Abstract: Folding casing formed of intersecting arches or rings and stretched by inner traction elements.

Abstract: A supporting apparatus such as a portable seat that can be opened and closed is disclosed having a plurality of poles hinged to junctions. A part of the poles form the legs and another portion form an anchorage on which a foldable surface is stretched when the apparatus is opened. The apparatus also includes traction elements cooperating with the folding surface and which join one another at the end of the poles that do not converge at the junctions. The configuration preset by the orientation of the poles, along with the structural configuration of anti-prism or other extremely stable and rigid configurations, are such that they spread most of the torsional and bending stresses.

Abstract: The present invention concerns a group of portable supporting apparatuses of extendible kind and that can be opened and closed again, the apparatuses are composed of a junction; a plurality of poles hinged to the junctions a part of the poles which, when the apparatus is on using extended modality, branches off from the lower junction, in order to form legs and another part branches off upwards, so as to form an anchorage whereon a foldable surface is stretched that in use forms a supporting surface traction elements cooperating with the folding surface, which join one another all the ends of the poles that do not converge to the junctions. Thanks to a configuration preset by the orientation of the same poles, take together with them the structural configuration of anti-prism or other extremely stable and rigid configurations such as they can release the apparatuses, spread when in use, of the most torsional and bending stresses.

Abstract: An apparatus, an adjustable tool with variable diameter aimed at tightening and twisting nuts, bolts or other prismatic objects, with polygonal section or circular section outlines suitable for performing several actions around different kinds of objects, working on such objects through two different ways to move a variable number of teeth, which, while working, close like a diaphragm around the sides of such objects, perfectly adapting to their diameter and their section or capacity.