Powered support assembly

摘要

The invention relates to a powered support assembly which consists of a low-pressure part on the goaf side and linked to it a high-pressure part on the coal-face side. The design of the low-pressure part on the goaf side as a temporary chock enables the roof to be carefully supported over a large area and at the same time enables the working space to be shielded from the caved space. The temporary chock consists of a box-shaped base part, which has a recess open towards the floor, and of a head part. The base part and the head part are extended by a low-pressure medium by means of roller bellows. The low-pressure medium (air or emulsion) can at the same time be used for cooling the face. The powered support assembly can be varied in its overall length by hydraulic cylinders which are connected between the low-pressure part and the high-pressure part. The floor bar, designed as a winning rail, plunges through the recess in the temporary chock when the overall length of the powered support assembly is reduced.