end 6 of the member 4 other configurations are possible in this regard the bend section 8 may comprise a pivot joint between the members 4 10 which joint is lockable at a predetermined angle the hub 2 comprises a hollow tube 12 radiating perpendicularly outwardly from which are four arms 13 each arm 13 terminates in a hinge fitting 14 to which the end 5 of the corresponding leg 3 is pivotably attached extending slidably through the tube 12 is a flexible shaft 15 having a free end 16 adapted to form the apex of a structure created when a fabric skin is applied to the frame 1 in this regard the end 16 comprises a first fitting 17 engageable with the fabric skin positioning of the shaft 15 relative to the tube 12 may be fixed or adjusted by way of a locking means not shown such as for example a screw or the like once the position is determined it can be maintained by way of a padlock of the like to ensure that the frame 1 is not collapsed by an unauthorised person pivotably connected to the other end 18 of the shaft 15 are four bracing elements 19 each element 19 is also pivotably connected to a corresponding one of the members 4 of the legs 3 for convenience of manufacture and assembly disassembly the shaft may be comprised of three sections a first section extending from the top end of the tube 12 corresponding to the free end 16 a second section slidable within the tube 12 and a third section depending from the bottom end of the tube 12 corresponding to the end 18 extending outwardly from each bend section 8 is a second fitting.