| 摘要 |
FIELD: plastic metal working, possibly manufacture of hollow cylindrical articles. ^ SUBSTANCE: method comprises steps of making blank out of rolled sheet by cutting it along the whole width of sheet and simultaneously forming in one end of blank at least one main arc-shaped protrusion and in other end of blank forming at least one main arc-shaped recess; at each side of main protrusion forming in addition at least one adjacent to it additional arc-shaped recess; at each side of main recess forming in addition at least one additional arc-shaped protrusion adjacent to it; then bending aside ends of blank, preliminarily bending and finally bending blank and simultaneously joining ends of blank without gap. ^ EFFECT: lowered labor consumption, improved metal using factor. ^ 7 cl, 4 dwg |
