| 摘要 |
A shingle-pattern roofing sheet manufactured of sheet metal profile by means of bending or press-forming, the roofing sheet having an advantageous, durable and attractive appearance which is achieved by utilizing the strength and ductility properties of the raw material. The successive steps (2) formed in the sheet metal profile are winding with respect to the direct cross-section of the sheet so that the bending directions (3, 4) of the sides (5, 6) of successive bent steps (2) are essentially divergent, and that the bending angles of the respective sides are preferably chosen so that the step-like pattern can be created without stretching the material, so that every second step has a positive bending angle ( alpha ) and the rest have a negative bending angle ( alpha ). |
