Abstract: A flanged connector for removably fastening an elongate rod or tube to a flat surface has two modes of operation. The connector has a flange with a flat bottom and a tubular member extending up from the base. In a first mode, the flanged base is fastened to the surface with the tubular member upstanding to receive the rod in a central passage. A threaded aperture in the wall of the tubular member receives a set screw that advances transversely through the wall to engage the rod and secure it in place. In a second mode, the connector is inverted and mounted below the support surface with the flat face of the base in a common plane with the support surface. A set screw that passes at an acute angle to the passage axis extends from the flat face to the central passage to secure the rod. When the rod is removed, the support surface is unobstructed.

Abstract: A connector system joins together long rods or tubes at various angles to form a wide variety of shelter frames for diverse applications as well as railings, racks, and the like. The diverse connectors required are assembled from modules of the invention which are bolted together in various combinations. The modules fasten at one end to the rods or tubes. The other end of the module terminates in an annular gear adapted to intermesh at an adjustable angle with one or more gears of other modules. Once bolted together the modules form a rigid connector. The modules may be unbolted and reused to form a connector of another configuration. The few module types required to form the many connector configurations reduces inventory and manufacturing requirements.