Abstract: Foldable carriages, strollers, wheeled-chairs, carts and the like assemblies which simultaneously fold in two of their three dimensions to form a folded stick-like or umbrella like bundle, i.e., of the Maclaren type, are provided with complementary collapsing structure for supporting a pram-type cot, which is interchangeable with a stroller-type seat. The specific supporting structure, cot structure and interchangeable seat are disclosed.
Abstract: A collapsible volume frame, when erected, presents in each of two opposite side elevations a side space frame defined by four points which if joined would form a quadrilateral; and presents further space frames in the four other aspects. The side space frames are braced by at least one frame element disposed transversely and articulated to them in a triangulated manner. Releasable means resist collapse of the volume frame. These side and further space frames are foldable so that the volume frame when collapsed forms a bundle.