The present invention relates to an openable roof having two pairs of half dome openable roofs provided on a ring shaped set roof having a flat upper surface. In the center of the set roof, an aperture is provided; this aperture being opened or closed by these two pairs of openable roofs. Furthermore, either respective pair of these two pairs of openable roofs may be selected and utilized to open and close the aperture as necessary.

A structure having a movable dome-type roof including a plurality of independently movable shell sections which nest one beneath the other. A frame superstructure is arched over the dome to support the upper ends of the shell sections. The lower edges of the shell sections are mounted on self-powered carriages and are independently shiftable about a circular base of the structure. By selectively shifting individual shell sections, the dome may be contracted or expanded as desired. The superstructure may be mounted on a circular track or on a pair of linear tracks to expedite the opening and closing of the dome.

An auditorium has a domed roof formed by a first part spherical portion covering, without intermediate support, most of an amphitheatre accommodating an audience, and a second part spherical portion covering a stage adjacent the amphitheatre, the first portion being supported only at its periphery, and the second portion consisting of segmental leaves which can open about a common pivot supported by the first portion to uncover the stage, the common pivot being at a vertical axis of the second portion of the roof and above the amphitheatre and the vertical axis of the first portion being above the stage. Wall panels behind the stage can be moved apart to open the rear of the stage to the exterior.

An openable roof includes a plurality of movable roof members. Each of the movable roof members is of a generally sectorial shape in two-dimensional projection. The sectorial shape has a radially outer edge portion and a radially inner edge portion. The outer edge portion of the movable roof member is movably disposed on an outer arcuate support. The inner edge portion of the movable roof member is movably disposed on an inner arcuate support. The outer and inner arcuate supports are disposed concentrically about a common axis. Accordingly, each of the movable roof members is able to revolve around the axis of the arcuate supports so as to participate to open and close a sectorial opening portion provided between the arcuate supports.

A dome shaped roof structure suitable for a stadium for indoor athletic sports is disclosed. The dome shaped roof structure comprises a main frame for covering the inside of the stadium and a reinforcing frame. The reinforcing frame comprises: cables disposed in the inner side of the main frame and extended radially from the central portion of the main frame to the bottom peripheral border; circular cables disposed concentrically about the peripheral border of the main frame; and strut members that have each upper end connected to the steel member of the main frame at an intersecting point of the radiating cables and the circular cables, and the strut members vertically supported by the radiating cables and the circular cables; and wherein tension is introduced to the radiating cables in the direction of the bottom peripheral border and the outer ends of the radiating cables are fixed with the main frame, so that the steel members of the main frame are thrust up by the strut members of the reinforcing frame.