High-strength tubular beam of folded corrugated cardboard

Claim 2

A tubular beam of folded corrugated cardboard as heretofore described, characterised by being constituted by a single corrugated cardboard sheet (1) having its corrugations orthogonal to its longitudinal axis (2), said sheet (1) being folded back several times on itself parallel to its axis (2) to form an overall section of right angled or isosceles trapezium form (4, 6', 8', 8, 6), and divided into two adjacent half sections (4, 6', 8', 18') - (4, 6, 8, 18), which mate along the longitudinal symmetrical axis of the beam (101), and which each comprise two triangular channel configurations (16', 14', 12') - (8', 10', 12'), (10, 8, 12) - (16, 14, 12) which mate along a common diagonal (12'), (12), and are mutually inverted.

Claim 3

A tubular beam as claimed in claim 1, characterised in that said single cardboard sheet (1) arranged to constitute said overall section of right angled or isosceles trapezium form (4, 6', 8', 8, 6) is of constant width and indefinite length, and comprises, on both sides of a longitudinal central portion (4), seven predetermined creasing lines (3, 5, 7, 9, 11, 13, 15) - (3', 5', 7', 9', 11', 13', 15'), of which the first four (3, 5, 7, 9) - (3', 5', 7', 9') are concordant with respect to their folding direction, the other three (11, 13, 15) - (11', 13', 15') being discordant with the preceding (3,5,7,9) - (3', 5', 7', 9'); said lines defining, starting from said central portion (4), a first (6, 6'), a third (10, 10'), a fifth (14, 14') and a seventh (18, 18') strip of width substantially equal to the height of the beam (101), a fourth strip (12, 12') of width substantially equal to the common diagonal of the triangular channel configurations, and a second (8, 8') and a sixth strip (16, 16') of width substantially equal to one half the width of the beam.

Claim 4

A tubular beam as claimed in claim 1, characterised in that the first three strips (6, 8, 10), (6', 8', 10') of each set provided to the side of said central portion (4) are bent towards this latter to define a beam half section comprising a first configuration of rectangular or rectangular trapezium cross-section, within which there extends in opposite directions from said common diagonal (12, 12'), or fourth strip, an internal configuration of triangular cross-section which emerges from said first rectangular configuration by way of the seventh and last strip (18, 18'), which mates with the corresponding last strip (18', 18) of the other half section.

Claim 5

A tubular beam as claimed in claim 1, characterised in that between the contacting faces of said strips which compose the two half sections there are provided adhesive zones arranged to ensure the consistency of said overall ri;ht angled or isosceles trapezium section (4, 6', 8', 8, 6).

Claim 6

A disposable load-carrying platform constructed with tubular beams (101) in accordance with claims 1 to 4.