APPAREIL POUR FORMER EN CONTINU UN CONDUIT À JOINT EN SPIRALE, PROCÉDÉ DE FORMATION ET CONDUIT EN SPIRALE

摘要

Apparatus (1) for continuously forming a spiral seamed conduit (5) from a metallic strip (2) comprising a feeding plane (3) for said metallic strip (2); a forming head (4,4') rotating about a forming axis (A) substantially parallel to the feeding plane (3) and tilted by a forming angle (a) with respect to a direction orthogonal (0) to a feeding direction (F) of the metallic strip, wherein the forming head (4,4') is adapted to drive in rotation said metallic strip (2) for defining a spiral conduit (5); a lock-seaming device (6) configured to continuously lock two portions of said metallic strip (2) along opposite profiles for forming said spiral seamed conduit (5); wherein said forming head (4,4') is provided with one or more forming elements (7,9) arranged and configured so to define a substantially polygonal shape for the section of said spiral conduit (5) during the drive in rotation of said metallic strip (2); wherein said lock-seaming device (6) is configured to move along a seaming direction (G) so to lock said two portions along a side of said conduit (5); and wherein said apparatus (1) further comprises means configured to move the forming head (4,4') according to a plurality of axes. The present invention also relates to a process for forming in continuous a spiral conduit (5) having a substantially polygonal section and a spiral conduit (5) having a substantially polygonal section and four flat sides.