Abstract: An expansion anchor for mounting in a receiving socket in base material to enable an object to be clamped thereto. The anchor comprises a longitudinally split tubular sleeve (1) to which an internally threaded expansion body (6) is retained by means of lugs (10) thereof engaging slots (2,3,11) in the body of the sleeve (1). The slots (2,3,11) are provided to permit the tubular sleeve (1) to expand into gripping contact with the receiving socket as the expansion body (6) is drawn axially within the sleeve (1) by a threaded anchor rod (15). The sleeve (1) is provided with support means (8,12,13,14) for the anchor rod (15) when in engagement with the expansion body (6). The support means (12,13,14) constitute telescopic spacer elments between the head of the anchor rod (15) and the tubular sleeve (1) which allow free relative movement between the expansion body (6) and the head of the anchor rod (15) until the anchor is set in the receiving socket.

Abstract: An anchor bolt for clamping an object tightly against a receiving surface comprises a threaded elongated anchor rod having a head, an expansion body threadedly received on the rod in spaced relation to the head, and an expansion sleeve on the expansion body that is expanded as the rod is threaded into the expansion body. The anchor rod extends through an outer sleeve between an abutment on the head and an abutment on the expansion body, and spacers, such as a coiled spring or further sleeves, are provided between the anchor rod and the outer sleeve. The bolt provides improved shear resistance and anti-vibration efficiency.