Abstract: This invention relates to a clamping device for plates (3, 4) comprising at least one clamping head (5) including a body (11), a clamping member (12) adapted for rotating around a fixed axle (22) and rotation means (23) for rotating said clamping member (12) around said fixed axle (22) comprising at least a link (24) pivotably fixed to said clamping member (12), a carriage (28) provided with a roller (30) moveable substantially linearly along at least one guiding ramp (31) having a curved contact surface for engagement with the concave roller the curvature axis of which are located on one side of the fixed axle (22) with respect to the plane (45) defined by the central axis (26') of the link (24) and the central axis (29') of the roller (30).

Abstract: An article is provided with resilient hinges becoming rigid under tension, comprising at least two rigid elements (2,3), means for hinging these two elements together and means for locking these elements with respect to each other in a folded up position. The hinge means (1) comprise a part with resilient properties (4) connecting these two elements together, said hinge means being adapted so as to cause the part with resilient properties to occupy a relaxed position when the two elements are not locked with respect to each other and a tensioned position when the two elements are locked with respect to each other. Good rigidity of the hinge joining the two elements together is thus provided when the locking means are activated.