| 摘要 |
<p>Articles of adjustable diameter and of adjustable rigidity are disclosed. Articles of adjustable rigidity may contain articles (180) having engageable surfaces that are only engaged upon expansion of a member (175) within the article. Tubes having elongated flexible rods with frictional surfaces are flexible when the rods are free to move relative to one another and rigid when the rods are fixed relative to one another by pressure, adhesives, or other techniques. Tubes having adjustable diameter have internal expansion mechanisms such as bladders containing material that expands upon heating and a source of heat, or bimetal actuators that actuate upon exposure to heat.</p> |
