Patent Publication Number: US-7901307-B2

Title: Multifunctional protection system for a sports ground

Description:
FIELD OF THE INVENTION 
     The present invention relates to a multifunctional protection system for a sports ground, and in particular to a simple and quick device that is suitable for spreading out a protection cover over a sports ground in order to protect it from bad weather. 
     STATE OF THE ART 
     Protecting sports grounds is a constant concern and various systems are known in the existing state of the art. 
     Document U.S. Pat. No. 4,050,972 describes the assembly in situ of a covering for sports grounds, consisting in unrolling rolls of sheets of plastic materials that are mounted on spaced vehicles. The axles of the rolls are parallel and offset so that the sheets overlap and can be sealingly joined together as they are unrolled. 
     Documents EP 0 236 983, EP 0 427 677 and DE 4137295 also disclose various means for rolling and unrolling a protection cover for a sports ground. 
     In international patent application WO 95/09681, the covering of a sports ground is achieved by an assembly of panels telescopically linked so as to shift from a position covering the surface to a position uncovering it. 
     International patent application WO 88/05678 discloses an automatic device for covering sports grounds, comprising a series of modular strips that can slide over each other and are operated by a unrolling or rolling means. 
     Lastly, document WO 99/01187 discloses a motorized device for spreading out a protection cover over a sports ground, that can move across the ground in order to fold or unfold a cover. This motorized device comprises a frame equipped with wheels or rollers and a transmission system for its motion across the sports ground; it also comprises a cover arranged like a accordion in its folded position and a means for spreading out and folding back up the cover synchronously with a transmission system for moving the frame. One of the difficulties encountered with this device lies in the synchronisation of the motion speed of the various attached modular elements of the frame-chest required to cover the entire width of sports grounds. This difficulty is connected to the surface state of the ground which is not even and therefore offers different levels of resistance to the wheels or rollers at different spots and hence does not allow optimum synchronisation when the various bearing elements (attached to each other) are driven by individual motors. Moreover, the guiding ropes in this system are not efficiently collected when the cover is being folded up and the rings or buckles are not efficiently guided to ensure the correct folding of the cover. 
     AIMS OF THE INVENTION 
     The present invention aims to provide a protection system for a sports ground that does not have the drawbacks of the state of the art and that not only allows to spread out a protection cover over a sports ground in the simplest and quickest manner but also allows to fold this cover back up without problems. 
     SUMMARY OF THE INVENTION 
     The present invention discloses a protection system for a sports ground comprising a frame-chest with a protection cover, said frame being able to move across the entire length of the ground whilst unfolding or folding said protection cover by means of an unfolding and folding mechanism, wherein said frame-chest is connected to a network of cables spread out in advance over the sports ground, said cables being driven by motorized pulleys, in order to ensure the motion of said frame-chest over said sports ground. 
     According to particular embodiments, the invention comprises one or more of the following features:
         The frame-chest is divided into several modular elements that move synchronously over the sports ground thanks to said network of cables to which they are connected and that are driven by said motorized pulleys during unfolding or folding of said cover;   The unfolding and folding mechanism for the cover comprises nipping rollers, said nipping rollers being themselves motorized and equipped with a regulation for their pressure force by means of arms with springs exerting a pressure force on pressure rollers, pressing them onto said cover, the cover being nipped between said nipping rollers and the pressure rollers;   The unfolding and folding mechanism for the cover comprises guiding ropes fixed to the edge of the ground that are threaded through threading buckles located underneath said cover and guide said cover when it is folded or unfolded;   When the cover is being folded up, said guiding ropes and said threading buckles are threaded through and around a threading tube, respectively;   The mechanism comprises a reel for said guiding ropes, equipped with a winding spring that allows to progressively wind up or unwind the guiding rope, during the unfolding or folding of said cover, respectively;   The unfolding and folding mechanism for the cover comprises a synchronisation system that synchronises the motion speed of said frame-chest by means of said motorized pulleys with the folding or unfolding speed of the cover by means of the motorized nipping rollers;   Both the network of cables and said motorized pulleys are concealed at the edge of the ground when it is uncovered;   The network of cables is gathered up at the edge of the ground by means of several winches;   The frame-chest comprises a system for heating said cover;   The frame-chest comprises a watering system;   The frame-chest comprises a seeder for sowing grass;   The frame-chest comprises supports for advertising signs;   The cover may serve as an advertising support;   The cover is translucent.       

    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  shows a general view of a sports ground with the network of cables and the frame-chest elements located at the edge of the sports ground. 
         FIGS. 2 and 3  show the mechanism for spreading up the network of cables across the entire ground before activating the synchronous motion of the frame-chest elements. The network of cables is shown schematically and the double cables for each pulley are not shown. 
         FIG. 4  shows the sports ground with the network of cables completely spread out. 
         FIG. 5  shows the frame-chest comprising several elements in the middle of the sports ground, with a cover half spread out. 
         FIG. 6  shows the sports ground with a cover completely spread out by means of the system of the invention. 
         FIG. 7  shows a profile view of the system with the frame-chest comprising the mechanism for spreading out the cover, as well as a view of the motorized pulleys with their double cables used to move the frame-chest like a cable car, once the network of cables is set in place. The size of the ground is greatly reduced in the figure. 
         FIG. 8  shows a detailed view of the frame-chest with the option to attach advertising banners. The other functions are not shown in detail. 
         FIG. 9  shows a detailed view of all the elements making up the mechanism for spreading out the cover, which is located on the frame-chest. 
         FIG. 10  shows a detailed view of the mechanism for folding up the cover, with in particular the reel for the guiding ropes and the threading tube for the guiding ropes and the buckles attached to the cover. 
         FIG. 11  shows an overall view of the heating and watering option on the frame-chest. The arrow shows the motion direction of the frame-chest. 
         FIG. 12  shows a front view of a section through the frame-chest comprising a little more than one modular element, with a view of the linking parts connecting the modules of this frame-chest. 
     
    
    
     DEFINITIONS 
     The term “cable” in the expression “network of cables” must be interpreted in the widest sense and may of course mean “wire” or even “rope.” The nature of the material used is not relevant as long as sufficient mechanical strength and the result sought are achieved. 
     The term “cover” should also be understood in the widest sense and as a general covering, it may for example mean “canvas.” 
     The term “rope” or “guiding rope” is also to be understood in the widest sense and in the system for rolling up the cover by means of the buckles attached to the cover, “rope” may mean “string” or “wire.” 
     The term “frame-chest” is also to be understood in the widest sense and in fact means that this is a trolley comprising a frame with support axles having wheels and/or rollers and a chest allowing to store the cover. 
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention discloses a multifunctional protection system for a sports ground, in particular football, rugby and hockey grounds, tennis courts and others, against the risks of bad weather such as torrential rain, long periods of frost or snow, . . . . 
     The system as in the invention has numerous advantages that are not restricted to the simple protection of sports grounds. Mention may be made of the following elements without restricting the possibilities:
         The protection cover  2  or canvas may serve as a large-scale support for advertising so it may be financed by a sponsor;   The resistance of a protected ground that is rarely frozen or soaked is highly superior to that of an unprotected ground and therefore allows to organise numerous matches even off-season or when other grounds are not available;   The number of training grounds for a single club may be reduced, which entails major benefits in terms of real estate;   Lastly, improving the game conditions allows a general reduction in injuries and more skilful play at all times of year.       

     The protection system as in the present invention comprises two essential elements, on the one hand a network of cables  3  that must be spread out by operators on the sports ground and on the other a frame-chest  1  capable of folding and unfolding the cover  2 . These cables, to which the frame-chest is attached, will serve to move the frame-chest  1  in the manner of a cable car, which spreads out or folds up the protection cover over the ground. This frame-chest normally comprises several modular elements  22  for covering the entire width of the ground. Each modular element of the frame-chest  1  preferably has a width of from 4 to 10 meters (13.1 feet to 32.8 feet) and preferably from 5 to 8 meters (16.4 feet to 26.2 feet) and, as a particular preference, 6 meters (19.7 feet). For a football ground, twelve 6-meters (19.7 feet) elements will thus be required to achieve a width of 72 meters (236.2 feet) in total. The modular elements  22  will have to move perfectly synchronously to ensure the correct spreading out of the protection cover  2 . The elements are connected to each other by linking parts  21  that are shown in  FIG. 12 . 
     It turned out that equipping each individual element with a motor did not optimally ensure this synchronized motion for the reasons explained above (condition of the ground). To solve this problem, the present invention discloses a network of cables  3 , to which the frame-chest  1  is attached, which will drive and guide its various elements like a cable car with motorized pulleys  4  incorporated to the edge of the ground.  FIG. 7  shows how these pulleys  4  are positioned in a trench  10  at the edge of the ground. These pulleys may also be fixed to the ground without being buried if there is enough space at the edge of the ground. This embodiment is not shown in the figures. The position of the motor  9  is also indicated. It is also shown that the frame-chest  1  is attached to these cables underneath the frame, which is supported by the motion rollers  7  that allow it to move when the pulleys  4  turn and set the cables and hence the frame-chest in motion. The length of the cables  3  is about twice the length of the ground since two cables  3  are positioned in parallel at each attachment point. In the example of a football ground that is 72 meters (236.2 feet) wide, as shown in  FIGS. 1 to 6 , the cables  3  are stretched between twelve pulleys  4  positioned on either side of the ground. The network of cables  3  only has to be removed when people want to play on the ground. This network of cables  3  may therefore remain in place during the periods when the ground is covered and uncovered depending on the weather forecasts. 
     Winches  5  are provided along the sides for tidying away at the edge of the ground the relatively heavy cables  3  and they are used to draw in the network of cables  3  and gather it up. These winches  5  can be seen in  FIGS. 1 to 3  and there are four of them. How these cables are gathered up is not shown in the figures but is provided for by means well known to those skilled in the art. It is also possible to roll up these cables  3  on coils that can be rolled across the ground after the cover  2  is folded up or before it is spread out (not shown). 
     On the lower side of the ground are located tanks  6  for the run-off water that would stagnate on the cover. These are intended to take the water from excess rain and may be equipped with a cellar-drainage pump or connected to the drain. 
     The cover  2  may be made of a single piece or made up of a patchwork of rectangular or square pieces (strips of technical textiles or canvas, of fixed width and continuous length). It is generally translucent and is placed directly on the ground, but it may also be raised if it is intended to blow air under the cover  2 . On its lower side, the cover  2  comprises threading buckles  12  for the guiding ropes  11 . These buckles  12  allow to create the folds in the canvas/cover  2  when it is being folded up in the frame-chest  1 . For a football ground, for example, there will be “x” times  73  buckles under the canvas/cover, (=73 buckles times “x” strips of canvas required to make up the more than 7,000 meters squared (75,347.4 square feet) of a cover to go over a football ground). 
     The guiding ropes  11  have an important function since they allow the even spreading out of the cover  2  over the entire width of the ground. The guiding ropes  11  are attached to the edge of the ground and when the cover is being spread out over the ground by the motion of the frame-chest  1 , they progressively come out of their case  16  where they are retained by a winding spring  18  so as to always have a certain tension, this is achieved like a dog&#39;s lead unwinding from its case. If one guiding rope is envisaged per meter of width of a football ground, 73 reels/cases will be required for the 72 meters (236.2 feet) of length of the frame-chest. When the cover is being folded up, the guiding ropes pass through the tubes  17  and are progressively rolled into the reels/cases  16  at the same time as the buckles  12  are threaded into these tubes  17 . 
     In order to fold up the cover  2  when the frame-chest  1  moves, the motorized canvas-nipping rollers  8  start up. The nipping force is adjusted by a traction spring exerting a force on an arm, on which a pressure roller  13  is located. The rollers  8  and  13  are usually equipped with a clinging surface to aid nipping the cover  2 . There is usually about one motor  23  per element of the frame-chest  1  for the nipping rollers  8 , which are connected to each other by bearings. This can be seen in  FIG. 12 . The adjustment of the nipping force by means of the spring  14  is required to possibly lift any puddle of water on the cover  2 . 
     When the cover is being folded up, the guiding rope II and the buckles  12  are threaded into or over a threading tube  17 . The ropes passing through the tube  17  and the buckles  12  moving to the outside around the tube  17  allow the cover  2  to be folded into a perfect accordion shape in the frame-chest  1 . These various functions are shown in  FIG. 9 . Thus, as many threading tubes  17  per meter of width of the cover will be required as there are buckles  12  and guiding ropes  11 . 
     The system of the present invention, and in particular the frame-chest  1 , may be equipped with a whole series of options. Besides the advertising function mentioned earlier and shown in  FIG. 8 , the more traditional options are shown in  FIG. 11 , where the frame-chest  1  comprises a heating system  20  for the cover  2  and a watering system  19 . The heating system shown in  FIG. 11  comprises several radiant heat sources  20 . These allow to limit heat losses and to heat up the cover  2  in order to dry it and make it less stiff in the event of frost before it is folded back into the frame-chest  1 . 
     Other options are of course possible such as for example a mechanism  40  that allows to sow grass seeds on the ground (shown schematically at  FIG. 11 ). 
     The frame-chest as in the invention is built as a mechanical device by assembling parts that can easily be replaced in the event of wear. All these elements may easily be removed and reinstalled. 
     KEY 
     
         
           1 . Frame-chest 
           2 . Cover 
           3 . Network of cables 
           4 . Motorized pulleys 
           5 . Winch 
           6 . Tanks for run-off water 
           7 . Motion rollers for the frame-chest 
           8 . Nipping roller for the cover 
           9 . Pulley motor 
           10 . Pulley trench 
           11 . Guiding rope 
           12 . Threading buckle 
           13 . Pressure roller for nipping 
           14 . Traction spring 
           15 . Protection canvas for the frame-chest 
           16 . Guiding-rope reel 
           17 . Threading tube for the buckles and the guiding rope 
           18 . Winding spring 
           19 . Watering system 
           20 . Heating system (radiant heat source) 
           21 . Linking part for the elements of the frame-chest 
           22 . Modular element of the frame-chest 
           23 . Motors for the nipping rollers