Retractable Dome

The desirability of providing an arena or stadium which can be fully open to the sun and fresh air in times of good weather and yet can be closed or partially closed, in times of inclement weather or excessive wind, is widely recognized. To accomplish this goal is very difficult because of the massive size of such structures.

It is therefore an object of this invention to provide a relatively simple design for such a stadium which is capable of being fully open as well as fully closed, which utilizes conventional spaceframe technology, which does not require an excessive amount of land, and in which the panels that move are relatively small and lightweight, thereby simplifying the support and actuation thereof, as well as the speed of movement thereof.

Other advantages and features will become apparent from the following specification taken in connection with the accompanying drawings.

FIG. 1 is a pictoral view of a retractable dome stadium embodying the principles of the present invention, showing the dome in a closed position;

FIG. 2 is a view similar to FIG. 1 but showing the dome in an opening position;

FIG. 3 is a transverse vertical sectional view taken generally along line 3--3 in FIG. 1;

FIG. 4 is a view similar to FIG. 3 but taken at right angles thereto, the left portion of the figure showing the dome in its closed position and the right-hand portion of the figure showing the dome in its open position;

FIGS. 5, 6 and 7 are diagrammatic sectional views taken generally in the same plane as FIG. 4 and illustrating the sequence of movement of the dome panels from a closed to an open position;

FIG. 8 is an enlarged fragmentary diagrammatic sectional view taken generally in the same plane as FIG. 3 and illustrating the manner in which the ends of the dome panels are supported and actuated, the panels being shown in their open stacked position;

FIG. 9 is a fragmentary vertical sectional view taken generally along line 9--9 in FIG. 8; and

FIG. 10 is a fragmentary view taken generally from line 10--10 in FIG. 3, with parts broken away.

The present invention is applicable to virtually any type of stadium or the like, but for exemplary purposes is illustrated embodied in the athletic stadium of FIGS. 1-4. The stadium generally comprises an activity surface in the form of a playing area 10, a plurality of tiers of seating 12, seating boxes 14, parking levels 16, pedestrian ramp 18 and like features common to most stadiums.

The present stadium is unique in that it can be fully opened and closed utilizing an improved retractable dome arrangement, generally comprising a plurality of generally equal width lune-shaped dome panels 20 movable between a closed position such as shown in FIGS. 1 and 4 (left side) in which the panels are disposed in side-by-side relationship to define a generally spherical segment shaped dome, and an open position such as shown in FIGS. 2 and 4 (right side) in which the panels are stacked one above the other. A lune is the surface of a sphere included between two great circles disposed at a given included angle of inclination. The dome of the present invention approximates a circular segment of a sphere and it is the shape of a truncated lune which is used for each of the movable dome panels. In a preferred embodiment of the present invention, the circular segment of the sphere defining the dome has an included angle of approximately 60 degrees and the included angle between the two great circles defining each lune-shaped panel is between 5 and 10 degrees. The top of the stadium complex is provided with a deck 22 defining a generally circular opening 24 disposed in close and slightly overlapping relationship with the outer ends of panels 20 in all positions thereof.

Panels 20 are supported intermediate their ends by a pair of arcuate support rails 26 each having an upper surface having a plurality of arcuate steps 28, one for each panel 20 (FIG. 5-7), and which lie generally on a great circle of the imaginary sphere defined by the dome. The center of curvature of each step 28 is coincident with the center of the imaginary sphere with the radius of each step surface differing from the adjacent step surface by an amount approximately equal to the thickness of a panel 20. Each panel 20 has at least two supporting wheels 30 in alignment with each rail 26, and when the dome is closed each panel 20 is directly supported by rail 26 (FIG. 5) with the adjacent edges of panels 20 slightly overlapping one another to provide a weatherproof joint. The two centermost panels 20 abut one another at an interface 32 (FIG. 1) which can be provided with a suitable weatherproof seal. When panels 20 are moved downwardly and outwardly to the open position they roll from rail 26 onto the top surface (properly reinforced) of the next lower panel, and so on (FIG. 6-7) until they reach the nested or stacked condition shown at the right side of FIG. 4. Rails 26 are held in position by a suitable pair of arcuate supports 34, which can also be located on great circles of the imaginary sphere.

Panels 20 are also supported on arcuate arches 40 disposed at each end thereof. Arches 40, illustrated generally in FIGS. 3 and 4, are substantially parallel to one another, being disposed in parallel vertical planes equally spaced from the center of the dome. The overall arc of each arch is the arc defined by the intersection of the vertical plane in which the arch lies and the imaginary sphere of the dome itself. Each arch 40 has a flat inclined arcuate surface 42 facing the ends of each panel 20 and being perpendicular to the longitudinal axis thereof. Surfaces 42 each lie on the plane of a great circle of the imaginary sphere of the dome, and each has on the face thereof a plurality of parallel arcuate slots 44 through which extend end supports 46 for each of the panels 20. Each support 46 extends for the full width of each panel 20 and is in turn supported on its lower surface by means of a plurality of rollers 48. Support 46 has upstanding outer flange 47 supported on opposite sides by a plurality of rollers 50 and 52 and at the upper edge of flange 47 is a rack 54 engaged by a pinion 56 driven by a plurality of motors 58. Slots 44, in plan, are arcs of a circle having the same center as the imaginary sphere of the dome, and are of a length to accommodate the maximum length of travel of the panel or panels (i.e., at opposite sides of the stadium) disposed therein. The motors 58 for each track are spaced apart a distance less than the length of rack 54 so that each panel will always be under the control of at least one motor. The same is true for the sets of rollers 48, 50 and 52.

As best seen in FIGS. 8 and 9, each support 46 has rigidly affixed thereto a plurality of rods 60 each slidably received within a cylindrical bore 62 at the free end of each panel 20. Each rod 60 extends generally in the direction of the longitudinal axis of the panel and the inner free end thereof is connected to a suitable shock absorbing and/or fluid-type compensating device 64 which is in turn affixed to panel 20. Device 64 can be of any desired construction and serves the purpose of dampening flopping movement of the panels under high wind conditions. They also can serve to compensate for thermal expansion and contraction of the entire structure.

Panels 20 may be of any desired lightweight construction, such as a standard spaceframe construction, with the outer panel skin being either fabric or metal, or a combination of both. The structural design of the panels, rails, arches, tracks, etc. can be in accordance with standard engineering and architectural practices based on the anticipated structural and weather loading.

In operation, if the dome is closed it is opened by first actuating the motors in the top tracks which control the centermost panel to cause it to start retracting. As it retracts, it rolls over the top of the next centermost panel until they are fully stacked (FIG. 6). Thereafter, the motors for both these panels are actuated to cause them both to retract together (FIG. 7); and so on until the dome is fully opened, or at least opened to the desired extent. Both halves of the dome can be opened simultaneously if desired. The dome may be closed by simply reversing the opening sequence. Operating can be accomplished using conventional controls, sensors and the like.

While it will be apparent that the preferred embodiments of the invention disclosed are well calculated to provide the advantages above stated, it will be appreciated that the invention is susceptible to modification, variation and change without department from the proper scope or fair meaning of the subjoined claims.