| 摘要 |
A flexible conduit (10) is formed in part with a helically wound band of metal (11) that provides resistance to burst pressure. The band has a leading edge lip or hook (22) and a trailing edge hook (23) that engage and interlock when the band is helically wound. The cross section of the band has an asymmetrical Z-shaped profile with a main body section intermediate the band edges. An upstream valley (26) is formed between the leading edge hook (22) and the main body (21), and a downstream valley (27) is formed between the trailing edge hook (23) and the main body (21). When the band is helically wound, the downstream hook of one turn of the band is received in the upstream valley of the previous turn of the band so that the downstream and upstream hooks form an interlock holding the windings together. In the wound configuration, the thickness of the profile between the upstream valley and the internal surface of the tube is greater than the thickness of the profile between the downstream valley and the external surface of the tube to provide greater material thickness to reduce contact stress at the hook and valley interface and to reduce alternating stresses in the valley corners.
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