Method of and apparatus for forming an outwardly projecting bulge in a steel wire strand for forming an anchor in concrete

摘要

To form a radially outwardly extending bulge in a steel wire strand made up of a plurality of individual wires, the strand is compressed along an axial length so that the individual wires deform radially outwardly and in spaced relation to one another. Compressive force is applied to one end of the strand and the strand is anchored at an axially spaced location from the end. A tubular member with a cylindrically shaped inside surface forms a limiting boundary for the outward movement of the individual wires. The tubular member is located between the end of the strand and the location where it is anchored. The end of the strand and the tubular member are rotatably supported. Each individual wire extends along an angular path about the axis of the strand between the end of the strand and the anchor location.