Screw-bush grouted into concrete rail sleeper - has permanently-resilient casing round top part resistant to temperatures occurring during mfr.

摘要

The bush (2) secures a screw in a concrete sleeper. At the top end (3) towards the sleeper surface it is enclosed in a casing (4) of permanently resilient material, and which is resistant to temperatures occurring during mfr. of the sleeper. This can be formed by dipping the bush end in a bath of suitable wax or similar material. Alternatively this can be sprayed onto it. As a further alternative, a sleeve of foam material can be fitted over the bush before mounting in the sleeper shuttering. USE/ADVANTAGE - Screw bush mounting avoids hairline cracking of concrete railway sleeper due to stress at hole edge.