Mine roadway arch segment set - uses specified tangent and intersection angles between identically curved lengths to form each segment

摘要

The triple segment set is for mine roadway arches from four segments all congruent in shape and each made of two longitudinal parts, at constant crank angle. Both part lengths are curved. The tangents at the arch centre of the short length and that to the arc of the long part are at the same distance from the intersection of the part lengths. The arc centre of the short length forms a constant angle of approx. 153 deg.. The shorteer of the two segment lengths is as long as the strap connection between aligned segments. Both length parts are of identical curvature.