Patent attributes
The invention provides an extendible member (10) which is configurable between a coiled form (11) and an extended form (12). The extendible member (10) comprises: a primary member (14) comprising a sheet of material resiliently biased in a slit tube form, wherein the slit tube can be opened out at the slit to assume an open form in which it has a flattened cross section; at least one resilient secondary member (15) having first and second connections to the primary member (14) at respective different circumferential positions on the primary member (14), wherein in the extended form, the primary member (14) is in its slit tube form and the resiliency of the secondary member (15) causes at least part of the secondary member (15) to displace towards the slit in the primary member (14) to provide torsional and axial stiffness to the primary member (14), and wherein in the coiled form (11), the primary member (14) is in its open form and the secondary member (15) conforms to the flattened cross section of the primary member (149) so that primary and secondary member can be co-coiled. Corresponding methods are also provided.
