Patent Publication Number: US-10774554-B1

Title: Freeform pool

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation application of pending U.S. application Ser. No. 14/165,264, filed on Jan. 27, 2014, now U.S. Patent XYZ, which claims priority to U.S. Provisional Application Ser. No. 61/756,722, filed Jan. 25, 2013, the disclosures of which are incorporated by reference herein in their entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to swimming pools, and more particularly free form swimming pools. 
     Free form swimming pools require particular structural detail to account for the stress imparted to the curved walls when the pool is filled with water. Without appropriate bracing, convex walls will shift, buckle, and ultimately fail due to the distribution of the static loading. 
     SUMMARY OF THE INVENTION 
     A swimming pool consisting of a plurality of panels that withstands water pressure in both a concave and convex configuration to create any freeform shape or size. Each panel consists of an adhered wall of skinning of metal or plastic over expanded polystyrene or expanded urethane foam. The density of the foam is adjusted as necessary to increase the strength of the wall based on static loading of water when swimming pool is assembled as a whole and fully filled with water. Panels with water pressure in the convex direction have adjusters attached at the bottom to allow for vertical movement during installation and horizontal tabs (anchor plate) locking into a concrete foundation as the pool is assembled. The swimming pool can be installed fully above ground, semi-in-ground or fully in-ground. 
     According to one aspect, an embodiment of the present invention comprises a section of a swimming pool wall comprising: a panel, having a first and a second surface a top and a bottom and at least one anchor extending radially outward from at least one surface of the panel, and dimensioned to, when in use, lock the panel into a concrete foundation. 
     According to another aspect, a section comprising at least one adjuster extending downward from the bottom of the panel, adapted to permit vertical movement during the panel&#39;s installation. 
     According to another aspect a section comprising at least one a-frame support attached to the panel. 
     According to another aspect, the A-frame support comprises a post, having a top and a bottom, attached to and extending along the second surface of the panel; a crossmember, extending radially outward from second surface of the panel and attached to the bottom of the post, wherein the crossmember locks into the concrete foundation when in use; a leg, having a first end a second end, wherein the first end is attached to the post and the second end is attached to the crossmember. 
     According to another aspect, the anchor is a tab. 
     According to another aspect, the anchor is a plate. 
     According to another aspect, the panel comprises a skinning over a foam interior. 
     According to another aspect, the panel is bowed. 
     According to another aspect, the curve of the panel is bowed outward, relative to the interior of the pool when in use. 
     According to another aspect, the anchor extends radially outward from the bottom of the panel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view/photograph of a swimming pool including a plurality of panels in accordance with an embodiment of the present invention. 
         FIG. 2  is a rear perspective view of a pool panel of the pool assembly of  FIG. 1  in accordance with an embodiment of the present invention. 
         FIG. 3  is a front perspective of a pool panel of the pool assembly of  FIG. 1  in accordance with an embodiment of the present invention. 
         FIG. 4A  is a diagram/perspective view of a pool assembly including a plurality of panels in accordance with an embodiment of the present invention. 
         FIG. 4B  is a diagram/perspective view of A-frame supports of the pool assembly of  FIG. 4A  in accordance with an embodiment of the present invention. 
         FIG. 4C  is a diagram/illustration of a panel joint of the pool assembly of  FIG. 4A  in accordance with an embodiment of the present invention. 
         FIG. 5  is a diagram/illustration of loads and boundary conditions of a pool assembly in accordance with an embodiment of the present invention. 
         FIG. 6  is a deflection plot illustration of a pool assembly from a front perspective view in accordance with an embodiment of the present invention. 
         FIG. 7  is a deflection plot illustration of a pool assembly from a rear perspective view in accordance with an embodiment of the present invention. 
         FIG. 8  is a von Mises stress plot illustration of a pool assembly in accordance with an embodiment of the present invention. 
         FIG. 9  is a von Mises stress plot illustration of a polystyrene foam layer of a pool assembly in accordance with an embodiment of the present invention. 
         FIG. 10A  is a von Mises stress plot illustration of aluminum panels of a pool assembly in accordance with an embodiment of the present invention. 
         FIG. 10B  is a magnified view of a “cutout” aluminum panel portion as shown in  FIG. 10A  in accordance with an embodiment of the present invention; 
         FIG. 11  is a von Mises stress plot illustration of aluminum panels of a pool assembly in accordance with an embodiment of the present invention. 
         FIG. 12A  is a von Mises stress plot illustration of an aluminum spline of a pool assembly in accordance with an embodiment of the present invention. 
         FIG. 12B  is a magnified view of a “cutout” aluminum spline as shown in  FIG. 12A  in accordance with an embodiment of the present invention. 
         FIG. 12C  a magnified view of the aluminum spline as shown in  FIG. 12B  in accordance with an embodiment of the present invention. 
         FIG. 13A  is a von Mises stress plot illustration of an aluminum spline of a pool assembly in accordance with an embodiment of the present invention. 
         FIG. 13B  is a magnified view of a “cutout” aluminum spline as shown in  FIG. 13A  in accordance with an embodiment of the present invention. 
         FIG. 14A  is a von Mises stress plot illustration of aluminum supports of a pool assembly in accordance with an embodiment of the present invention. 
         FIG. 14B  is a magnified view of a “cutout” aluminum support as shown in  FIG. 14A  in accordance with an embodiment of the present invention. 
         FIG. 15  is a von Mises stress plot illustration of a polystyrene foam layer of a pool assembly in accordance with an embodiment of the present invention. 
         FIG. 16  is a von Mises stress plot illustration of a pool assembly in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to the drawings wherein like reference numerals refer to like parts throughout, there is seen in  FIG. 1  a swimming pool  10  comprising a plurality of panels  12 , most of which are either concave or convex. Each panel comprises a wall of skinning  14  of plastic or metal formed over expanded polystyrene or expanded urethane foam  16 . The density of the foam is selected to increase the strength of the wall based on the static load conditions of water when the pool is fully assembled (thus, dependent on overall size volume of the pool). Those panels  12  with water pressure being asserted in the convex direction have adjusters  18  attached at their bottom to permit vertical movement during installation, horizontal tabs  20  (or an anchor plate) locking into a concrete foundation as the pool is assembled, and A-frame supports  22 . Pool  10  can be a fully above ground pool, a partially above ground pool, or an entirely in-ground pool. 
       FIG. 4A  shows a diagram of the assembled swimming pool, including pool wall panels.  FIG. 4B  shows a diagram of the A-frame support, and  FIG. 4C  shows a diagram of the panel joint when in use. 
       FIGS. 4-16  show a structural analysis of a free-form 18′×32′ pool constructed from an embodiment of the present invention, to demonstrate the structural integrity of such a pool. To summarize the results, the maximum deflection in the assembly is 0.057″, and the maximum stress is 8,259 psi, which occurs at the aluminum sheet metal. The maximum stress is still well below the tensile yield strength of the pool. The resulting factor of safety for the aluminum A-frame supports is 3.03, the aluminum spline is 3.78, and the polystyrene foam is 20. These figures demonstrate that the embodiment of the invention is safe under the fully filled water condition. 
     The following assumptions were made in the analysis: (1) linear material properties of aluminum and polystyrene are assumed for the purpose of the analysis; (2) 18′×32′ Lagoon Swimming Pool is considered filled with water; and (3) liquid specific gravity is assumed to be equal to water density. All units are English units. Material properties were simulated with the properties shown in Table 1: 
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                   
                 Young&#39;s  
                 Poisson&#39;s  
                 Tensile Yield 
               
               
                   
                 Material 
                 Modulus (psi) 
                 Ratio 
                 Strength (psi) 
               
               
                   
                   
               
             
            
               
                   
                 Aluminum 
                 10E+6 
                 0.33 
                 21029.73 
               
               
                   
                 Polystyrene 
                 5.221E+5 
                 0.34 
                 6671.7-8702.3 
               
               
                   
                   
               
            
           
         
       
     
       FIG. 5  shows the loads and boundary conditions of the interior surface of the pool. The graph demonstrates that the liquid column applied on the floor was simulated to be 1.8 psi, and a variable pressure was simulated on the pool faces, ranging from 0.1044 to 1.4232 psi. 
       FIGS. 6 and 7  are deflection plots of the pool from opposite sides. Both deflection plots demonstrate that the maximum deflection is 0.057 inches at the apex of the pool wall&#39;s convex curves. 
       FIGS. 8-16  show von-Mises stress plots (in psi) of various components of the structure of the pool assembly.  FIG. 9  shows the stress of the polystyrene layer is 328 psi. Assuming a tensile yield strength of 6671.7 psi, results in a factor of safety of 20 for the polystyrene layer per the equation shown in Table 2 below. 
     
       
         
           
               
             
               
                 TABLE 2 
               
               
                   
               
             
            
               
                 
                   
                     
                       
                         
                           SAFETY 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           FACTOR 
                         
                         = 
                         
                           
                             
                               YIELD 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               STRENGTH 
                             
                             
                               WORKING 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               STRESS 
                             
                           
                           = 
                           
                             
                               6671.7 
                               328 
                             
                             = 
                             20 
                           
                         
                       
                     
                   
                 
               
               
                   
               
            
           
         
       
     
       FIGS. 10A-B  show the stress of a concave aluminum panel is 8259 psi. Assuming the tensile yield strength is 21029.73, results in a factor of 2.55 for the concave aluminum panel per the equation shown in Table 3 below. 
     
       
         
           
               
             
               
                 TABLE 3 
               
               
                   
               
             
            
               
                 
                   
                     
                       
                         
                           SAFETY 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           FACTOR 
                         
                         = 
                         
                           
                             
                               YIELD 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               STRENGTH 
                             
                             
                               WORKING 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               STRESS 
                             
                           
                           = 
                           
                             
                               21029.73 
                               8259 
                             
                             = 
                             2.55 
                           
                         
                       
                     
                   
                 
               
               
                   
               
            
           
         
       
     
     Similarly,  FIG. 11  shows the stress of a convex aluminum panel is 5697 psi, resulting in a factor of safety of 3.69.  FIGS. 12A-C  and  13 A-B show the maximum stresses of an aluminum spline are 5556 psi and 4509 psi at the highest points, yielding a stress factor 3.78 at the spline per the equation shown in Table 4 below. 
     
       
         
           
               
             
               
                 TABLE 4 
               
               
                   
               
             
            
               
                 
                   
                     
                       
                         
                           SAFETY 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           FACTOR 
                         
                         = 
                         
                           
                             
                               YIELD 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               STRENGTH 
                             
                             
                               WORKING 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               STRESS 
                             
                           
                           = 
                           
                             
                               21029.73 
                               5556 
                             
                             = 
                             178 
                           
                         
                       
                     
                   
                 
               
               
                   
               
            
           
         
       
     
       FIGS. 14A-B  show the stress of the aluminum A-frame supports are 6929 psi and 3981 psi at the highest points, resulting in a safety factor of 3.03 per the equation shown in Table 5 below. 
     
       
         
           
               
             
               
                 TABLE 5 
               
               
                   
               
             
            
               
                 
                   
                     
                       
                         
                           SAFETY 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           FACTOR 
                         
                         = 
                         
                           
                             
                               YIELD 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               STRENGTH 
                             
                             
                               WORKING 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               STRESS 
                             
                           
                           = 
                           
                             
                               21029.73 
                               6929 
                             
                             = 
                             3.03 
                           
                         
                       
                     
                   
                 
               
               
                   
               
            
           
         
       
     
       FIG. 15  shows a von Mises stress plot, for all stresses on the polystyrene foam layer rising above 6672 psi, demonstrating that at no point does the stress rise above 6672. Similarly,  FIG. 16  shows a von Mises stress plot for all stresses on the pool assembly rising above 21029, demonstrating that no stresses rise above 21029 psi.