Abstract:
A modular bunk cover apparatus and system for protecting the hull of a watercraft from abrasive contact with a bunk, such as the bunks found on boat trailers, boat lifts, boat storage racks, and the like. The modular bunk cover apparatus and system can be installed on an existing bunk without removing the bunk from the trailer or other structure. The modular bunk cover apparatus and system facilitates easy launching and loading of a boat on a trailer or boat lift. The system is a replacement for carpet systems that tend to degrade over time, eventually falling off the bunk and subsequently creating a hazard for marine life, birds, and mammals.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS 
   This application is a continuation in part of applicant&#39;s patent application Ser. No. 11/171,662 filed on Jun. 30, 2005 now abandoned. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates generally to watercraft supporting structures, and more particularly to a modular apparatus and system for covering a watercraft supporting structure. 
   2. Description of Related Art 
   Many forms of watercraft trailers, lifts, and hoists require the use of rollers, bunks, skids, glides, or similar devices to both ease the movement of a watercraft on the trailer, lift, or hoist, and to support the watercraft on the trailer, lift, or hoist. Carpet covered bunks are commonly used on watercraft trailers, lifts and hoists for such purposes. Bunks are typically elongated planks of wood or metal that traverse the bottom of a watercraft to support the watercraft on a trailer, lift or hoist. The purpose of the carpet covering on the bunk is primarily to protect the bottom of the watercraft from potential damage that could be inflicted by contact of the bunk with the bottom of the watercraft. The carpet also serves to increase surface friction between the watercraft hull and the bunk. 
   The use of carpet on a bunk presents several problems to the watercraft owner. U.S. Pat. No. 6,189,909 to Danchuk, entitled “Friction-Reducing Support Member Protection Device” (page 1, lines 51-54) states that “the skid-covering carpet tends to deteriorate quickly with continued use. And although skids with deteriorated coverings may still support a watercraft, worn spots increase sliding friction and can permanently damage watercraft hulls.” 
   U.S. Pat. No. 6,651,997 to Higginson, entitled “Trailer Bunk Cover Assembly” (page 1, lines 46-61) explains that “bunk-covering carpet tends to deteriorate quickly with continued use. The carpet material when exposed to moisture, and in this case when submerged in water, traps the moisture thereby exposing the wood bunks to an extended period of moisture exposure. Further, the carpet material will deteriorate through environmental conditions such as mildew brought about by moisture. And although bunks with deteriorated coverings may still support the boat, worn spots increase sliding friction and can permanently damage boat hulls. As a result, the carpet material is replaced frequently, and the wood bunks are replaced more often.” 
   Carpet material that deteriorates and subsequently falls from a boat trailer or boat lift bunk is often times left in the water through either lack of notice or lack of care by the owner of the boat and trailer. The carpet material often times remains in the body of water, and becomes unraveled and further deteriorated over time. This creates not only a degradation to the water environment, but poses a threat to marine life and birds, who may become entangled in a partially decomposed and unraveled mass of carpet material. 
   U.S. Pat. No. 6,651,997 to Higginson, entitled “Trailer Bunk Cover Assembly” discloses a soft vinyl cover assembly with recessed portions that is mounted to the top surface of a trailer bunk. Soft Vinyl covers are sold by Harley Corporation, Evansville, Ind. under the tradename BUNKAPS®, and are marketed through the internet at www.bunkaps.com. 
   In addition to carpet material, there are various pads that can be used to cover a bunk. For example, one such device is a product known as “E-Z SLIDE TRAILER PADS” by IRONWOOD PACIFIC™, Inc. of Lake Oswego, Oreg. Reference also is made to U.S. Pat. No. 5,993,063 to Stewart entitled “Skid Plate for Installation on a Boat Trailer Bunk”. The skid plates disclosed in the &#39;063 patent comprise an elongate main body that is attached to a bunk. 
   U.S. Pat. No. 6,830,410 to Davidson and Hey, entitled “Bunk Beam and Bunk Cushion Apparatus for Supporting a Watercraft” discloses an apparatus for supporting the hull of a watercraft using a flexible bunk beam and a convex cushion attached to the beam using locking elements. 
   U.S. Pat. No. 6,189,909 to Danchuk, entitled “Friction-Reducing Support Member Protection Device” discloses a watercraft trailer support skid assembly that includes a protective sleeve sized and shaped to fit the contoured free end of an existing watercraft support skid. 
   Many of the bunk covering devices of the related art are attached to a bunk or skid using metal fasteners that have a tendency to corrode or work loose, creating the potential for damage to a hull of the boat that they were designed to protect. Many of the bunk covering devices of the related art also have a tendency to retain moisture which, over the long term, causes damage to both the bunk and the boat hull. In addition, many of the bunk covering devices of the related art do not provide uniform hull weight distribution across the length of the bunk. Many of the bunk covering devices of the related art are also cumbersome to ship and to install, and must be cut to size prior to application to a bunk. Many of the bunk covering devices of the related art also do not expand and contract at the same rate as the bunk, and will distort and buckle with temperature changes. It is therefore an object of the present invention to provide a modular bunk cover apparatus and system that does not rely on metal fasteners for retention to a bunk. It is another object of the present invention to provide a modular bunk cover apparatus and system that does not retain moisture. It is yet another object of the present invention to provide a modular bunk cover apparatus and system that uniformly distributes the weight of a watercraft hull across the length of the bunk. It is still another object of the present invention to provide a modular bunk cover apparatus and system that can be easily installed in small sections. It is still a further object of the present invention to provide a modular bunk cover apparatus and system that will not distort or buckle with changes in temperature. It is a further object of the present invention to provide a modular bunk cover apparatus and system that will allow for a coefficient of friction that varies along the length of a bunk, and may be customized to fit a particular application. 
   BRIEF SUMMARY OF THE INVENTION 
   In accordance with the present invention, there is provided a modular bunk cover comprising a first half sleeve having a plurality of tongues wherein each tongue contains a slot and a plurality of receivers wherein each receiver contains a locking tab, the first half sleeve being connected to a second half sleeve having a plurality of tongues wherein each tongue contains a slot and a plurality of receivers wherein each receiver contains a locking tab; wherein the tongues of the first half sleeve are mated to the receivers of the second half sleeve and wherein the tongues of the second half sleeve are mated to the receivers of the first half sleeve and wherein the locking tabs of the first half sleeve receivers are inserted in the slots of the second half sleeve tongues and the locking tabs of the second half sleeve receivers are inserted in the slots of the first half sleeve tongues. 
   The foregoing paragraph has been provided by way of introduction, and is not intended to limit the scope of the following claims. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be described by reference to the following drawings, in which like numerals refer to like elements, and in which: 
       FIG. 1  is a perspective view of a modular bunk cover apparatus and system in use on a boat trailer; 
       FIG. 2  is an exploded view of the modular bunk cover apparatus and system on a bunk; 
       FIG. 2A  is a perspective view of a modular bunk cover apparatus showing the half sleeves interconnected; 
       FIG. 3  is a perspective view of an overmolded half sleeve of the modular bunk cover apparatus; 
       FIG. 4  is a top plan view of an overmolded half sleeve of the modular bunk cover apparatus; 
       FIG. 5  is a cutaway sectional view of an overmolded half sleeve of the modular bunk cover apparatus; 
       FIG. 6  is a top plan view of a half sleeve of the modular bunk cover apparatus; 
       FIG. 7  is a perspective view of a half sleeve of the modular bunk cover apparatus; 
       FIG. 8  is a cutaway sectional view of a half sleeve of the modular bunk cover apparatus; 
       FIG. 9  is a side view of the modular bunk cover apparatus in use showing a half sleeve coupled to an overmolded half sleeve. 
       FIG. 10  is a perspective view of an end cap of the modular bunk cover apparatus and system; 
       FIG. 11  is an inside perspective view of an end cap of the modular bunk cover apparatus and system; 
       FIG. 12  is a top view of an end cap of the modular bunk cover apparatus and system; 
       FIG. 13  is a bottom view of an end cap of the modular bunk cover apparatus and system; 
       FIG. 14  is an end view of an end cap of the modular bunk cover apparatus and system; and 
       FIG. 15  shows the modular bunk cover apparatus and system in use on a trailer carrying a tunnel hull boat. 
       FIG. 16  shows the modular bunk cover apparatus and system in use on a boat lift. 
       FIG. 17  shows the modular bunk cover apparatus and system in use on a dock. 
       FIG. 18  shows the modular bunk cover apparatus and system in use on a boat storage rack. 
   

   The present invention will be described in connection with a preferred embodiment, however, it will be understood that there is no intent to limit the invention to the embodiment described. On the contrary, the intent is to cover all alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims. 
   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   For a general understanding of the present invention, reference is made to the drawings. In the drawings, like reference numerals have been used throughout to designate identical elements. 
   In this specification, a bunk is defined to be an elongated member that traverses a surface of a watercraft to support or otherwise retain the watercraft on a trailer, lift, hoist, trolley, rack, dock, pier, or the like. 
     FIG. 1  is a perspective view of a modular bunk cover apparatus and system in use on a boat trailer. Referring to  FIG. 1 , a typical boat trailer  102  is shown. The boat trailer  102  has two bunks  110  that are used to retain a boat and guide the boat on and off the trailer. Some boat trailers may have variations to the bunks  110  that are depicted in  FIG. 1 . The boat trailer  102  in  FIG. 1  is provided is to exemplify a typical application for the modular bunk cover apparatus and system, but is not intended to be a limitation of the present invention. Shown covering the bunks  110  in  FIG. 1  are a plurality of modular bunk covers  104  that are interconnected, and terminate at either end of the bunk  110  with an end cap  106 . The modular bunk covers  104  may vary in length from about 3 inches to about 36 inches. In one embodiment of the present invention, the modular bunk covers  104  are about 18 inches in length. The end caps  106  may vary in length from about 1 inch to about 9 inches. In one embodiment of the present invention, the end caps  106  are 3 inches in length. Other lengths of modular bunk covers  104  and end caps  106  may also be used, without departing from the spirit and scope of the present invention as defined by this specification and the appended claims. The plurality of bunk covers  104  and end caps  106  are interconnected to form a modular bunk cover system. 
   For a better understanding of the modular bunk cover apparatus and system, and the way in which the modular bunk cover  104  is made and used, we refer now to  FIG. 2 . The modular bunk cover  104 , prior to being attached to a bunk support member  206 , is comprised of a half sleeve  600  and an overmolded half sleeve  300 . The half sleeve  600  and the overmolded half sleeve  300  are of the same basic geometry, and will interconnect about a bunk support member  206 . Each half sleeve contains a plurality of tongues  306  and alternating receivers  304 . Each tongue  306  contains a slot  203  and each receiver  304  contains a tab  201 . To use the modular bunk cover apparatus and system, two half sleeves are placed about a bunk support member  206  such that the tongues of one half sleeve align with the receivers of an opposing half sleeve. The two half sleeves are then brought together about the bunk support member  206  such that the tabs  201  of one half sleeve are inserted in the slots  203  of the opposing half sleeve. The tabs  201  will engage in the slots  203  of the opposing half sleeve, causing the two half sleeves to be retained together. The tabs  201  may, in some embodiments of the present invention, contain a beveled edge or similar locking structure to prevent the tab  201  from backing out of the slot  203 . The overmolded half sleeve  300  may also, in some embodiments of the present invention, be replaced with a half sleeve  600 . It should be noted that the half sleeve  600  and the overmolded half sleeve  300  are interchangeable due to the alternating pattern of tongues  306  and receivers  304  contained on each half sleeve. To form a modular bunk cover  104 , a first half sleeve and a second half sleeve are joined about a bunk support member. The half sleeves may be any combination of half sleeves  600  and overmolded half sleeves  300 , as they are fully interchangeable. The overmolded half sleeve  300  and the half sleeve  600  also contain an expansion joint  302  that serves several purposes. The expansion joint  302 , as will be seen further in subsequent drawings, is an accordion-like structure that allows each half sleeve to expand and contract along the length of the bunk support member  206 . This becomes of particular importance when a boat trailer, for example, has been sitting in a hot parking lot all day, and is then immersed in cool water when used. The expansion joint  302  may also, in some embodiments of the present invention, serve to interlock one modular bunk cover apparatus  104  with an adjacent modular bunk cover apparatus  104 , both of which are placed on a bunk support member  206 . As will be further described later in this specification, the overmolded half sleeve  300  has a friction altering overmolded material, referred to as an overmold, on a portion of it&#39;s surface. The modular bunk cover system may also include an end cap  106 . 
     FIG. 2A  shows a modular bunk cover apparatus  104  after the overmolded half sleeve  300  and the half sleeve  600  are interconnected as previously described. The bunk support member  206  is not shown for clarity. The cooperation between the tab  201  and the slot  203 , and the related tongue and receiver structures of each half sleeve is clearly shown. 
     FIG. 3  shows a perspective view of an overmolded half sleeve  300  of the modular bunk cover apparatus. The tongues  306  and the receivers  304  can be clearly seen. The slots  203  can be seen on each tongue  306 . The tabs  201  are not however, visible in this perspective view, but are located within each receiver  304 . The overmolded half sleeve contains a plurality of fingers  310  interspersed by a plurality of opposing fingers  312 , and separated by a drainage space  314 . The fingers  310  and the opposing fingers  312  serve as a contact surface where a boat hull (not shown) will rest. The drainage space  314  formed by the interspersed fingers  310  and opposing fingers  312  serves to drain water away from a boat hull. The overmolded half sleeve  300  may be molded from a plastic using injection molding techniques that are commonly known to those skilled in the art. The overmolded half sleeve  300  may be primarily made from a plastic such as polypropylene, polystyrene, Acrylonitrile-butadiene-styrene, Polycarbonate, Nylon, Polyethylene-terephthalate, Acetal Resin (such as DELRIN™ from DUPONT™), or an acrylic, metal, fiberglass, molded graphite, wood, or another plastic material. In a preferred embodiment of the present invention, the overmolded half sleeve  300  is made from a plastic that contains an ultraviolet inhibitor. Other additives to the plastic may include antimicrobials such as Clariant MBP 9661 manufactured by Ashland Chemical Company in Dublin, Ohio. Scratch and mar resistant additives such as Siloxane manufactured by Ashland Chemical Company in Dublin, Ohio may also be added to the plastic. Other additives and formulations may also be used without departing from the spirit and broad scope of the invention as described herein. The overmold  308  may be formed from an elastomeric material such as a thermoplastic elastomer. An example of a thermoplastic elastomer is SANTOPRENE™ from Advanced Elastomer Systems, Akron, Ohio. The overmold  308  may, in some embodiments of the present invention, be pigmented to provide contrasting color to the overmolded half sleeve  300 . The overmold  308  may be attached to a surface of the overmolded half sleeve  300 , such as the fingers  310  and the opposing fingers  312 , using bonding techniques such as chemical bonding, thermal bonding, mechanical bonding, or other such techniques that are known to those skilled in the art. The overmold  308  may also be attached to a surface of the overmolded half sleeve through a coinjection molding process, such as the coinjection molding process described in U.S. Pat. No. 6,562,276 entitled “Process for Forming a Multilayer, Coinjected Article”, the entire disclosure of which is incorporated by reference herein. 
   In use, one may place the modular bunk cover  104  that contains the overmolded half sleeve  300  at various points along a bunk to facilitate the loading and unloading of a boat on a trailer. For example, one may assemble modular bunk covers  104  made of two half sleeves  600  toward the front of a bunk, with the rear of the bunk containing modular bunk covers  104  made of an overmolded half sleeve  300  and a half sleeve  600 . This technique will allow a boat to slide freely from a trailer when the trailer and boat are partially submerged in water, making the loading and unloading process easier. In other applications, one may use various overmolded half sleeves  300  containing varying overmolds to change the performance characteristics of the bunk cover system. 
   Referring now to  FIG. 4 , a top plan view of an overmolded half sleeve  300  of the modular bunk cover apparatus is shown. A plurality of fingers  310  interspersed by a plurality of opposing fingers  312 , and seperated by a drainage space  314 , is clearly seen in  FIG. 4 . The overmold  308  is also shown on the fingers. Also, expansion joints  302  can be seen at either end of the overmolded half sleeve  300 . An overmolded half sleeve  300 , in one embodiment of the present invention, is capable of interconnecting with a half sleeve  600  or another overmolded half sleeve  300  to form a modular bunk cover  104 . 
   Turning now to  FIG. 5 , a cutaway sectional view of an overmolded half sleeve  300  is depicted. In one embodiment of the present invention, spikes  502  are formed on the inside surface of the overmolded half sleeve  300 . The inside surface is defined to be the surface of the overmolded half sleeve  300  that faces a bunk support member such as a section of dimensional lumber. The spikes  502  are, in one embodiment of the present invention, injected molded with the overmolded half sleeve  300 . The spikes  502  are, in other embodiments of the present invention, mechanically, chemically, or thermally bonded to the inside surface of the overmolded half sleeve  300 . The spikes may, in some embodiments of the present invention, be made from a plastic or a metal.  FIG. 5  also shows end detail of the expansion joint  302 . 
     FIG. 6  is a top plan view of a half sleeve  600  of the modular bunk cover apparatus. A plurality of fingers  310  interspersed by a plurality of opposing fingers  312 , and seperated by a drainage space  314 , is clearly seen in  FIG. 6 . Expansion joints  302  can also be seen at either end of the half sleeve  600 . A half sleeve  600 , in one embodiment of the present invention, is capable of interconnecting with another half sleeve  600  or an overmolded half sleeve  300  to form a modular bunk cover  104 . 
     FIG. 7  is a perspective view of a half sleeve  600  of the modular bunk cover apparatus. The tongues  306  and the receivers  304  can be clearly seen. The slots  203  can be seen on each tongue  306 . The tabs  201  are not however, visible in this perspective view, but are located within each receiver  304 . The half sleeve  600  contains a plurality of fingers  310  interspersed by a plurality of opposing fingers  312 , and separated by a drainage space  314 . The drainage space  314  formed by the interspersed fingers  310  and opposing fingers  312  serves to drain water away from a boat hull. The half sleeve  600  may be molded from a plastic using injection molding techniques that are commonly known to those skilled in the art. The half sleeve  600  may be primarily made from a plastic such as polypropylene, polystyrene, Acrylonitrile-butadiene-styrene, Polycarbonate, Nylon, Polyethylene-terephthalate, Acetal Resin (such as DELRIN™ from DUPONT™), or an acrylic, metal, fiberglass, molded graphite, wood, or another plastic material. In a preferred embodiment of the present invention, the half sleeve  600  is made from a plastic that contains an ultraviolet inhibitor. 
     FIG. 8  is a cutaway sectional view of a half sleeve  600  of the modular bunk cover apparatus. In one embodiment of the present invention, spikes  502  are formed on the inside surface of the half sleeve  600 . The inside surface is defined to be the surface of the half sleeve  600  that faces a bunk support member such as a section of dimensional lumber. The spikes  502  are, in one embodiment of the present invention, injected molded with the half sleeve  600 . The spikes  502  are, in other embodiments of the present invention, mechanically, chemically, or thermally bonded to the inside surface of the half sleeve  600 . The spikes may, in some embodiments of the present invention, be made from a plastic or a metal.  FIG. 8  also shows end detail of the expansion joint  302 . 
     FIG. 9  is a side view of the modular bunk cover apparatus in use showing a half sleeve  600  coupled to an overmolded half sleeve  300 . A bunk support member  206  has not been shown, for clarity. In some embodiments of the present invention, A half sleeve  600  is capable of interconnecting with another half sleeve  600  or an overmolded half sleeve  300  to form a modular bunk cover  104 . 
     FIG. 10  is a perspective view of an end cap  106  of the modular bunk cover apparatus and system. The end cap  106  attaches to either end of a bunk support member  206 , as shown previously in  FIG. 1 . The end cap  106  serves to protect the hull of a boat from the blunt ends of a typical bunk support member  206 , such as a typical bunk support member made from dimensional lumber. The end cap  106  also serves to retain modular bunk covers  104  that have been installed on a bunk support member  206 , as shown previously in  FIG. 1 . The end cap  106  may be primarily made from a plastic such as polypropylene, polystyrene, Acrylonitrile-butadiene-styrene, Polycarbonate, Nylon, Polyethylene-terephthalate, Acetal Resin (such as DELRIN™ from DUPONT™), SANTOPREN™ from Advanced Elastomer Systems, Akron, Ohio, or an acrylic, metal, fiberglass, molded graphite, wood, or another plastic material. In a preferred embodiment of the present invention, the end cap  106  is made from a plastic that contains an ultraviolet inhibitor. The end cap  106  further contains drainage coves  1002  to facilitate removal of water that could become trapped between a boat hull and a bunk. The end cap  106  may also, in some embodiments of the present invention, contain a truncated drainage cove  1006 . The sides of the end cap  106  may also contain channels  1004 . Each channel  1004  may contain an optional screw location  1008 . To place the end cap  106  on a bunk support member, the end cap  106  is merely pushed onto an end of the bunk support member. Should additional mechanical retention be necessary, a screw may be placed in the optional screw location  1008  and driven into the bunk support member  206 . 
     FIG. 11  shows an inside perspective view of an end cap  106  of the modular bunk cover apparatus and system. Circumscribed about the perimeter of the end cap  106  is a lip  1101 . The lip  1101  allows the end cap  106  to be connected to a modular bunk cover  104 , as shown previously in  FIG. 1 . As can also be seen in  FIG. 11 , the interior of the end cap  106  contains ribs  1103  that add structural strength to the end cap  106  and provide for a tight fit of the end cap  106  to a bunk support member  206 . 
     FIG. 12  is a top view of an end cap  106  of the modular bunk cover apparatus and system. The drainage coves  1002  and the truncated drainage cove  1006  can be seen. 
     FIG. 13  is a bottom view of an end cap of the modular bunk cover apparatus and system also showing the drainage coves  1002  and the truncated drainage cove  1006 . 
     FIG. 14  is an end view of an end cap  106  of the modular bunk cover apparatus and system. The drainage coves  1002 , the truncated drainage coves  1006  and the channels  1004  can be seen. A product name, product logo, or other information, may be molded into, or placed on, the end cap using techniques that are known to those skilled in the art. In some embodiments of the present invention, an overmold may be placed on the end cap  106 , using materials and processes that are similar to the overmold  308  placed on the overmolded half sleeve  300  that has been previously described. 
     FIG. 15  shows the modular bunk cover apparatus and system in use on a trailer  1502  carrying a tunnel hull boat  1500 . The placement and configuration of the modular bunk cover apparatus and system can vary substantially based on application.  FIG. 1  has previously portrayed a standard boat trailer that contains two bunks. In  FIG. 15 , a highly specialized tunnel hull boat  1500  is shown placed on four bunks  110  that are attached to a trailer  1502 . The modular bunk covers may be interconnected to accommodate varying bunk lengths and applications. The applications are not limited to boat trailers, but rather, include any structure where contact with a boat occurs. For example,  FIG. 16  shows a boat lift  1600  that contains two bunks  110  that support a boat  1601 . The boat lift  1600  may be a cantilever style lift, a suspension lift, a vertical lift, a beach rail system, or the like. The modular bunk cover apparatus and system may also be used in a docking system.  FIG. 17  shows a dock  1700  with a bunk  110  that is protected with the modular bunk cover apparatus and system of the present invention. The bunk  110  may be mechanically connected to the dock  1700  using fasteners such as screws, bolts, brackets, and the like. There are numerous other applications for the modular bunk cover apparatus and system.  FIG. 18  shows a marina storage rack  1800  that uses bunks  110  protected with the modular bunk cover apparatus and system of the present invention. Other applications will become evident to those skilled in the art. 
   It is, therefore, apparent that there has been provided, in accordance with the various objects of the present invention, a modular bunk cover apparatus and system. While the various objects of this invention have been described in conjunction with preferred embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims.