BELT BEING FORMED OF MATERIAL SUBSTANTIALLY NOT EXHIBITING LINEAR EXPANSION

摘要

A band made from a material normally elastically non-stretchable in its longitudinal direction to which elastic stretchability is imparted by one or more sections which include lateral non-rectilinear band portions on both sides of the central longitudinal band plane which are concavely shaped as viewed from the central longitudinal plane to form a central window which at least approximately resembles an hourglass. The lateral non-rectilinear band portions are thereby made by cut-outs in the band along its longitudinal sides and in the center area. In one embodiment, the cut-outs along the sides are segmentally shaped while the window in the central area is made of a shape resembling an hourglass. Adjacent sections are connected with each other by transversely extending web portions delimited in the longitudinal direction by end surfaces of the central cut-outs.