Elongate structures and devices and methods for manufacturing same

An elongate structure, comprising:

• a hollow outer portion formed of sheet material;
• a hollow inner portion formed of sheet material;
• and
• a U-shaped reinforcement portion formed of sheet material and disposed within the hollow inner portion;
• wherein the hollow outer portion includes at least a first outer side surface that defines a first plane, a second outer side surface that defines a second plane, and a third outer side surface that defines a third plane,
• wherein the first plane intersects with the second plane at a first dihedral angle, the second plane intersects with the third plane at a second dihedral angle, and third plane intersects with the first plane at a third dihedral angle,
• wherein the sum of the first dihedral angle, the second dihedral angle and the third dihedral angle is about 180°,
• wherein the hollow inner portion is disposed within the hollow outer portion,
• wherein the hollow inner portion contacts a first inner side of the hollow outer portion opposite the first outer side surface, a second inner side of the hollow outer portion opposite the second outer side surface, and a third inner side of the hollow outer portion opposite the third outer side surface, and
• wherein the hollow inner portion includes at least a first panel that extends between the first inner side of the hollow outer portion and the second inner side of the hollow outer portion so as to define a first hollow inner triangular channel, and a second panel that extends between the second inner side of the hollow outer portion and the third inner side of the hollow outer portion so as to define a second hollow inner triangular channel.

A method for manufacturing an elongate structure, the method comprising:

• providing a substantially flat piece of sheet material provided with a plurality of creases that define fold lines;
• contacting a leading edge portion of the sheet material to a mandrel;
• rotating the mandrel in a first direction at a first rotational speed to fold the sheet material on the fold lines so as to form the elongate structure, said elongate structure including a hollow outer portion and a hollow inner portion disposed within the hollow outer portion, wherein the hollow outer portion includes at least a first outer side surface that defines a first plane, a second outer side surface that defines a second plane, and a third outer side surface that defines a third plane, wherein the first plane intersects with the second plane at a first dihedral angle, the second plane intersects with the third plane at a second dihedral angle, and third plane intersects with the first plane at a third dihedral angle, wherein the sum of the first dihedral angle, the second dihedral angle and the third dihedral angle is about 180°, wherein the hollow inner portion contacts a first inner side of the hollow outer portion opposite the first outer side surface, a second inner side of the hollow outer portion opposite the second outer side surface, and a third inner side of the hollow outer portion opposite the third outer side surface, and wherein the hollow inner portion includes at least a first panel that extends between the first inner side of the hollow outer portion and the second inner side of the hollow outer portion so as to define a first hollow inner triangular channel, and a second panel that extends between the second inner side of the hollow outer portion and the third inner side of the hollow outer portion so as to define a second hollow inner triangular channel;
• and
• compressing the first outer side surface of the elongate structure against the hollow inner portion using a compressive member while the elongate structure is on the mandrel.