Wall plugs

Claim 1

A WALL PLUG COMPRISING A SUBSTANTIALLY CYLINDRICAL METALLIC CASING HAVING AN ANNULAR PROJECTION AT ONE END THEREOF AND HAVING A PLURALITY OF WIDE LONGITUDINAL SLOTS THEREIN DIVIDING THE SAME INTO AT LEAST TWO ARCUATE WALL PORTIONS ALL CONNECTED TO SAID ANNULAR PROJECTION, AND AN INSERT OF COMPRESSIBLE MATERIAL WITHIN AND SUBSTANTIALLY COMPLETELY FILLING SAID CASING FOR RECEIVING A CONNECTING MEANS AFTER INSERTION OF SAID WALL PLUG INTO A HOLE, SAID METALLIC CASING HAVING A TAPERED END PORTION INCLUDING AXIALLY EXTENDING NARROW STRIPS CONNECTING OPPOSING ONES OF SAID ARCUATE WALL PORTIONS, SAID SLOTS EXTENDING INTO SAID TAPERED END PORTION, SAID STRIPS FORMING AT LEAST PARTS OF SAID TAPERED END PORTION, SAID TAPERED END PORTION BEING PROVIDED WITH CUT-OUTS EXTENDING TRANSVERSE TO AND JOINING SAID LONGITUDINAL SLOTS PROVIDING WEAKENED REGIONS IN SAID TAPERED END PORTION WHEREBY, WHEN SAID PLUG IS DRIVEN INTO A HOLE OF SMALLER DIAMETER THAN THE CYLINDRICAL CASING, SAID TAPERED END PORTION IS TRANSFORMED BY THE WEDGING ACTION OF SAID HOLE OF SMALLER DIAMETER INTO A MORE CYLINDRICAL FORM OF A SMALLER DIAMETER THAN THAT OF SAID CYLINDRICAL CASING WITHOUT CREATING WRINKLES AT THE TRANSITION BETWEEN SAID TAPERED END PORTION AND SAID CYLINDRICAL WALL PORTIONS AND THE WALL PORTIONS WILL THEN BE COMPRESSED BY THE CAMMING ACTION OF SAID HOLE OF SMALLER DIAMETER INTO A CYLINDRICAL CASING OF A SMALLER DIAMETER THUS PRESTRESSING SAID COMPRESSIBLE MATERIAL WITHIN SAID CASING.