| 摘要 |
A self-erecting, coiled metal tube comprises a helically wound ribbon of spring material having an inside surface and an outside surface, the ribbon having adjacent turns stressed to coil in tight overlapping and telescoping engagement, and a textured surface formed on the outside surface of the ribbon so that when the ribbon is extended, the textured surface of an underlapped turn of ribbon bears against the inner surface of an overlapped turn of ribbon to create friction between the adjacent turns of ribbon and control the length of extension of the ribbon tube and strengthen the tube.
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