Self-locking fastener and method of making same

Claim 1

A FASTENING ASSEMBLY FOR COOPERATION WITH A COMPLEMENTARY THREADED ELEMENT COMPRISING: A FASTENING MEMBER HAVING A PORTION WITH A SCREW THREAD FOR ENGAGEMENT WITH THE THREAD OF SAID COMPLEMENTARY ELEMENT; A LONGITUDINAL GROOVE IN SAID PORTION CUTTING THROUGH THE TURNS OF THE SCREW THREAD WITH CUT PORTIONS OF THE TURNS OF THE SCREW THREAD TERMINATING AT THE OPPOSITE SIDES OF THE GROOVE; AN ELONGATED RESILIENTLY DEFORMABLE PLASTIC INSERT BOTTOMED IN SAID GROOVE AND EXTENDING OUTWARDLY TO AT LEAST THE PITCH DIAMETER OF SAID SCREW THREAD BOTH IN THE REGIONS OF THE TURNS OF THE SCREW THREAD AND IN THE REGIONS OF THE VALLEYS FORMED BY THE TURNS OF THE SCREW THREAD AND PROTRUDING LATERALLY FROM THE GROOVE AT A PLURALITY OF POINTS AT EACH SIDE OF THE GROOVE IN INTERLOCKING ENGAGEMENT WITH PORTIONS OF THE TURNS OF THE SCREW THREAD IMMEDIATELY ADJACENT THE GROOVE TO ANCHOR THE INSERT AGAINST LONGITUDINAL MOVEMENT AT A FIRST SERIES OF LONGITUDINALLY SPACED POINTS AND TO MAKE PRESSURE CONTACT WITH SAID THREAD OF THE COMPLEMENTARY ELEMENT, CREST PORTIONS ONLY OF SAID CUT PORTIONS OF THE TURNS OF THE SCREW THREAD OVERHANGING THE GROOVE AND THE OUTER SURFACE OF THE INSERT FROM OPPOSITE SIDES OF THE GROOVE AND BEING DEFORMED TO PRESS ON THE OUTER SURFACE OF THE INSERT TO RETAIN THE INSERT UNDER PERMANENT TRANSVERSE COMPRESSION AGAINST THE BOTTOM OF THE GROOVE AND TO PREVENT BUCKLING OF THE INSERT AND TO ANCHOR THE INSERT AGAINST LONGITUDINAL MOVEMENT AT A SECOND SERIES OF LONGITUDINALLY SPACED POINTS, THE TWO SERIES OF POINTS BEING STAGGERED, THE LONGITUDINAL PORTIONS OF THE INSERT BETWEEN THE SUCCESSIVE CREST PORTIONS OF SAID CUT PORTIONS CONSTITUTING THE MAJOR PORTION OF THE LENGTH OF THE INSERT AND BEING FREE FROM RESTRAINT BY OVERHANGING MATERIAL OF THE SCREW THREAD.