Abstract: An elongated, curved framework with a variable degree of curvature. The framework comprises plural link members, joint units connecting the link members together, and elements for bending the link members at the joints. A desired number of link members can be connected together to provide a desired length of elongated, curved framework. Inside the joint unit is located a bolt-engaging member, and the joint unit and the bolt-engaging member are joined together by a bolt. The bolt is engaged with a nut. Rotating the bolt in one direction causes the link members to bend at the joint in one direction. Rotating the bolt in an opposed direction causes the link members to bend at the joint in an opposed direction. Three pins can be used to enable the link members to withstand load well.

Abstract: A clamp 100A for connecting formwork panels 50, 50 together at a right angle has a symmetrical shape and comprises a generally triangular central section 1, one intermediate lever 3 connected pivotally to each of opposed sides of the central section 1, and an L-shaped holding arm 2 connected to the intermediate lever 3 by means of a link 4 that is pivotally joined with both the intermediate lever 3 and the holding arm 2. The central section 1 has two equal sides a, a which extend perpendicular to each other and at which the central section 1 engages with joint members 52, 52 of formwork panels 50, 50. Notches 1c are formed on each side a, and are adapted to bite into one joint member 52. Each side a of the central section 1 is thus capable of engaging very closely with the joint member 52. The holding arm 2 is also provided with notches 2c, so that the holding arm 2 also can engage very closely with the joint member 52.