Patent · US Active

Hydraulic circuit for longwall support

US8876218B2 · kind B2 · utility

0Cited by

11References

2Claims

0Family size

Assignee

TIEFENBACH CONTROL SYSTEMS GMBH · DE

Inventors

Wilfried Weigel · Werne, DE
Gerhard Wülfing · Velbert, DE
Peter Rahms · Billerbeck, DE

Key dates

Filing date	Mar 15, 2012
Grant date	Nov 4, 2014
Priority date	—
Expiry date	Jul 25, 2032

Classification

Technology area (CPC E)Fixed Constructions
CPC primaryE21C35/302
WIPO fieldCivil engineering
WIPO sectorOther fields

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.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.