Air conduit spirally wound and provided with a plurality of holes, related manufacturing machine and method and related strip

Abstract

Apparatus () for forming a spirally wound conduit () from a flat strip () comprising: a forming device () comprising a bending section () configured to spiralling bend the strip () and a joining section () configured to join opposite longitudinal sides (A,B) of the strip () each other; a feeding device () of the strip () along a feeding direction (F) parallel to the longitudinal edges () of the strip (); a cutting device () arranged upstream the forming device () comprising a cutting head () for cutting the strip () and moving means configured to move said cutting head () along a plurality of moving axes (X,Y,Z) orthogonal to each other; a control unit () configured to command said moving means according to diameter (D) of the conduit () to be realized and to the width (B) of the strip () so that said cutting head () realizes on the strip () a plurality of arrays () of holes () each one tilted with respect to one of the longitudinal edges () of the strip () by an angle (α) function of the width (B) of the strip () and of the diameter (D) of the spiral conduit () to be realized. The present invention relates also to a air conduit (), a perforated strip (') and a coil () of a perforated strip (′) comprising a plurality of said arrays () of holes () wherein said holes () comprise at least two different shapes.