LAND PROTECTING MEANS

Abstract: Land (4) protecting means comprising covering means (1; 10; 20; 30; 40) that can be unfolded on said land (4) and air cushion generating means (3; 11; 21; 41; 92), said air cushion being suitable for keeping said covering means (1; 10; 20; 30; 40) at a distance from the surface of said land (4).

Description: Land protecting means The invention relates to land protecting means, particularly a land intended for the practice of sport activities, in order to protect it from the effects of atmospheric agents. It is known from EP-B-0 302 087 an apparatus for covering lands, in particular lands intended for the practice of sport activities, comprising a web that has a size slightly greater than the land size and can be wound and unwound by suitable winding and unwinding means which can be inserted into pits at opposite sides of the land, so as to disappear; said web is constituted by a plurality of modular strips, driven by said winding and unwinding means, each strip being able to slide parallel to adjacent strips; each strip is constituted by two superimposed sheets of elastic plastic material, between which a resistance heating device in inserted; the visible surface of the web is prearranged for the application of advertisements . The above disclosed apparatus has several disadvantages. First of all the web, during winding and unwinding operations, creeps on the land, which is particularly harmful in the case of grasslands, as, for example, football fields, because the creep of the web on the land damages necessarily the grass. Furthermore, the contact between the web and the land prevents aeration of the land when it is covered by the web, with further damages for the grass surface. Finally, the electric resistance heating, even if it is suitable to prevent the formation of ice and to melt possible snow-drifts deposited on the web, subjects the grass surface to a thermal stress that further increases damages. Furthermore, the above mentioned defects prevent said web from being used to protect cultivated lands from atmospheric agents, because it would cause unacceptable damages to the plants to be protected. It is an object of the present invention to remedy the above mentioned disadvantages. According to the present invention there is provided land protecting means comprising covering means that can be unfolded over said land, characterized in that it further comprises air cushion generating means capable of keeping said covering means at a distance from the surface of said land. In this way there is no contact between the land and the covering web, which makes possible to prevent any mechanical damage to the vegetation covering the land and to ensure the aeration of the above mentioned vegetation. The invention will be better understood and put into practice with reference to the following description and to the attached drawings, in which: Figure 1 is a schematic cross section of a first version of the land covering means according to the invention; Figure 2 shows a variation of the first version illustrated in Figure 1; Figure 3 is a schematic cross section of a second version of the land covering means according to the invention; Figure 4 shows a variation of the second version illustrated in Figure 3; Figure 5 is a schematic cross section of a third version of the land covering means according to the invention; Figure 6 shows a variation of the third version illustrated in Figure 5; Figure 7 is a schematic cross section of a fourth version of the land covering means according to the invention; Figure 8 shows a variation of the fourth version illustrated in Figure 7 ; Figure 9 is a schematic cross section of a fifth version of the land covering means according to the invention; Figure 10 is a schematic top view of a first version of an apparatus for winding and unwinding the covering means according to the invention; Figure 11 is a schematic view from left of Figure 10; Figure 12 is a schematic top view of a second version of an apparatus for winding and unwinding the covering means according to the invention; Figure 13 is a schematic view from left of Figure 12; Figure 14 is a schematic elevation view of a third version of an apparatus for winding and unwinding the covering means according to the invention; Figure 15 is a detail of Figure 14; Figure 16 is a top view of a football field with the covering means according to the invention, before said means are spread on the land; Figure 17 is a view like Figure 16 during spreading of the covering means on the football field. Referring to Figure 1, a first version of the protecting means according to the invention is illustrated, comprising covering means 1 of a land 4, constituted by a web 2, for example of flexible and waterproof material, provided with side stripes 3 constituting a lateral support of the web 2 on a land 4. Amongst the web 2, the side stripes 3 and the land 4 a volume 5 is defined into which a pressurized gaseous fluid can be introduced in order to create an air cushion capable of keeping the web 2 raised with respect to the land 4 and ensuring aeration of vegetation covering the land 4. If a land 4 has a great extension, the web 2 can be divided into strips parallel to each other, having preferably the same width, each of which is provided with said side stripes 3. In Figure 2 a variation la of the covering means of Figure 1 is illustrated, wherein a second web 6, for example of flexible and waterproof material, is fixed over the web 2 along lines parallel to each other, for example by means of seams 7. Volumes 8 are defined between the web 2 and the second web 6, into which a pressurized gaseous fluid can be introduced, so as the second web 6 assumes the corrugated configuration visible in Figure 2. This second web 6 has the function of making easier to drain the rainwater from the covering means la, through a set of channels that are defined on said second sheet 6, in the regions of the seams 7, when the pressurized gaseous fluid is introduced into the volumes 8. Furthermore, when snowdrifts build up on the covering means la, it is possible to easily cause or speed up the melting of the snow by conducting a heated fluid into the volumes 8, the heat of the heated fluid, confined into the volumes 8 being not able to damage the vegetation on the land 4. In Figure 3 a second version of the protecting means according to the invention is illustrated, wherein the covering means 10 is constituted by said web 2 in which the side strips 3 are replaced by respective cylindrical support elements 11 for supporting the web on the land 4, constituted, . for example, by flexible pipes with a metal helical core. In the figure 4 a variation of said second version of the covering means is illustrated, in which the second web 6, already described with reference to Figure 2, is fixed on the web 2. In the Figure 5 a third version of the protecting means according to the invention is illustrated, comprising covering means 20 of the land 4 constituted by a set of tube-shaped flattened elements 21, for example of flexible and waterproof material, connected to each other at their lateral surfaces and provided, in the respective lower faces 22 facing the land 4, with a set of holes distributed on said lower faces 22. By introducing a pressurized gaseous fluid into the tube-shaped elements 21, this fluid escapes through the holes made on said lower faces 22, along the directions shown by the arrows F and creates an air cushion that keeps the tube-shaped elements 22 raised with reference to the land 4 and ensures the aeration of the land 4. In the Figure 6 a variation 20a of the covering means is illustrated, in which an additional web 23 is arranged on the flattened tube-shaped elements 21, fixed to the flattened tube-shaped elements 21 along lines 24 parallel to each other, for example by means of seams. Between the additional web 23 and the tube-shaped elements 21, volumes 25 are defined in which a pressurized fluid can be introduced. The function of the additional web 23 is quite similar to the second web 6 previously described. In Figure 7 a fourth version of the protecting means according to the invention is illustrated. In this fourth version the covering means 30 is constituted by the flattened tube-shaped elements 21, connected to each other by means of further tube- shaped elements 31, for example constituted by flexible tubes with a metallic spiral core, each of said further tube-shaped elements 31 being interposed between two adjacent tube-shaped elements 21. In Figure 8 a variation 30a of the covering means is illustrated, in which the further web 23, already described with reference to the Figure 6, is fixed on the flattened tube-shaped elements 21. In Figure 9 a fifth version of the protecting means according to the invention is illustrated comprising covering means 40 of the land 4 constituted by a plurality of lenticular tube- shaped elements 41, for example of flexible and waterproof material, a volume 42 being defined at the inside of each element. The tube-shaped elements 41 are connected to each other along substantially parallel connecting lines 43, at the edges of their lenticular section. The connection is carried out so that the volumes 42 of adjacent tube-shaped elements 41 communicate with each other. In addition, the tube-shaped elements 41 are slidingly coupled to a rope 44, parallel to the land 4, so that they can be moved along the rope, like bellows, between a non-operative position in which the tube- shaped elements are arranged side by side, with the major axis of the lenticular section oriented in a substantially vertical direction, and an extended operative position, shown in Figure 9, in which the tube-shaped elements 41 are arranged in a sloped configuration. Each tube-shaped element 41 is provided with holes on its surface facing the land 4. By introducing a pressurized gas into the volumes 41, the gas escapes from the above mentioned holes according in the direction shown by the arrows FI, creating an air cushion between the tube-shaped elements 41 and the land 4. Said air cushion ensures the aeration of the land 4 and, by pushing upward the tube-shaped elements 41, prevents their weight from loading the land 4, or allows only a minimal part of the weight to load the land 4, protecting therefore the grass surface or any other vegetation present on the land 4 from damages of mechanical type. Figures 10 and 11 illustrate a first version of an apparatus 50 for unwinding the protecting means according to the invention on the land 4 and for winding them after use. The apparatus 50 comprises a plurality of drums 51, one for each section of the protecting means, provided with rotation axes 52 mutually aligned with each other and supported by fixed supporting elements 53. Each drum 51 is internally hollow and is closed at its ends by closing elements 54, provided with openings for the passage of a pressurized gaseous fluid. Furthermore, each drum 51 is provided at its ends with restraint boards 56. A section of the covering means according to the invention can be wound on each drum 51. The restraint boards 56 serve to prevent the coils of the section of the covering means wound around a drum 51 from slipping out of the drum. In Figures 10 and 11, the covering means wound around the drums 51 is the covering means of the third version 20 illustrated in the Figure 5. However, any one of the first four versions of the covering means, and the respective variations, illustrated in Figures 1 to 8 can be wound around the drums 51 of the apparatus 50. A first end 21a of the flattened tube-shaped elements 21 wound on each drum 51 communicates with the hollow interior of the drum 51, while a second end 21a, opposed with respect to said first end 21a, can be connected to traction means 57 suitable to unwind the flattened tube-shaped elements 21 from the respective drum 51. The apparatus 50 can be placed into a pit 58 provided at one side of the land to be protected, possibly equipped with a covering 59, provided with an opening 61 for the passage of the tube-shaped elements 21 during winding and unwinding operations of the covering means. At the inside of the pit, idler rollers 60 can be installed, in order to facilitate the sliding of the tube-shaped elements 21 during the winding and unwinding operations. The traction means 57 can be operated by any type of driving means, for example a pneumatic engine. The traction means 57 can also be replaced by traction ropes that can be operated manually or by means of suitable actuating devices (not illustrated) . Annular lip seals 62, the function of which will be described later, are arranged between adjacent drums 51, . In order to unfold the protecting means 20 on the land 4 to be protected, the traction means 57, connected to the ends 21b of the tube-shaped elements 21, is actuated and the traction means are moved away from the pit 58, whilst a pressurized gas, for instance air, is introduced, via the openings 55, into an end drum of the set of drums 51, through proper inlet means 93 (Fig. 17). The pressurized air flows from the end " drum to the other drums 51 through the openings 55 made on the closing elements 54 and then into the tube-shaped elements 21, through their first end 21a. The pressurized air, escaping through the holes made on the face of each tube-shaped elements 21 facing the land 4 creates an air cushion that prevents the tube-shaped elements 21 from creeping on the land 4 when the covering means 20 is unwound, so protecting the grass or any other vegetation present on the land 4 from damages caused by said creeping. The annular lip seals 62 limit to a minimum the air escape through the free spaces between adjacent drums 51 during rotation of the drums. Once the protecting means 20 has been completely unfolded on the land, the above mentioned air cushion not only prevents the tube-shaped elements 21 from resting with their weight on the land 4, but also keeps ventilated the vegetation present on the land, allowing, for example, an optimal conservation of a grass surface that covers the land. Figures 12 and 13 illustrate a second version of an apparatus for unwinding the covering means according to the invention on the land 4 to be protected and for rewinding it after use. The apparatus 70 includes a plurality of drums 71, one for each section of the protecting means. Each drum 71 is rotatingly connected to the adjacent drums 71 so that each drum can rotate around a rotation axis A. Each drum 71 is internally hollow and is closed at its ends by a first closing element 72 provided with a central pin 73 and by a second closing element 74 provided with a central bearing 75, for example a rolling bearing, suitable for receiving the central pin 74 of an adjacent drum 71. The first closing element 72 and the second closing element 74 are provided with openings 76 that allow a pressurized gas to be introduced into the first drum 71 of the set of drums 71 and to pass from this one to the other drums 71. Furthermore each drum 71 is provided at one of its ends with a restraint and sealing flange 77. Around each drum 71 a section of the protecting means according to the invention can be wound. The flanges 77 serve to prevent the coils of the protecting means wound around a drum 71 from axially slipping out of the drum 71 and furthermore form a seal against the discharge of the pressurized gas introduced into the drums 71 from the free spaces between two adjacent drums 71. The covering means wound around the drums 71 in Figures 12 and 13 is the covering means of the fourth version 30 shown in the Figure 7. However any one of the first four versions of the covering means, and respective variations, shown in Figures 1 to 8 can be wound around the drums 71 of the apparatus 70. A first end 21a of the flattened tube-shaped elements 21 wound on each drum 71 communicates with the hollow interior of the drum 71, while a second end 21b, opposed with respect to said first end 21a, can be connected to traction means 57 suitable to unwind the flattened tube-shaped elements 21 from the respective drum 71. The apparatus 70 can be arranged in the pit 58 previously described. The drums 71, with the protecting means 30 wound around them, are supported by rolling elements 78, that can be installed in the pit 58. In order to unfold the covering means 30 on the land 4 to be protected, the procedure is analogous to that described with reference to the first version 50 of the apparatus: the traction means 57, connected to the ends 21b of the tube- shaped elements 21, are actuated and the traction means are moved away from the pit 58, whilst a pressurized gas, for example air, is introduced through the openings 76 of the first closing element 72 of an end drum 71 of the set of drums 71. The pressurized air flows from the end drum to the other drums 71 through the openings 76 made in the first closing elements 72 and in the second closing elements 74 of the drums 71 and then into the tube-shaped elements 21, through their first end 21a. The pressurized air, escaping from the holes made on the face of each tube-shaped element 21 facing the land 4, creates an air cushion that prevents the tube-shaped elements 21 from creeping on the land 4 when the covering means 30 are unwound and keeps the covering means raised from the land 4 after they have been completely unfolded on it. Figures 14 and 15 illustrate a third version of an apparatus 80 for unwinding the covering means according to the invention on the land 4 to be protected and for rewinding it after use. The apparatus 80 includes a plurality of drums 81 on each of which a section of the covering means according to the invention is wound, so as to form a reel 88. Each drum 81 is provided at its ends with wheels 82, suitable to roll on the surface of the land 4. The wheels 82 have a diameter greater than the diameter of the drum 81, so as to serve also as restraint boards for the covering means, when these last are wound around the drum 81. One of the two wheels 82 is provided with a pulley 83, mounted on the axis of the wheel 82, an end of a rope 89 being fixed to said pulley whilst the opposite end is fixed to a second pulley 84, or roller, rotatingly supported by a stationary supporting element 85. The more external end 87 of the protecting means wound around the drum 81 is provided with a connecting element 86 that can be connected to supply means 92 of pressurized gas. By introducing pressurized gas into said more external end 87 of the protecting means, this end will tend to inflate, exerting a push against the reel 88 and causing it to roll on the land 4, along the direction of the arrow F2 in Figure 14, with a progressive unwinding of the protecting means from the reel 88, up to the complete unfolding of the protecting means on the land 4. During this operation the rope 89 unwinds from the second pulley 84 and winds around the first pulley 83. In order to rewind the covering means it is enough to rotate, manually or through actuating means not shown, the second pulley 84 so as to wind around it the rope 89, which will produce a rotation of the reel 88 in a direction opposite to the arrow F2 , causing the covering means to rewind around the reel 88. The second pulley 84 can be replaced by an annular groove (not shown) provided on the outer surface of one of the two wheels 82, said annular groove acting as a seat for the winding and unwinding of the rope 89. When the covering means is not used, the reel 88 and the second pulley 84, with its support 85, can be stored into a containing structure 90 placed at one side of the land 4. This structure 90 can be provided with a closing door 91. Figures 16 and 17 show the unfolding operations of the covering means on the land 4, for example a football field, by using the apparatus 50 or the apparatus 70, for unfolding and folding the covering means. In Figure 16 the starting condition of the unfolding operation is shown, with various sections of the covering means not yet unfolded, whilst in Figure 17 a step of the unfolding of the covering means is shown, with the sections of the covering means partially unfolded on the land 4 and kept raised from the land 4 by the air cushion generated by a pressurized gas introduced into the covering means through the supply means 92. In a variation, not shown, the pressurized gaseous fluid can contain nutritive substances for the lawn. In the practical implementation, the materials, the dimensions and the execution details can be different from those indicated, but technically equivalent thereto, without leaving, for this reason, the juridical domain of the present invention.

Claims: CLAIMS 1. Land (4) protecting means comprising covering means (1; 10; 20; 30; 40) that can be unfolded on said land (4), characterized in that it further comprises air cushion generating means (3; 11; 21; 41; 92), said air cushion being suitable for keeping said covering means (1; 10; 20; 30; 40 ) at a distance from the surface of said land (4). 2. Protecting means according to claim 1, wherein said air cushion generating means includes supply means (92) supplying a pressurized gaseous fluid. 3. Protecting means according to claim 1 or 2, wherein said covering means (1; 10; 20; 30; 40) is made of a flexible and waterproof material. 4. Protecting means according to any of claims 1 to 3, wherein said covering means (1; 10) includes web means (2), provided, at two mutually opposite sides, with supporting elements (3; 11) resting on the land (4) suitable for defining, in conjunction with said web means (2), a volume (5) for the formation of said air cushion. 5. Protecting means according to claim 4, wherein said supporting means comprises side stripes (3) of said web means (2) . 6. Protecting means according to claim 4, wherein said supporting means comprises cylindrical supporting elements (11) . 7. Protecting means according to claim 6, wherein said cylindrical supporting elements (11) are made of flexible material and are provided with metallic core. 8. Protecting means according to any of claims 4 to 7, comprising further web means (6), fixed to said web means (2) along fixing lines (7) substantially parallel to each other. 9. Protecting means according to any of claims 1 to 3, wherein said covering means (20; 30; 40) comprises flattened tube-shaped elements (21; 41), connected to each other along connecting lines substantially parallel to each other, said flattened tube-shaped elements (21; 41) being provided with a plurality of holes in a face designed to be oriented towards said land (4) . 10. Protecting means according to claim 9, wherein said flattened tube-shaped elements (21) are connected with each other through the interposition of further tube-shaped elements (31) . 11. Protecting means according to claim 10, wherein said further tube-shaped elements (31) are made of flexible material and are provided with metallic core. 12. Protecting means according to any of claims 9 to 11, and further comprising further web means (23) fixed to said flattened tube-shaped elements (21) along fixing lines substantially parallel to each other. 13. Protecting means according to claim 9, wherein said flattened tube-shaped elements (41) have a substantially lenticular section. 14. Protecting means according to claim 13, wherein said flattened tube-shaped elements (41) are connected with each other so as the interior (42) of each tube-shaped element (41) communicates with the interior (42) of the tube-shaped elements (41) adjacent to it. 15. Protecting means according to claim 13 or 14, wherein said flattened tube-shaped elements (41) are slidingly coupled to rope means (44) . 16. Protecting means according to any of claims 1 to 15, wherein said covering means (1; 10; 20; 30; 40) is divided into sections which can be unfolded on said land (4) parallel to each other. 17. Protecting means according to any of claims 1 to 16, and further comprising unfolding means (50; 70; 80; 57) for unfolding said covering means (1; 10; 20; 30; 40) on said land (4) . 18. Protecting means according to claim 17, wherein said unfolding means (50; 70; 80) comprises at least a drum (51; 71; 81) around which said covering means (1; 10; 20; 30; 40) can be wound. 19. Protecting means according to claim 18, wherein said at least one drum (51; 71) is internally hollow. 20. Protecting means according to claim 19, wherein said at least one drum (51; 71) is provided at its axial ends with closing elements (54; 72, 74) at least one of which is provided with openings (55; 76) suitable to allow the flow of a fluid through them. 21. Protecting means according to claim 19 or 20, wherein said at least one drum (51) is rotatingly supported by stationary supporting elements (53) . 22. Protecting means according to claim 19 or 20, wherein said at least one drum (71) is rotatingly supported by rolling supporting elements (78). 23. Protecting means according to any of claims 17 to 22, and further comprising traction means (57) of said covering means (1; 10; 20; 30; 40) . 24. Protecting means according to any of claims 18 to 23, wherein said unfolding means (50; 70; 80) comprises a plurality of drums (51; 71; 81) around which said covering means (1; 10; 20; 30; 40) can be wound. 25. Protecting means according to claim 24, wherein said drums (51; 71) are aligned along a common longitudinal axis (A) . 26. Protecting means according to claim 25, wherein sealing means (62) is interposed between two adjacent drums (71). 27. Protecting means according to claim 26, wherein said sealing means includes an annular lip seal (62) . 28. Protecting means according to claim 24, wherein, in each drum (71) , a first closing element (72) of said closing elements (72, 74) is provided with a central pin (73) and a second closing element (74) of said closing elements (72, 74) is provided with a central bearing (75) suitable for receiving the central pin (73) of the first closing element (72) of an adjacent drum (71) . 29. Protecting means according to claim 18 or 24, wherein each end of said at least one drum (81) is provided with rolling means (82) having a diameter greater than the diameter of said at least one drum (81) . 30. Protecting means according to claim 29, wherein said rolling means (82) of one of said ends comprises winding means (83) to which a first end of a rope (89) can be fixed. 31. Protecting means according to claim 30, further comprising further winding means (84) to which a second end of said rope (89), opposite with respect to said first end, can be fixed, said further winding means (84) being rotatingly supported by supporting means (85) . 32. Protecting means according to any of claims 29 to 31, wherein one end (87) of said covering means (1; 10; 20; 30) is provided with connecting means (86) that can be connected to said supply means (92) of pressurized fluid.

Inventors: BONICELLI IVO DOMENICO, BORTOLANI GIUSEPPE NANDO, BONICELLI, IVO, DOMENICO, BORTOLANI, GIUSEPPE, NANDO
Applicants: BONICELLI IVO DOMENICO, BORTOLANI GIUSEPPE NANDO, CT ANALISI TECHNAIR S R L, BONICELLI, IVO, DOMENICO, BORTOLANI, GIUSEPPE, NANDO, CENTRO ANALISI TECHNAIR S.R.L.
Application year: 2000
Main classification: A63C19
IPC codes: A01G13, A63C19