| 摘要 |
PCT No. PCT/AU86/00373 Sec. 371 Date Aug. 4, 1987 Sec. 102(e) Date Aug. 4, 1987 PCT Filed Dec. 8, 1986 PCT Pub. No. WO87/03518 PCT Pub. Date Jun. 18, 1987.A method of and apparatus for press forming sheet metal into articles, such as roof cladding element (10), having intersecting fold lines. A strip of metal is advanced through a forming die which has first (20) and second (21) stages and a press forming operation is performed on the metal strip in each stage of the die during each closing stroke of the die. One portion of the metal strip is formed in the second stage (21) of the die during a first time interval of each closing stroke of the die and a further portion of the metal strip is movably clamped in the first stage (20) of the die during the same time interval in order that it may be pulled into said second stage (21) of the die during the first time interval. During a second time interval of each closing stroke the metal strip is immovably clamped in both stages (20 and 21) of the die. The first stage (20) of the die is employed to preform longitudinally extending fold lines such as rib (12) and the second stage (21) employed to form transversely extending fold lines such as flutes (14) and channels (15).
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