Spiral forming methods can be used to join edges of a rolled material along a spiral joint to form conical and/or cylindrical structures. Alignment of the edges of the rolled material can be controlled in a wrapping direction as the material is being joined along the spiral joint to form the structure. By controlling alignment of the edges of the material as the edges of the material are being joined, small corrections can be made over the course of forming the structure facilitating control over geometric tolerances of the resulting spiral formed structure.

A method for creating a tapered spiral welded conical structure where the overall shape of the cone is first graphically slit axially and unwrapped, and then a series of construction arcs and lines are created to form the edge lines of a strip that can then be wrapped (rolled) to form a tapered conical structure. The edges of the spirally wound strip can be welded together, and a very large conical structure can thus be achieved. Various construction options are presented from a constant width strip to strip made from straight segments. Equations are given for the formation of the strips to enable those skilled in the art of spiral welded tubing to practice the invention.

Feeding stock used to form a tapered structure into a curving device such that each point on the stock undergoes rotational motion about a peak location of the tapered structure; and the stock meets a predecessor portion of stock along one or more adjacent edges.

A method for creating a tapered spiral welded conical structure where the overall shape of the cone is first graphically slit axially and unwrapped, and then a series of construction arcs and lines are created to form the edge lines of a strip that can then be wrapped (rolled) to form a tapered conical structure. The edges of the spirally wound strip can be welded together, and a very large conical structure can thus be achieved. Various construction options are presented from a constant width strip to strip made from straight segments. Equations are given for the formation of the strips to enable those skilled in the art of spiral welded tubing to practice the invention.

Feeding stock used to form a tapered structure into a curving device such that each point on the stock undergoes rotational motion about a peak location of the tapered structure; and the stock meets a predecessor portion of stock along one or more adjacent edges.

A product having a metal strip and a central longitudinal axis. The strip has two or more strip parts, each having a common radius of curvature defining a helix having an angle being offset from one another in the direction of the axis. A cross section of the strip parts causes them to be interlocked together throughout their lengths to define a flexible metal tube. The outside diameter of the tube is between ⅜″ and 1⅜″ and the helix angle of each strip part is between eight and thirty degrees.

Disclosed is a tubular core on which sheets of metal or other material can be wound and supported, for shipment, handling and dispersal, and a method for forming the core. The core comprises a metal sheet or strip which has a rectangular-ribbed cross-sectional profile comprising rectangular, flat ribs, and which is wound spirally into a tubular configuration. The core is formed by passing the strip through a plurality of roll-forming stands, to progressively form sections of the ribs and progressively define the sections into the rectangular ribbed profile in which the flat ribs collectively form a support surface for the sheets which are to be wound on the core.

A method for creating a tapered spiral welded conical structure where the overall shape of the cone is first graphically slit axially and unwrapped, and then a series of construction arcs and lines are created to form the edge lines of a strip that can then be wrapped (rolled) to form a tapered conical structure. The edges of the spirally wound strip can be welded together, and a very large conical structure can thus be achieved. Various construction options are presented from a constant width strip to strip made from straight segments. Equations are given for the formation of the strips to enable those skilled in the art of spiral welded tubing to practice the invention.

A machine that includes a first feeder, able to unwind a first tape; a profiler comprising an upstream profiling stage able to profile the first tape to form a pre-profiled first tape; a second feeder, able to unwind a second tape, the second tape being a flat tape. A profiler that includes an intermediate joining stage able to receive the second tape as a flat tape from the second feeder and able to join the pre-formed first tape and the flat second tape; and at least a downstream profiling stage configured to jointly profile the first tape and the second tape received from the intermediate joining stage and form a combined profiled strip.

Apparatus (1) for forming in continuous 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 lock in continuous 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.