Plastic anchor-type fastener and driver means for expanding same

Claim 1

A RE-USABLE ANCHOR-TYPE FASTENER, COMPRISING THE COMBINATION OF AN EXPANDABLE INSERT MOLDED OF SYNTHETIC RESIN HAVING THE GENERAL PROPERTIES OF NYLON AND HAMMER-DRIVEN MEANS TO EXPAND SAID INSERT, SAID INSERT HAVING A LONGITUDINAL HOLE FORMED THEREIN AT ONE END OF RECEIVE SAID HAMMER-DRIVEN MEANS, THE OPPOSITE END OF SAID INSERT BEING LONGITUDINALLY SLOTTED TO FORM A PLURALITY OF OUTWARDLY FLEXIBLE PORTIONS, SAID HAMMER-DRIVEN MEANS COMPRISING A HEADED NAIL HAVING A SUBSTANTIALLY CYLINDRICAL SHANK WITH A POINTED TIP ADAPTED FOR WEDGING ENTRY BETWEEN SAID OUTWARDLY FLEXIBLE PORTIONS TO FORCE THEM RADIALLY OUTWARDLY UPON BEING DRIVEN THROUGH SAID LONGITUDINAL HOLE AND INTO SAID SLOTTED END OF THE INSERT, SAID NAIL HAVING SMOOTH-CRESTED SCREW-THREADS, WHEREIN SAID SMOOTH CREST JOINS THE THREAD FACES BY ROUNDED EDGES, SAID SCREW THREADS BEING FORMED ON SAID SHANK ADJACENT ITS HEAD AND TERMINATING APPROXIMATELY MIDWAY OF THE LENGTH OF THE SHANK TO ENGAGE THE WALL OF THE LONGITUDINAL HOLE IN THE INSERT WITHOUT REAMING ACTION AS THE SAME IS FORCED INTO SAID INSERT BY A TRANSLATORY MOVEMENT AND TO FORM TRANSITORY THREADS THEREIN COMPLEMENTARY TO SAID NAIL THREADS, SAID HEAD BEING ALSO FORMED WITH MEANS ADAPTED TO BE ENGAGED BY A TOOL TO ROTATE SAID NAIL TO CAUSE RETROGRADE MOVEMENT THEREOF AND REMOVAL FROM THE INSERT.