Abstract:
A sports board that is ridden by a person standing upon it includes an elongated metal board having a front end, a rear end, a top surface, a bottom surface, a left edge and a right edge, and one or more longitudinally elongated cavity forming sections. This basic structure can be utilized as the basic component for sports boards such as skateboards, wakeboards and snowboards.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. patent application Ser. No. 09/206,720, filed on Dec. 7, 1998 U.S. Pat. No. 6,203,037. 
    
    
     BACKGROUND OF THE INVENTION 
     The invention relates to sports boards that are ridden by a person standing upon them, and more specifically to one whose basic structure is an elongated metal board. Some examples of sports boards are skateboards, snowboards and wakeboards. 
     The earliest skateboards were made of a plain flat piece of wood. Later models were made of other materials and had improved structure. The Gaber U.S. Pat. No. 4,161,326 discloses an improved skateboard having a replaceable arc-tail with a wear surface and further having wheels wells. 
     The Stevenson U.S. Pat. No. 4,182,520 discloses a skateboard structure having a central platform formed of a top piece and a bottom piece. The two pieces may be shaped to define an inner surface of cellular configuration so that when the two pieces are fitted together they define an internal reinforcing honeycomb-like core. The Stevenson U.S. Pat. No. 4,337,963 discloses the top and bottom pieces being formed of appropriate injection molded plastic material, such as polypropylene, polyethylene, polycarbonate, plexiglass, or other plastic material which is susceptible to injection molding; or aluminum casting or compression molded fiberglass; or any other material which may be molded or cast. 
     The Meredith U.S. Pat. No. 4,458,907 discloses a skateboard having a front member and a rear member and structure for allowing the length of the skateboard to be extended or retracted. 
     The Scheurer et al U.S. Pat. No. 4,897,063 discloses a reaction injection molded recreation board with spaced rectangular reinforcing rods. The rods are rectangular in cross section and are disposed between upper and lower surfaces of the board. 
     The Smisek U.S. Pat. No. 5,267,734 discloses a hollow elongated board having openings, formed in the underside of the board, adapted to receive standard skateboard wheels. The skateboard further employs wheel ramps on opposite sides of each wheel to provide a smooth under surface to aid in negotiation of large obstacles such as curbs, stairs, etc. and to allow the skateboard to glide over smaller objects. 
     In the late 1970&#39;s, an American skateboard manufacturer made his boards of aluminum plate material. These boards proved to be too heavy and too expensive and were not very popular. The edges of the skateboard, after heavy use, became razorblade sharp and were extremely dangerous. 
     The inventors recognized the problems of the prior art aluminum metal skateboards when they attempted to make the skateboards out of flat sheet aluminum. The flat sheet metal bent in the middle and could not endure hard riding. It was then decided to go with a thicker piece of aluminum and cutout sections of the metal to make it lighter while still maintaining sufficient structural support. The problem of razorblade sharp edges still occurred with the metal board and the metal board was still too heavy. Additionally, it also bent or buckled in the middle of the board when it was subjected to hard use. 
     It is an object of the invention to provide a novel metal board that is lightweight yet capable of withstanding the hard use of jumping actions by the rider and not bend or break. 
     It is another object of the invention to provide a metal board that could be used as a sports board that is ridden by a person standing upon it. 
     It is also an object of the invention to provide a novel metal board whose left and right edges have hollow or cavity-forming rails that are not subject to becoming razorblade sharp. 
     It is an additional object of the invention to provide a novel metal board that could be used in multiple sports such as skateboarding, wakeboarding and snowboarding. 
     It is a further object of the invention to provide a novel metal board that is economical to manufacture and market. 
     SUMMARY OF THE INVENTION 
     The novel sports board has been designed to be formed of a light-weight metal material having one or more longitudinally elongated cavity-forming sections formed by multiple support walls in the board, thereby allowing it to be as light, thin and strong as possible. The strength imparted to the board by the multiple support walls allow the sports board to be ridden hard without worrying about the board bending or breaking. A preferred embodiment of the metal board is made of 6000 series T-6 aircraft aluminum. Different aluminum or titanium may be used depending upon the physical properties desired such as tensile strength, yield strength, weight, etc. 
     The use of the sports board as a skateboard subjects it to tremendous forces when the rider is performing jumps. For instance, a 200-lb. rider that jumps from a height of 3 feet and absorbs the impact by bending his knees 3.6 inches subjects the skateboard to a force of 2000 lbs. A jump from a height of 6 feet produces a force of 4000 lbs. These forces will break wooden and flat plate metal skateboards. 
     Static tests for different aluminum boards for skateboards produced the following data: 
     For a flat board 0.100 inch think (without rails) 
     
       
         
               
               
               
             
           
               
                   
                   
               
               
                   
                 Weight 
                 Deflection 
               
               
                   
                   
               
             
             
               
                   
                 200 lbs. 
                 1.07 inch 
               
               
                   
                 250 lbs. 
                 1.34 inch 
               
               
                   
                   
               
             
          
         
       
     
     For a flat plate board 0.1875 inch thick (without rails) 
     
       
         
               
               
               
             
           
               
                   
                   
               
               
                   
                 Weight 
                 Deflection 
               
               
                   
                   
               
             
             
               
                   
                 200 lbs. 
                 .162 inch 
               
               
                   
                 250 lbs. 
                 .203 inch 
               
               
                   
                   
               
             
          
         
       
     
     For a board according to the inventors&#39; design with a plate 0.100 inch thick and with the two rails 0.500 inch high and 0.625 inch wide with walls having a thickness of 0.0625 inch. 
     
       
         
               
               
               
             
               
               
               
             
           
               
                   
                   
               
               
                   
                 Weight 
                 Deflection 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                 200 
                 lbs. 
                 .048 inch 
               
               
                 250 
                 lbs. 
                 .060 inch 
               
               
                 1000 
                 lbs. 
                 .240 inch 
               
               
                   
               
             
          
         
       
     
     The weight of the hollow rail design above was well below 2.6 lbs. The weight of the board is thus lighter than either a wooden board or an aluminum plate board and much stronger than either of them. 
     The above advantages are obtained by a sports board adapted to be ridden by a person standing upon it. The sports board includes an elongated metal board having a front end, a rear end, a top surface, a bottom surface, a left edge and a right edge, and one or more longitudinally elongated cavity forming sections. This basic structure can be utilized as the basic component for sports boards such as skateboards, wakeboards and snowboards. 
     In an embodiment of the invention, wherein the elongated metal board includes a top wall, a bottom wall and N longitudinally elongated support walls that define N−1 longitudinally elongated cavity forming sections. 
     In another embodiment of the invention, the one or more longitudinally elongated cavity forming members extend from the front end to the rear end of the board. 
     In a further embodiment of the invention, the sports board is made of an aluminum or a titanium material. 
     In a still further embodiment of the invention, the metal board has an arcuate shaped front end and an arcuate shaped rear end. End guards made of a material such as plastic or wood may be secured to the front and the rear ends of the metal board. 
     In an additional embodiment of the invention, the metal board has a bent-up front tip portion and a bent-up rear tip portion. 
     In another embodiment of the invention, the metal sports board is designed for use as a skateboard, and accordingly, includes front and rear skateboard trucks secured to the bottom wall of the metal board. 
     In a further embodiment of the invention, the board deflects less than 0.162 in. with a load of 200 lbs. 
     In a still further embodiment of the invention, the board deflects less than 0.203 in. with a load of 250 lbs. 
     In an additional embodiment of the invention, at least one of the one or more longitudinally elongated cavity-forming sections includes a filler and the filler is a member selected from the group consisting of foam, foam plastic, wood, wood composite, compressed air, and an inflatable bladder. 
     In an additional embodiment of the invention, the one or more longitudinally elongated cavity-forming sections includes a generally rectangular cross section. 
     In an additional embodiment of the invention, the metal sports board includes a length L 1  of 24-60 inches, a width W 1  of 5-12 inches, and a height H 1  of 0.20-0.80 inches. 
     In a further embodiment of the invention, the metal sports board includes a length L 1  of 24-72 inches, a width W 1  of 6-25 inches, and a height H 1  of 0.20-0.80 inches. 
     In a still further embodiment of the invention, the metal sports board includes a length L 1  of 24-65 inches, a width W 1  of 6-35 inches, and a height H 1  of 0.20-0.80 inches. 
     Another aspect of the invention includes a method of manufacturing a sports board. The method includes providing an elongated metal board having a front end, a rear end, a top surface, a bottom surface, a left edge, a right edge, and one or more longitudinally elongated hollow sections; and shaping the metal board near said front end and rear end at a predetermined angle. 
     In an embodiment of the invention, the method includes heat treating the metal board to reduce stresses formed in the metal board. 
     In an additional embodiment of the invention, the elongated metal board is manufactured by extruding a metal board. 
     In a further embodiment of the invention, the step of providing a metal board includes providing a metal board in less than a T-5 tempered hardness condition. 
     In another embodiment of the invention, the elongated metal board is manufactured by casting a metal board around a filler material. The filler material is a member selected from the group consisting of foam, foam plastic, wood, wood composite, and an inflatable bladder. 
     In an additional embodiment of the invention, the method includes shaping the front and rear ends of the metal board into a predetermined shape. 
     In a further embodiment of the invention, the metal board is made of an aluminum material. 
     A further aspect of the invention involves a method of manufacturing a metal sports board. The method includes extruding an elongated metal board made of an aluminum alloy, the elongated metal board having a front end, a rear end, a top surface, a bottom surface, a left edge, a right edge, and one or more longitudinally elongated hollow sections; shaping the elongated metal board; and hardening the elongated metal board by subjecting the metal board to a heat treatment process. 
     In an embodiment of the invention, aluminum alloy is a 6000 series alloy. 
     In another embodiment of the invention, the aluminum alloy is a 6005 alloy. 
     In an additional embodiment of the invention, the metal board is in a T-4 tempered hardness condition before shaping the elongated metal board and is hardened by the heat treatment process to at least a T-5 hardness condition after shaping the metal board. 
     In a further embodiment of the invention, the method further includes annealing the elongated metal board. 
     In a still further embodiment of the invention, the aluminum alloy is a 6000 series alloy. 
     In an additional embodiment of the invention, the aluminum alloy is a 6061 alloy. 
     In another embodiment of the invention, the metal sports board is annealed to a T-0 tempered hardness condition. 
     In a further embodiment of the invention, the metal sports board is hardened by the heat treatment process to at least a T-5 tempered hardness condition after shaping the metal sports board. 
     An additional aspect of the invention involves a method of manufacturing a metal sports board. The method includes providing an elongated metal board, annealing the elongated metal board, shaping the elongated metal board, and hardening the elongated metal board. 
     In an embodiment of the invention, annealing includes annealing to less than a T-5 hardness condition. 
     In an alternative embodiment of the invention, hardening includes hardening to at least a T-5 hardness condition. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front perspective view of the novel metal board utilized as a skateboard; 
     FIG. 2 is a cross sectional view taken along lines  2 — 2  of FIG. 1; 
     FIG. 3 is a bottom plan view of one of the end guards for the metal board; 
     FIG. 4 is a partial bottom plan view of one end of the metal board; 
     FIG. 5 is a cross sectional view taken along lines  5 — 5  of FIG. 4; 
     FIG. 6 is a side elevation view taken along lines  6 — 6  of FIG. 4; 
     FIG. 7 is a bottom plan view of a metal board constructed in accordance with an additional embodiment of the invention; 
     FIG. 8 is a cross sectional view taken along lines  8 — 8  of FIG. 7; 
     FIG. 9 is a cross sectional view taken along lines  9 — 9  of FIG. 7; 
     FIG. 10 is a cross sectional view, similar to FIG. 9, of a metal sports board constructed in accordance with a further embodiment of the invention; 
     FIG. 11 is a cross sectional view, similar to FIG. 9, of a metal sports board constructed in accordance with a still further embodiment of the invention; and 
     FIG. 12 is a cross sectional view, similar to FIG. 9, of a metal sports board constructed in accordance with another embodiment of the invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A novel metal sports board constructed in accordance with an embodiment of the invention will now be described by referring to FIGS. 1-6 of the drawings. The illustrated sports board is a skateboard designated by the reference numeral  10  and its major component is an elongated light-weight metal board  12 . Although the novel metal sports board of the present invention is described for use as a skateboard, it will be readily apparent to those skilled in the art that the sports board may be used for other sports activities such as, but not by way of limitation, snowboarding and wakeboarding. 
     The metal board  12  has a length L 1  in the range of 24-60 inches and a width W 1  in the range of 5-12 inches. The metal sports board  12  includes a main body portion  13  and opposite tip portions  26 ,  27 . The board  12  includes an upper surface  29  with a concave transverse contour. 
     The metal board  12  also includes one or more longitudinally elongated cavity-forming sections. A first longitudinally elongated cavity-forming section identified as cavity-forming keel  14  is located in the center of the metal sports board  12 . The cavity-forming keel  14  has a substantially rectangular cross sectional shape and has a height H 1  in the range of 0.200-0.800 inch and a width W 2  in the range of 0.500-3.000 inch, when the metal board  12  is used as a skateboard. The first elongated cavity-forming section  14  includes a longitudinally elongated cavity  30  defined by top wall  32 , bottom wall  34  and opposite interior support walls  36 ,  38 . The thickness T 1  of the top wall of the metal board  12  is in the range of 0.050-0.250 inch. The first elongated cavity-forming section  14  preferably extends from a front arcuate edge  40  to a rear arcuate edge  42  of the metal sports board  12 . When the metal board  12  is used as a snowboard, the height H 1  is 0.200-0.800 inch, the width W 1  is 6-25 inches and the length L 1  is 24-72 inches. When the metal board  12  is used as a wakeboard, the height H 1  is 0.200-0.800 inch, the width W 1  is 6-35 inches and the length L 1  is 24-65 inches. 
     The metal board  12  also includes a second longitudinally elongated cavity-forming section identified as left rail  16  and a third longitudinally elongated cavity-forming section identified as right rail  18  that preferably extend from the front edge  40  to the rear edge  42  of the metal sports board  12 . Each longitudinally elongated cavity-forming section  16 ,  18  includes a longitudinally elongated cavity  46 ,  48  defined by top wall  32 , bottom wall  48 ,  50 , interior support wall  52 ,  54 , exterior support wall  56 ,  58  and inner inclined walls  17 ,  19 . The inner inclined walls  17 ,  19  of the respective rails  16 ,  18  are inclined to allow clearance space for the wheels when the rider weights the metal board heavily to a particular side edge. The rails  16 ,  18  preferably have a height H 2  in the range of 0.200-0.800 inch and a width W 3  in the range of 0.300-1.00 inch. 
     Although the longitudinally elongated cavity-forming sections  14 ,  16 ,  18  are described as extending the full length of the metal sports board, it will be readily appreciated by those skilled in the art that any or all of the elongated cavity-forming sections  14 ,  16 ,  18  may extend less than the full length of the metal sports board  12 . Further, just as the longitudinally elongated hollow sections  14 ,  16 ,  18  share a common top wall  32 , they may similarly share a common bottom wall. Any or all of the elongated cavity-forming chambers  30 ,  46 ,  48  may be filled with an appropriate light-weight filler material such as, but not by way of limitation, a foamed plastic, a wood material, a wood composite material or an inflatable bladder to aid in the strength and/or manufacturing of the metal sports board  12 . The elongated cavity-forming sections  14 ,  16 ,  18  improve the strength of the metal sports board  12  without adding significantly to the weight of the board  12 . The improved strength is provided by the longitudinally elongated generally vertical support walls  36 ,  38 ,  52 ,  54 ,  56 ,  58 . 
     A pair of skateboard trucks  24  are secured to the bottom surface of the main body portion  13  of the metal board  12 . Each truck  24  has a pair of wheels  25 . 
     The metal sports board  12  includes upwardly inclined tip portions  26 ,  27  near the respective edges  40 ,  42 . The tip portions  26  are inclined upwardly with respect to the main body portion  13 . End guards  28  may be secured to the edges  40 ,  42  of the tip portions  26 ,  27 . The end guards  28  preferably include one or more protruding portions  29  that plug into respective cavities in the metal sports board  12 . The end guards  28  may be additionally secured to the edges  40 ,  42  using appropriate fasteners. In an alternative embodiment, the end guards  28  do not include the protruding portions  29  and, hence, are secured to the outside of the board  12  with appropriate fasteners. The end guards  28  may be made of plastic, wood or similar material. 
     It will be readily apparent to those skilled in the art that in alternative embodiment of the invention, the metal sports board  12  may have one or no upwardly inclined tip portions. For example, if the metal sports board was used for snowboarding, the board may have only one upwardly inclined tip portion. Alternatively, if the metal sports board was used for wakeboarding, the board may have no upward inclined tip portion. Further, the edges  40 ,  42  may have a shape other than arcuate. 
     FIG. 4 is a partial bottom plan view of a front part of the metal sports board  12  without the trucks  24  and wheels  25  shown. In the illustrated embodiment shown in FIGS. 1-6, the rear part of the board  12  is substantially identical. 
     FIG. 5 is a cross sectional view taken along lines  5 — 5  of FIG.  4  and illustrates the elongated cavity-forming nature of the board  12 , especially the central longitudinally elongated portion  14 . 
     FIG. 6 is a side elevation view taken along lines  6 — 6  of FIG. 4 of the front part of the metal sports board  12  and illustrates the front edge  40  of the board  12  without the end guard  28 . 
     With reference to FIGS. 7-9, a bottom plan view of a light-weight metal sports board  60  constructed in accordance with an additional embodiment of the invention is shown. The metal sports board  60  has similar W 1 , H 1  and T 1  measurements to those described above. The metal sports board  60  includes a main body portion  62  and opposite tip portions  64 ,  66 . The metal sports board  60  also includes one or more longitudinally elongated cavity-forming sections. A first or central longitudinally elongated cavity-forming section  68  having a generally rectangular cross section preferably extends from a front edge  70  to a rear edge  72  of the board  60 . The central longitudinally elongated cavity-forming section  68  includes a longitudinally elongated cavity-forming chamber  74  defined by top wall  76 , bottom wall  78  and opposite interior support walls  80 ,  82 . 
     The metal board  60  also includes an adjacent second longitudinally elongated cavity-forming section  84  and an adjacent third longitudinally elongated cavity-forming section  86 , both of which preferably extend from the front edge  70  to the rear edge  72  of the metal sports board  12 . Each longitudinally elongated cavity-forming section  84 ,  86  includes longitudinally elongated cavities  88 ,  90  defined by top wall  76 , bottom wall  78 , generally vertical interior support walls  80 ,  82 , and exterior support walls  92 ,  94 . Although the support walls  80 ,  82 ,  92 ,  94  are illustrated as being generally vertical, it will be readily apparent to those skilled in the art that any or all of these supporting walls may be inclined at an angle other than 90° with respect to the walls  76 ,  78 . The second longitudinally elongated cavity-forming section  84  and third longitudinally elongated cavity-forming section  86  both have a generally rectangular cross section, similar to the central longitudinally elongated cross section  68 , except the sections  84 ,  86  are wider. 
     Similar to the metal sports board  12  described above with respect to FIGS. 1-6, although the longitudinally elongated cavity-forming sections  68 ,  84 ,  86  are described as extending the full length of the metal sports board  60 , it will be readily appreciated by those skilled in the art that any or all of the elongated cavity-forming sections  68 ,  84 ,  86  may extend less than the full length of the metal sports board  60 . Also, any or all of the elongated cavities  68 ,  84 ,  86  may be filled with an appropriate light-weight filler material such as, but not by way of limitation, a foamed plastic, a wood material, a wood composite material or an inflatable bladder to aid in the strength and/or manufacturing of the metal sports board  60 . The elongated cavity-forming sections  68 ,  84 ,  86  improve the strength of the metal sports board  60  without adding significantly to the weight of the board  60 . The improved strength is provided mainly by the longitudinally elongated generally vertical support walls  80 ,  82 ,  92 ,  94 . 
     With reference to FIG. 10, in an alternative embodiment of the metal sports board  60 , the generally vertical interior walls  80 ,  82  may be thicker in order to provided more support for the board  60 . Also, the bottom wall  78  may be thicker in order to support fasteners for a pair of trucks such as trucks  24  described above. 
     With reference to FIG. 11, a light-weight metal sports board  100  constructed in accordance with an additional embodiment of the invention will be described. The metal sports board  100  is similar to the embodiments of the metal sports board  60  described in conjunction with FIGS. 7-10. Consequently, like elements are identified with the same reference numerals and are not described in further detail below. The metal sports board  100  includes a first or central longitudinally elongated cavity-forming section  102  having a longitudinally elongated cavity  104  with a cross-like cross section preferably extending from a front edge  70  to a rear edge  72  of the board  100 . 
     With reference to FIG. 12, a cross sectional view of a light-weight metal sports board  110  constructed in accordance with an additional embodiment of the invention is shown. The metal sports board  110  has similar W 1 , H 1  and T 1  measurements to those described above. The metal sports board  110  includes one or more longitudinally elongated cavity-forming sections. A first or central longitudinally elongated cavity-forming section  112  having a generally rectangular cross section preferably extends from a front edge  70  to a rear edge  72  of the board  110 . The central longitudinally elongated cavity-forming section  112  includes a longitudinally elongated cavity-forming cavity  114  defined by top wall  116 , bottom wall  118  and opposite interior support walls  120 ,  122 . 
     The metal board  110  also includes an adjacent second longitudinally elongated cavity-forming section  124  and an adjacent third longitudinally elongated cavity-forming section  126 , both of which preferably extend from the front edge  70  to the rear edge  72  of the metal sports board  110 . Each longitudinally elongated cavity-forming section  124 ,  126  include longitudinally elongated cavities  128 ,  130  defined by top wall  116 , bottom wall  118 , generally vertical interior support walls  120 ,  122 , and second interior support walls  132 ,  134 . The second longitudinally elongated cavity-forming section  124  and third longitudinally elongated cavity-forming section  126  both have a generally rectangular cross section, similar to the central longitudinally elongated cross section  112 , except the sections  124 ,  126  are narrower. 
     The metal board  110  also includes an adjacent fourth longitudinally elongated cavity-forming section  136  and an adjacent fifth longitudinally elongated cavity-forming section  138 , both of which preferably extend from the front edge  70  to the rear edge  72  of the metal sports board  110 . Each longitudinally elongated cavity-forming section  136 ,  138  include longitudinally elongated cavities  140 ,  142  defined by top wall  116 , bottom wall  118 , generally vertical second interior support walls  132 ,  134 , and third interior support walls  144 ,  146 . The fourth longitudinally elongated cavity-forming section  136  and fifth longitudinally elongated cavity-forming section  138  both have a generally rectangular cross section, similar to cross section of the central longitudinally elongated cavity-forming section  112 . 
     The metal board  110  also includes an adjacent sixth longitudinally elongated cavity-forming section  148  and an adjacent seventh longitudinally elongated cavity-forming section  150 , both of which preferably extend from the front edge  70  to the rear edge  72  of the metal sports board  110 . Each longitudinally elongated cavity-forming section  148 ,  150  include longitudinally elongated cavities  152 ,  154  defined by top wall  116 , bottom wall  118 , generally vertical third interior support walls  144 ,  146 , and fourth exterior support walls  156 ,  158 . The fourth exterior support walls  156 ,  158  have an arcuate cross section. The sixth longitudinally elongated cavity-forming section  148  and seventh longitudinally elongated cavity-forming section  150  both have a generally rectangular cross section, similar to cross section of the central longitudinally elongated cavity-forming section  112 . 
     Similar to the metal sports board  12  described above with respect to FIGS. 1-6, although the longitudinally elongated cavity-forming sections  112 ,  124 ,  126 ,  136 ,  138 ,  148 ,  150  are described as extending the full length of the metal sports board  110 , it will be readily appreciated by those skilled in the art that any or all of the elongated cavity-forming sections  112 ,  124 ,  126 ,  136 ,  138 ,  148 ,  150  may extend less than the full length of the metal sports board  100 . Also, any or all of the elongated cavities  112 ,  124 ,  126 ,  136 ,  138 ,  148 ,  150  may be filled with an appropriate light-weight filler material such as, but not by way of limitation, a foamed plastic, a wood material, a wood composite material or an inflatable bladder to aid in the strength and/or manufacturing of the metal sports board  110 . The large number of elongated cavity-forming sections  112 ,  124 ,  126 ,  136 ,  138 ,  148 ,  150  improve the strength of the metal sports board  110  without adding significantly to the weight of the board  110 . The improved strength is provided mainly by the longitudinally elongated generally vertical support walls  120 ,  122 ,  132 ,  134 ,  144 ,  146 ,  156 ,  158 . Generally, the number of elongated hollow sections in the metal sports board is N−1, where N is the number of longitudinally elongated support walls. 
     It will be readily appreciated by those skilled in the art that in a further embodiment of the invention, the metal sports board may include a number of adjacent longitudinally elongated hollow sections and support walls not shown and described herein. 
     The metal sports board of the present invention is preferably manufactured by extruding an elongated metal board made of an aluminum alloy to have one or more longitudinally elongated cavity-forming sections. Preferably, the metal sports board has the three longitudinally elongated cavity-forming sections as discussed above with respect to FIGS. 9-11. Although the metal sports board is preferably made of aluminum, other metal materials such as, but not by way of limitation, a titanium alloy may be used. The aluminum alloy preferably used is either a 6061 alloy or a 6005 alloy in the 6000 series of this alloy. Of course, other alloys may be used. 
     If a 6061 alloy is used, the method of manufacture preferably includes extruding the elongated metal board, annealing or softening the metal board to less than a T-5 hardness condition, preferably a T-0 tempered hardness condition (e.g., spraying the metal board with water within a few seconds after the metal board comes out of the mold), bending or shaping the metal board, and hardening the metal board so as to retain the desired shape by a heat treatment process to at least a T-5 tempered hardness condition (e.g., solution aging the metal board for approximately 8 hours at 350 degrees). 
     If a 6005 alloy is used, the annealing process described above is not required because after the extrusion step, the metal board is at a T-4 tempered hardness condition. The method further includes shaping the metal board, and hardening the metal board by a heat treatment process to at least a T-5 tempered hardness condition. If the metal sports board is to be used as a skateboard, the board is preferably shaped by bending the front and rear portions of the metal sports board to a predetermined angle so that a bent-up tip portion and a bent-up rear tip portion are formed. Obtaining the desired shape of the front and rear parts may also involve machining the front and rear parts of the metal board into a predetermined shape. 
     In summary, the novel method of manufacturing a metal sports board includes providing the metal sports board, e.g., extruding the board, annealing or softening the metal sports board to inhibit stress formation or cracking in the board, shaping the board, and hardening the board to retain its shape, e.g., heat treatment process. The metal sports board is preferably annealed to less than a T-5 hardness condition before shaping the board and hardened to at least a T-5 hardness condition. As discussed above, if the metal sports board is initially provided in a sufficient soft condition, less than a T-5 hardness, the annealing step may not be used. By not shaping the metal sports board while it is in a hard condition, e.g., a T-6 condition, the method of the present invention inhibits cracking and breaking of the board over time, allowing the rider to ride the sports board hard without worrying about the board bending or breaking. 
     Although the step of providing an elongated metal board preferably includes extruding the elongated metal board, other manufacturing processes besides extruding may be used to manufacture the metal sports board. For example, the metal sports board may be manufactured by bending a single piece of aluminum or other metal to the desired shape. Alternatively, a separate top sports board member and bottom sports board member may be manufactured and affixed together so as to form a metal sports board having one or more longitudinally elongated cavity-forming sections. For example, the top sports board member and the bottom sports board member may each be separate pieces of aluminum that are bent to a desired shape and welded together. Alternatively, the separate members could be extruded separately and welded together to form the metal sports board. Alternatively, the one or more longitudinally elongated cavity-forming sections may be formed by casting or extruding the metal sports board with a fluid filled air bladder on the inside and removing the bladder after forming the metal sports board. Other light-weight filler materials such as, but not by way limitation, foam, wood, or wood composite in the shape of the longitudinally elongated cavity may be used to assist in creating the one or more longitudinally elongated cavity-forming sections. These light-weight filler materials may also help to reduce the weight of the metal sports board while increasing the strength of the sports board. Using an air bladder or other filler material also allows longitudinally elongated cavity-forming sections to be shorter than the full length of the board to be formed. 
     It should be noted, the type of metal sports manufactured, e.g., skateboard, snowboard, wakeboard, dictates how the board will be manufactured. For example, if the metal sports board is intended for use as a wakeboard or snowboard, the metal sports board will be shaped differently than that shown and described above. 
     While the particular invention as herein shown and disclosed in detail is fully capable of obtaining the objects and providing the advantages stated, it is to be understood that this disclosure is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended other than as described in the appended claims.