Yieldable connection
OwnerFranz Powondrainventor
Life of this patent
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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.
Claims10
Process for attaining a yieldable connection between a metallic rod-shaped body and a holding means through which it passes, which comprises:
- forming recesses in the periphery of the rod-shaped body;
- fitting between the rod-shaped body and the holding means shear bodies which project into the recesses in the rod-shaped body;
- and causing relative longitudinal movement between the holding means and the rod-shaped body which on sliding of the latter in the holding means form grooves in the rod-shaped body.
Apparatus for providing a yieldable connection, said apparatus comprising:
- a rod-shaped body having at least one peripheral recess for receiving a shear body, at least one shear body having an inner end extending into a recess in said rod-shaped body and having a hardness greater than that of said rod-shaped body and a holding means having an opening through which the rod-shaped body passes and provided with support means for supporting the shear bodies, whereby relative longitudinal movement of said rod-shaped body toward said support means of said holding means causes said shear body to form a groove in said rod-shaped body.
Dependencies are inferred from the claim text.