Hydraulic telescopic concrete mine support column formwork - has diametrally opposite piston units clamped to top and bottom half shells

摘要

Two telescoping tubular formwork housing units, with the bottom one supporting a hydraulic thrust-piston assembly, in contact with the roof, for the top one, make up a mechanism for erecting a concrete or similar pillar-type support in a mine. Both bottom and top housing units are in the form of open-ended interconnectable half-shells. Two diametrally opposed hydraulically activated piston assemblies are clampable, by means of hinge plates on the bottom unit for the cylinders and on the top unit for the piston rods. A number of axially spaced grooves may be worked in the upper units periphery.