Abstract: A collapsible dome-shaped frame for a tent or similar structure includes a polygonal top ring formed of alternating fixed and pivotal sections, with a foldable, arcuate leg or pole connected to each pivotal section. In the collapsed condition of the frame, the poles extend downwardly, substantially at a right angle to the plane of the top ring forming a barrel-shaped cage for carrying a tent and groundsheet. In order to open the frame, the poles and each pivotal section are rotated relative to the fixed sections of the top ring, so that the poles extend outwardly from the top ring in the same plane as such ring, and the pivotal sections are locked in the open position. The poles, which are formed of arcuate segments interconnected by self-locking hinges, are unfolded to the open position, in which they define the dome-shaped frame with the top ring.

Abstract: A self-locking hinge for interconnecting two structural elements such as sections of tent poles includes a pair of bifurcated lugs in opposed end-to-end relationship and a yoke extending between the arms of the lugs. A pin extends through the arms of each lug and a slot or slots in the yoke for pivotally connecting the lugs to the yoke. The pins are biased towards each other by a spring in the slot or by springs in the slots, so that projections on the arms of one lug are biased into grooves in the arms on the other lug to lock the hinge in an open position. In order to close the hinge, the lugs are pulled slightly apart against the action of the spring(s) to remove the projections from the grooves, permitting rotation of the lugs relative to the yoke and to each other.