Hydraulic roof support control system
US4327628A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 24, 1980 |
| Grant date | May 4, 1982 |
| Priority date | — |
| Expiry date | Jun 24, 2000 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21D23/26
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A hydraulic control system is provided for a mine roof support assembly constituted by a plurality of roof support units positioned side-by-side. The control system comprises a respective control valve assembly having a plurality of similar control valves each of which controls a respective hydraulic appliance associated with the corresponding roof support unit. Each control valve can be actuated optionally by an actuator mounted on either one of the two adjacent roof support units, or by either one of two actuating devices mounted one on each of said two adjacent roof support units. Each control valve includes two servo valves having a pair of first and second axially aligned servo-pistons which are separate and independently operable with respect to each other.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.