is prevented since more than one support structure 108 and or 133 is used for each said panels one such an embodiment is designed as a u201c scissor u201d type of linkage mechanism 160 shown in the schematic drawing of fig9 the scissor mechanism is constructed with a series of pairs of links 171 that are joined together as shown in fig9 with hinges 172 on the foundation 170 side one of the links 171 is hinged to the support 165 which is in turn fixed to the foundation 170 the other link 171 of the scissor mechanism 160 is hinged to the support 166 the support 166 rests over the surface of the foundation 170 and is free to translate along the line connecting the supports 165 and 166 similarly on the panel 161 side one of the links 171 is hinged to the support 164 which is fixed to the plate 173 the other link 171 is then hinged to the support 175 which is free to translate along the line connecting the supports 164 and 175 the panel 161 is then supported by the scissor type mechanism via the ball joint 174 the panels 161 are attached together as previously described by the hinge joints 162 the ball joint 174 may be a living joint in the schematic drawing of fig9 the translation of the support 166 over the surface of the foundation 170 away from the fixed support 165 is prevented by the locking element 168 which is positioned between the support 166 and the stop 167 which is fixed to the foundation 170 when the locking element 168 is positioned as shown in fig9 between the support 166 and the stop 167 then.