Abstract:
A retractable fin watercraft accessory that provides steering and tracking for a watercraft such as stand-up paddle boards. The retractable fin system gently retracts as it comes in contact with subsurface objects such as rocks, logs and such, allowing the watercraft to freely pass over the object. The system includes a sloped leading edge which can more easily slide past an obstacle. The retractable fin system simply attaches to the watercraft&#39;s existing fin mounting box and can be removed from the watercraft without altering the original state of the watercraft prior to being attached. No drilling, welding, gluing or other such custom fabrication is required. The system allows for quick interchangeability between the retractable fin and various rigid style fins, depending on the user&#39;s preferences.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    Provisional application No. 62/389,826 filed on Mar. 11, 2016 
     
    
     STATEMENT OF FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not Applicable 
       THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT IF THE CLAIMED INVENTION WAS MADE AS A RESULT OF ACTIVITIES WITHIN THE SCOPE OF A JOINT RESEARCH AGREEMENT 
       [0003]    Not Applicable 
       REFERENCE TO A “SEQUENCE LISTING,” A TABLE, OR A COMPUTER PROGRAM LISTING APPENDIX SUBMITTED ON A COMPACT DISC AND AN INCORPORATION BY REFERENCE OF THE MATERIAL ON THE COMPACT DISC 
       [0004]    Not Applicable 
       COPYRIGHT NOTICE 
       [0005]    A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. 
       TECHNICAL FIELD 
       [0006]    The present invention relates to the field of paddleboards or watercraft suitable for use in water sports or other activities, particularly to a retractable fin for tracking or steering. 
       BACKGROUND 
       [0007]    Watercraft such as stand-up paddle boards, surfboards, kayaks, kite boards, wake boards, and other such watercraft are used in water sports and allow a user to navigate a body of water. A single or multiple fin/skeg (hereinafter “fin”) is traditionally used on watercraft to improve directional stability, tracking and steering. They are typically mounted near the aft of a watercraft. Most of these types of watercraft incorporate a fin mounting box which is permanently mounted and embedded into cavities drilled or routed into the underside of the watercraft body. Or in some cases, such as with inflatable watercraft, the fin mounting box is adhered to the underside exterior of the watercraft body. The fin mounting box is designed in such a way that fins can be quickly and conveniently disconnected from a fin mounting box typically with a screw(s) or sometimes with a quick connect latch or other such mechanism, and replaced by different fins or moved forward or aft within the fin mounting box for different stability and maneuverability characteristics. 
         [0008]    The drawback with these prior art fin mounting box systems is that the fins are mounted to the fin mounting box in a rigid fashion and cannot retract when coming into contact with subsurface objects. This can be problematic when traveling in shallow waters. When the rigid mount fin comes in contact with and subsurface object, the watercraft can abruptly jerk or stop suddenly. This can result in an uncomfortable experience for the watercraft occupant. In the case of a standing occupant, this could involve falling to ones knees or possibly falling from the watercraft. 
         [0009]    Additionally, it is possible that after striking an object, the fin and/or fin mounting box can become damaged. Damage to the marine ecosystems could also occur if the fin was to strike an object such as a coral reef or marine life. The rigid mount fin also has a tendency to catch kelp and other marine debris on its forward edge thereby slowing the watercraft. 
         [0010]    Accordingly, there exists a need for a retractable fin system. The prior art has recognized a need for a retractable fin system, as evidenced by several patents disclosing different types of retractable fin systems. Retractable fin system prior art is typically permanently affixed to the watercraft and manufactured integral to the body of the watercraft at the time of initial watercraft assembly. This is because retractable fin system prior art can only operate with a unique fin box mechanism that is custom designed to operate with one specific retractable fin. Other retractable fin system prior art requires expert/professional installation such as drilling, epoxy or gluing. None of the retractable fin prior art can be affixed to the rigid fin mounting box prior art. Additionally, the retractable fin system prior art does not provide the interchangeability benefits that the rigid fin mounting box prior art systems provide such as the ability to be conveniently disconnected from a fin mounting box and replaced by different fins or moved about the fin mounting box for different stability and maneuverability characteristics. 
         [0011]    In order to enjoy the benefits of the retractable fin prior art, the watercraft user is either required to purchase an entire watercraft with this feature already fabricated into the hull or they are required to hire an expert/professional to permanently fasten the retractable fin system to a watercraft in some way. Both of these options can be costly and do not provide the versatility of a quick connect, interchangeable and adjustable fin mounting box that the rigid fin prior art provides and is common place in the industry. In both options, the watercraft is permanently modified in order to retain the retractable fin feature. 
       SUMMARY 
       [0012]    The present invention is a retractable fin watercraft accessory that is generally comprised of a fin and bracket apparatus and sometimes, but not always, is further comprised of a retraction mechanism. The fin provides steering/tracking for a watercraft using a retractable/rotatable vertical blade. The bracket apparatus provides a connection between the fin and the watercraft&#39;s existing fin mounting box. Additionally, the bracket apparatus provides a pivot point for the fin. The retraction mechanism generally consists of a spring or another elastic device which is connected to the fin and to the bracket apparatus. 
         [0013]    The present invention addresses the shortcoming in the existing rigid fin mount prior art by allowing the fin to gently retract as it comes in contact with subsurface objects such as rocks, logs, coral reef and such allowing the watercraft to freely pass over the object. By doing so, the occupant experiences little to no unsettledness, allowing them to proceed in comfort and confidence. Potential damage to the present invention, fin mounting box and marine ecosystem is also minimized. Trapping of kelp and other marine debris is also minimized. Storage or transport of watercraft is also simplified as multiple watercraft can be stacked adjacent each other without the need to remove the fin. 
         [0014]    Additionally, the present invention addresses the shortcomings of retractable fin prior art by the ease in which it can be attached and detached from watercraft. The present invention attaches directly to the watercraft&#39;s existing fin mounting box and can be removed from the watercraft without altering the original state of the watercraft prior to being attached. The present invention acts as an accessory to existing watercraft which may have been originally designed to accommodate only rigid mount fins. No drilling, welding, gluing or other such custom fabrication is required. It is intended to be an attachment to a watercraft and not an integral member, allowing the benefits of the present invention without the need to alter or customize the watercraft. The system allows for quick interchangeability between the retractable fin and various rigid style fins, depending on the user&#39;s preferences. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    The accompanying drawings illustrate prior art related to the present invention and various example embodiments of the present invention itself which serve to provide context and further clarify the advantages, principles and features of the present invention: 
           [0016]      FIG. 1  is a top and side view of an example watercraft that includes an example fin mounting box installed in the watercraft body and an example rigid fin. 
           [0017]      FIG. 2  is an isometric, side, top and front close up view of the example fin mounting box shown in  FIG. 1 . 
           [0018]      FIG. 3  is a side and front view of the present invention mounted to the example fin mounting box shown in  FIG. 2 . In this embodiment, the retraction mechanism is shown aft of the pivot point. The fin is shown in both its upright and retracted positions. 
           [0019]      FIG. 4  is a side, top, isometric and front close up view of the present invention shown in  FIG. 3 . For clarity, the fin is not shown in the top, isometric and front views. 
           [0020]      FIG. 5  is a side view of the present invention mounted to the example fin mounting box shown in  FIG. 2 . In this embodiment, the retraction mechanism is shown forward the pivot point. The fin is shown in both its upright and retracted positions. Only a portion of the fin is shown. 
           [0021]      FIG. 6  is a side, top, isometric and front close up view of the present invention shown in  FIG. 5 . For clarity, the fin is not shown in the top, isometric and front views. 
           [0022]      FIG. 7  is a side view of the present invention mounted to the example fin mounting box shown in  FIG. 2 . The example fin mounting box is shown attached external to the watercraft&#39;s body, as is typically the case for inflatable stand-up paddle boards. In this embodiment, the retraction mechanism is shown forward the pivot point. The fin is shown in both its upright and retracted positions. Only a portion of the fin is shown. 
       
    
    
     DETAILED DESCRIPTION 
       [0023]    The components included in  FIG. 1  and  FIG. 2  are prior art and not part of this present invention but are included to provide context and background. Top and side views of an example watercraft, or more specifically a stand-up paddle board, are illustrated in  FIG. 1 .  FIG. 1  includes a watercraft body  10 , fin mounting box  15  installed in the watercraft body  10  and a rigid fin  20 . More detail of the fin mounting box  15  is shown in isometric, side, top and front views in  FIG. 2 . The fin mounting box  15  is permanently mounted and embedded into cavities drilled or routed into the underside of the watercraft body  10 . In some cases, such as with inflatable watercraft, the fin mounting box  15  is adhered to underside exterior of the watercraft body  10 . 
         [0024]    The first illustrated embodiment of the present invention is shown in  FIG. 3  and  FIG. 4  and is generally comprised of a fin  25 , retraction mechanism  35 , bracket apparatus  30  and associated hardware. The fin  25  provides steering/tracking for a watercraft using a retractable/rotatable vertical blade. The fin  25  can be rigid or flexible in nature consisting of a variety of materials including but not limited to, plastic, fiber reinforcement, carbon fiber, aluminum, steel, wood or a combination thereof. The shape and depth of the fin  25  can vary depending on the user&#39;s preferences. The fin  25  includes a pivot hole  60  located at its base which is the point at which the fin pivots. The fin  25  pivots about and is connected to the bracket apparatus  30  via pivot mounting hardware  65 . Pivot mounting hardware  65  consists of a binder bolt and washers or other such hardware. The fin  25  is illustrated in both the upright position  26  and the retracted position  27 . The fin  25  is configured with a unique protrusion on the trailing edge, or fin stop  80 , to keep the fin from touching and potentially damaging the watercraft when the fin is in the retracted position  27 . 
         [0025]    The retraction mechanism  35  generally consists of a stainless-steel tension spring or other elastic device which is connected to the fin  25  and to the bracket apparatus  30 . The fin  25  connection is via a screw eye hook  48  which is mounted to the fin  25 . The retraction mechanism  35  connection to the bracket apparatus  30  is described in detail in the following bracket apparatus  30  paragraphs. 
         [0026]    The bracket apparatus  30  provides a connection between the fin  25  and the watercraft&#39;s fin mounting box  15 . Additionally, the bracket apparatus  30  includes a pivot hole  60  to provide a pivot point for the fin  25 . 
         [0027]    Additionally, the bracket apparatus  30  includes two retraction mechanism mounting holes  40 , one of which retain the retraction mechanism mounting hardware  45 . The retraction mechanism mounting hardware  45  consists of a screw  46  with two nuts  47  which are used to retain one end of the retraction mechanism  35 . The second retraction mechanism mounting hole  40  allows for alternative mounting of the screw  46  and two nuts  47 , providing for alternative retraction mechanism  35  tension. 
         [0028]    Additionally, the bracket apparatus  30  includes a bracket apparatus fin slot  70 . The purpose of the bracket apparatus fin slot  70  is to allow the retraction mechanism  35  to remain in the fin mounting box slot  16  and at the same time allow the fin  25  to rotate between the upright position  26  and the retracted position  27 . Allowing the retraction mechanism  35  to remain in the fin mounting box slot  16  minimizes the potential for retraction mechanism  35  damage due to foreign object impact and also minimizes the risk of bodily injury. 
         [0029]    Additionally, the bracket apparatus  30  includes two bracket apparatus fin notches  75 . In addition to the pivot mounting hardware  65 , the purpose of the two bracket apparatus fin notches  75  is to fit securely around the fin  25  to provide stability to the fin  25  when it is in the upright position  26 . The stability minimizes fin  25  vibration and wobble which are undesirable fin attributes. 
         [0030]    Furthermore, the bracket apparatus  30  includes two bracket apparatus mounting holes  50  to retain the bracket apparatus mounting hardware  55 . The bracket apparatus mounting hardware  55  consists of two screws  56  and two square nuts  57 , one set for each bracket apparatus mounting hole  50 . The square nuts  57  are inserted into the fin mounting box  15 , within the square nut slot  17 . 
         [0031]    Furthermore, the forward portion of the leading edge  90  of the bracket apparatus  30  is sloped in such a way as to deflect objects. This shape allows the watercraft to “slide over” objects with less resistance following an impact. The bracket apparatus  30  is generally channel shaped in the cross-section view. The shape and depth of the bracket apparatus  30  can vary depending on the user&#39;s preferences. 
         [0032]    Furthermore, the bracket apparatus  30  is generally rigid in nature consisting of a variety of materials including but not limited to, plastic, fiber reinforcement, carbon fiber, aluminum, steel, wood or a combination thereof. 
         [0033]    Having described the structure and components of the first illustrated embodiment, operation will now be explained. The present invention is mounted to the watercraft body  10  via the fin mounting box  15 . This is done by placing two square nuts  57  into either end of the square nut slot  17 . The present invention is then placed on the fin mounting box  15  with the base of the bracket apparatus resting on the fin mounting box  15 . The bracket apparatus mounting holes  50  are then lined up with the square nuts  57 . Two screws  56  are inserted through the bracket apparatus mounting holes  50 , the two square nuts  57  and then the two screws  56  are tightened. At this point the present invention is fully mounted to the fin mounting box  15  and ready for use. 
         [0034]    While under use, if the fin  25  comes into contact with an object, the fin rotates, causing further tension in the retraction mechanism  35 . The fin  25  will either partially rotate or fully rotate into the retracted position  27  and then stop rotation. After the fin  25  is no longer in contact with the object, the retraction mechanism  35  will compress, causing the fin  25  to rotate back to its full upright position  26  and then stop rotation as it comes in contact with the bracket apparatus fin notch  75 . 
         [0035]    The second illustrated embodiment of the present invention is shown in  FIG. 5  and  FIG. 6 . In this embodiment, the retraction mechanism  35  is shown forward the pivot hole  60 . The bracket apparatus  30  also includes a protrusion  85  which inserts into the fin mounting box slot  16  providing for a sturdy connection between the present invention and the fin mounting box  15 . 
         [0036]    Furthermore, the forward portion of the leading edge  90  of the bracket apparatus  30  includes a shallower slope than that of the first illustrated embodiment providing less resistance and improved deflection capabilities. The fin  25  shape can complement the leading edge  90  of the bracket apparatus  30  in such a way that it forms a continuous slope when in the retracted position  27  as viewed from the side. With no abrupt angle along the leading edge  90 , both the bracket apparatus  30  and the fin  25  smoothly slide past subsurface objects. 
         [0037]    The third illustrated embodiment of the present invention is shown in  FIG. 7 . The example fin mounting box  15  is shown attached external to the watercraft body  10 , as is typically the case for inflatable watercraft such as stand-up paddle boards. This embodiment is similar to the second embodiment illustrated in  FIG. 5 . and  FIG. 6 , with the difference being the leading edge  90  shape of the bracket apparatus  30  which extends forward of the fin mounting box  15 . This forward wedge design minimizes the potential for jolting the watercraft when the forward edge of the fin mounting box  15  comes in contact with a subsurface object, allowing the watercraft to slide past the object. 
         [0038]    In another embodiment, the present invention could be altered in such a way as to mate the present invention with fin mounting boxes shaped differently from that illustrated in  FIG. 2 . The shape of the fin mounting box  15  shown in  FIG. 2  is for illustrative purposes only and should not be construed as a limitation of the present invention. 
         [0039]    In another embodiment, the fin  25  could be altered in such a way as to accommodated a propulsion device. 
         [0040]    In still yet another embodiment, the number and arrangement of retraction mechanisms  35  could vary. Various types of retraction mechanisms  35  can be employed such as elastic materials, weights, magnets or gravity alone. Various types of springs placed in various different locations and configurations around the pivot hole  60  and could include compression, tension and torsion which could operate in either tension, compression or torsion. 
         [0041]    At least one embodiment of the present invention produces a simple and effective device for a retractable watercraft fin. While a number of embodiments and variations of the present invention have been described in detail herein, these should not be construed as limitations on the scope, but rather as an exemplification of one or more embodiments thereof. 
         [0042]    Many other variations of size, material, shape, and configurations are possible. For example, the bracket apparatus  30  can take a variety of shapes and sizes and can be adapted to mount to various different types of fin mounting boxes  15  and assemblies. The size of many components can vary. A variety of suitable structural materials could be employed, including steel, aluminum, plastic, wood, composites, and carbon fiber. A variety of fin types, styles, shapes and numbers could be utilized. The present invention could be attached to various types and configurations of watercraft, including stand-up paddle boards, surfboards, kayaks, kite boards, wake boards, rowing shells, crew boats, and various other types of boats, pontoons or floats. 
         [0043]    Accordingly, the scope should be determined not by the embodiments identified herein, but by the appended claims and their legal equivalents.