ADVANCING ASSEMBLY AND POWERED SHIELD SUPPORT HEREWITH

摘要

An advancing assembly for underground powered shield support having at least one floor skid for supporting the powered shield support, an advancing beam and a substantially perpendicularly arranged lift cylinder for lifting the floor skid relative to the advancing beam during an advancing movement. The lift cylinder has a cylinder foot supported above the advancing beam and a cylinder head buttressed on a bridge and hydraulically displaceable relative to the cylinder foot. In order to improve a powered shield support and in particular the advancing assembly of a powered shield support, the lift cylinder is a double lift cylinder having a first cylinder stage, comprising the cylinder head, and a second cylinder stage, wherein a compression spring is arranged between the cylinder stages.