Abstract: The invention provides a yieldable connection between a metallic rod-shaped body and a holding means through which it passes and is intended particularly for yieldable rock bolts (roof bolts) anchor bolts and yieldable props, e.g. for mining and tunnelling. For that purpose shear bodies, e.g. spheres or inclined cylindrical pins are provided between the holding means and the slidable rod-shaped body and project some distance into the cross-section of the rod-shaped body. On sliding of the latter, in the holding means, these shear bodies form grooves in the rod, whereby energy is absorbed.

Abstract: Force transmission device suitable for the performance of deformation work comprising a bush having a tapering interior, including a particulate filling material in the form of spheres and/or a granulate and a ribbed rod passing through the bush, the particulate filling material being present in at least two different sizes and the larger sized bodies of the filling material being essentially accommodated at the converging end of the interior, at least some of the bodies of the filling material being larger than the magnitude by which the ribs of the rod project.

Abstract: To form a joint between members, a projection of at least one member is introduced into a bore of another member and is held therein by particulate material, which has been filled into the space provided between the interextending portions of the members to be joined and has entered recesses provided in the mutually confronting surfaces of the interextending portions.