Self-locking insert having a protective collar covering the locking means

Claim 1

IN A SELF-LOCKING INSERT FOR MOLDING IN PLACE IN A MOLDED BODY, THE COMBINATION OF: A HEAD LOCATED WITHIN SAID MOLDED BODY AND HAVING A KNURLED EXTERIOR SURFACE FOR ENGAGEMENT WITH THE BODY TO PREVENT BOTH ROTATIONAL AND AXIAL MOVEMENT THEREOF WITHIN SAID MOLDED BODY; A PIN-RECEIVING STEM FORMED INTEGRAL WITH SAID KNURLED HEAD AND EXTENDING THEREFROM WITHIN SAID MOLDED BODY AND INCLUDING A CYLINDRICAL WALL HAVING AN OPEN END AND A CLOSED END AND DEFINING A THREADED CHAMBER THEREWITHIN COMMUNICATING WITH SAID OPEN END, AN ANNULAR GROOVE EXTENDING CIRCUMFERENTIALLY ABOUT THE EXTERIOR OF SAID CYLINDRICAL WALL AND DEFINING A CIRCUMFERENTIAL AIR SPACE, AND A CONICALLY SHAPED INWARDLY EXTENDING RECESS LOCATED IN THE BOTTOM OF SAID GROOVE AND INDENTED A DISTANCE SUFFICIENT TO DEFLECT A PORTION OF SAID WALL INTO THE THREAD PATTERN OF SAID CHAMBER; AND A COLLAR HAVING A CYLINDRICAL INNER WALL AND OPPOSING OPEN ENDS, SAID COLLAR SURROUNDING THE CYLINDRICAL WALL OF SAID PIN-RECEIVING STEM IN A PUSH-FIT RELATIONSHIP AND HAVING A WIDTH GREATER THAN THE WIDTH OF SAID GROOVE AND SUFFICIENT TO COMPLETELY COVER SAID GROOVE SO AS TO SEAL SAID CIRCUMFERENTIAL AIR SPACE FROM SAID MOLDED BODY, AND SAID COLLAR HAVING A KNURLED EXTERIOR SURFACE FOR ENGAGEMENT WITH THE BODY TO PREVENT BOTH ROTATIONAL AND AXIAL MOVEMENT THEREOF WITHIN SAID MOLDED BODY.