| 摘要 |
A forming apparatus ( 50 ) includes a roll former ( 51 ) operative to roll form a metal strip ( 100 ) to form a profiled metal section ( 10 ) of generally C section profile including a pan ( 12 ) and a pair of upstanding edge margins ( 14 and 16 ). The section profile incorporates a longitudinal precamber which is introduced by the forming apparatus by incorporating a prestretching apparatus ( 52 ) upstream from the roll former ( 51 ), and a bending apparatus ( 53 ) located downstream of the roll former ( 51 ). The prestretching apparatus differentially stretches the metal strip ( 100 ) in its longitudinal direction so as to form portions ( 101, 102 ), which are more elongated than a laterally adjacent portion ( 103 ) of the strip ( 100 ). The differential stretching compensates for longitudinal shortening of the metal strip in forming the profiled section in the roll former ( 51 ). The bending apparatus ( 53 ) uses a (3) point bending process and includes a reaction stage ( 60 ), a fulcrum stage ( 61 ), and an action stage ( 62 ). The action stage ( 62 ) which induces loading onto the profiled section ( 10 ) so as to bend the section about the fulcrum stage ( 61 ) is incorporated with the shearing assembly. A method of forming a metal section from sheet metal strip is also disclosed. In a further aspect a shearing assembly is disclosed which is height adjustable and which also includes a cutting element ( 77 ) and shearing block ( 78 ) which are pivotally mounted to an assembly frame ( 74 ).
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