SPECIFIC FORMED CHANNEL SECTION AND METHOD FOR MANUFACTURE OF SUCH SECTION Russian patent published in 1999 - IPC

FIELD: plastic working of metals. SUBSTANCE: formed section has wall and vertical equal height strips. One of strips is provided with flange disposed at section inner side and having width at least three times as large as triple thickness of section, and other strip is provided with member of doubled thickness equal to 0.5-0.75 of strip height. Method involves sequential bending of section members in rolls by directing section through passes; bending flange and member of doubled thickness in first passes to obtain their ultimate configuration, with section member transverse motion being limited; providing simultaneous bending of both strips in following passes, with bending angles relative to section wall being equal and section wall being disposed in horizontal forming plane; bending strip with flange in forming pass for an angle of (90 deg + δ₁), and strip with doubled-thickness member for an angle of (90 deg + δ₂), where δ₁ and δ₂ are values of resilient springing of flange and doubled-thickness member, respectively. Method allows special-purpose formed channel-type section to be produced. EFFECT: increased efficiency, improved rigidity of produced sections and enhanced reliability in operation. 3 cl, 2 dwg