Abstract: An extendible, coilable member is reversibly configurable between a coiled form and an extended form. At least one surface of the member, typically an inner surface, is provided with resilient protrusions. Upon extension of the member to the extended form, the protrusions adopt a first state in which they protrude from the surface of the member. Upon rolling of the member to the coiled form, the protrusions flex so as to lie between the turns of the coiled member.

Abstract: An elongate element in the form of a longitudinally split tube (2) is arranged to be progressively flattened and wound about an axis (6) extending transversely to the longitudinal extent of the tube to form a coil (4). To enable the tube (2) to be structurally rigid, but yet to enable it to be easy to wind and to remain coiled without being potentially explosive, a second layer (10, 12, 14 or 16) is affixed to the layer of spring steel (8) forming the tube (2). The second layer is arranged to be stressed to oppose the bias of the spring steel (8) which favours the formation of the tube.

Abstract: An extendible sheet member is configurable between first and second states. The first state is a coiled state (1.1) in which the member is coiled substantially parallel to a first axis and the second state is an extended state (1.2) in which the member extends substantially parallel to a second axis at some angle to the first axis. The member is made wholly or in part from a material or materials which give rise to internal stresses upon extension, these stresses acting at some angle to the second axis such as to bias the member to the second state. In many embodiments these stresses are produced by fibers which form part of the structure of said member. Said member is preferably reversibly configurable between said first and second states.