Wedge type expansion bolt

Claim 1

A SECUREMENT DEVICE ADAPTED FOR INSERTION IN A WALL BORE COMPRISING A BOLT MEMBER HAVING A CYLINDRICAL SHANK WITH A FORWARDLY DIVERGENT LEADING END SECTION ON THE SHANK FOR INSERTION IN THE WALL BORE, SAID SHANK BEING PROVIDED WITHA A FIXED ENLARGED ANNULAR PORTION ON THE PERIPHERAL SURFACE OF SAID SHANK IN REARWARDLY SPACED RELATION TO THE LEADING END SECTION AND A MOVABLE ENLARGED ANNULAR PORTION ON THE PERIPHERAL SURFACE OF SAID SHANK BETWEEN SAID FIXED PORTION AND THE LEADING END PORTION, A SPRING MEMBER INTERPOSITIONED BETWEEN SAID FIXED AND MOVABLE PORTIONS WITH OPPOSITE ENDS OF SAID SPRING ABUTTING SAID FIXED AND MOVABLE ANNULAR PORTIONS AND BEING BIASED TO NORMALLY URGE SAID MOVABLE PORTION IN A DIRECTION TOWARD THE LEADING END SECTION, A PAIR OF SLEEVE-LIKE WEDGING ELEMENTS ARRANGED IN SURROUNDING RELATION TO THE LEADING END SECTION OF SAID SHANK AND INCLUDING MEANS CONNECTING THE FORWARD ENDS OF SAID WEDGING ELEMENTS WITH THE REARWARD TRAILING END OF SAID WEDGING ELEMENTS FREELY ABUTTING THE MOVABLE ANNULAR PORTION OF SAID SHANK, SAID WEDGING ELEMENTS HAVING INNER SURFACES COMPLEMENTARY TO THE FORWARDLY DIVERGENT LEADING END SECTION AND BEING MOVBALE REARWARDLY AGAINST SAID MOVABLE PORTION AND AGAINST THE URGING OF SAID SPRING MEMBER WHEN THE SHANK IS INSERTED IN THE WALL BORE, AND SAID SPRING MEMBER URGING SAID WEDGING ELEMENTS FORWARDLY AND OUTWARDLY ALONGT THE LEADING END SECTION INTO WEDGING ENGAGEMENT WITH THE WALL OF THE BORE UPON MOVEMENT OF SAID SHANK IN THE DIRECTION OF WITHDRAWAL FROM THE WALL BORE.