| 摘要 |
<p>The invention consists of a structure which is a combination of one or more stiff tubular sections and one or more sections sliding inside the former, those of each type consecutive or interleaved with those of the other type, those in succession connected together in a rigid manner, with hinge or joint of the telescopic type, such as to permit the movement and/or relative shifting of adjacent sections from a "contracted" configuration, or configuration of maximum penetration, to one of maximum width, or maximum relative shift. <IMAGE></p> |
