Jack for voids in mining - has outer skin containing expandable absorbent material

摘要

The flat jack is for filling voids in mining, partic. ruptures in the roof of a gallery. It consists of an outer skin which is filled with a material whose volume increases by a multiple of its original by an expanding medium and water. A suitable moistening feed (6,7,8) is installed inside the cushion (3) complete with water connection (5) to thoroughly soak the material (2) inside the cushion. USE/ADVANTAGE - Cheap and easy to produce. Easy to place in position.