Strata movement indicator
AssigneeCoal Industry (Patents) Limited
InventorAlan S. Bloor
Life of this patent
Estimating the term…
Abstract
A strata movement indicator includes at least two lengths of suspension wire respectively for remote and near anchors locatable in the same borehole. Each wire carries a cylinder provided with indicator markings, the cylinders being moveable with respect to one another and to a reference tube fixed in the mouth of the borehole. Relative movement of the cylinders with respect to one another and/or to the reference tube indicates the degree of strata movement.
Claims8
A strata movement indicator for use in association with a borehole formed in strata, the indicator including at least two flexible elongate suspension members, anchors for anchoring the suspension members at spaced apart locations in use within the borehole formed, a guide through which the members pass, the guide being fixable in use within the borehole, and a cylindrical indicator element held on each suspension member and movable in relation to the guide and to one another in the manner of a piston, the movement of each element being indicative of strata movement.
Dependencies are inferred from the claim text.