Abstract: A collapsible three dimensional framework includes a plurality of tubular rods (10) connected to each other by means of articulation joints. Each of the joints consists of a block divided into two matching pieces (28, 30). The block has a plurality of cavities (18a, 18b) each of which is open on a respective side face and on a back face of the block. The ends of respective rods (10) are inserted in the cavities (18a, 18b) and are connected to the block by transverse pivot pins (24). Each of the cavities has articulation seats (32) which received the pivot pins (24) When the two pieces (28, 30) of the block are secured to each other, the pivot pins (24) are entrapped in respective seats (32). The two pieces (28, 30) of the block are clamped together by releasable fastening means such as a screw (40) and a nut (42).