Abstract: A collapsible framework capable of being manipulated between a collapsed condition and an expanded, locked condition includes a plurality of legs and a plurality of collapsible quad sections. The legs are disposed generally in parallel with one another and in a bundle when the framework is in the collapsed condition. Each quad section includes two split step scissor units and two step scissor units. Each split step scissor unit is joined at one end to a respective leg, and including two arms that are pivotally joined, at least one of the arms being telescopic and including means for locking the arm at a predetermined length. Each step scissor unit is joined at one end to the other end of a respective split step scissor and at its other end to the other step scissor unit, and each step scissor unit includes two arms that are pivotally joined, at least one of the arms being telescopic and including means for locking the arm at a second predetermined length.

Abstract: Disclosed is a building system which utilizes structural modules (10) to form a shelter (89, 132) having a spherical surface. The shelter includes flat portions (A) composed of flat modules (7), arch portions (B) composed of cylindrical modules (8), and spherical triangle portions (C) composed of spherical modules (9). The modules (10) are composed of crossed pairs of struts (13a-16b) which are hingedly interconnected by hubs (18-25). The structural modules preferably include periphery cables (27-30) and diagonal cables (31, 32, 44, 45), each cable being held in place by a cable keeper member (33-36, 46, 47). The structure also features a locking bar mechanism (26) for maintaining the modules (10) in an expanded configuration, and hubs (114) having radial cutout portions (115) for accommodating angular distortion of the structural framework.

Abstract: A simplified hub and strut system for the construction and assembly of geodesic domes. The system is characterized by the outer faces of the hubs and struts being provided with recessed rabbets which function as shoulders for receiving flat nesting panels of transparent or opaque rigid sheet material comprising the outer skin of an assembled dome. The inner faces of the struts are desirably also provided with recessed rabbets to function as shoulders on which to seat interior panels of rigid sheet material. The system is also characterized by the use of aligning dowels to facilitate initial assembly of hubs and struts preliminary to fastening.

Abstract: A jig for the accurate and precise measurement of rigid sheet material for making panels for geodesic dome structures. The jig is intended for use in the assembly of geodesic domes of the type having a plurality of generally flat polygonal hub plates and interconnecting struts, each hub having a recessed panel-receiving rabbet in at least some of its edges and each strut having a recessed panel-receiving rabbet in its outer edges. The jig comprises three shoes, each adapted to engage the recessed rabbets of adjacent hubs of an assembled dome which, with their associated struts, define a triangular opening into which a panel is seated to enclose the dome. Each shoe has a length which is the same as the longitudinal back wall of the hub rabbet. The shoes are connected by three elongated bars, each extending between two of the shoes and adjustably fastened thereto.

Abstract: A portable shelter framework is formed by a series of end-interconnected modules, each defining a separate arch portion of the framework extending in different directions relative to each other. Each module is formed of elongate struts capable of being expanded into arched three dimensional form and collapsed into bundled form.