Abstract:
A surfboard, the construction of which makes a minimal impact on the environment, the components are readily available, and which, if disposed of, biodegrades. The surfboard delivers performance characteristics comparable to any currently commercially produced wave-propelled craft, with no significant increase in materials costs. The surfboard is composed of a pattern of wood veneers over a wooden framework, creating a hollow wooden body. All pieces used in construction are connected using food grade gelatin glue. Casein from skim milk added to the glue provides a general water-resistance to the structure. Fins attached to the bottom of the surfboard give stability to the craft in the water. Routed fin boxes incorporated into the body of the surfboard, supplied with a wooden locking mechanism, allow the fins to be quickly changed for various wave conditions. A wooden leash plug as part of the construction permits a leash to be connected to the surfboard. The whole is varnished with a waterproof combination of rosin and tung oil.

Description:
REFERENCES CITED 
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                 U.S. Patent Documents 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 1,830,015 
                 November 1931 
                 Carmichael 
                 441/74 
               
               
                   
                 1,872,230 
                 August 1932 
                 Blake 
                 441/74 
               
               
                   
                 2,355,302 
                 November 1940 
                 Kirchner 
                 441/74 
               
               
                   
                 2,389,729 
                 November 1943 
                 Howland 
                 441/74 
               
               
                   
                 4,209,867 
                 July 1980 
                 Abrams, III 
                 441/74 
               
               
                   
                 4,302,859 
                 December 1981 
                 Kozminski 
                 441/74 
               
               
                   
                 4,798,549 
                 January 1989 
                 Hirsch 
                 441/74 
               
               
                   
                 5,514,017 
                 May 1996 
                 Chum 
                 441/65 
               
               
                   
                 6,800,006 B1 
                 October 2004 
                 Itnyre et. al 
                 441/74 
               
               
                   
                   
               
             
          
         
       
     
       BACKGROUND OF THE INVENTION 
       [0002]    The field of the invention is wave-propelled watercraft, namely surfboards. 
         [0003]    Usually, surfboards are made by taking a foam-core blank, some size larger than the intended surfboard shape and cutting or sanding away the excess foam. The foam core is then coated with a synthetic resin. The shaper typically must wear protective gear to protect from the toxic dust and fumes released in the process. Subsequent repairs to the surfboard also require synthetic resin or epoxy that release toxic fumes. Inventions that reduce the waste involved in carving foam blanks are known, yet still have the disadvantage of requiring synthetic resins, for example U.S. Pat. Nos. 4,798,549; 5,514,017; 6,800,006 B1. 
         [0004]    The original surfboards were solid wooden carvings made from a single log. Modifications on the solid wood design, as shown in U.S. Pat. No. 2,355,302 demand great upper body strength to catch a wave and lack ease of shifting on the wave. 
         [0005]    Hollow wooden surfboards are known to the art The first hollow wooden surfboard was patented in 1932, U.S. Pat. No. 1,872,230. That design is too heavy for current demands of maneuverability in the water, and is prone to leakage, requiring regular draining. Although intended for a different use, the similar invention shown in U.S. Pat. No. 1,830,015 has like drawbacks. Similarly, the hollow surfboard indicated in U.S. Pat. No. 2,389,729, although not specified as being made from wood, would be so heavy as to preclude easy turning on a wave. 
         [0006]    Closer to the present invention is U.S. Pat. No. 4,209,867. This design, however, doesn&#39;t meet the demand of light weight for maximum turning ability and requires a synthetic resin coating for waterproofing. The distance between the spacers separating the upper from the lower decks, along with many cuts required in its rails, contribute to a potential weakness in the body. The method of manufacture indicated in U.S. Pat. No. 4,302,859, and slight modifications thereon, have been employed by a number of surfboard makers, to good effect. These surfboards still are heavier than the current invention, require a bulkiness to the body of the surfboard that limits versatility, and typically use synthetic glues and synthetic resin coatings with similar drawbacks to the most commonly employed method of shaping and coating urethane foam blanks. 
       BRIEF SUMMARY OF THE INVENTION 
       [0007]    It is an object of the present invention to provide a surfboard that meets standards of performance of currently produced surfboards, namely light weight and maneuverability on a wave, made with renewable, environmentally friendly materials. 
         [0008]    The present invention meets this object by using a system of wood veneers as a skin over a lightweight wooden frame, adhered with food grade gelatin glue made water-resistant by the addition of skim milk, and then waterproofed with a varnish of rosin dissolved in tung oil. Alternately, walnut oil or raw linseed oil may be used in place of the tung oil. 
         [0009]    The framework is composed of a wooden stringer, running the length of the board, with thin spacers placed transversely, extending at intervals from the stringer to the rails. The rails are made of two long, thin wooden laths glued together in a form to hold a wide arc shape typical of the side of a surfboard. These rails are carved with a blade to shape the outer edge into an curve, a broader arc towards the top deck of the board and a sharper one towards the bottom of the board, allowing the rail to hold its position on a wave, and still be easy to grab with the hands. In the preferred embodiment, the framework is made of a lightweight wood such as pine, spruce, fir, or balsa. 
         [0010]    Fins extend downward from the bottom rear of a surfboard to provide stability on the wave and to aid in turning on the wave. Fins may be built as permanent aspects of a surfboard or made modular to increase the versatility of the board by allowing switching of fins of different lengths and shapes to adapt to different wave conditions. The preferred embodiment of the present invention uses modular fins. As part of the framework, fin boxes are placed towards the aft portion of the surfboard. Short surfboards, less than 7 feet long, will typically have three fins; surfboards longer than 7 feet may have one central fin or three fins, one central and one on each side close to the rails. The central fin box is drilled and routed in the stringer in such a fashion as to produce a slit with a right-angled overhang, into which a fin, equipped with projections to hold it under the overhang, may be slid. The fin is then secured with a locking mechanism. The fin boxes for the side fins are made of a solid block of wood, roughly rectangular in shape, drilled and routed to create a slit with a right-angled overhang, into which fins may be secured using the same method as the central fin box. The fins themselves are made of several hardwood veneers cut into the fin shape, glued together, with hardwood dowels placed transversely through the fore and aft portions of each fin as projections to secure the fins in the fin boxes. 
         [0011]    It is customary in the art to fashion a means for the surfboard to be attached to a leash, to prevent the surfboard from moving out of the surfer&#39;s control when the surfer is separated from the board. Incorporated into the top rear portion of the present invention is a leash plug. This is made from a hardwood ring with a hardwood dowel inserted crosswise midway through the ring. A hole is drilled into the stringer and the ring/dowel assembly is glued in place flush with the top of the stringer. 
         [0012]    The skins for the top and bottom decks are made of a ply formation of three veneers; the two outer veneers of the ply have grain oriented along the length of the board and the grain of the central veneer is placed perpendicular to the length of the board. In the preferred embodiment, hardwood veneers are used, combining the strength and durability of hardwood with the flexibility of veneer, the layered fashion of construction allowing exceptional strength of the skin in spite of its thinness. The skins are attached over the framework, leaving the wood of the rails exposed. The skin immediately over the slits in the fin boxes is cut away to expose the slits. The skin is also cut away over the open portion of the leash plug. A final layer of veneer is now adhered over all of the surface of the board, the pattern of which may be varied and include any type of wood, including different species, to maximize aesthetic effect. The veneer over the fin slits and leash plug is again cut away. 
         [0013]    The entire surfboard is varnished with several layers of the rosin/oil mixture. The fins are varnished in the same way. After sufficient time for the varnish to dry and cure, the entire surface is coated with a layer of carnauba wax. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
         [0014]      FIG. 1  is a perspective view showing the underside of the surfboard of the present invention. 
           [0015]      FIG. 2  is a cross sectional view taken along line III-III of  FIG. 1 . 
           [0016]      FIG. 3  is a cross sectional view taken along line IV-IV of  FIG. 1 . 
           [0017]      FIG. 3A  is an enlargement of a portion of  FIG. 3 , showing the pattern of veneers. 
           [0018]      FIG. 4  is a top plan view of the inner framework of the surfboard. 
           [0019]      FIG. 5  is a side elevation view of the inner framework of the surfboard. 
           [0020]      FIG. 6  is a top plan view of the rear portion of the surfboard. 
           [0021]      FIG. 6A  is a portion of a cross sectional view taken along line V-V of  FIG. 6 . 
           [0022]      FIG. 7  is a side plan view of one of the fins. 
           [0023]      FIG. 7A  is a rear plan view of one of the fins. 
           [0024]      FIG. 7B  is an enlargement of the upper portion of  FIG. 7A . 
           [0025]      FIG. 8  is a bottom view of the central fin box showing, in phantom lines, routed channels for passage of fin dowels and fin lock dowel, as well as the location of the leash plug on the top side of the stringer. 
           [0026]      FIG. 8A  is a cross sectional view taken along line VI-VI of  FIG. 8 . 
           [0027]      FIG. 8B  is a top plan view of a portion of the framework, showing one of the side fin boxes, and in phantom lines, channels for the passage of fin dowels and fin lock dowel. 
           [0028]      FIG. 9  is a portion of one of the side fin boxes, showing the locking mechanism in detail, with, in phantom lines, the channel for the passage of the fin lock dowel and a portion of the channel for the passage of fin dowels. 
           [0029]      FIG. 9A  is a cross sectional view taken along line VII-VII of  FIG. 9 . 
           [0030]      FIG. 9B  is a top plan view of the fin lock, showing, in phantom lines, the portion of the fin lock dowel inserted into the fin lock. 
           [0031]      FIG. 9C  is a side plan view of the fin lock, showing, in phantom lines, the portion of the fin lock dowel inserted into the fin lock. 
           [0032]      FIG. 9D  is a bottom plan view of the tail portion of the board showing the fin lock in place and locked, with the fin removed. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0033]    A surfboard of the present invention is shown in perspective view in  FIG. 1 . The surfboard has a deck  11 , a bottom  12 , a nose  15 , a tail  16 , left and right rails  13 , and three fins  14  projecting downward from the bottom rear of the board to provide stability. Three fins are most commonly used on surfboards, but the board may have only one central fin or only two side fins, or more, if desired to suit the style of surfing of a particular surfer. As shown in  FIG. 1 , the surfboard appears to be a conventional surfboard of the type most widely available. 
         [0034]    It is in cross-section, as seen in  FIG. 2 ,  FIG. 3  and  FIG. 3A , that the present invention is demonstrated.  FIG. 2  shows the system of overlapping veneers adhered over a wooden framework. The overall plan of the framework is shown in  FIG. 4 . The value of using veneer in the construction can be determined by viewing  FIG. 5 , which shows the upward slope of the nose and the tail portions of the surfboard, known in the art as the nose and tail rocker. Rocker improves surfboard performance. Veneers, which are flexible, preserve the rocker while eliminating the waste produced when carving or sanding down solid wood planks to match the curved shape. 
         [0035]    Surfboard leashes increase safety in the water. One end of the leash is attached to the leash plug in the surfboard and the other end is connected to the surfer. Existing leash plugs are made of plastic or a combination of plastic and metal. To make a surfboard that uses no metal or synthetic parts, a new type of leash plug is required. The leash plug of the current invention is shown in  FIG. 6  and  FIG. 6A . 
         [0036]    All existing modular surfboard fin designs use metal or synthetic materials in the locking mechanisms employed to fix the fins in place.  FIG. 7 ,  FIG. 7A , and  FIG. 7B  show the fin equipped with projections  33 ,  34  to allow the fin to be fixed into the board, but still be easily removed if a fin of a different shape or size is desired. A method of fixing the fin in the board is the intention of the fin channel  37  and fin locking mechanism, as shown in  FIG. 8 ,  FIG. 8A ,  FIG. 8B ,  FIG. 9 ,  FIG. 9A ,  FIG. 9B ,  FIG. 9C , and  FIG. 9D . 
         [0037]    The strength of the hardwood veneers, increased by using the long known gelatin glue, allows the surface to be thinner than any hollow wooden surfboards yet produced. Due to the strength of the veneers, the inner framework can be thinner and lighter than previous hollow wooden surfboards. The strength and relative rigidity of the gelatin glue allows the wooden fins to be thinner and stronger than previous wooden fins that were not reinforced with fiberglass and synthetic resin. The tung oil and rosin varnish is durable and effective. Tung oil is known as a below-the-waterline waterproofing agent on wooden boats. The rosin in the finishing varnish increases the durability of the finish. Linseed oil and walnut oil are considered acceptable alternatives to tung oil. 
         [0038]    All glue in the preferred embodiment is food grade gelatin, heated and dissolved in a mixture of skim milk and water, to make a glue that is workable while warm, but that sets quickly as it cools. The casein in the milk adds water resistance. 
         [0039]    In the preferred embodiment, the inner wooden framework is made of a lightweight wood such as pine, spruce, fir, or balsa. 
         [0040]    The inner wooden framework is composed of a central stringer  20  shaped in side plan to match the desired rocker, as indicated in  FIG. 5 . The stringer is shaped in top and bottom plan to come to a point at the nose  15  of the board, to accommodate the narrowing at the nose as the rail assemblies  17  come together, as seen in  FIG. 4 . 
         [0041]    The tail piece of frame  27  is cut and shaped in side plan to fit the desired tail rocker, as indicated in  FIG. 5 . In top plan the tail piece of the frame is cut with a notch to fit the base of the stringer. The tail end of a surfboard in top and bottom plan is square or rounded, or sometimes shaped into a V-shape or inverse V-shape depending on the performance characteristics desired for the board. In side plan the tail is also square or rounded, or sometimes shaped into a V-shape. All are allowed by the present invention. The tail end of the tail piece of the frame is shaped as desired. 
         [0042]    Left and right rail assemblies  17  are made. Each rail assembly is made of two wooden laths glued together  18 ,  19 . Each lath is cut to match the desired rocker in side plan, as indicated in  FIG. 5 . Then the laths of each assembly have glue applied to the sides facing each other. They are bent and placed in a form the desired shape of the side of the surfboard and clamped until the glue is dry. The rail assemblies are glued to the stringer at the nose and to the sides of the tail piece of frame at the tail. 
         [0043]    Spacers  21  are cut from laths in a length to extend from the stringer to the rail assemblies. The spacers are curved slightly on top to allow a gentle slope from the high point of the elevation of the board at the stringer, to the low point of the elevation of the board at the rails. The spacers should be slightly lower in elevation than the top of the rails to allow the 3-ply veneer assembly of the deck to sit flush with the top of the rails. Similarly the spacers should be set slightly higher in elevation at the bottom of the rails to allow the 3-ply veneer assembly of the bottom of the board to sit flush with the edge of the bottom of the rails. The spacers are set perpendicular to the stringer at intervals. In the preferred embodiment, the intervals are of approximately 3 to 6 inches. 
         [0044]    At the desired location of the side fins, fin boxes  22  are placed in such a fashion as to make the outside portion of the fin boxes to be flush with the bottom of the spacers. 
         [0045]    All parts of the inner wooden framework are glued together. Then the outer piece of the rail assembly  19  is shaped for the desired performance of the surfboard. The wood is carved or sanded. The most common shape is a shallow arc towards the top of the rail and a sharper arc towards the bottom of the rail, as indicated in  FIG. 3A . 
         [0046]    Once the glue has cured, the leash plug  28  should be made. The leash plug is composed of a wooden ring  29  the height of the stringer where the plug is to be inserted, or slightly less than the height of the stringer at that point. The ring has a hole drilled in a straight line through two opposite sides of the ring, to accommodate a dowel  30  whose length is equal to the diameter of the ring  31 , as indicated in  FIG. 6A . The dowel is placed as close to the middle of the ring in height and diameter as possible to allow space for the leash to be attached to the dowel  32 . In the preferred embodiment, hardwood is used for all parts of the leash plug. A hole is drilled towards the tail end of the stringer the size of the wooden ring. The hole will be drilled completely through the stringer if the wooden ring is the height of the stringer, or as deep as the ring, if the ring is not as high in elevation as the stringer at the point where the leash plug is to be inserted. The leash plug is inserted and glued in place so that the top of the wooden ring is flush with the top of the stringer. 
         [0047]    The central fin box is drilled and routed, as in  FIG. 8 . The side fin boxes, one of which is shown in  FIG. 8B , may be drilled and routed at this time, but it will be more convenient to have them prepared before gluing them in place in the inner wooden framework. The method of constructing all of the fin boxes is as follows. A hole  41  is drilled about three-fourths way through the fin box starting on the bottom outside side. The hole should be large enough to accommodate the width of the front and rear fin dowels  33 ,  34 , plus the several coats of varnish used to seal the fin box. Once the hole is drilled, a router is used to create a channel  37  extending from the hole towards the nose of the surfboard the length of the bottom of the fin, through which the fin will slide, until it is correctly seated in place. At the same time, the router will create a fin channel overhang  38  that will prevent the fin from being pulled out accidentally, the fin dowels being situated against the outside edge of the fin channel overhang  39 . 
         [0048]    The fins, once seated in their channels are prevented from sliding in the channel by a fin lock,  FIG. 9B  and  FIG. 9C . The fin lock consists of a wooden cylinder  40  with a dowel inserted midway, perpendicular to the axis of the cylinder and projecting therefrom  44 . The top of the fin lock has a groove  43  to allow a coin to be inserted and turned to turn the lock into a locking position or out of a locking position. The lock is operated by inserting the fin lock into the fin lock hole  41  with the fin lock dowel entering the fin lock dowel channel  42  at its outside opening. When the lock is seated, the lock is turned, using a device such as a coin to turn the groove clockwise until the dowel holds the lock in place. The fin lock dowel channel is made by routing a groove from the outside edge of the fin lock hole at the part of the hole closest to the tail, as seen in  FIG. 8  and  FIG. 8A , to a depth to accommodate the fin lock dowel; then the groove is continued at a right angle clockwise so that the fin lock may turn 90 degrees, as shown in  FIG. 9  and  FIG. 9A . To minimize drag in the water, when the fin lock is in the locked position, the fin lock groove is oriented lengthwise with the board, as shown in  FIG. 9D . 
         [0049]    The primary veneer portion of the deck and the bottom is constructed by first making a three-veneer ply assembly  24  cut in the shape of the outline of the board in top plan but smaller than the overall shape on the sides, in such a fashion as to fit inside the rail assemblies on each side. The 3-ply veneer does extend from the nose to the tail in length. The rail assembly  17  thins to a point in top and bottom plan at the nose, allowing the 3-ply veneer to be set on top and bottom of the framework at that point. On both deck and bottom, the 3-ply veneer assembly extends to the edge of the tail, in whatever shape it is configured. The 3-ply veneer assembly is placed on and glued onto the spacers  21  to make the deck and the bottom of the board. As seen in  FIG. 3A , the spacers are cut in such a way as to allow the outside surface of the 3-ply veneer assembly to sit flush with the top and bottom edges of the rail assemblies. 
         [0050]    The veneer on top is then cut out over the leash plug, to match the inside diameter of the leash plug, the overlapping of the veneers acting as added strength to hold the plug in place. The veneer on bottom is cut out over the fin boxes, exposing the fin channels  37 , the fin lock hole  41 , and the outside portion of the fin lock dowel channel  42 . 
         [0051]    The outside veneer is then applied with the glue. It may be applied in as many sections and in whatever pattern will be aesthetically pleasing, as long as care is taken to overlap the 3-ply veneer assembly  26 , so as not to create a weak joint in one location of the veneer all the way through. 
         [0052]    The tung oil and rosin varnish is applied in 5 to 10 coats to the entire surface, including the partially interior portions of the fin boxes and the leash plug, allowing sufficient drying time between coats. 
         [0053]    When the varnish has cured, pure carnauba wax is applied over the entire surface, including the partially interior portions of the fin boxes and the leash plug, to add protection to the finish. 
         [0054]    The fins  14  are made of several veneers, cut into the typical surfboard fin shape, as shown in  FIG. 7B , and glued together. In the preferred embodiment seven veneers are used with the grain alternating direction on adjacent veneers. In  FIG. 7 , the fin is shown in side plan view. The front bottom of the fin is rounded  35  to allow easy insertion and sliding into the fin channel. The rear bottom corner of the fin  36  is a right angle to increase effectiveness of the fin lock.  FIG. 7  and  FIG. 7A  show the fin dowels  33 ,  34 . The fin dowels are inserted through holes drilled through the front and back lower portions of the fins. The fin dowels are glued in place such that the projecting portions of the dowels project equidistant from the center, as shown in  FIG. 7A . The fins, once glued with the dowels emplaced, are varnished and waxed with the same varnish and wax used for the rest of the surfboard. 
         [0055]    The fins are inserted in the fin channel through the fin lock hole, front corner first, the front fin dowel  33  fitting against the outside edge of the fin dowel channel  39 , then the dowel of the back corner  34  is inserted into the fin channel, fitting against the outside edge of the fin dowel channel. The fin is then locked in place using the fin lock. 
         [0056]    While the construction so described is that of a surfboard, similar embodiments could be made in the form of equipment used in other water sports, particularly for those who desire an environmentally friendly method of construction, using renewable materials, and minimizing both waste and toxicity.