Mine explosion barrier trough - has plastics box with top lugs for lid locking into recesses to support adjoining stacked box

摘要

The mine explosion water barrier trough is a plastics block shaped box which tapers downward and has an upper lid flange and vertical stiffening pleats in the sides and inside lugs to bear against the adjoining trough when stacked. The lugs (7) project from the inside of the lid flange (5) and engage hollows underneath the lid. When stacked, the lug surfaces (8) support the top ends of the stiffener pleats (9) lying below the lugs in the adjoining trough. The supporting surfaces on the lugs (8, 7) and the endfaces (10) of the pleats (9) are horizontal. Thus the lugs combine the functions of lid support for easy release, and locking member in the stacked position.