Abstract: This convertible structural element comprises two link chains (1, 2) which, after assembly, are capable together of assuming the form of a rigid beam. The links (3, 4) of the two chains are provided with antagonistic bearing points (10, 11), the first bearing point (10) of a link of rank n of each chain interacting with a second bearing point (11) of a link of rank n-1 in order to trap fastening elements which the pins (7, 8) of the links of the other chain form, when the element is made rigid. At least some links of at least one of the chains of the structural element exhibit a row of teeth (13) which, together with the teeth of the neighbouring links in the direction of the length of the element, form a continuous toothing extending laterally over the entire length of the element.

Abstract: A structural element is disclosed which is substantially composed of a linked chain and of a flexible connection which can be a chain of identical links and which can be assembled together as required to form a rigid beam. The linked chain comprises opposing support points, the first support point of one link of row n of the chain cooperating with the second support point of a link of row n-1 to contain, while the element is being rendered rigid, hooking elements integral with the flexible connection and which, in the preferred embodiment of the invention, are the pins of the second chain. The structural element can be assembled or disassembled using a special device.