Patent Number: 8,876,218

Title: Hydraulic circuit for longwall support

Abstract: A hydraulic circuit for longwall support for use in underground mining for supporting a longwall by means of a plurality of support shields includes in the annular piston line of each cylinder/piston unit a pressure sensor. The pressure sensor, upon reaching a predetermined maximum pressure activates a pressure deviation signal, causes the entire longwall to be depressurized by means of a longwall shut-off valve. The pressure deviation signal is blocked for one of the hydraulic valves against each triggering signal.

Inventors: Weigel; Wilfried (Werne, DE), Wulfing; Gerhard (Velbert, DE), Rahms; Peter (Billerbeck, DE)

Assignee: Tiefenbach Control Systems GmbH

International Classification: E21D 23/26 (20060101); E21C 35/16 (20060101)

Expiration Date: 2019-11-04 0:00:00