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.

Tube forming methods can be used for efficient transition in the production of tubes having varying thickness. Material used to form consecutive tubes may have the same thickness along a separation plane separating a first discrete section from a second discrete section of the material, and the first discrete section and the second discrete section may each have varying thickness in a feed direction of the material. With such a thickness profile, the first discrete section of the material may be formed into a first cylinder having varying thickness and separated from the second discrete portion as the second discrete section is formed into a second cylinder having varying thickness. In particular, the transition between the first cylinder and the second cylinder may be achieved without scrap and/or interruption, resulting in cost-savings and improvements in production throughput associated with forming tubes having varying thickness.

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 tool for mounting a set of helical rods around an elongated central core includes a pair of cartridges mounted opposite each other around the central core, so that the rods extend along the central core. Each cartridge has a first part comprising a through-hole for receiving one of the rods, and a second part comprising a through-hole for receiving another rod, the second part being movable with respect to the first part from an open position to a closed position. In the closed position, the parts form an annular body extending around a central opening for receiving the central core, the cartridge comprising a surface configured to engage with a driving wheel or a driving belt for transfer of torque to the cartridge. In the open position, a gap is provided between the parts so that the central opening is accessible from a position radially outside of the cartridge.

An apparatus for forming spiral pipe includes a spiral pipe forming station having a feeding device for feeding a continuous strip and a bending device that receives the strip fed from the feeding device. The bending device has a fixed rolling element that forms a spiral pipe having a longitudinal axis and a sidewall. The apparatus also includes a cutting station having a cutting device movably extending in a direction of the longitudinal axis of the spiral pipe. A controller is operatively connected to the spiral pipe forming station and the cutting station to continuously operate the pipe forming station while the cutting station is operated to cut through the sidewall of the spiral pipe to define the one or more register holes.

A control system for forming a tapered structure includes a sensor providing feedback for a machine for forming a tapered structure including at least three rolls having at least one bend roll and at least two guide rolls. The guide rolls may include rollette banks having a plurality of rollettes. The machine may also include an adjustment mechanism to position at least one of the rolls, where a diameter of the tapered structure being formed is controlled by relative positions of the rolls. The machine may also include a joining element to join edges of a stock of material together as it is rolled through the rolls to form the tapered structure. The control system may also include a controller to receive feedback from the sensor and to send a control signal based on the feedback to the adjustment mechanism for positioning at least one of the rolls.

A method of producing a carcass for a flexible pipe, the carcass and a flexible pipe with the carcass includes providing at least one first metallic strip a cover metallic strip. Shaping the first strip to have a profile with a first fold adapted to face towards the carcass axis and a second fold adapted to face away from the carcass axis. Pretreating an anchor width section of the cover strip including a weakening treatment of resistance against length extension and/or a length extension of the pretreated part of the anchor width section. Inserting the anchor width section of the cover strip into the first fold, ensuring that a cover width section of the cover strip extends beyond the second fold. Helically winding the first metallic strip and the cover strip, to provide that the first fold engages and interlocks with the second fold and that the cover width section covers a helical interstice between windings of the first metallic strip on the inner side of the carcass.

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 process for winding a convolutely wound tubular structure having a machine direction, a cross-machine direction coplanar thereto, and a Z-direction orthogonal to both the machine- and cross-machine directions is disclosed.

A control system for forming a tapered structure includes a sensor providing feedback for a machine for forming a tapered structure including at least three rolls having at least one bend roll and at least two guide rolls. The guide rolls may include rollette banks having a plurality of rollettes. The machine may also include an adjustment mechanism to position at least one of the rolls, where a diameter of the tapered structure being formed is controlled by relative positions of the rolls. The machine may also include a joining element to join edges of a stock of material together as it is rolled through the rolls to form the tapered structure. The control system may also include a controller to receive feedback from the sensor and to send a control signal based on the feedback to the adjustment mechanism for positioning at least one of the rolls.