Stadium cover
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention pertains to a stadium cover, and more particularly to a gas-filled cover that can be opened and closed. 
     2. Prior Art 
     It has been known heretofore to cover the playing field of a stadium with a tarpaulin to protect against snow, rain or the like. It has also been known heretofore to provide a permanent dome over a stadium so as to protect the occupants from the elements. A tarpaulin really does nothing for the spectators, and a dome construction is rather costly. 
     SUMMARY OF THE INVENTION 
     The present invention comprises a pair of complemental canopies that are filled with a gas such as helium and which can be installed above an existing stadium structure, there being means for anchoring and selectively moving or pivoting the canopies. 
     Accordingly, it is an object of the present invention to provide an inexpensive gas-supported stadium cover which can be opened and closed. 
     Many other advantages, features, and additional objects of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheet of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example. 
    
    
     ON THE DRAWINGS 
     FIG. 1 is a cross-sectional view through a stadium provided with a stadium cover in accordance with the present invention, and taken generally along the line I--I on FIG. 2; 
     FIG. 2 is a plan view thereof in reduced scale with one canopy removed to simplify illustration; 
     FIG. 3 corresponds to FIG. 1 in reduced scale showing the canopies open in one mode; and 
     FIG. 4 corresponds to FIG. 1 in reduced scale and showing the canopies open in another mode. 
    
    
     AS SHOWN ON THE DRAWINGS 
     The principles of the present invention are particularly useful when embodied in a stadium cover as shown in FIG. 1, generally indicated by the numeral 10. The cover 10 is disposed in superimposed relation to a stadium 11 and includes a pair of complemental canopies 12, 13. The canopies preferably comprise sheet material such as plastic or other material that will be inert with respect to a gas used for buoyancy, such as helium. To prevent the cover from inflating like a balloon, numerous webs 14 are provided so that each of the canopies has several compartments 15. The webs 14 may be in the form of heat seals. If desired, more than one type of material may be utilized. For example, some of the compartments may be opaque, some translucent, and some transparent so as to provide a desired degree of capability of transmitting light. If a given compartment 15 does not need to be filled with gas, it can be replaced with a single panel having the desired properties. 
     In this embodiment, winches, cables and pulleys provide anchoring, reference, and movement. In the disclosed embodiment, there is a set of four winches 16-19 disposed as pairs on opposite sides of the stadium 11. As shown in FIGS. 1 and 2, the winch 16 is connected to a cable set 20 which leads to a number of anchoring points 21 disposed along one edge of the canopy 12. The opposite or central edge of the canopy 12 is connected by a further cable set 22 to the winch 18. In like manner as shown in FIG. 1, the canopy 13 has a cable set 23 connecting one edge thereof to the winch 19 and a cable set 24 connecting the opposite edge thereof to the winch 17. There is a natural tendency for the canopies 12, 13 to rise, and they are anchored in a vertical sense by the cables sets 20, 22-24 to the winches 16-19. The winches have been illustrated as being beyond the perimeter of the stadium for ease of illustration, but in an actual installation would undoubtedly be placed within the stadium, that is beneath the seating area, and provided with additional pulleys and guards for the cables. The present illustration is simpler to understand. Whenever the winches are located, a suitable number of pulleys are utilized and they can be adapted to be supported on the stadium itself or on other columns provided for such purpose. The locations of the pulleys thus provide a reference for the points where each canopy is held or moored. In the event that the winches 16, 19 and the cable sets 20, 23 are permitted to remain in the illustrated position, then they function as a means for pivotally supporting each of the canopies along one edge thereof at opposite sides of the stadium. 
     As shown in FIG. 3, if cable is payed out by the winches 17 and 18, the canopies will pivot about their outer edges, substantially as shown in FIG. 3. The canopies can be opened in this manner to the extent desired to admit sunshine, light, rain, or whatever may be desired at the time. If the four winches 16-19 are operated to pay out cable at the same effective rate, then the canopies will rise jointly as shown in FIG. 4 to provide ventilation while still providing protection against sun, rain, snow or the like directed from above. 
     The canopies can have various configurations depending upon the shape of the stadium and the area that is desired to be covered. In this embodiment, the canopies jointly have a hollow generally hemispherical shape, and they have abutting edges that meet in a central vertical plane indicated by the numeral 25. (In FIG. 2, the canopy 13 and its cables are shown in phantom lines.) Further, the generally hemispherical shape can be horizontally elongated along the plane 25. In this embodiment, the canopies 12, 13 have substantially identical configurations or shapes so that two canopies of the same construction can be used jointly. With the pulleys such as those disposed at 26 and 27 in FIG. 1 supported on posts or columns, the stadium cover becomes actually independent of the stadium 11 and can be used as free-standing structure for other purposes such as a form of tent that has no central poles as well as for other types for uses such as a cover for stored material such as grain. 
     Although various minor modifications might be suggested by those versed in the art, it should be understood that I wish to embody within the scope of the patent warranted hereon all such embodiments as reasonably and properly come within the scope of my contribution to the art.