Ram for prop and roadway support for underground mining and tunnelling

摘要

The ram has a pressure limiting valve coupled to an inner space via a rising pipeline on the outside of external ram. A single, telescopic ram is used. A swirl damper is fitted to the pipeline end in front of the pressure limiting valve. The damper divides the vol. flow into fine partial flows. Pref. the swirl damper has a chamber (12) with much larger opening cross-section than that of the feed and discharge line (13,14). In the chamber is located a perforated plate (15), transversely to the flow direction (18), with several through bores (16,17).