Methods for the production of curved pieces from continuous metal elements
Methods for making curved pieces from continuous metal elements are provided. Such methods include advancing a continuous metal element through a calendering station such that each length of the element assumes a pre-established curvature; stopping advancement of the element after a curved length thereof has passed through a wrap-bending station located downstream of the calendering station; wrap-bending the length of the element located at the station, while simultaneously conveying the curved portion to a stretch-bending station; stretch-bending the curved portion; resuming advancement of the element until the wrap-bent length is at a cutting station; and cutting the element in the wrap-bent length, thus producing the desired curved piece. Curved pieces produced by such methods are also provided.
1. A method for the production of a curved piece from a continuous metal element, which is a profiled element or a tube, extending along a longitudinal axis and advancing along a direction defined by said longitudinal axis, said method comprising the steps of:
advancing said continuous metal element through a calendering station such that each length of the continuous metal element assumes a pre-established curvature,
stopping advancement of the continuous metal element after a curved portion thereof has passed through a wrap-bending station located downstream of the calendering station and is supported by a support,
wrap-bending the length of the element located at said wrap-bending station and gripped by a block, by rotation of said block and a body of the wrap-bending station about a fixed pivot, while simultaneously conveying said curved portion to a stretch-bending station, wherein a distal end of said continuous metal element is locked by a clamp,
stretch-bending said curved portion by a rotary movement about a translating pivot of a shaping element which comes into contact with said curved portion,
resuming advancement of the continuous metal element until the wrap-bent length is at a cutting station, and
cutting said continuous metal element in the wrap-bent length, thus producing the curved piece.
2. The method of claim 1 , wherein the pre-established curvature imparted by said calendering station is determined independently for each length of the continuous metal element.
3. The method of claim 1 , wherein a final curvature of each length of the piece is determined independently of that of adjacent lengths.
4. The method of claim 1 , wherein said piece is a rib having strongly curved ends and a gently curved central portion.
5. The method of claim 4 , wherein the curvature of said strongly curved ends is imparted by said wrap-bending station and the curvature of the gently curved central portion is imparted by said stretch-bending station.
6. The method of claim 1 , wherein said cutting station is a laser cutting station.
7. The method of claim 1 , wherein said continuous metal element is cut approximately in the center of the wrap-bent length.
8. The method of claim 1 , wherein said calendaring station comprises a plurality of rollers which are selectively movable relative to one another to form a passage for said continuous metal element.