Abstract:
The present disclosure relates generally to knee braces for boats. The knee braces described herein are particularly suitable for use with lightweight, inflatable rafts and kayaks, for example packrafts used in backcountry boating. The knee braces include a fabric body and a plurality of adjustable straps configured to attach the fabric body to a side wall of the boat.

Description:
RELATED APPLICATION 
       [0001]    This application is a continuation application of U.S. patent application Ser. No. 14/832,546, filed Aug. 21, 2015, the entire contents of which is hereby incorporated by reference. 
     
    
     BACKGROUND 
       [0002]    Boats for use in navigating whitewater, e.g., whitewater kayaks, canoes and rafts, are typically outfitted with some type of knee brace, to allow the paddler to use his or her leg strength and body weight to help maneuver the boat. 
         [0003]    In some cases, for example in open cockpit kayaks, the brace may take the form of a thigh strap, for example as disclosed in U.S. Pat. No. 5,493,982. Thigh straps provide some control of the craft, but control can be limited because force is applied predominately by the user&#39;s thigh and shin. 
         [0004]    Hard shell boats, e.g., molded plastic and fiberglass whitewater kayaks, often have rigid, molded “hard shell” knee braces, which in some cases are lined with foam for comfort and to provide some conformability to the user&#39;s leg shape. Knee braces of this type generally provide good control of the boat, but may lack adjustability and generally cannot be used with inflatable boats. In particular, such braces are not suitable for use with lightweight inflatable boats, such as packrafts designed for backcountry use. 
       SUMMARY 
       [0005]    The present disclosure relates generally to knee braces for boats. The knee braces described herein are particularly suitable for use with lightweight, inflatable rafts and kayaks, for example packrafts used in backcountry boating. The knee braces may be used, for example, in whitewater boating, as well as other applications such as sea-kayaking or expedition use. 
         [0006]    In one aspect, the disclosure features a knee brace for a watercraft, the knee brace comprising: (a) a fabric body, (b) four attachment points, each attachment point comprising a strap having a fixed end attached to the fabric body, a standing portion configured to be attached to a side wall of the watercraft, and a free end, and (c) an adjustment buckle disposed on each of the straps and configured to allow adjustment of the length of the free end of the strap. 
         [0007]    Some implementations may include one or more of the following features. The straps may be configured to allow the user to apply a pulling along the midline of the user&#39;s knee during use of the boat. The straps may be configured to allow the user to pull the free ends of the straps toward his or her torso when tightening the straps. In some cases, the adjustment buckles are configured to allow one-handed loosening of the straps. 
         [0008]    The knee brace may further include one or more fasteners configured to releasably attach the standing portions of one or more of the straps to the side wall. At least one of the fasteners may include a portion of a quick release buckle. 
         [0009]    The straps may be formed of webbing. The fabric body may include a stretch material, configured to be positioned over the user&#39;s kneecap during use. In some implementations, the fabric body also includes a substantially non-elastic material disposed along an inner edge of the fabric body to provide stiffness to the fabric body. The fabric body may also include a pre-tensioned ribbon tape along an inner edge of the fabric body. 
         [0010]    In another aspect, the disclosure features an inflatable boat comprising: (a) a boat body having a side wall, and (b) a knee brace comprising (i) a fabric body, and (ii) four attachment points securing the knee brace to the side wall, each attachment point comprising a strap having a fixed end attached to the fabric body, a standing portion configured to be attached to the side wall, and a free end. 
         [0011]    Some implementations of this aspect of the disclosure may include any of the features discussed above. Implementations may also include one or more of the following features. 
         [0012]    The side wall may include attachment locations to which the attachment points are secured. For example, the side wall may include an array of attachment loops to which one of the attachment points can be secured, allowing the user to choose one of the loops to adjust the fit of the knee brace. In some cases, two of the attachment locations are configured to receive ends of a rod from which two of the straps can be suspended when the knee brace is mounted on the boat. 
         [0013]    In yet another aspect, the disclosure features a method of releasably attaching a fabric knee brace to an inflatable boat. The method includes securing the knee brace to the side wall using four releasable attachment points, each attachment point comprising a strap having a fixed end attached to the fabric body, a standing portion configured to be attached to the side wall, and a free end. 
         [0014]    In some implementations, securing comprises releasably attaching a rod to the side wall by positioning ends of the rod in receiving pockets on the side wall, and suspending two of the straps from the rod. Securing may also include releasably attaching a clip on one of the straps to one of an array of attachment loops on the side wall, and/or securing one of the straps to the side wall using a quick release buckle. 
         [0015]    The knee braces described herein provide control and steering similar to what is provided by a rigid knee brace, while still being packable with an inflatable boat. The knee braces are highly adjustable, providing good leg support and enhancing user comfort. The design of preferred knee braces allows the user to pull along the midpoint of the knee, maximizing the torque that can be applied to the boat and providing excellent control of the tip of the boat in waves. These features may allow a user to use the knee braces to Eskimo roll the boat, even in the case of a flat-bottomed raft, a craft that is notoriously difficult to Eskimo roll. In preferred implementations, the knee brace defines an enclosed cup that minimizes risk of entanglement in the event of the boat capsizing or deflating. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0016]      FIG. 1  is a perspective view of a packraft including knee braces according to one implementation. Certain elements of the packraft are omitted for clarity. 
           [0017]      FIGS. 2-7  are detailed perspective views showing steps of applying the knee brace shown in  FIG. 1  to a user&#39;s leg and adjusting the straps of the knee brace. 
           [0018]      FIG. 8  is perspective view of the knee brace shown in  FIG. 1 . 
           [0019]      FIGS. 9-15  are detailed perspective views showing steps of attaching the knee brace to the packraft. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    A packraft  10  including a pair of knee braces  12  is shown in  FIG. 1 . Typically, the packraft would also include other components to support the user, for example a seat, hip pads, foot braces, and other components well known in the raft and kayak art. These components have been omitted for clarity. 
         [0021]    Each knee brace  12  includes a fabric body  14  and a plurality of adjustment and attachment straps, which will be described in detail below. Importantly, the straps provide four points of adjustable attachment of the knee brace around the user&#39;s knee. This arrangement has been found to provide the best balance of control of the boat with ease of use, user comfort and safety. 
         [0022]    As shown in  FIG. 8 , the fabric body includes an elastic portion  20  and a non-elastic portion  22 . The elastic portion  20  provides a comfortable, secure pocket for the knee, and its presence prevents entrapment if the raft were to deflate or capsize. The user will tend to drive his or her knee up into the stretch material during use, and the elasticity of the material advantageously allows it to form around the user&#39;s knee under these conditions. This application of upward pressure is similar to the feeling a user has when pushing against a hard shell knee brace. The lack of any straps extending over the knee facilitates this upward movement. Elastic portion  22  may be formed, for example, from four-way stretch woven nylon, or other stretch dry suit materials such as heavy duty LYCRA® fabric. 
         [0023]    The non-elastic portion  22  provides a strong, stiff area for attachment of the adjustment straps, and gives the user a stiff strap with which to apply force to the raft. The non-elastic portion may be formed, for example, of heavy pack cloth or other stiff, tightly woven material. Preferably, the non-elastic portion  22  is configured so that the grain of the fabric is substantially perpendicular to the length of the user&#39;s leg, and the edge  29  is curved in a manner so that tensile forces applied to the brace during use are applied along the grain of the fabric rather than on the diagonal. 
         [0024]    For optimal stiffness of the non-elastic portion  22 , it is preferred that the edge  29  be reinforced with a ribbon tape  33 . This also provides reinforcement to the attachment points of straps  32  and  34 , discussed below, as these straps can be stitched to the fabric body under or with the ribbon tape as well as with additional stitching inboard of the tape. The ribbon tape may be formed, for example, from nylon webbing, and is preferably held under tension as it is being applied to the edge. This pre-tensioned ribbon tape provides the non-elastic portion  22  with a hard edge that exhibits substantially no stretch under normal use conditions. 
         [0025]    The elastic portion  20  and/or the non-elastic portion  22  may include sewn darts or the like to provide more fullness in the fabric portion in the area where the user&#39;s kneecap will be positioned. 
         [0026]    In the implementation shown in  FIG. 1 , each knee brace is removably attached to the side wall  16  of the raft with an attachment system that will be described below with reference to  FIGS. 8-15 . Removable attachment of the knee braces can make the raft easier to pack, and makes the braces replaceable if damaged. However, in some implementations the knee braces may be permanently attached to the raft, for example if a very lightweight, custom-fitted boat is desired. In either case the preferred positioning of the attachment points will be substantially the same. 
         [0027]    As shown in  FIG. 1 , the knee brace is attached to the side wall  16  at two upper attachment points  18 , a forward attachment point  19 , and a rearward attachment point  21 . Referring to  FIGS. 8 and 15 , a pair of side straps  32 ,  34  extend from the upper attachment points  18  (attached to a rod  27  that extends between the attachment points, as will be described further below) to edge  29  of the non-elastic portion  22  of fabric body  14 . A shin strap  24  extends between the forward attachment point  19  and an attachment point on a forward portion of the non-elastic portion  22 , with an underlying flap  25  ( FIG. 8 ) protecting the user&#39;s shin. A central strap  28  extends from an attachment point in a central portion of the non-elastic portion  22 , adjacent edge  29 , to rearward attachment point  21 , with a curved portion of edge  29  extending under the strap to protect the user&#39;s skin. Together, the side straps, shin strap, and central strap provide the four points of adjustable attachment discussed above. 
         [0028]    Strap  32  is preferably attached to edge  29  by first stitching the strap edge in line with the edge  29 , for secure attachment, and then applying another, inboard, line of stitching at an angle, as shown in  FIG. 15 , so that the strap angles up and out so as to contour to the user&#39;s knee during use. 
         [0029]    Central strap  28  is threaded through a retainer loop  31  (a short length of webbing secured at both ends to the fabric body) and then through a buckle  30  in a manner such that the tail of the central strap is positioned to be pulled toward the user. The other straps can also be adjusted without the user having to pull away from his or her torso. This arrangement facilitates adjustment of the strap from a seated position in the raft, which is particularly advantageous for “on the fly” adjustments when the raft is on the water. 
         [0030]    As shown in  FIG. 15 , the standing portion of strap  28 , extending between the buckle  30  and the attachment point  21 , is doubled. This arrangement provides leverage when tightening the strap, and the tendency of the doubled portion to spread apart during use enhances the security of the attachment of the knee brace to the user&#39;s leg. 
         [0031]    A preferred sequence of adjusting the straps will now be discussed, with reference to  FIGS. 2-7 . 
         [0032]    Referring to  FIG. 2 , the user first positions him or herself in the raft. Next, the user pulls the fabric body  14  over the knee, with the upper attachment points  18  holding the knee brace securely in place on side wall  16 . The user then pushes the knee up into the fabric body  14  to seat the knee in the cup formed by the fabric body. 
         [0033]    Referring now to  FIG. 5 , the user begins to attach the knee brace by adjusting the shin strap  24  ( FIG. 8 ) through forward buckle  26  until the shin strap  24  is comfortably positioned on the user&#39;s shin. 
         [0034]    The user then adjusts central strap  28  through central buckle  30 , as shown in  FIG. 6 , until a snug fit of the non-elastic portion  22  against the inner knee is achieved. 
         [0035]    Finally, as shown in  FIG. 7 , the user fine tunes the adjustment of the knee brace and tightens it against the side wall  14  by adjusting side straps  32 ,  34 , though buckles  36 ,  38  ( FIG. 8 ). At this point, the user&#39;s knee is held securely in place against the side wall  16 , and the user is able to apply force to the side wall through all four points of attachment. The arrangement of the straps is configured to allow the user to pull along the midline of the knee, where the most torque can be applied. 
         [0036]    The straps may become loose during use, particularly as the webbing gets wet. The system described above allows the user to easily re-adjust the fit of the knee brace as any loosening occurs. The buckles  26 ,  30 ,  36  and  38  are also configured to allow the user to easily loosen or release the straps with one hand, e.g., by lifting up on the curved end of the buckle with the user&#39;s thumb. 
         [0037]    A preferred sequence of steps for attaching the knee brace to the raft will now be discussed, with reference to  FIGS. 9-15 . It is generally preferred that this sequence of steps be performed before the raft is fully inflated, so that there is some give to side wall  16 . 
         [0038]    The installation process begins with the knee brace receiving portion of the raft in the position shown in  FIG. 9 . As shown in  FIG. 9 , the upper attachment points  18  include rod pockets  40  and securing straps  42  (which are disposed in an open position at this stage.) The forward attachment point  19  includes a plurality of attachment loops  44  and a buckle  46  to which an adjustable foot brace (not shown) can be attached. The rearward attachment point  21  includes the female buckle portion  48  of a quick release buckle. For durability, it is generally preferred that these features be mounted on reinforcing patches, as shown. 
         [0039]    Referring now to  FIGS. 10-12 , the knee brace is attached first to the upper attachment points  18 . To accomplish this, first one end and then the other of the rod  27  of knee brace  12  is inserted into the rod pockets  40 . Because the rod  27  is formed of an inflexible material (e.g. rigid metal), this procedure is facilitated by the raft not being fully inflated. Once the ends of the rod  27  are securely positioned in the rod pockets, tension applied to the straps  32 ,  34  will be transferred to the rod  27  and thus to the side wall  16  through the rod pockets  40 . 
         [0040]    Referring now to  FIG. 13 , in order to ensure that the ends of rod  27  remain securely in the rod pockets  40  during use, the straps  42  are joined between the rod pockets by fastening a quick release buckle  50 . 
         [0041]    Next, the forward attachment point  19  is established by attaching a hook-type fastener  52  through one of the attachment loops  44 . The attachment loop to be used is selected by the user to provide a comfortable fit on the user&#39;s leg. The strap is flipped over during attachment, as indicated by the arrows, such that the hook is inserted in a direction away from the user&#39;s torso. Flipping the strap over in this manner causes the strap  24  to extend across the user&#39;s knee with a flatter profile, enhancing user comfort. 
         [0042]    Finally, as shown in  FIG. 15 , the rearward attachment point is established by attaching the central strap  28  by joining a male buckle portion  54  to female buckle portion  48 . 
       Other Embodiments 
       [0043]    A number of embodiments have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the disclosure. 
         [0044]    For example, the knee brace can be attached to the packraft either removably or permanently using other techniques than that shown in  FIGS. 9-15 . As but a few examples, the knee brace could be permanently welded to the boat, or attached to the boat with D-rings and straps. 
         [0045]    Moreover, the removable attachment arrangement described above may be modified, for example by providing fewer attachment loops  44  or by utilizing different types of buckles. 
         [0046]    If desired, the protective flap  25  underlying the shin strap may be omitted. 
         [0047]    It should also be understood that the sequences described above for applying the knee brace to the knee and attaching the knee brace to the boat are given by way of example. The steps can be performed in any desired order, and in the case of re-adjustment, may be performed individually rather than as a sequence. 
         [0048]    Accordingly, other embodiments are within the scope of the following claims.