Mine roof support and method in longwall mining of thick mineral seams
US4065929A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 8, 1976 |
| Grant date | Jan 3, 1978 |
| Priority date | — |
| Expiry date | Mar 8, 1996 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21D23/082
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A bi-directional shearing machine mines a longwall face at the bottom of a thick mineral seam in a retreat operation under the protection of a row of adjacent powered roof supports each of which extends in a direction transverse to the solid face. Progressive advance of these roof supports allows the overlying mineral strata to cave. Each roof support is separated into articulated forward and aft units provided with separate sets of hydraulic props and having their solid canopies interfitted in end-to-end relation. The bases of the two units are interconnected with a push-pull hydraulic ram which enables relative longitudinal movement between the two units so that they may be advanced independently along a common axis toward the solid longwall face as the work progresses. During the advance of the forward units to provide face support, plowing and loading of caved mineral on the gob side may proceed without interruption. To accelerate caving, the aft units are independently advanced with an attached gob side chain conveyor and gob plow retracted beneath their canopies for protection. Starting from this retracted position, the gob conveyor and gob plow are allowed to load gradually …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.