Retractable Air Beam Roof for Large Stadiums

Abstract

The detailed principle, structure, manufacture and designing method of a retractable roof for large stadiums or other huge spaces are established. This roof is formed by using a number of connected and paralleled inflatable arc shaped tubes (called “air beams”) made of soft material (membrane). Using successive inflation to the tubes can realize deploying of the roof, and using successive deflation of tubes can realize retraction of the roof. All these processes can be completed by an automatically controlled program. A rigorous mathematics derivation and mechanics proof show that, the retractable air beam roof with durable membrane of ordinary durability can have a large span of over 100 meters, and can withstand in a regularly extreme (critical) weather (heavy wind, rain, snow and hail). The outstanding strong point of this kind of retractable roof is absolutely safe for spectators and performers (or competitors) inside the stadium.

1 - 3 . (canceled) 
     
     
         4 : An Air Beam, comprising:
 an Air Body, shaped as a cylinder of certain length and certain diameter, and bended as a circular arc with certain arc degree;   a Cylindrical Shaped Soft Membrane Tube (Air Tube) of the same size and same shape (when fully inflated) as the said Air Body, made of durable membrane material (for example, nylon reinforced fabric), with the function of confining the said Air Body and separating the Air Body with the outside atmosphere;   an End-Structures installed at each end of the said air tube, made of both soft membrane and solid material (such as nylon reinforced fiberglass), which has three functions: A. sealing the air, B. supporting the air beam and the load (if any) on the air beam, C. sliding (moving) along a track to change the location of said air beam;   is initiated and established by inventor Keh C. Liu (Jun. 2, 2006 filed in the National Patent Office of China, Beijing, File No. 200610083730.8, titled “Air Beam and Inflatable, Retractable Mobile Roof for Large Spaces”).   
     
     
         5 : A Method of Math and Phys Derivation for the physical characteristics of a said single Air Beam, and of the entire Retractable Air Beam Roof of large size, under various weather conditions, comprising:
 using Rigorous mathematics derivation and dynamics and statics analyses; to   finding the relations (calculation formulas) between the length, diameter, span, arc degree of the said Air Beam, the wind speed, wind direction, snow accumulation thickness, the air pressure inside the air tube, the tension stress in the membrane, especially at the end portion of the air tube, and the durability of the membrane material; which   forming the foundation and basis for properly, correctly and quantitatively designing the Retractable Air Beam Roof; and   resulting that, a properly designed retractable air beam roof with regular membrane durability will be able to work for large stadium of over one hundred meter span and over 180 meter length and for any regularly severe weather conditions.   is initiated and established by inventor Keh C. Liu (Jun. 2, 2006 filed at National Patent Office of China, Beijing, File No. 200610083730.8, titled “Air Beam and Inflatable, Retractable Mobile Roof for Large Spaces).   
     
     
         6 : An Air Beam as in  claim 4 , wherein additional devices, comprising:
 an End-Structure at each end portion of said air beam, comprising:   a Pair of Triangle Shaped Plates made of solid material (for example, nylon reinforced fiberglass), connected through a Hinge, openable as a book;   One or Two Pieces of Durable Membrane installed between the two said solid plates, forming as a Cone, for the functions of connecting, sealing and freely moving along with the air beam inflation and deflation;   a Steel Block (or Sliding Block), connected with the said two solid plates through the hinge, onto which (the steel block), a Steel Wheel with ball bearing, and a Sliding Ditch with cylindrical roller bearing are installed for the function of that, the end-structure will be able to smoothly slide along a Sliding Track and a Sliding Bar, and the end-structure will be able to keep certain correct orientation;   an Air Valve, a Motor with wire for opening and closing the air valve, and an Air Duct installed on one of the said four solid plates for each said air beam, for the function of inflation and deflation operations;   is initiated and established by inventor Keh C. Liu (Jun. 2, 2006 filed at National Patent Office of China, Beijing, File No. 200610083730.8, titled “Air Beam and Inflatable, Retractable Mobile Roof for Large Spaces).   
     
     
         7 . A (completely) Retractable Air Beam Roof, comprising:
 a Number (obtained from the length of the space, which needs roof covering, and the diameter of the air beam, which can be obtained from the results in  claim 5 ) of the Air Beams, equally divided into two Groups;   each said Group of Air Beams, paralleled and connected in certain way to form a half of the roof for large spaces, such as stadiums;   Two Group of Air Beams, forming the entire roof of a large space, which can be simultaneously retracted apart towards to the opposite ends of the space (stadium), during the retraction operation;   a Rain Strip (made of soft membrane) installed (firmly stuck) onto each pair of neighboring air beams for rain and snow proof.   a Pair of Rain Gutters installed on the front side of top air beam of each group of air beams, coupling together when the inflation and deployment process completed;   two Straight Line Shaped and Horizontal Sliding Tracks and Sliding Bars, installed to match the end-structures of the air beams as in  claim 6 , for smoothly sliding operation;   two End Portions of each said sliding track and sliding bar, bended down within the same vertical plane, forming a 90 degree circular arc, keeping the same incline orientation (optimum angle about 30 degree from the vertical direction), for the deflated air beams be neatly stacked;   four Main Winding Machines and four Pulling Chains (with length of about 120 meter each, and capacity about 1.5 ton), functioning simultaneously, needed for retraction of the air beam roof during the successively deflating the air beams, starting from the bottom one in each group of air beams;   two Inflators (Inflation Machines), installed at each end, but at only one side, of the stadium, needed for the successively inflation of all the air beams, starting from the top air beam in each group simultaneously, until the said pair of rain gutters coupled, and deployment of the air beam roof completed, operating the inflators inversely also be used for speeding up the deflation and retraction process;   two Main Air Ducts (with length of about 100 meter each), leading from the two inflation machines, through T-joints to the valves of every air beam, for both inflation and deflation operations;   is initiated and established by inventor (Jun. 2, 2006 filed at National Patent Office of China, Beijing, File No. 200610083730.8, Titled “Air Beam and Inflatable, Retractable Mobile Roof for Large Spaces).   
     
     
         8 . A air beam as in  claim 4 , and a retractable air beam roof as in  claim 7 , wherein additional devices and methods (measures) needed for Strengthening the Ability of Wind Resistance of the said retractable air beam roof, comprising:
 i) Math derivation and Physics analysis, resulting the Optimum Arc Angle of the Air Beams about 120 degree for reaching the strongest wind resistance ability;   ii) eight Nylon Reinforced Ropes installed on each air beam, four on each side, with an apart distance of about double the diameter of the air beam (tube), leading to the end-structure at the other side of the air beam, with adjustable, variable tension forces along with the wind speed;   iii) a hard rib strip, made of nylon reinforced fiberglass, installed along the inner (lower) side of each air beam, with the same length as the air beam, for the function of strengthening the wind resistance ability of the air beam, and for connection of nylon ropes;   iv) doubly strengthened membrane material used for the area near the end-structure of each air beam due to the effect of stress concentration occurring during the weather of strong wind;   is initiated and established by inventor Keh C. Liu (Jun. 2, 2006 filed at National Patent Office of China, Beijing, File No. 200610083730.8, Titled “Air Beam and Inflatable, Retractable Mobile Roof for Large Spaces).   
     
     
         9 . A Method of Math and Phys Derivation for Physical Characteristics as in claim  14 , wherein additional methods, comprising:
 a method of finding the total pulling force needed to pull each side of an entire half of the air beam roof when the deflation and retraction just start, comprising:   simulating the operation of a locomotive pulling a train; and   supposing that, the system of chain pulling (sliding) the end-structures has a much worse friction condition, i.e. a much larger friction coefficient, than that of a train system, say ten times bigger for a conservative estimation;   calculating and resulting that, an ordinary winding machine with a regular capability will be able to handle it;   calculating the mutual pressure forces between the neighboring air beams in various weather conditions, and their effects to the air pressure inside the air tubes and to the supporting forces at the end-structures;   are initiated and established by inventor.   
     
     
         10 . A Retractable Air Beam Roof as in  claim 7 , wherein additional devices, comprising:
 a Supporting Structure made of angle steel for firmly supporting each of the sliding tracks and the sliding bars, with its form and size closely depended on the basis and location, where the air beam roof is built;   two pieces of flat, dry and absolutely clean Ground or Platform at the two end-area of the stadium, for placing the retracted, deflated and stacked air beams, securely guarded;   an Air Duct Guider and a Wire Guider installed on the end-structure at the air valve side of each air beam, for neatly collection of the air duct and electrical wires during the deflation and retraction process;   are initiated and established by inventor.   
     
     
         11 . A Retractable Air Beam Roof as in  claim 7 , wherein additional devices and methods, comprising:
 four Additional Winding Machines installed at the area at two ends of the stadium (two at each end area), for retraction of the air beam roof needs, operating in case of severe weather conditions, extremely low temperature, and membrane material stepping to aging (although the said device does not need in ordinary cases, it is still set in operation in all the cases for the reason of security, reliability and convenience);   four pieces of Nylon Rope around the upper portion of the top air beam, two pieces for each group of air beams, leading to the said additional winding machines, with length of about 260 meter for each piece of rope;   a number of Open Soft Rope Guiders, made of soft, smooth, flexible fiberglass nylon reinforced material, firmly stuck onto the air beams, for guiding the rope, two pairs on each air beam on its top, twelve pieces on each of the top air beams on its top and upper front side;   twenty pieces of Closed Soft Rope Guiders, made of soft, smooth, flexible fiberglass nylon reinforced material, firmly stuck onto the front lower side of the two top air beams, ten pieces on each top air beams, five pieces at each rope location, for the function of preventing rope dislocation;   a number of Closed Hard Rope Guiders, made of hard, smooth fiberglass nylon reinforced material, for guiding the rope, two of them installed on each rib strip of each air beam, at the rope location, and two of them installed underneath the platform for the stacked deflated air beams, for the said nylon rope be smoothly moving through;   membrane material of Double Durability used for the top air beam of each group of air beams;   calculating and estimating the rope pulling forces needed, closely relied on the weather conditions (wind, snow and temperature) and degree of membrane material aging, from zero to 800 kg for each winding machine;   are initiated and established by inventor.   
     
     
         12 . A Retractable Air Beam Roof as in  claim 7 , wherein additional devices, comprising
 an Automatic Air Leaking Detecting Machine by using the method of chemical smoke, which is able to find which air beam and which portion there exists a leaking hole, so that, the repair work can be quickly proceeded in time;   an Automatic Snow Removing Machine, installed at the area, where the deflated air beam stacked;   an Automatic Dust and Stain Cleaning and Moisture Drying Machine, installed at the area, where the deflated air beams stacked;   are initiated by inventor.   
     
     
         13 . A Retractable Air Beam Roof as in  claim 7 , wherein additional devices, comprising:
 a Central Control Table and an Automatic Central Control Panel for automatic control of the operation of entire Retractable Air Beam Roof an Electrical Wire System, connecting all the motors (controlling valves) on each air beam with the central control table, and connecting all the eight winding machines and the two inflation machines with the central control table;   wirelessly connecting the local weather forecast station with the central control table;   wirelessly connecting the local police station with the central control table;   wirelessly connecting the headquarter office with the central control table;   an electrical wire system, connecting the loudspeaker system to spectators and players with the central control table;   Programming the entire procedures starting from the weather forecast until completion of roof deployment or retraction, for the purpose of automatic operation;   are initiated and established by inventor (Jun. 2, 2006 filed at National Patent Office of China, Beijing, File No. 200610083730.8, Titled “Air Beam and Inflatable, Retractable Mobile Roof for Large Spaces).