Anchor bolt with anti projection mechanism

Abstract

An anchor bolt for fastening an object in a drilled borehole in a rock mass formation, which is to absorb violent impact loads such as those occurring during earthquakes in an energy dissipating manner. The anchor bolt comprises a split sleeve and a bolt component inserted in the split sleeve that, when pulled outwardly, expends the split sleeve until a key protruding from the surface of the bolt component abuts a ring, thereby informing the operator that appropriate anchoring and pre-tensioning of the anchor bolt in the borehole is reached. Another ring, interfacing with the split sleeve about the entry of the borehole, is designed to force expansion of the split sleeve, preventing a breaking anchor bolt to become a high-speed projectile.

Dependencies are inferred from the claim text.