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US 4,065,929 AGranted
Mine roof support and method in longwall mining of thick mineral seams
AssigneeAtlantic Richfield Company
InventorTerry Lee Simpson
Life of this patent
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AssigneeAtlantic Richfield Company
InventorTerry Lee Simpson
Estimating the term…
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 out into the flushed coal.
In a longwall mining system, a roof support adapted to extend transversely between a face and a gob side conveyor comprising:
In a longwall mining system, a roof support adapted to extend transversely between a face and a gob side conveyor comprising:
In a system for longwall mining of a thick subsurface mineral seam wherein a longwall face is established below the top of the seam and wherein adjacent powered roof supports are progressively advanced to the longwall face as it is mined in retreat so as to induce sublevel caving of the overlying strata behind said advancing roof supports, the improvement wherein each of said roof supports comprises:
Dependencies are inferred from the claim text.