Resilient material securing equipment - has nut forming stop on screw shank turning only under predetermined reactive torque

摘要

The equipment secures a layer of resilient material in particular to a base structure, being particularly for insulating material to a building wall. It comprises a screw with drill bit at the tip and engaged by a spanner at its rear end. This is passed through a bush with flange bearing against the material surface. The bush contains an inner stop for the part of the screw engaging in the structure. A nut (25) on the threaded portion (22) of the screw shank clear of the drill tip (23) forms a stop (26), and engages with the shank to a degree such that it only turns on it under reactive torque above a predetermined value. This torque is sufficient to drive the drill tip into the structure (10). USE/ADVANTAGE - The screw can be driven home for a predetermined length irrespective of the material thickness.