Patent Abstract:
Modular inflatable cover for buildings, comprising separate coaxial conduits ( 30 ) secured together by tensionable link ( 50 ) and fluid-connected by coaxial inflatable tube ( 24 ). Tube ( 24 ) securely embraces sliders ( 32 ) that in turn closely but freely embrace conduits ( 30 ). Sliders ( 32 ) are urged by springs ( 34 ) to keep tube ( 24 ) taught. Elastic cinctures ( 26 ) on tube ( 24 ) and springs ( 34 ) tensionably cooperate against inflation means to provide reliable control of openings between adjacent modules in an assembly. Conduits ( 30 ) are securely torqued to ground anchors ( 40 ) by coupling ( 42 ). End covers ( 44 ) and sliders ( 32 ) are provided to compensate for and facilitate length shrinkage of tube ( 24 ), upon inflation. The present invention provides a variable cover with integral support that is uniquely capable of exploiting canyons and other ground depressions for an unprecedented scale of environment control. Applications include greenhouses, shutters, insulation and shelters.

Full Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The Tensioned Inflatable Cover Module relates to inflatable buildings and in particular to systems for regulating the flow of fluids and radiation into enclosed spaces as provided, for example, in greenhouses and shelters.  
         [0003]     2. Description of the Prior Art  
         [0004]     Inflatable buildings have been used extensively in the greenhouse and leisure industries where the relatively low weight, cost and ease of installation are major advantages over more rigid structures built of glass or composite materials. The purpose of these installations has been primarily the provision of more or less controlled environments for plant growth or human activities; an increasingly popular benefit of these microclimate zones has been public enjoyment as provided in garden centers, botanical gardens and sports complexes. With the unabating current deforestation worldwide and the consequent environment degradation, these oasis of life may become increasingly important and perhaps even essential to our continued survival on this Earth. Looking ahead, the initial establishment of human settlements on distant planets, currently focused on Mars, is likely to be dependent on the provision of pockets of controlled environment within the inhospitable alien atmospheres. Among inflatable buildings, greenhouses offer great challenges in design because of the need, on one hand, to allow radiation into the enclosed space for plant growth, and on the other hand also regulate temperature within the often tight limits that are compatible with the biology of the plants being grown.  
         [0005]     Current greenhouse designs suffer from limitations in scale or expanse of coverage attributable mostly to the need for a construction frame to support the transparent cover and means for ventilation in the form of motorized fans and shutters. Another limitation to the scale of environment control is the economics that dictate heating the minimum volume of air necessary for plant growth. The small air volumes enclosed by current greenhouses provide little buffering against variations in external climatic factors such as radiation, temperature, wind and precipitation. This low buffering necessitates frequent cycling of climate control means to either remove excess heat by ventilation or to add heat by usually burning fossil fuels. To improve heating efficiency, insulation is usually provided in the form of an inflated air gap between either separate cover sheets or within discreet tubes disposed adjacent to one another to provide a modular, more or less air-tight cover. The double cover, wherein two layers of very large sheets are draped over the outside of the greenhouse frame, has been the main construction method. The apparatus is laborious to assemble and necessitates additional equipment for ventilation in the form of motorized fans and shutters. There has been a steady effort to improve inflatable greenhouses by providing an inflatable cover with variable openings between tubular modules as shown in U.S. Pat. No. 3,328,926 to Reinhard (1967), U.S. Pat. No. 4,027,437 to Monsky et al (1977). Attention to the practical application of this concept has been extended to inflatable insulation covers inside greenhouses as shown in U.S. Pat. No. 4,301,626 to Davis et al (1981), U.S. Pat. No. 4,290,242 to Gregory (1981), U.S. Pat. No. 6,000,170 to Davis (1999), U.S. Pat. No. 6,442,903 B1 to Hebert (2002). All the aforesaid designs are limited to small scale, mostly indoor applications mainly because of their dependency on a supporting frame and the lack of rugged integral means for module support. These designs also lack dependable means of maintaining openings between the tubes in windy outdoors conditions mostly because they utilize gravity-dependent mechanisms of tube deflation. Deflation of the tube per se does not automatically provide consistent gaps between modules because the tubes tend to flatten, sag and flap in the wind. The embodiment in U.S. Pat. No. 4,027,437 to Monsky et al (1977) achieves tube deflation by powered suction of air from the inflatable tube via ducting additional to that providing inflation air; whereas this dual plumbing system can inflate and deflate the device, consistent ventilation gaps between tubes are restricted to the side walls where spatially-offset tube assemblies part upon deflation. In fact, when the contiguous, oval tube arrangement disclosed in the aforesaid patent is deflated, a flattened ribbon-like curtain is created on the roof of the building mostly because the spacing between inflated tubes, center to center, is less than the tube maximum diameter, causing the flattened tubes to remain contiguous, if not overlapped. U.S. Pat. No. 3,328,926 to Reinhard (1967) does not disclose any reliable or consistent method of achieving ventilation gaps between inflatable tubes, upon deflation.  
         [0006]     Therefore, it is an object and advantage of the Tensioned Inflatable Cover Module to provide a novel cover module suitable for outdoor use, fitted with integral support and dependable means of achieving ventilation gaps between adjacent modules. It is an object and advantage of the Tensioned Inflatable Cover Module to provide novel frame-less means of covering enclosed areas for environment control. It is also an object and advantage of the Tensioned Inflatable Cover Module to enable provision of enclosed spaces of unprecedented volume to afford improved buffering capacity against changes in external environmental factors. It is yet another object and advantage of this invention to exploit natural features such as canyons, craters, valleys, coulees, water bodies or man-made depressions to dispense of the need for construction frames. It is a further object and advantage of this invention to provide a novel variable cover that can also be used on framed building structures. Other objects and advantages of my invention will become apparent from the detailed description that follows and upon reference to the drawings.  
       SUMMARY OF THE INVENTION  
       [0007]     The Tensioned Inflatable Cover Module is an inflatable apparatus or assembly thereof designed to provide reliable control of the flow of fluids and radiation between an enclosed space and its surroundings. Essentially the invention comprises an inflatable tube mounted on end supports that can move along end fluid conduits, the conduits being fluidly-connected to the tube. One conduit is open for transit of inflation fluid in and out of the inflatable tube and another conduit is closed to retain fluid within the apparatus. End covers and the tube&#39;s movable supports are provided to compensate for and facilitate shrinkage of the length of the inflatable tube, which occurs upon inflation. Steady tension is maintained on the inflatable tube by the squeezing action of peripheral elastic cinctures and the tugging of springs on the tube&#39;s end supports, from a minimum deflated bundle outer diameter to a substantially larger inflated outer diameter. A structural, tensionable member secures the conduits together. Conduits are in turn adjustably secured either to building frames or to peg-like anchors, which may be driven into the ground or fastened to building frames, posts and the like. The desired size of gaps between adjacent modules of an assembly can be set at installation on site and can be controlled in operation by varying the extent of tube inflation. Control of the size of the gaps in turn affords control of the flow of fluids and radiation between the enclosed space and its surroundings. The Tensioned Inflatable Cover Module is particularly suited for novel inflatable building structures that can span natural and man-made depressions, e.g. canyons, craters, valleys, coulees, embankments and the like, to provide unprecedented scale of ground and space coverage. Other uses include insulation, shutters, shelters, and cover for greenhouse frames.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]     In drawings which illustrate embodiments of the invention,  
         [0009]      FIG. 1A  shows a deflated module fitted with end covers, in isometric view  
         [0010]      FIG. 2A  shows a partially-inflated module fitted with end covers, in isometric view  
         [0011]      FIG. 3A  shows a fully-inflated module fitted with end covers, in isometric view  
         [0012]      FIG. 1B  is a sectional view of the module shown in  FIG. 1A  along line  1 B- 1 B,  
         [0013]      FIG. 2B  is a sectional view of the module shown in  FIG. 2A  along line  2 B- 2 B,  
         [0014]      FIG. 3B  is a sectional view of the module shown in  FIG. 3A  along line  3 B- 3 B,  
         [0015]      FIG. 4A  shows a deflated module fitted with bellows, in isometric view  
         [0016]      FIG. 5A  shows a partially-inflated module fitted with bellows, in isometric view  
         [0017]      FIG. 6A  shows a fully-inflated module fitted with bellows, in isometric view  
         [0018]      FIG. 4B  is a sectional view of the module shown in  FIG. 4A  along line  4 B- 4 B,  
         [0019]      FIG. 5B  is a sectional view of the module shown in  FIG. 5A  along line  5 B- 5 B,  
         [0020]      FIG. 6B  is a sectional view of the module shown in  FIG. 6A  along line  6 B- 6 B,  
         [0021]      FIG. 7A  is an isometric view showing a module fitted with torsional deployment means for the inflatable tube, installed over a valley section,  
         [0022]      FIG. 7B  is an enlarged view of the closed end of the module shown in  FIG. 7A  with the inflatable tube sectioned to show internal details of construction,  
         [0023]      FIG. 8A  is an exploded view showing construction of the tube support ring,  
         [0024]      FIG. 8B  shows support rings inside an inflated inflatable tube, in isometric view  
         [0025]      FIG. 8C  shows support rings in a deflated inflatable tube, in isometric view  
         [0026]      FIG. 8D  shows radial reinforcing sheet system inside an expanded inflatable tube,  
         [0027]      FIG. 8E  is a partial sectional view of chordate sheets inside a reinforced inflatable tube,  
         [0028]      FIG. 9A  is a partial view showing a plurality of modules installed as a cover on square channel frames to form a greenhouse or shelter,  
         [0029]      FIG. 9B  is a partial view showing a plurality of modules installed as a cover on arched square tubing frames to form a greenhouse or shelter,  
         [0030]      FIG. 10  shows a cross-section of a valley landscape covered by an assembly of modules to provide environment control on a large scale.  
     
    
     REFERENCE NUMERALS IN DRAWINGS  
       [0000]    
       
           20  open end  
           22  closed end  
           24  inflatable tube  
           26  elastic cincture  
           28  fluid transit hole  
           30  conduit  
           32  slider  
           34  compression spring  
           36  block  
           38  extension spring  
           40  anchor  
           42  tension coupling  
           44  end cover  
           46  bellows  
           48  end plate  
           50  ends link  
           52  plug  
           56  clamp  
           58  spring hole  
           60  dextrarotary spring  
           62  levorotary spring  
           64  link retainer  
           68  bellows fluid hole  
           70   a  group of modules in deflated state  
           70   b  group of modules in partial inflation state  
           70   c  group of modules in full inflation state  
           72   a  upright channel  
           72   b  horizontal channel  
           72   c  channel cover  
           74  end frame assembly  
           76   a  inflation means  
           76   b  fluid duct  
           78  arched end frame  
           80   a  conduit aperture  
           80   b  conduit access hole  
           80   c  access hole plug  
           82  main duct  
           84  secondary duct  
           86  enclosed valley  
           88  support ring  
           90   a  inflatable bag  
           90   b  ring walls  
           90   c  ring wall aperture  
           90   d  ring wall edge  
           90   e  ring fastener  
           90   f  carriage hole  
           90   g  fluid passage  
           90   h  edge weld  
           90   k  ring to tube weld  
           90   l  radial reinforcing sheet  
           90   m  sheet to tube weld  
           90   n  central tubing  
           90   p  chordate sheet  
           92  deflation hole  
           94  spacer sheath  
       
     
       DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0000]     Scope and Materials  
         [0086]     The present invention relates to buildings and more particularly to a novel, modular inflatable building particularly adapted for use as a greenhouse, shelter and the like. Materials suitable for constructing the Tensioned Inflatable Cover Module are well known to those skilled in the art. Essentially one needs fasteners, inflatable tubes, cables or ropes, springs, bars, sheets and tubing. Inflatable covers for greenhouses are usually made out of polymers e.g. clear polyethylene. However, where light is not required other flexible material, e.g. fabric, opaque polymers, may be used to construct the inflatable tubes. Other components of this module can be made out of sheets, tubing and bars of metal, polymer or composite, which may be cut to size, shaped, drilled, threaded, glued, or welded for fastening. Current plumbing supplies or like products can also be used. The choice of materials is only limited by the intended use and engineering considerations and would be obvious to those skilled in the art. The preferred embodiments of the Tensioned Inflatable Cover Module will now be discussed starting with the embodiment fitted with end covers, followed by the embodiment fitted with bellows, followed by the embodiments fitted with torsional deployment and reinforcements of the inflatable member. A brief discussion of alternative embodiments of the present invention will close the description. Hereafter the Tensioned Inflatable Cover Module will alternatively be referred to simply as the module.  
         [0000]     Module Fitted with End Covers— FIG. 1A-3A ,  1 B- 3 B  
         [0087]     Reference will now be made to the isometric view of the Tensioned Inflatable Cover Module depicted in  FIG. 1A  and related details of construction illustrated in the sectional view of  FIG. 1B . The Tensioned Inflatable Cover Module comprises at least an open end  20 , open to the surrounding fluid environment and a closed end  22 , closed to the surrounding fluid environment, connected to each other by an inflatable tube  24  which may be fitted with peripheral elastic cinctures  26 . The open end  20  and the closed end  22  comprise a conduit  30  fluid-connected to the inflatable tube  24  via at least one fluid transit hole  28 . The conduit  30  at the closed end  22  is closed by means of a plug  52 . The inflatable tube  24  is securely attached onto a slider  32  by means of a clamp  56 , the slider  32  closely but freely embracing the conduit  30  on which it may rotate and translate. An elastic device, e.g. a compression spring  34  confined to the conduit  30  by a block  36 , is secured to and acted upon by rotational and translational movements of the slider  32  along the conduit  30 . Spring  34  is confined to the conduit  30  by the block  36  and may also be fastened at its ends to the slider  32  and to the block  36  by welding or bonding. The conduit  30  may be threaded and adjustably secured either to a building framing member, not shown, or to an end anchor  40  by means of a tension coupling  42 . An end cover  44 , integral with the end anchor  40  or fastened to it, may be provided to more or less embrace the inflatable tube  24 . The conduits  30  at the module&#39;s ends may be secured to each other by a tensionable ends link  50 , secured onto the block  36  by means of a link retainer  64 . Tension of the ends link  50  may be adjusted via torquing of the tension coupling  42  onto a threaded conduit  30  and bearing against the face of the end anchor  40  or any suitable framing member, not shown, used as support for the conduits  30 .  
         [0000]     Module Fitted With Bellows— FIG. 4A-6A ,  4 B- 6 B  
         [0088]     Reference will now be made to the isometric view of the Tensioned Inflatable Cover Module depicted in  FIG. 4A  and related details of construction illustrated in the sectional view of  FIG. 4B . The module fitted with bellows comprises at least the open end  20 , open to the surrounding fluid environment and the closed end  22 , closed to the surrounding fluid environment, connected to each other by the inflatable tube  24  which may be fitted with peripheral elastic cinctures  26 . The open end  20  and the closed end  22  comprise the conduit  30  fluid-connected to the inflatable tube  24  via at least one fluid transit hole  28 . The conduit  30  at the closed end  22  is closed by means of the plug  52 . The inflatable tube  24  is securely attached onto the slider  32  by means of the clamp  56 . The inflatable tube  24  is extended past the slider  32  and secured to the conduit  30  to provide an inflatable bellows  46 , which more or less embraces the inflatable tube  24 ; the bellows  46  is buttressed by a steady end plate  48 , integral with the end anchor  40  or fastened to it. The portion of the conduit enclosed by the bellows  46  is provided with a bellows fluid hole  68  fluidly-connecting the bellows  46  to the lumen of the conduit  30 . The slider  32  closely but freely embraces the conduit  30  on which it may rotate and translate. An elastic device, e.g. an extension spring  38 , confined to the conduit  30  by the block  36 , is secured to and acted upon by rotational and translational movements of the slider  32  along the conduit  30 . Spring  38  is confined to the conduit  30  by the block  36  and may also be permanently fastened at one end to the slider  32  and to the conduit  30  at the other end, by welding, bonding or by securing its end hooks into a spring hole  58 .  
         [0089]     The conduits  30  may be secured to each other by a tensionable ends link  50 , secured onto the block  36  by means of the link retainer  64 . Tension of the ends link  50  may be adjusted via torquing of the tension coupling  42  onto a threaded conduit  30  and bearing against the face of the anchor  40  or any suitable framing member, not shown, used as support.  
         [0000]     Module Fitted with Torsional Deployment of the Inflatable Tube— FIG. 7A, 7B   
         [0090]      FIG. 7A  illustrates that embodiment of the Tensioned Inflatable Cover Module making use of helical folding of the inflatable tube  24 , by spring-assisted torsion, to strengthen the tube  24  and assist with its deflation. Helical folding of the inflatable tube  24  can assist with its deflation and impart to it increased strength in the same manner that twisted threads give a rope its strength. The module of this embodiment comprises at least the open end  20 , open to the surrounding fluid environment and the closed end  22 , closed to the surrounding fluid environment, connected to each other by the inflatable tube  24  which may be fitted with peripheral elastic cinctures  26 . The open end  20  and the closed end  22  each comprise the conduit  30  fluid-connected to the inflatable tube  24  via at least one fluid transit hole  28 . The conduit  30  at the closed end  22  is closed by means of the plug  52 . Details of the aforesaid construction are illustrated in the enlarged view of the closed end  22 , shown in  FIG. 7B . The inflatable tube  24  is securely attached onto the slider  32  by means of the clamp  56 , the slider  32  closely but freely embracing the conduit  30  on which it may rotate and translate. Counter-rotating elastic devices, e.g. rotating or wound to the right as in a dextrarotary spring  60  and to the left as in a levorotary spring  62 , are secured to and acted upon by rotational and translational movements of the slider  32  along the conduit  30 . Springs  60 ,  62  are confined to the conduit  30  by the block  36  and are also fastened at one end to the slider  32  and to the block  36  at the other end, by welding, bonding or by securing their end hooks into the spring hole  58 . To install the tube  24  of this embodiment the inflatable tube  24  is first secured on the slider  32  by clamp  56  at the closed end  22 . One or more helical twists are then imparted to the inflatable tube  24  before fastening onto the slider  32  at the open end  20 , via clamp  56 , to give the twisted conformation depicted in  FIG. 7A . The conduit  30  may be threaded and adjustably secured either to a building framing member, not shown, or to the anchor  40  by means of the tension coupling  42 . The conduits  30  at the module&#39;s ends may be secured to each other by the tensionable ends link  50 , secured onto the block  36  as previously described. Tension of the ends link  50  may be adjusted via torquing of the tension coupling  42  onto the threaded conduit  30  and bearing against the face of the end anchor  40  or any suitable framing member, not shown, used as support.  
         [0000]     Embodiments providing reinforcement of the inflatable tube  
         [0091]     In addition to the support provided to tube  24  by sliders  32 , as previously discussed, structural stability of the module can be increased by internal walling of the inflatable tube  24  and anchorage on the ends link  50 . The embodiment making use of a support ring as shown in  FIG. 8A-8C  will be described first, followed by the embodiment making use of radial reinforcing sheets as depicted in  FIG. 8D  and lastly by the embodiment making use of chordate sheets as shown in  FIG. 8E .  
         [0000]     Support Ring for Inflatable Tube— FIG. 8A-8C   
         [0092]      FIGS. 8A-8C  illustrate construction of the support ring  88 , an internal wall that anchors the inflatable tube  24  onto the ends link  50 . Where module length or load conditions dictate additional support of the inflatable tube  24  about the ends link  50 , a support ring  88 , more or less centered on the ends link  50  through a carriage hole  90   f,  may be provided. The support ring  88  is welded to the inner surface of the inflatable tube  24  by a ring to tube weld  90   k,  as shown in  FIG. 8B . The support ring  88  can be made from any material suitable for the intended application; for a greenhouse application, ring walls  90   b  made out of clear, flexible polymer sheeting are first welded together along ring wall edges  90   d  by an edge weld  90   h  to form a bag, as shown in  FIG. 8A . Ring fasteners  90   e,  their fluid passages  90   g  aligned, are then welded co-axially to the outer surface of the ring walls  90   b,  along the line of a ring wall aperture  90   c,  to form an inflatable bag  90   a.  The inflatable bag  90   a  can be inflated with fluid e.g. air, through fluid passages  90   g.  While inflated, the Bag  90   a  is then sealed by welding together the opposing ring fasteners  90   e,  previously welded to the ring walls  90   b.  The resulting sealed inflated support ring  88  can then be slid onto the ends link  50  through the carriage hole  90   f  and positioned inside the inflatable tube  24  for the ring to tube weld  90   k  to be effected, as shown in  FIG. 8B . Once welded to the inflatable tube  24 , the inflated support ring  88  can be deflated by making a deflation hole  92  through the ring to tube weld  90   k.  The support ring  88  resulting from the aforesaid description anchors the inflatable tube  24  onto the ends link  50  as shown in  FIG. 8B  and allows deflation of the inflatable tube  24  to occur as illustrated in  FIG. 8C . Location and number of support rings  88  inside the inflatable tube  24  is dictated by the nature and magnitude of anticipated stress loads on tube  24 . Location of the support rings  88  inside the inflatable tube  24  may be controlled by means of the length of a spacer sheath  94 , the latter preferably made out of a rigid tubular material. The spacer sheaths  94  embraces the ends link  50  and are installed between the support rings  88  to confine them to design locations prior to welding to the inflatable tube  24 , as previously described.  
         [0000]     Radial Reinforcing Sheets for the Inflatable Tube— FIG. 8D   
         [0093]      FIG. 8D  shows how one or a plurality of similar size reinforcing sheets  90   l  can be fastened longitudinally to the inner surface of the tube  24 , by sheet to tube welds  90   m,  approximately along radius lines and to a central tubing  90   n  that embraces the ends link  50 . Reinforcement may be localized or run the length of the tube  24 , depending on engineering requirements. Current practice in the manufacture of polymer tubing could easily accommodate modifications for dies to extrude the embodiment described as a walled tube with a small sheath at its center.  
         [0000]     Chordate Reinforcing Sheets for the Inflatable Tube— FIG. 8E   
         [0094]      FIG. 8E  shows how one or a plurality of reinforcing sheets  90   p  can be fastened longitudinally to the inner surface of the tube  24  and along truncated chord lines, by sheet to tube welds  90   m  and to a central tubing  90   n  that embraces the ends link  50 . The Sheets  90   p  have a height substantially smaller that the natural inflated diameter of tube  24 , in the vertical axis and a width substantially greater than the natural inflated diameter of tube  24 , in the horizontal axis. The Sheets  90   p  of this embodiment form an internal web that sets a desired inflated distance between opposing surfaces of tube  24 , upon inflation. Current practice in the manufacture of polymer tubing could easily accommodate modifications for dies to extrude the embodiment described as an internally-walled tube with a small sheath at its center.  
       Alternative Embodiments of the Invention  
       [0095]     The preferred embodiments of the Tensioned Inflatable Cover Module, as described above, extend to simplified versions, substitutions, omissions or combinations of components so long as the principle of operation is maintained. Some alternative embodiments are discussed below.  
         [0096]     The conduit  30  at the closed end  22  of the module could be replaced by a solid body, given that module inflation can proceed from the conduit  30  at the open end  20 . A single modified conduit, extending from the open end  20  to the closed end  22 , could replace the conduits  30  and the ends link  50  to combine fluid transit and structural link functions. The ends link  50 , more or less coaxial in the preferred embodiment of this invention could be supplemented or substituted altogether by a plurality of structural members linking the conduits  30 . One or more similar structural members may also be provided external to the inflatable tube  24  and attached either to other suitable supports, not shown, or to the module&#39;s anchors  40  or end covers  44  and supporting the inflatable tube  24  by means of suitable fasteners, e.g. brackets, hooks, rings or elastic devices.  
         [0097]     In some applications, the module remains useful without the use of elastic cinctures  26 , end covers  44 , bellows  46 , anchors  40  and one spring per module. These applications include installations in which structural support is provided for the conduits  30  by means of existing framing members or other means, e.g. beams or posts. Other pertinent applications include installations using relatively short module length, powered fluid withdrawal from the module and whenever compensation of shrinkage of coverage, upon expansion, is not required. End covers  44  are shown as cylindrical structures in the preferred embodiments but could be made into any shape convenient for the intended building so long as the internal diameter can accommodate the inflatable tube  24 . For example, a square outer shape for the cover  44  would provide a better seal between covers  44  on a level installation whereas a trapezoidal outer shape would achieve the same for a curved wall of covers  44  as would be used on an arched conventional greenhouse frame. Interlocking covers  44  is another, among many other forms and methods of construction that could be employed without departing from the spirit of the present invention.  
         [0000]     Operation  
         [0000]     Overview  
         [0098]     Inflation means are well known to those skilled in the art and are usually provided in the form of a motorized fan pumping a fluid, e.g. air, in and out of the inflatable cover. The Tensioned Inflatable Cover Module or a plurality thereof may be expanded from a minimum bundle outer diameter in the deflated state ( FIG. 1A, 4A ) through a continuum of variable stages of expansion ( FIG. 2A, 5A ) to the fully-expanded stage shown in  FIG. 3A, 6A . In order to provide openings of the desired size between adjacent modules of an assembly, the maximum outer diameter at full expansion may be designed to be substantially larger than the minimum bundle diameter in the deflated state. During the development of this invention I found that expansion of the inflatable tube  24  causes a reduction of its length, the extent of which is a function of the size differential between the tube maximum inflated diameter and the diameter of the tube&#39;s end supports, embodied by the sliders  32 . In order to compensate for this length shrinkage, the end cover  44  in  FIG. 1A  and the bellows  46  in  FIG. 4A  were devised. The operation of the embodiment making use of end covers  44  to compensate for length shrinkage of the inflatable tube  24  will be described first, followed by that making use of the bellows  46  to achieve the same. The operation of the embodiments making use of torsional deployment of the tube  24  and reinforced inflatable members will also be described.  
         [0000]     Module Fitted with Covers  44  for Compensation of Shrinkage of the Tube  24   
         [0099]     The outward appearance of modules in the sequence of operation of this embodiment is illustrated in  FIG. 1A-3A . Related internal details of mechanisms of operation are shown in the cross-sectional views of  FIG. 1B-3B . Inflation means are well known to those skilled in the art and are usually provided in the form of a motorized fan pumping a fluid, e.g. air, in and out of the inflatable cover. Starting with the deflated module in  FIG. 1A, 1B , expansion of the module or assembly thereof may be achieved by forcing fluids or fluidized substances into the inflatable tube  24  from the open end  20 , via the conduit  30  and through at least one fluid transit hole  28  into the inflatable tube  24  and through it to the conduit  30  at the closed end  22 . Fluid escape from the module is minimized by way of the conduit plug  52 , the close fit between slider  32  and conduit  30  and fastening, via clamp  56 , of the inflatable tube  24  onto the slider  32 , which it embraces. Increase of fluid pressure inside the inflatable tube  24 , relative to the outside, causes the tube  24  to expand against the peripheral restriction of the elastic cinctures  26  and the linear urging restriction of the compression springs  34  on the sliders  32 ; the resulting constricted conformation is depicted in  FIG. 2A, 2B ; at this stage the slider  32  has translated along the conduit  30  and towards the fluid transit hole  28  from its original position as shown in  FIG. 1B  to a new position as shown in  FIG. 2B . Further increase of fluid pressure may completely overcome Spring  34  and Cincture  26  restrictions to expand the inflatable tube  24  to its full diameter as shown in  FIG. 3A, 3B ; at this fully-expanded stage, the slider  32  has translated furthest along the conduit  30  and length shrinkage of the inflatable tube  24  is maximal. The space created by shrinkage of the inflatable tube  24  is covered by the end cover  44  which embraces the fully-expanded tube  24  and thus compensates for the loss of spatial coverage.  
         [0100]     The module&#39;s outer diameter may be reduced by withdrawing fluids from the inflatable tube  24 , the process being assisted by the squeezing action of the elastic cinctures  26  and the linear pulling action of the Springs  34  on the tube  24 . Deflation of the module proceeds in a process reverse to that occurring during expansion, going from the fully-expanded stage in  FIG. 3A, 3B  and through constricted stages in  FIG. 2A, 2B  and back to the deflated state depicted in  FIG. 1A, 1B . Inflation pressure controls the degree of inflation of the module and hence the size of the gaps between adjacent modules in an assembly and between the modules and their surroundings. Size of the openings between adjacent modules and between modules and surroundings determines the extent of fluid and radiation flow between the enclosed space and its surroundings. Thus, control of the inflation pressure of the module can afford control of the enclosed environment.  
         [0000]     Module Fitted with Bellows  46  for Compensation of Shrinkage of the Tube  24   
         [0101]     The outward appearance of modules in the sequence of operation of this embodiment is illustrated in  FIG. 4A-6A . Related internal details of mechanisms of operation are shown in the cross-sectional views of  FIG. 4B-6B . Inflation means are well known to those skilled in the art and are usually provided in the form of a motorized fan pumping a fluid, e.g. air, in and out of the inflatable cover. Starting with the deflated module in  FIG. 4A, 4B , expansion of the module or assembly thereof may be achieved by forcing fluids or fluidized substances into the inflatable tube  24  from the open end  20 , via the conduit  30  and through at least one bellows fluid hole  68  into the bellows  46  and through at least one fluid transit hole  28  into the inflatable tube  24  and through it to the conduit  30  at the closed end  22 . Fluid escape from the module is minimized by the conduit plug  52 , the close fit between slider  32  and conduit  30  and fastening, via clamps  56 , of the inflatable tube  24  onto the slider  32  and past the slider  32  onto the conduit  30 , both of which it embraces. Increase of fluid pressure inside the inflatable tube  24 , relative to the outside, causes the tube  24  to expand against the peripheral restriction of the elastic cinctures  26  and the linear urging restriction of the extension springs  38  on the sliders  32 ; the resulting constricted conformation is depicted in  FIG. 5A, 5B ; at this stage the slider  32  has translated along the conduit  30  and towards the fluid transit hole  28  from its original position as shown in  FIG. 4B  to a new position as shown in  FIG. 5B . Further increase of fluid pressure inside the tube  24  may completely overcome cincture  26  and spring  38  restrictions to expand the tube  24  and its extension, the bellows  46 , to their full diameter as shown in  FIG. 6A, 6B . At this fully-expanded stage the slider  32  has translated furthest along the conduit  30  and towards the fluid transit hole  28 ; length shrinkage of the inflatable tube  24  is maximal. The space created by shrinkage of the length of the tube  24  is covered by the expanded bellows  46  which embraces the fully-expanded tube  24  and thus compensates for the loss of spatial coverage.  
         [0102]     The module&#39;s outer diameter may be reduced by withdrawing fluids from the inflatable tube  24  and the bellows  46 , the process being assisted by the peripheral squeezing action of the elastic cinctures  26  and the linear pulling action of the Springs  38  on the inflatable tube  24 . Deflation of the module proceeds in a reverse process, going from the fully-expanded stage in  FIG. 6A, 6B  and through constricted stages in  FIG. 5A, 5B  and back to the deflated state in depicted in  FIG. 4A, 4B . Inflation pressure controls the degree of inflation of the module and hence the size of the openings between adjacent modules in an assembly and between the modules and their surroundings. Size of the openings between adjacent modules and between modules and their surroundings in turn determines the extent of fluid and radiation flow between the enclosed space and its surroundings. Thus, control of module inflation pressure can afford control of the enclosed environment.  
         [0000]     Torsional Deployment of the Inflatable Tube  
         [0103]      FIG. 7A  illustrates that embodiment of the Tensioned Inflatable Cover Module making use of helical folding of the inflatable tube  24 , by spring-assisted torsion, to strengthen the tube  24  and assist with its deflation. Helical folding of the inflatable tube  24  can assist with its deflation and impart to it increased strength in the same manner that twisted threads give a rope its strength. Dextrarotary spring  60 , secured at its ends to the slider  32  and to the block  36 , is installed at the open end  20  and the levorotary spring  62  is installed similarly at the matched closed end  22 , both springs being in a substantially relaxed state. The order of spring installation may be reversed and is given only as a guide. Details of the aforesaid construction are illustrated in the enlarged view of the closed end  22 , shown in  FIG. 7B . The inflatable tube  24  is first secured on the slider  32  by clamp  56  at the closed end  22 . One or more helical twists are then imparted to the inflatable tube  24 , anti-clockwise, before fastening onto the slider  32 , via clamp  56 , at the open end  20  to give the twisted conformation depicted in  FIG. 7A . Inflation of the module proceeds as described previously but with the added helical unfolding of the twisted inflatable tube  24  against the torsion resistance of the counter-rotating springs  60 ,  62 . The fully-expanded stage of this alternative embodiment of the module appears similar to the conformations depicted in  FIG. 3A, 6A . Deflation to the minimum bundle diameter of the module proceeds in helical folding of the inflatable tube  24  back to the conformation depicted in  FIG. 7A , the process being driven by the rotation of the Springs  60 ,  62  back to their initial, more relaxed state. Torsion of the inflatable tube  24  in the aforesaid manner is designed to assist with deflation of the tube  24 , support by wrapping the tube  24  on itself or around the ends link  50 , when used, and reduction of the bundle diameter by twisting. As discussed previously, reduction of tube  24  diameter increases the size of the gaps between modules and hence fluid and radiation flow between the space enclosed by the modular cover and its surroundings. Control of gap size thus affords control of the enclosed environment.  
         [0000]     Embodiments Providing Reinforcement to the Inflatable Tube  
         [0000]     Support ring  
         [0104]      FIGS. 8A-8C  show one embodiment devised to provide additional support to the inflatable tube  24  of the Tensioned Inflatable Cover Module. Where module length or load conditions dictate increased support, the tube  24  can be anchored on the ends link  50 . A support ring  88 , more or less centered on the ends link  50  through the carriage hole  90   f,  may be provided. The support ring  88  is welded to the inner surface of the tube  24  and thus anchors the tube  24  onto the ends link  50  as shown in  FIG. 8B  and allows deflation of the tube  24  to occur as illustrated in  FIG. 8C . Location and number of support rings  88  inside the inflatable tube  24  is dictated by the nature and magnitude of anticipated stress loads on the tube  24 . The support rings  88  anchor the inflatable tube  24  on the ends link  50  and thus control swaying, displacement and alignment of modules in a cover assembly, all important considerations particularly for outdoor installations exposed to winds, snow, rain and other meteorological variables. Support of the tube  24  is maximal at full inflation when the transverse radial walls of the support ring  88  are fully extended.  
         [0000]     Radial Reinforcing Sheets for the Inflatable Tube  
         [0105]      FIG. 8D  shows how reinforcing sheets  90   l  are welded longitudinally and radially to the inner surface of the tube  24  to anchor the tube  24  on the ends link  50  via the central tubing  90   n.  The aforesaid reinforcements control swaying, displacement and alignment of modules in a cover assembly. Control of swaying, displacement and alignment of modules ensures stability and reliability of outdoor installations exposed to winds, snow, rain and other meteorological variables. Reinforcement may be localized or run the length of the tube  24 , depending on engineering requirements. Support of the tube  24  is maximal at full inflation when the reinforcing sheets  90   l  are fully extended.  
         [0000]     Chordate Reinforcing Sheets for the Inflatable Tube  
         [0106]      FIG. 8E  shows how chordate sheets  90   p  are welded longitudinally to the inner surface of the tube  24  and along truncated chord lines, by sheet to tube welds  90   m  and to a central tubing  90   n  that embraces the ends link  50 . The Sheets  90   p  have a height substantially smaller that the natural inflated diameter of tube  24 , in the vertical axis and a width substantially greater than the natural inflated diameter of tube  24 , in the horizontal axis. The Sheets  90   p  of this embodiment form an internal web that sets a desired inflated distance between opposing surfaces of tube  24 , upon inflation. In addition to providing support, control of the distance between opposing surfaces of the inflated tube  24  affords the opportunity to limit the curvature of the inflated tube  24  and extend spatial coverage, as illustrated in  FIG. 8E .  
         [0000]     Uses  
         [0107]     The Tensioned Inflatable Cover Module may be assembled in any desired configuration, e.g. single layer side by side and generally parallel lengthwise, multi-layers at angles to each other, to achieve the desired pattern and extent of coverage; the extent of space and ground coverage is determined by module size, spacing between modules and number of modules assembled.  
         [0108]     The Tensioned Inflatable Cover Module or an assembly thereof may be provided with wire, netting, screens or other supports or guides to meet specific installation requirements, e.g. pest control. The following are some of the applications to which the module can be put to use.  
         [0000]     Novel Square Frame Greenhouse or Shelter  
         [0109]     An assembly of the Tensioned Inflatable Cover Module can be installed on suitable supports to form a greenhouse, as shown in  FIG. 9A . A novel and convenient way of installing the modules on a greenhouse frame makes use of framing members as dual purpose building elements namely for structural support and as fluid transit ducting between modules and inflation means. In  FIG. 9A  an end frame assembly  74  comprises upright channels  72   a  secured together by a horizontal channel  72   b.  A channel cover  72   c  is provided for fastening over the open channels  72   a,    72   b  by, for example, screws, bolts, glue or epoxy to provide a substantially sealed fluid conveyance duct between inflation means  76   a  and groups of inflatable modules  70   a,    70   b,    70   c  via the fluid duct  76   b.  Modules  70   a,    70   b,    70   c,  without anchors  40 , are installed onto the frames  74  by inserting their threaded conduits  30  (See  FIG. 1A ) into aligned conduit apertures  80   a  drilled into the opposing faces of end frame assemblies  74 . The conduits  30  are secured on the inside of the Channels  72   a,    72   b  by torquing the tension coupling  42  onto the conduits  30 , against the inner face of the conduit aperture  80   a  as described for the anchors  40  and illustrated in  FIG. 1A, 1B .  
         [0110]     It will be obvious to those skilled in the art that sealing and backing washers may be provided to better seal the conduit  30  against the inner surface of the framing channels  72   a,    72   b.  The aforesaid installation results in at least one conduit  30 , at the open end  20  of modules  70   a,    70   b,    70   c  being in fluid communication with the lumen of one end flame assembly  74 . Alternatively, the plug  52  at the closed end  22  of modules  70   a,    70   b,    70   c  may be omitted altogether, resulting in conduits  30  at both ends of a module being in fluid communication with the lumens of both frame assemblies  74 . It will be obvious to those skilled in the art that the extremities of the Frame Assemblies  74  would have to be sealed to maintain fluid pressure during inflation of the modular cover.  
         [0111]     It will also be obvious to those skilled in the art that the Tensioned Inflatable Cover Module may be secured to any suitable support by fastening the anchors  40  thereto by way of, for example, bolts, screws or even more permanently by welding and the like. Anchors  40  may be trimmed, shaped or made to the length appropriate for the installation. It will equally be obvious to those skilled in the art that common plumbing ware and practice may be used to connect the invention modules of groups  70   a,    70   b,    70   c  together and to the inflation means  76   a.    
         [0112]     Differential expansion control by means of pre-set known valves may be adopted to provide the desired air flow pattern between the building or greenhouse space and the surrounding atmosphere by keeping a combination of a group of modules in full inflation state  70   c,  a group of modules in deflated state  70   a  or another group of modules in partial inflation state  70   b.  Control of air flow between greenhouse and the surrounding atmosphere by means of the Tensioned Inflatable Cover Module can afford control over the enclosed environment by regulating radiation, temperature and humidity. The Tensioned Inflatable Cover Module can be used as a cover on any suitable building flame.  
         [0000]     Novel Arched Frame Greenhouse or Shelter  
         [0113]     The Tensioned Inflatable Cover Module, without the anchors  40 , can provide useful cover on a building or greenhouse with an arched frame, as illustrated in  FIG. 9B . It is known that the arched framing members of such buildings are usually fabricated out of steel tubing, although the choice of material is only limited by the intended use and engineering considerations. conduit access holes  80   b  are drilled through opposing arched end frames  78  and are aligned to receive the module&#39;s conduits  30 , which may be threaded for fastening. The conduits  30  are then fastened to the inside of the square tubing by torquing the tension coupling  42  onto the conduits  30 , against the inside face of the arched frames  78 , as previously described for the square frame greenhouse of  FIG. 9A . Access for installation is facilitated by the through-hole design of the conduit access holes  80   b  which allows passage of the tension coupling  42  and necessary tooling. It will be obvious to those skilled in the art that sealing and backing washers may be provided to better seal the conduits  30  against the inner surface of the arched frames  78 . The aforesaid installation results in at least one conduit  30 , at the open end  20  of modules  70   a,    70   b,    70   c,  being in fluid communication with the lumen of one of the arched frames  78 . Alternatively, the plug  52  at the closed end  22  of modules  70   a,    70   b,    70   c  may be omitted altogether, resulting in conduits  30  at both ends being in fluid communication with the lumen of the arched frames  78 . It will be obvious to those skilled in the art that the extremities of the frames  78  would have to be sealed to maintain fluid pressure during inflation of the modular cover. For the same reason, the conduit access hole  80   b  is sealed using an access hole plug  80   c.  The foregoing disclose the building Frames  78  as substantially sealed fluid conveyance ducts between inflation means  76   a  and the groups of modules  70   a,    70   b,    70   c  via the fluid duct  76   b.  It will also be obvious to those skilled in the art that the Tensioned Inflatable Cover Module may be secured to any suitable support by fastening the anchors  40  thereto by way of, for example, bolts, screws or even more permanently by welding and the like. Anchors  40  (see  FIG. 1 ) may be trimmed, shaped or made to the length appropriate for the installation. It will equally be obvious to those skilled in the art that common plumbing ware and practice may be used to connect the invention modules in groups  70   a,    70   b,    70   c  together and to the inflation means  76   a.    
         [0114]     Differential expansion control by means of pre-set known valves may be adopted to provide the desired air flow pattern between the building or greenhouse space and the surrounding atmosphere by keeping a combination of a group of modules in fill inflation state  70   c,  a group of modules in deflated state  70   a  or another group of modules in partial inflation state  70   b.  Control of the flow of air and radiation between greenhouse and the surrounding atmosphere by means of the Tensioned Inflatable Cover Module can afford control over the enclosed environment by regulating radiation, temperature and humidity. The Tensioned Inflatable Cover Module can be used as a cover on any suitable building frame.  
         [0000]     Large Scale Environment Control Through Exploitation of Topography  
         [0115]      FIG. 10  illustrates how an assembly of the Tensioned Inflatable Cover Module can be installed over a valley landscape to provide a variable cover for environment control. For illustration purpose a group of modules in deflated state  70   b  is shown spanning an enclosed valley  86  to afford large scale control of the enclosed environment. Inflation means  76   a  are provided to convey a fluid, e.g. air, into and out of modules  70   b  via suitable main duct  82  and secondary duct  84  connections. The modules  70   b  span the width of the valley and are anchored into the high grounds directly by means of the anchors  40  or by fastening the anchors  40  onto other suitable support, e.g. posts, beams. Air exchange between the enclosed valley  86  and the surrounding atmosphere can be controlled by varying the size of the openings between modules of the assembly  70   b  and between modules of the assembly  70   b  and the ground. Size of the openings between modules in assembly  70   b  is in turn determined by inflation pressure, which can be controlled. It would be obvious to those skilled in the art that control of inflation pressure can be achieved by controlling inflation means  76   a  using appropriate electronic wares, e.g. thermostats, humidistats, solar panels coupled to proportional controllers, computers and the like. Whole cities or leisure resorts could be built under the cover of the Tensioned Inflatable Cover Module to benefit from the controlled environment. When a light-transmitting cover is used, the enclosed controlled environment is in effect also a giant greenhouse where the length, width and ceiling could be as high as the topography permits. The scale of the building could allow use of construction and agricultural machinery, vehicles, crafts, associated ware and the like.  
         [0000]     Other Uses  
         [0116]     The Tensioned Inflatable Cover Module can also be used as a light or radiation filter by inflating the invention with colored or particulate fluids or by fitting modules with appropriate reflectors, paints, dyes or simply by using light-restricting materials like fabric for the construction of the inflatable tube  24 . The uses outlined above are given as examples only and are far from exhaustive.  
         [0000]     Warnings  
         [0117]     A cover provided by means of the Tensioned Inflatable Cover Module could be installed at great height and span; sound and safe engineering practice in design and erection of the modular cover is recommended to prevent damage, harm to property and life that could be caused by falling snapped support means or other components of the module. Periodic dumping of snow and rain may be required to prevent overload of modules and associated dangers. Installations of the Tensioned Inflatable Cover Module may require protection from wildlife, e.g. perching birds, climbing animals and other animals; established methods of wildlife and pest management may be considered. Grounding of outdoor installations is recommended to minimize damage and loss due to lightning strikes or other like discharges.

Technology Classification (CPC): 0