE TENDING TO SHORTEN SAID SLEEVE, AND AN EXTERNAL SCREW THREAD AXIALLY BETWEEN SAID HEAD AND SAID SECOND END AND HAVING AT THE AXIAL END THEREOF REMOTE FROM SAID SECOND END A CIRCUMFERENTIALLY CONTINUOUS PORTION PARTLY ON EACH SAID ANNULAR PORTION AND HAVING PREDETERMINED MAJOR, MINOR AND PITCH DIAMETERS AND AT THE AXIAL END THEREOF REMOTE FROM SAID HEAD A CIRCUMFERENTIALLY DISCONTINUOUS SELF-TAPPING PORTION IN PHASE WITH SAID CONTINUOUS PORTION AND HAVING AT THE AXIAL END THEREOF ADJACENT SAID CIRCUMFERENTIALLY CONTINUOUS PORTION SAID MAJOR, MINOR AND PITCH DIAMETERS, FOR TAPPING ALIGNED CYLINDRICAL HOLES OF PREDETERMINED DIAMETER LESS THAN SAID MAJOR DIAMETER THROUGH INNER AND OUTER PLATES TO BE CLAMPED TOGETHER BY SAID SLEEVE, AND SAID SLEEVE FURTHER HAVING AN UNTHREADED CYLINDRICAL EXTERNAL SURFACE AXIALLY BETWEEN SAID HEAD AND SAID CONTINUOUS THREAD PORTION AND JOINING THE LATTER AND HAVING A DIAMETER SUBSTANTIALLY EQUAL TO SAID PITCH DIAMETER, SAID UNTHREADED CYLINDRICAL EXTERNAL SURFACE EXTENDING AXIALLY FROM SAID HEAD A DISTANCE WHICH IS GREATER THAN THE AXIAL LENGTH OF SAID CYLINDRICAL HOLE OF SAID OUTER PLATE AND LESS THAN THE SUM OF SAID LENGTH AND THE AXIAL LENGTH OF SAID CYLINDRICAL HOLE OF SAID INNER PLATE, WHEREBY SAID SLEEVE CAN BE ROTATED INTO SAID PLATES, WITH SAID SECOND END OF SAID SLEEVE ENTERING SAID OUTER PLATE, TO CAUSE SAID SELF-TAPPING PORTION TO TAP SAID CYLINDRICAL HOLES AS AFORESAID, AFTER WHICH SAID UNTHREADED EXTERNAL CYLINDRICAL SURFACE WILL BEND OVER THE THREADS SO TAPPED EXCEPT FOR PART OF THE THREADS SO TAPPED IN SAID INNER PLATE, THUS TO CREATE A TIGHT FIT BETWEEN SAID UNTHREADED EXTERNAL CYLINDRICAL SURFACE AND SAID PLATES AND ASSURING THAT SAID PLATES WILL BE TIGHTLY DRAWN TOGETHER PRIOR TO OUTWARD DEFORMATION OF SAID SECOND ANNULAR PORTION OF SAID SLEEVE TO FORM A BULGE AGAINST SAID INNER PLATE.