Abstract:
In broad embodiment, the present invention is a removable surfboard fin adapter that allows removable fins, fin boxes and fin systems from different manufacturers to be compatible with each other. The present invention is a device used to enable a two-tabbed type removable surfboard fin to be received and secured in the recess of a single-tab type surfboard fin receiving box that, without said device, would not be able to receive and secure a two-tabbed type removable surfboard fin. The present invention solves a common problem for surfboard owners who own multiple surfboards, which contain removable fin systems from the two most common removable fin system manufacturers. It is a disadvantage for the surfboard owner in situations like this because the surfboard owner must purchase multiple sets of fins for each respective removable fin system and bring multiple sets of fins for each removable fin system when traveling.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This patent application claims the benefit of an earlier provisional patent filing dated Dec. 13, 2013 with patent Ser. No. 61/916,106 and having the same inventorship. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not Applicable 
       REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISK APPENDIX 
       [0003]    Not Applicable 
       BACKGROUND OF THE INVENTION 
       [0004]    The present invention is in the field of fins attached to the underside of watercrafts. More particularly, the present invention is in the field of removable surfboard fins. Specifically, the present invention gives a surfer the ability to securely fasten a two-tabbed removable fin to a single-tab fin box, which would otherwise not be possible. 
         [0005]    The ability to change the fins on a surfboard has various advantages for the owner of a surfboard. Many surfboard owners experiment with different removable surfboard fin designs and materials to find a fin configuration that best suits their surfing style, surfboard performance and ocean conditions. 
         [0006]    Surfboards, Stand-Up Paddleboards and Kayaks typically have either 1 large fin or 3 small fins and less frequently 2, 4 or 5 fins. In the case of 1-fin surfboard, the fin is usually fixed on the underside of the board towards its tail along the centerline. A 3-fin surfboard usually includes a fin attached to the underside of the rear of the board on its centerline, and 2 other side fins placed symmetrically towards the outside edges of the board, which are canted outward. 
         [0007]    Different fin arrangements change the performance of the surfboard. Typically, a 1-fin arrangement improves the speed of a surfboard. A 2-fin arrangement improves the maneuverability of a surfboard. A 3-fin arrangement is the most common and gives the board a mix of characteristics from a 1-fin and 2-fin arrangement. However, the 3-fin arrangement increases drag and can make a surfboard slower in the water. A 4-fin arrangement has two outer fins on the left and right side of a surfboard but no center fin. A 4-fin arrangement has similar properties to that of a 2-fin arrangement but it lacks control when compared to a 1-fin or 3-fin arrangement. A 5-fin arrangement has a similar arrangement to that of a 4-fin arrangement and also includes a center fin (typically smaller). A 5-fin arrangement has similar properties to that of 3-fin arrangement in terms of controllability but is typically faster like a 4-fin arrangement. 
         [0008]    In some cases, surfboard fins are fixed to a surfboard permanently using various materials that typically include resins and fiberglass. In other cases, surfboard fins are temporarily fixed to surfboards by means of removable fin systems. As mentioned previously, the ability to change fins with a removable fin system has numerous advantages when compared to a surfboard with a permanently fixed fin or fins to the underside of the surfboard. When traveling with one or more surfboards, the ability to remove fins from a surfboard enables the surfer to reduce the space needed to pack the surfboard, saving the area that would otherwise be needed for the clearance of the fin or fins. Also, when traveling with one or more surfboards, it is common for the surfboard to be handled by airline, train, or bus staff. In many cases, surfboards get damaged during the handling process. A common area of damage to a surfboard during this process is the breakage of fixed fins on the surfboard. By removing the one or more removable fins, a surfer greatly reduces the risk of damage to the surfboard, prolonging the life and usefulness of the surfboard. 
         [0009]    Another advantage to surfboard owners is having the ability to change out the removable fins on a surfboard with a removable fin system to improve surfboard performance. It is common practice for surfers to change their removable fins depending on the wave conditions, surfboard shape, and desire for experimentation, all of which can lead to performance improvements. Having a surfboard with a removable fin system allows a surfer to use fins with different base lengths, foils, rake, heights, materials, and other design elements. These are some of the many advantages that explain why a majority of surfboards today are manufactured with removable fin systems compared to a surfboards manufactured with a fixed fin or fins. 
         [0010]    Several removable fin systems currently exist, which removably secure removable fins to fin boxes or fin plugs embedded in the underside of a surfboard. Examples of existing removable fin systems include U.S. Pat. No. 5,830,025, U.S. Pat. No. 5,464,359, and U.S. Pat. No. 5,975,974. The receiving component of the removable fin systems, commonly known as fin boxes or fin plugs, are usually embedded into the underside of a surfboard during the surfboard manufacturing process. Generally a fin box or fin plugs consist of one or two slots which allow the receiving and securing of single-tabbed and two-tabbed removable fins respectively. There are many fin systems available that use various methods to retain a removable fin in the fin box or fin plug. Some fin systems allow fins to snap into the fin boxes or fin plugs while others require tools for installation and removal of a fin from its fin box or plugs. Many of these fin systems are designed to only accept removable fins of their corresponding unique design. More specifically, the unique fin attachment methods of the most systems do not allow removable fins from other incompatible systems to be securely fastened. This is a disadvantage for surfboard owners with these types of removable fin systems because as many surfboard owners desire to experiment with varying fin designs, shapes, and materials from systems other than the system embedded in their surfboard they are typically restricted to solely using fins originally designed to be accepted by the type of system in their boards. It is possible to remove the existing fin boxes or fin plugs from a surfboard by routing-out the existing fin boxes or fin plugs and embedding new fin boxes or plugs into the surfboard using resins and fiberglass. However, surfers rarely use this practice because it negatively impacts the overall structural integrity of the surfboard, which can decrease performance and increase the risk of surfboard or fin system failure and or breakage. The practice of replacing the original fin system on a surfboard can also add weight to the surfboard because of the added materials needed to embed the new fin system into the routed cavities. Not only are surfers sensitive to any increases in weight of their surfboards but also to the distribution of weight or “balance” of a surfboard. This fin re-routing and re-embedding method both adds weight and changes the optimal weight distribution or “balance” of a surfboard. The fin, fin system and fin accessory market is estimated to be at least $100 million annually and growing. This trend suggests that a mature market exists for related surf accessory products. 
         [0011]    Prior art for fin adapters currently exist for limited number of removable fin systems. Examples of prior art include the 2005 U.S. patent application Ser. No. 20,070,202,760, U.S. Pat. No. 7,497,752, and U.S. Pat. No. 7,285,031. In the mentioned prior art, the removable fin is attached to the adapter by angled set-screws which are threaded into the side of the removable fin system embedded in the water craft. This is a limiting factor and disadvantage because this prior art cannot be used with removable fin systems that use one angled set-screw positioned on the front part the removable fin system embedded on the under side of the surfboard. 
         [0012]    At the time of this writing, research suggests that, over 90% of surfboards are manufactured with one of two removable fin systems shown in U.S. Pat. No. 5,830,025 and U.S. Pat. No. 5,464,359. U.S. Pat. No. 5,830,025 uses one set-screw positioned at the front part of the removable fin system embedded on the underside of the surfboard to secure a single-tabbed fin to said removable fin system. U.S. Pat. No. 5,464,359 uses two fin plugs that each contain one set-screw positioned on the side of the respective fin plug used to secure a two-tabbed removable fin to the underside of the surfboard. As mentioned earlier, sales for compatible removable fins and accessories are estimated to be S100 million industry and growing, reaffirming the demand for removable fins of these two removable fin systems. It is common for a surfboard owner to own multiple surfboards, which each contain one of these two removable fin systems. It is a disadvantage for the surfboard owner in situations like this because the surfboard owner must purchase multiple sets of fins for each respective removable fin system and bring multiple sets of fins for each removable fin system when traveling. 
         [0013]    The present invention distinguishes over this art with an inventive attachment method that allows for a removable two-tabbed fin to be adapted using the present invention for compatibility with a removable fin system that uses one set-screw located on the front portion of the receiving fin box as in U.S. Pat. No. 5,830,025, which would otherwise not be possible. 
         [0014]    The advantages of the present invention include, without limitation, the ability to securely fasten a two-tabbed removable fin to a single-tab fin box, which would otherwise not be possible. 
         [0015]    In broad embodiment, the present invention is a removable surfboard fin adapter that enables removable fins, fin boxes and fin systems from different manufacturers to be compatible. Again, the surfing accessory market is major source of revenue for the growing $1 billion surf industry. 
         [0016]    Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed in the United States of America or elsewhere before the priority date of each claim of this application. 
       SUMMARY OF THE INVENTION 
       [0017]    The present invention is a device used to enable a two-tabbed type removable surfboard fin to be received and secured in the recess of a single-tab type surfboard fin receiving box that, without said device, would not be able to receive and secure a two-tabbed type removable surfboard fin. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1  is a perspective view of a the underside of a typical surfboard with a three fin arrangement and the embedded surfboard fin receiving boxes or plugs; 
           [0019]      FIG. 2  shows an axonometric view of a typical removable two-tabbed fin system consisting of a removable two-tabbed fin and its corresponding receiving plugs which are embedded in the underside of a surfboard; 
           [0020]      FIG. 3  shows an axonometric view of a typical removable single-tab fin system consisting of a removable single-tab fin and its corresponding receiving fin box which is embedded in the underside of a surfboard; 
           [0021]      FIG. 4  is a perspective view of the present invention illustrating the method for using the present invention for inserting and securing a two-tabbed surfboard fin into a single-tab fin box; 
           [0022]      FIG. 5  is a front elevation view of several preferred embodiments of the present invention, the left, center and right embodiments; 
           [0023]      FIG. 6  is an axonometric view of several preferred embodiments of the present invention, the left, center and right embodiments, shown as the top, center, and bottom image respectively; 
           [0024]      FIG. 7  is a front elevation view of an alternative embodiment for the left and right surf fin adapter. The right embodiment is simply a mirrored embodiment of the left embodiment. For this reason,  FIG. 7  only includes the left view of the alternative embodiment. 
           [0025]      FIG. 8  is an axonometric view of an alternative embodiment for the left and right surf fin adapter. The right embodiment is simply a mirrored embodiment of the left embodiment. For this reason, the  FIG. 8  only includes the left view of the alternative embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0026]    
       FIG. 1 
     
         [0027]      FIG. 1  shows the underside  1  of a surfboard  2  with a typical three-fin arrangement at the rear of the surfboard. Also shown are the fin retaining structures  3 ,  4 , and  5  which are embedded into the underside of the surfboard  1  and receive the removable surfboard fins  6 ,  7  and  8  and secure them to the surfboard  2 . More specifically, fin box  4  secures the center fin  7 , while fin boxes  3  and  5  secure the right outside fin  6  and left outside fin  8  respectively (the ‘left side of surfboard’ referring to the ‘left’ side when looking at the underside of the surfboard from the rear, where the fins are located, towards the front). 
         [0028]    
       FIG. 2 
     
         [0029]    Shown in  FIG. 2  is an existing two-tabbed removable surfboard fin system comprised of a two-tabbed removable surfboard fin  9  and its respective two tabs  10  as well as the two-tabbed fin receiving plugs  11  which are embedded into the underside of a surfboard  1 . Furthermore, also shown are the threaded holes  12  which receive set-screws that secure the two-tabbed fin  9  by engaging its two tabs  10  once inserted into the two-tabbed fin receiving plugs  11 . Typically an Allen Wrench is used to thread the set-screws into the threaded holes  12  of the fin plugs  11 . Note that the two-tabbed removable surfboard fin  9  may have tabs of different geometry than what is shown. 
         [0030]    
       FIG. 3 
     
         [0031]    Shown in  FIG. 3  is an existing single-tab removable surfboard fin system comprised of a single-tab removable surfboard fin  13  and its respective single-tab  14  as well as the single-tab fin receiving box  15  which is embedded into the underside of a surfboard  1 . Furthermore, also shown is the single-tab fin receiving box  15  and its retention member  16 , which engages the rear notch  17  of the single-tab surfboard fin tab  14 . Also shown, is the threaded hole  18 , which receives a set-screw that secures the single-tab removable surfboard fin  13  to the single-tab fin receiving box  15  by engaging the front notch  19  of single-tab surfboard fin tab  14 . Typically an Allen Wrench is used to thread the set-screw into the threaded hole  18  of the fin box  15 . 
         [0032]    
       FIG. 4 
     
         [0033]    Shown in  FIG. 4 , in perspective view, is a preferred embodiment of the invention, generally referenced as  20 , and how it allows a left side two-tabbed fin  9  to be received and secured by a left side single-tabbed fin box  15  in the left side of a surfboard. More specifically, the two tabs  10  of the left side two-tabbed fin  9  are received by the angled vertical slots  11 , separated by a spacer  29  that is slightly smaller than a space between two tabs  10  of a two-tabbed fin  9 , and secured to the present invention  20  by the set-screws  12 , which engage the lateral holes  13  at the front and rear ends of the present invention  20 . Once the two-tab fin  9  is inserted into and secured by the present invention  20 , that assembly is inserted into and secured to the underside of surfboard  1  by the embedded single-tab type surfboard fin box  15 . More specifically, the coupled two-tab fin  9  and the present invention  20  assembly is secured to the single-tab surfboard fin box  15  by means of the rear notch  17  of the present invention  20  engaging the retention member  16  of the single-tab type surfboard fin box  15  and the front notch  19  of the present invention  20 , being engaged by a set-screw received by the threaded hole  18  of the single-tab type surfboard fin box  15 . Also shown is the pullout hole  21  used to retrieve the present invention  20  from the single-tab surfboard fin box  15  in case the single-tab fin  9  becomes decoupled from the present invention  20  for any reason. Typically an Allen Wrench is used to thread the set-screws  12  into the threaded holes  13  of the present invention  20 . 
         [0034]    In further detail, still referring to the present invention  20  in  FIG. 4 , one embodiment of the invention has the angled vertical slots  11  sufficiently wide and deep to enable a close-fitting for each fin tab  10 , approximately 0.8 inches in length by 0.25 inches in width by 0.55 inches in depth. Set-screws  12  are sufficient in length such that when set-screws  12  are screwed into the present invention  20 , the set-screws  12  do not protrude beyond the exterior surface walls of the present invention. The pull-out hole  21  is a cylindrical hole approximately 0.16 inches in diameter and 0.375 inches in depth to enable a secondary release function in the event an existing two-tab fin  9  is inadvertently ejected allowing for easy removal from the present invention  20  from the existing single-tabbed fin box  15 . 
         [0035]    In further detail still referring to  FIG. 4 , when an existing two-tab fin  9  has tabs  10  of different geometry than what is shown in  FIG. 4 , the present invention would correspondingly have geometry that would allow a close-fit tongue and groove connection between the two fin tabs and the vertical slot or slots of the present invention, those vertical slots being either angled or straight. 
         [0036]    
       FIG. 5 
     
         [0037]      FIG. 5  shows several preferred embodiments of the present invention, right, center and left  24 ,  25  and  28  respectively, in front elevation view. In a typical three-fin arrangement the center fin is upright or perpendicular to the underside of the surfboard while the side fins are slightly canted outward towards the surfboards side rails since increasing the fins&#39; cant leads to a more responsive board through turns, while decreasing the cant (bringing it closer to a 90° angle relative to the bottom of the board) makes the board faster, especially when traveling in a straight line. Therefore, also shown is the angled nature of the vertical slots of the right and left embodiments of the present invention  24  and  28 , relative to the present invention&#39;s vertical sidewalls as well as the non-angled nature of the vertical slots of the center embodiment of the present invention  25 . In further detail shown using dimension lines and arrows are the angles  22  and  23  of the angled vertical slots of the right and left embodiments of the present invention  24  and  28  respectively. 
         [0038]    
       FIG. 6 
     
         [0039]      FIG. 6  shows the preferred embodiment of the present invention in its right, center and left-side embodiments 24, 25 and 28 respectively in axonometric view. The embodiment&#39;s left and right side versions of the present invention  24  and  28  incorporate angled vertical slots  26  and  11 , relative to the present invention&#39;s vertical side walls, to retain the side fins at corresponding canted angles, approximately between 0 to 8 degrees relative to the vertical side walls of the present invention. The embodiments left and right side versions of the present invention  24  and  28  respectively, include one or more side wall cut-outs  30  of a rectangular shape to maximize canted angles of the fins received and secured. The center embodiment of the present invention  25  has non-canted vertical slots  27 , relative to its vertical side walls. The center embodiment of the present invention  25  is shallower in height than the right and left embodiments of the present invention  24  and  28  to account for a shallower recess in its corresponding center single-tab surfboard fin box. The center single-tab surfboard fin box is shallower than the side fin boxes due to the center fin box being place further towards the rear of the surfboard where the thickness of the board is reduced. 
         [0040]    In further detail, still referring to  FIG. 6 , one embodiment of the present invention calls for the version to fit within a standard single-tabbed fin box. A preferred embodiment of the left and right versions of the present invention  24  and  28 , are sufficiently long, wide and deep to enable a close fit into their corresponding existing right and left single-tab fin boxes, approximately 4½ inches in length by ⅓ inches in width by ⅔ inches in depth, and particularly preferred embodiment calls for approximately 4.460 inches in length by 0.28 inches in width by 0.67 inches in depth. 
         [0041]    Similarly, one embodiment of the present invention  25  calls for the version to fit within standard single-tabbed fin box. A preferred embodiment of the present invention  25  is sufficiently long, wide and deep to enable a close fit into its corresponding existing center single-tab fin box, approximately 4½ inches in length by ⅓ inches in width by ½ inches in depth, particularly the preferred embodiment calls for approximately 4.445 inches in length by 0.28 inches in width by 0.5 inches in depth. The preferred embodiment of the present invention has a tight fit between the fin tabs and fin boxes but an alternate embodiment could have a looser fit allowing the fin&#39;s canted angle to fluctuate. 
         [0042]    The construction details of the invention as shown in  FIG. 6  are that the preferred right, center and left embodiments of the present invention  24 ,  25  and  28  could be made of sufficiently strong plastics and/or metals while alternate embodiments could be made out of plastics, metals, resins, resin/fiberglass, wood, carbon fiber, graphite, composites or any other known means commonly in use in the surfboard manufacturing industry. 
         [0043]    
       FIG. 7 
     
         [0044]      FIG. 7  shows another embodiment of the invention  31  in front elevation view. In more detail, the other embodiment of the invention  31  shown is the left embodiment, where the right embodiment is a mirrored embodiment of the left embodiment and is not shown in  FIG. 7 . This embodiment of the invention includes an alternative way to achieve canted angles using a folded tab and stepped vertical slot  32 . Other aspects of this other embodiment 31 are similarly described in  FIG. 5 . 
         [0045]    
       FIG. 8 
     
         [0046]      FIG. 8  shows another embodiment of the invention  31  in axonometric view. In more detail, the other embodiment of the invention  31  shown is the left embodiment, where the right embodiment is a mirrored embodiment of the left embodiment and is not shown in  FIG. 8 . This embodiment of the invention includes an alternative way to achieve canted angles using a folded tab and stepped vertical slot  32 . Other aspects of this other embodiment 31 are similarly described in  FIG. 6 . 
         [0047]    The advantages of the present invention include, without limitation, the ability to securely fasten a two-tabbed removable fin to a single-tab fin box, which would otherwise not be possible. 
         [0048]    In broad embodiment, the present invention is a removable surfboard fin adapter that allows removable fins and fin boxes from different manufacturers to be compatible. 
         [0049]    While the foregoing written description of the invention enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific embodiment, method, and examples herein. The invention should therefore not be limited by the above described embodiment, method, and examples, but by all embodiments and methods within the scope and spirit of the invention. 
       REFERENCE NUMBERS 
       [0000]    
       
         
           
               1 . Underside of surfboard 
               2 . Surfboard 
               3 . Right fin box 
               4 . Center fin box 
               5 . Left fin box 
               6 . Right fin 
               7 . Center fin 
               8 . Left fin 
               9 . Two-tabbed fin 
               10 . Tabs 
               11 . Angled vertical slot 
               12 . Set screws 
               13 . Threaded lateral holes 
               14 . Single-tab surfboard fin tab 
               15 . Single-tabbed fin box 
               16 . Retention member of single-tabbed fin box 
               17 . Rear notch for retention by single-tabbed fin box 
               18 . Threaded hole for of single-tabbed fin box 
               19 . Front notch for retention by single-tabbed fin box 
               20 . Invention, generally referenced, base unit 
               21 . Pullout hole 
               22 . Right fin angle of angled vertical slot 
               23 . Left fin angle of angled vertical slot 
               24 . Right fin adapter 
               25 . Center fin adapter 
               26 . Right fin angled slot 
               27 . Center fin vertical slot (not angled) 
               28 . Left fin adapter 
               29 . Spacer 
               30 . Adapter side wall cut-outs 
               31 . Other embodiment of invention 
               32 . Folded tab with stepped vertical slot