Abstract:
An inflatable dinghy includes a drop stitch inflatable floor made of high pressure drop stitch material; port and starboard drop stitch inflatable sides made of high-pressure drop stitch material attached at outside edges of the drop stitch inflatable floor, respectively; a rigid bow mold attached to the drop stitch inflatable floor and drop stitch inflatable sides; and a rigid stern transom attached to the drop stitch inflatable floor and drop stitch inflatable sides. The inflatable dinghy includes only three separate air compartments including the drop stitch inflatable floor and the drop stitch inflatable sides.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a continuation-in-part of prior U.S. application Ser. No. 14/505,749, filed on Oct. 3, 2014, to which the benefit is claimed under 35 U.S.C. §120 and the disclosure of which is incorporated herein by reference. 
    
    
     BACKGROUND 
     1. Field 
     Embodiments relate to watercraft, and more particularly, to inflatable boats having drop stitch construction. 
     2. Description of the Related Art 
     A kayak is a small watercraft having a narrow beam which typically is propelled by a user&#39;s manipulation of a double-bladed paddle. Traditional kayaks were first developed for hunting in inland lakes, rivers and coastal waters, and originally consisted of animal skins stretched over a wood or whalebone frame. 
     Modern kayaks have long been a popular form of watercraft due their shallow draught, low free board and easy maneuverability. More recently, the popularity of kayaking has increased due to the portability of a kayak, the ability for a user to paddle longer distances than in other self-propelled watercraft such as rowboats and canoes, and the exercise benefits of kayaking that simultaneously allows a user to enjoy their surroundings. 
     As kayaks entered the modern era, they were constructed of wood or fabric stretched over a wooden frame. More recently, fiberglass kayaks or kayaks constructed of rotomolded polethylene resins are the dominate types of kayak. 
     Inflatable coated fabric kayaks are also conventionally used. Inflatable coated fabric kayaks have the advantage in that they are easier to store and transport. An inflatable coated fabric kayak typically includes inflatable tubes joined to form the kayak. In particular single round inflatable tubes form both the port and starboard sides of the conventional inflatable coated fabric kayaks, which reduces the speed and maneuverability of the inflatable coated fabric kayaks since with the shape of a round inflatable tube prevents the hull of the inflatable coated fabric kayaks from having a V-shaped hull, and also decreases the speed of the inflatable coated fabric kayaks. 
     Accordingly, an inflatable kayak, and also other types of boats such as a dinghy and skiff, having the advantages of rigid kayaks, dinghies and skiffs are needed, while still retaining the advantages of economy and portability of their inflatable counterparts. 
     SUMMARY 
     Therefore, it is one aspect of the present invention to provide an inflatable kayak having flat sides constructed of drop stitch material to create an inflatable kayak having a V-shaped sides that flare out from the floor. This improves speed and ease of paddling. 
     Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the invention. 
     According to an aspect, an inflatable kayak includes an inflatable floor made of high pressure drop stitch material; and inflatable sides made of high-pressure drop stitch material formed at port and starboard sides of the inflatable floor, respectively. 
     The inflatable sides may be glued or welded directly to the port and starboard sides of the inflatable floor, and the inflatable sides are configured to be inclined outboard from the inflatable floor. Alternatively, the inflatable sides may be glued or welded to a non-inflated fabric floor and the inflatable floor made of high pressure drop stitch material may be positioned and attached to a top of the non-inflated fabric floor with the inflatable sides pressing against the inflatable floor made of high pressure drop stitch material. 
     The inflatable kayak may further include a rigid bow mold attached to the inflatable floor and inflatable sides. 
     The inflatable kayak may further include a rigid stern mold attached to the inflatable floor and inflatable sides. 
     In the inflatable kayak, the high pressure drop stitch material of the inflatable floor and inflatable sides may include a coated polyester fabric of approximately 1000 denier with 1000 denier drop stitch threads. 
     In the inflatable kayak, the inflatable floor and inflatable sides may be configured to be inflated to between 3-25 psi. 
     The inflatable kayak may have a length of between 9-21 feet. 
     The inflatable kayak may have a beam of between 22-32 inches. 
     In the inflatable kayak, a thickness of the drop stitch material used for the inflatable floor and the inflatable sides may be between 3-8 inches. 
     The inflatable may have an asymmetrical shape in a fore and aft direction, the inflatable kayak being slightly wider aft of an amidships portion and slightly narrower forward of the amidships portion. 
     The inflatable kayak may include one or more skegs formed on an after portion of a bottom of the inflatable floor, to improve tracking while paddling. 
     In the inflatable kayak, the rigid bow mold and the rigid stern mold may be made of rigid engineering or composite plastic. 
     According to another aspect an inflatable dinghy includes a drop stitch inflatable floor made of high pressure drop stitch material; port and starboard drop stitch inflatable sides made of high-pressure drop stitch material attached at outside edges of the drop stitch inflatable floor, respectively; a rigid bow mold attached to the drop stitch inflatable floor and drop stitch inflatable sides; a rigid stern transom attached to the drop stitch inflatable floor and drop stitch inflatable sides, where the inflatable dinghy includes only three separate air compartments including the drop stitch inflatable floor and the drop stitch inflatable sides. 
     The inflatable dinghy may further include oarlocks glued to each of the drop stitch inflatable sides, respectively. 
     The transom may be made of wood coated with plastic. 
     According to yet another aspect, an inflatable skiff includes a drop stitch inflatable floor made of high pressure drop stitch material; port and starboard drop stitch inflatable sides made of high-pressure drop stitch material attached at outside edges of the drop stitch inflatable floor, respectively; a drop stitch inflatable keel attached at a central portion of a bottom of the drop stitch inflatable floor; a rigid bow mold attached to the drop stitch inflatable floor and drop stitch inflatable sides; a rigid stern transom attached to the drop stitch inflatable floor and drop stitch inflatable sides, where the inflatable skiff includes only four separate air compartments including the drop stitch inflatable floor, drop stitch inflatable sides and drop stitch inflatable keel. 
     In the inflatable skiff, wherein at least one of the drop stitch inflatable floor and drop stitch inflatable keel includes a mast step configured to have a mast stepped therein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings in which: 
         FIG. 1  is top view of an inflatable kayak in accordance with an embodiment; 
         FIG. 2  is a side view of the inflatable kayak in accordance with the embodiment; 
         FIG. 3  is a cross-sectional view taken along lines  3 - 3 ′ of  FIG. 2  of the inflatable kayak in accordance with an embodiment; 
         FIG. 4  is a cross-sectional view taken along lines  3 - 3 ′ of  FIG. 2  of the rigid bow of the inflatable kayak in accordance with an embodiment including a non-inflatable floor; 
         FIG. 5  is a conceptual view of the drop stitch material of the interior of the inflatable kayak in accordance with an embodiment; 
         FIG. 6  is top view of an inflatable dinghy in accordance with another embodiment; 
         FIG. 7  is a side view of the inflatable dinghy in accordance with the embodiment; 
         FIG. 8  is top view of an inflatable skiff in accordance with another embodiment; and 
         FIG. 9  is a side view of the inflatable skiff in accordance with the embodiment. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The embodiments are described below to explain the present invention by referring to the annexed drawings. 
     As shown in  FIGS. 1 and 2 , the inflatable kayak  10  includes an inflatable floor  12  made of high-pressure drop stitch material. The inflatable floor  12  may be made of 1000 denier polyester fabric but may be made of other stronger or weaker fabric materials. An example of the drop stitch material is shown in  FIG. 5  where thousands of drop stitches are provided to maintain an equal distance between the top and bottom surfaces of the inflatable floor  12 . The drop stitch threads may be in a linear, zigzag or random pattern. The drop stitch thread may be configured in linear, or various other patterns including “X” and “V” patterns. The use of drop stitch material in the floor  12  allows the floor  12  to be inflated to a pressure of 15 psi. 
     Glued or welded directly to the inflatable floor  12  are inflatable sides  14 ,  16  which are also made of high-pressure drop stitch material formed at port and starboard sides of the inflatable floor  12 , respectively. The inflatable sides  14 ,  16  may also be made of 1000 denier polyester fabric but may be made of other stronger or weaker fabric materials. The drop stitch threads may be in a linear, zigzag or random patterns including “X” and “V” patterns. The use of drop stitch material in the inflatable sides  14 ,  16  allows the inflatable sides  14 ,  16  to be inflated to a pressure of 10 psi, 15 psi or greater psi. 
     Alternatively, as shown in  FIG. 4 , the inflatable sides  14 ,  16  may be glued or welded to a non-inflated fabric floor  28  and the inflatable floor  12  made of high pressure drop stitch material may be positioned and attached to a top of the non-inflated fabric floor  28  with the inflatable sides  14 ,  16  pressing against the inflatable floor  12  made of high pressure drop stitch material. 
     As shown in  FIG. 3 , the inflatable sides  14 ,  16  are configured to be inclined outboard from the inflatable floor  12  to give the inflatable kayak  10  V-shaped sides flaring out from the inflatable floor  12 . According to this structure, since the inflatable sides  14 ,  16  meet the inflatable floor  12  at an angle producing a chine, the speed and ease of paddling the inflatable kayak  10  is increased, particularly in difficult conditions. 
     The inflatable kayak  10  may have a length of between 9-21 feet, a beam may be between 22-32 inches, and a thickness of the drop stitch material used for the inflatable floor  12  and the inflatable sides  14 ,  16  may be between 3-8 inches. The inflatable kayak  10  also advantageously may have an asymmetrical shape in a fore and aft direction, being slightly wider aft of an amidships portion and slightly narrower forward of the amidships portion. 
     However, the shape of the inflatable kayak  10  is not limited to an asymmetrical shape and the inflatable kayak  10  may also be symmetrical in the fore and aft direction. 
     The inflatable floor  12  and the inflatable sides  14 ,  16  may each include an air valve  18 . The air valves  18  are preferably one-way air valves to prevent blow back during inflation, and to make it easier to close the air valves  18  with a valve cap. The air valves  18  may be locked in an open position for fast deflation prior to transportation and storage. 
     A skeg  20  is formed on the after portion of the bottom of the inflatable kayak  10 . The skeg  20  may be permanently attached or removable for storage or transportation. 
     At the bow portion of the inflatable kayak  10  is a rigid bow mold  22 . Since the drop stitch construction of the inflatable floor  12  and inflatable sides  14 ,  16  of the inflatable kayak  10  preclude having a sharp bow that is effective to cut waves and increase maneuverability, the inflatable kayak  10  of the present invention includes a rigid bow mold  22  that is attached to the inflatable floor  12  and inflatable sides  14 ,  16 , for example by gluing. 
     At the stern portion of the inflatable kayak  10  is a rigid stern mold  24 . Since the drop stitch construction of the inflatable floor  12  and inflatable sides  14 ,  16  of the inflatable kayak  10  preclude having a sharp stern that is necessary for reverse paddling in kayaking, the inflatable kayak  10  of the present invention includes a rigid stern mold  24  that is attached to the inflatable floor  12  and inflatable sides  14 ,  16 , for example by gluing. 
     The rigid bow mold  22  and rigid stern mold  24  of the inflatable kayak  10  may be made of rigid engineering or composite plastic construction or other plastic material, although other non-plastic materials may be used. The lateral sides of the needle nose  30  come together in a point at no more than a  60  degree angle. The rigid bow mold  22  and rigid stern mold  24  gives the inflatable kayak  10  a rigid bow and stern construction that enables a user to cut through waves and to paddle faster, further and easier as compared to conventional inflatable kayaks. 
     According to another embodiment, as shown in  FIGS. 6 and 7 , an inflatable dingy  100  includes an inflatable floor  102  made of high-pressure drop stitch material. The inflatable floor  102  may be made of 1000 denier polyester fabric but may be made of other stronger or weaker fabric materials. An example of the drop stitch material is shown in  FIG. 5 . 
     Glued or welded directly to the inflatable floor  102  are inflatable sides  104 ,  106  which are also made of high-pressure drop stitch material formed at port and starboard sides of the inflatable floor  102 , respectively. The tops of the drop stitch inflatable sides  104 ,  106  form gunnels  144 ,  166  that curve upwards from bow to stern. The inflatable sides  104 ,  106  may also be made of 1000 denier polyester fabric but may be made of other stronger or weaker fabric materials. 
     As previously discussed with reference to  FIG. 4 , the inflatable sides  104 ,  106  may be glued or welded to a non-inflated fabric floor  108  and the inflatable floor  102  made of high pressure drop stitch material may be positioned and attached to a top of the non-inflated fabric floor  108  with the inflatable sides  104 ,  106  pressing against the inflatable floor  102  made of high pressure drop stitch material. 
     The inflatable dinghy  100  may have a length of between 7-12 feet, a beam may be between 40-60 inches, and a thickness of the drop stitch material used for the inflatable floor  12  and the inflatable sides  14 ,  16  may be between 3-8 inches. 
     At the bow portion of the inflatable dinghy  100  is a rigid bow mold  112 . Since the drop stitch construction of the inflatable floor  102  and inflatable sides  104 ,  106  of the inflatable dinghy  100  preclude having a sharp bow that is effective to cut waves and increase maneuverability, the inflatable dinghy  100  of the present invention includes a rigid bow mold  112  that is attached to the inflatable floor  102  and inflatable sides  104 ,  106 , for example by gluing. 
     At the stern portion of the inflatable dinghy  100  is a rigid stern transom  114  which is attached to the inflatable floor  102  and inflatable sides  104 ,  106 , for example by gluing. The rigid stern transom  114  is made of wood coated with plastic, although other suitable materials may be used. The rigid stern transom  114  is adapted to receive an outboard motor. 
     Oarlocks  118  are disposed at each of the drop stitch inflatable sides  104 ,  106 , respectively. 
     According to another embodiment, as shown in  FIGS. 8 and 9 , an inflatable skiff  200  includes an inflatable floor  202  made of high-pressure drop stitch material. The inflatable floor  202  may be made of 1000 denier polyester fabric but may be made of other stronger or weaker fabric materials. An example of the drop stitch material is shown in  FIG. 5 . 
     Glued or welded directly to the inflatable floor  202  are inflatable sides  204 ,  206  which are also made of high-pressure drop stitch material formed at port and starboard sides of the inflatable floor  202 , respectively. The tops of the drop stitch inflatable sides  204 ,  206  form gunnels  244 ,  266  that curve upwards from bow to stern. The inflatable sides  204 ,  206  may also be made of 1000 denier polyester fabric but may be made of other stronger or weaker fabric materials. 
     A drop stitch inflatable keel  216  having an air foil shape is attached at a central portion of a bottom of the drop stitch inflatable floor  202 . At least one of the drop stitch inflatable floor  202  and drop stitch inflatable keel  216  includes a mast step  220  configured to have a mast stepped therein. 
     As previously discussed with reference to  FIG. 4 , the inflatable sides  204 ,  206  may be glued or welded to a non-inflated fabric floor  208  and the inflatable floor  202  made of high pressure drop stitch material may be positioned and attached to a top of the non-inflated fabric floor  208  with the inflatable sides  204 ,  206  pressing against the inflatable floor  202  made of high pressure drop stitch material. 
     The inflatable skiff  200  may have a length of between 10-20 feet. 
     At the bow portion of the inflatable skiff  200  is a rigid bow mold  212 . At the stern portion of the inflatable skiff  200  is a rigid stern transom  214  which is attached to the inflatable floor  202  and inflatable sides  204 ,  206 , for example by gluing. The rigid stern transom  214  is made of wood coated with plastic, although other suitable materials may be used. The rigid stern transom  214  is adapted to receive an outboard motor. 
     Oarlocks  218  are disposed at each of the drop stitch inflatable sides  204 ,  206 , respectively. 
     Although several embodiments of the invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents. For example, the present inventive concept may be applied to other types of inflatable watercraft such as a canoe, raft, barge, etc.