Lagging sheet for mine backfills - has double sheet spot welded from singles to form sealed surface with inserted sheets

摘要

The lagging sheet for use in mines, where it provides a sealed surface suitable for backfilling with instant packing material, consists of two sheets placed parallel to one another and spot-welded to produce a double sheet in which the internal spot welds are minimally spaced from the rims sufficient to allow an identical sheet to be inserted between, on all four sides. The sheets thus overlap to form a sealed join between for backfilling purposes. It is also possible to insert several double sheets into one another to form a sealed surface, or again arrange single and double sheets in a staggered array. The sheets may also be bent to produce curved shuttering surfaces.