Abstract: A coupler for collapsible joints consisting of a hollow body having an interior cavity, an exterior surface with an arcuate portion, and an arcuate slot extending radially from the interior cavity to the exterior surface over at least 90 degrees of the arcuate portion. A receptacle is provided for attaching a first support member to the body. An elongate fastening member extends through the slot, and is adapted to extend into a second support member thereby securing the body to the second support member. The body rotates about a first axis transverse to the fastening member to the extent that clearance is provided by the slot thereby positioning the support member between a first position in parallel alignment with the base and a second position substantially at right angles to the base. In the second position the body is rotatable about a second axis provided by the fastening member to alter the rotational positioning of the slot relative to the fastening member.