Abstract:
A hammock is supported by vertical supports connected to hammock spreader bars at the head end and the foot end of the hammock at two vertically displaced points. An intermediate support comprising a transverse flexible strap suspended between the vertical support members at a user&#39;s knee region of the hammock raises the hammock in the knee region so as to remove the concavity at the location and reduce backward knee joint stress on the person reclining in the hammock.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 61/803,267 filed Mar. 19, 2013, the entire disclosure of which is incorporated herein by reference for all purposes. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The invention is related to a hammock, in particular to a hammock having end supports and an intermediate support for removing the normal concavity of the hammock and providing support at the knees of the user. 
         [0004]    2. Description of Related Art 
         [0005]    Hammocks are well known in the art and are used in many settings as a place of rest or respite. From their origin as a temporary or makeshift sling between two posts or trees, or between two stanchions in the bowels of a sailing ship, hammocks have come to be found in back yards everywhere. No longer relying on the happenstance of a pair of handy trees with just the right spacing, hammocks can also be found now with their own provided support base, allowing placement of a hammock anywhere. 
         [0006]    Hammocks, however, have one common trait that has only been marginally addressed. Hammocks, by their very nature, are flexible and necessarily form a curved surface for supporting a user. The “sling” of the hammock forms a generally uniform curve, only deviating from that smooth curve as weight is added to the hammock in a non-uniform distribution. Human beings are generally non-uniform in their weight distribution and furthermore are constructed with several mono-directional joints. Those joints most affected are the hips and particularly the knees. A person lying on his back in a hammock will necessarily have an upward pressure exerted against the back of his lower calves, causing a hyperextension of the knees. 
         [0007]    It would be desirable to provide a hammock with a construction that reduces or relieves this stress in the knee region by allowing the legs to be stretched out straight, or by lowering the foot end of the hammock so that the knees can be bent in a natural fashion. 
       BRIEF SUMMARY OF THE INVENTION 
       [0008]    A hammock according to the invention is supported at the head end and at an intermediate position in the bed of the hammock, with the foot end supported separately to allow the foot end to hang at a lower position, allowing a natural resting position with the knees of the user bent and not hyperextended. 
         [0009]    In one embodiment, the hammock has a first end and a second end, each of the first end and the second end including a transverse spreader bar and being connected to a respective generally vertical support member to suspend the hammock over a surface. The second end is preferably hung closer to the surface than the first end. The hammock further includes a supplemental support structure positioned between the first end and the second end and connected to one of the vertical support members. The supplemental support structure forms a raised portion of the hammock between the first end and the second end. 
         [0010]    In a preferred embodiment, the supplemental support structure includes an intermediate spreader assembly. The intermediate spreader assembly is positioned below and adjacent to a knee engaging portion of the hammock body. The intermediate spreader assembly preferably includes at least two hollow members, with one hollow member extending longitudinally along the edge of the hammock directly adjacent each side edge of the hammock. Two cables extend along the sides of the hammock with one cable extending from the first vertical support member, through the head end of the hammock, through the foot end of the hammock, and connecting to a low point on the second vertical support member. The other one of each set of two cables extends from the first vertical support member, through the head end of the hammock, through the hollow member, up to the supplemental spreader bar and connects to a high point on the second vertical support member. Of the two cables that pass through the supplemental spreader bar, one passes through each end of the supplemental spreader bar. The assembly also includes a flexible spreader strap that extends transversely across the hammock body between raised side edges of the intermediate spreader, resiliently supporting an intermediate portion of the hammock. In some embodiments, the lateral tension on this strap is adjustable, preferably with a tie down ratchet or hook and loop fastener. 
         [0011]    Another aspect of the invention is a set of traces or sleeves that extend along the sides of the hammock body. When the four cables are inserted through the traces, the hammock is both supported upwardly by the cables and has additional transverse tension exerted upon it. The tension caused by the cables serves to maintain the shape of the hammock when a person is lying in it. 
         [0012]    In another embodiment of the invention, the hammock is supported by one cable on each side (rather than two cables per side). In this embodiment each cable extends from the first vertical support member, through the head end of the hammock, through the hollow member of the intermediate spreader assembly, through an end of the supplemental spreader bar, and connects to the second vertical support structure. The foot end of the hammock is connected to a spreader bar at the second end of the hammock, which is in turn suspended from a vertical support at the foot end to support the foot end at a relatively lower position to prevent reverse bending of the user&#39;s knees. 
         [0013]    These and other aspects of the present invention will be more fully understood following a review of the detailed description and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  is a perspective view of a hammock with intermediate support according to the invention. 
           [0015]      FIG. 2  is a side elevational view of the hammock of  FIG. 1 . 
           [0016]      FIG. 3  is a perspective view of an intermediate spreader assembly according to the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0017]    Referring to  FIG. 1 , a perspective view of a first embodiment of the present invention is presented. A hammock  10  having a first or “head” end  14  and a second or “foot” end  16  is formed by a sheet of fabric  12 . The sheet  12  is a generally elongated rectangular configuration and has parallel sides  18 ,  20 , the sides being generally longer than the first and second ends  14 ,  16  of the hammock  10 . It is contemplated that the fabric sheet  12  could be formed of cloth, woven threads, or line, as is known in the art. The hammock  10  is supported by two separated upright members  70 ,  72 . Fanned rope sets  22  and  24  extend, one from each end of the hammock  10 , to a respective one of the upright members  70 ,  72 . The ropes could be traditional rope, cable, or other flexible support line. 
         [0018]    In this embodiment, a rigid head end spreader bar  28  is attached to the first end of sheet  12  in a manner designed to maintain the hammock  10  in a general straight line at the head end  14  as a load (person) lies within the hammock. A foot end spreader bar  26  is attached to the second end of the sheet  12  to serve a like purpose. 
         [0019]    In a conventional hammock according to the prior art, two spreader bars and their associated rope sets are hung at approximately the same height relative to the ground surface and provide the only support for the hammock body, so that the length of the hammock between the spreader bars forms a generally uninterrupted smooth concave curve along the longitudinal axis of the hammock. 
         [0020]    In the present invention, the foot end  16  of the hammock  10  is desirably hung at a lower height than the head end  14 . To achieve the height difference between the ends of the hammock  10 , the foot end fanned rope set  24  can be attached to the upright support  72  at a lower position, or with a reduced tension or longer rope relative to the attachment of the head end fanned rope set  22  on the other upright support  70 . As a result, the foot end  16  is positioned lower than it would be in a conventional hammock according to the prior art. 
         [0021]    An intermediate spreader assembly  32  is provided at an intermediate position along the length of (and beneath) the hammock  10  in a position to provide an upward break in the uniform curve of the hammock body  12  corresponding to the approximate location of a user&#39;s knees. In this position, the spreader assembly  32  functions to support the knees and prevent hyperextension of the knees by removing upward force on the user&#39;s feet. In order to accomplish this, the intermediate spreader assembly  32  is also connected to the upright support  72  by upper side cable lines  58 ,  62  (discussed in more detail below). 
         [0022]    As shown in  FIG. 2 , the hammock  10  thus forms a uniform concave surface between the first spreader bar  28  and the intermediate spreader assembly  32 , rather than between the first and second spreader bars  28 ,  26 , as in the prior art. The portion of the hammock between the intermediate assembly  32  and the second spreader bar  26  hangs low enough so that the user&#39;s knees are not subjected to reverse bending pressure. Desirably, the second spreader bar  22  is positioned below the top of the intermediate spreader assembly  32 , forming a break in the arc of the hammock material  12  so that the user&#39;s knees can bend at the position of the intermediate spreader assembly  32 . 
         [0023]    A further feature of this embodiment of the invention is the inclusion of cable traces or sleeves  54 ,  56 ,  66 ,  68  in the side edges  18 ,  20  of the hammock fabric  12 . Two side cables extend through each of the upper sleeves  54 ,  56  and one side cable extends through each of lower sleeves  66 ,  68 . Specifically, an upper side cable  58  and lower side cable  60  extend adjacently along side  18  of hammock body  12 , from upright support  70 , through one end of the head end spreader bar  28 , through an upper side trace  54 . At the far end of upper side trace  54 , the upper cable  58  passes through intermediate spreader  32  and then diverges from lower cable  60 . Upper cable  58  then extends upwardly through one end of a supplemental spreader bar  30  and connects to upright support  72 . The lower side cable  60 , in contrast, passes out of upper side trace  54 , extends through spreader assembly  26 , and then extends through the lower side trace  66 , through one end of the foot end spreader bar  26 , and connects to upright support  72  (at a lower position than upper cable  58 ). Likewise, a corresponding upper side cable  62  and lower side cable  64  on the opposite side edge of the hammock extend through corresponding paths from upright support  70 , through a second end of head end spreader bar  28  and through upper side trace  56 , and intermediate support  32 . The cables diverge thereafter, with upper cable  62  passing out of trace  56 , through spreader assembly  32 , and extending back upwardly through the second end of supplemental spreader bar  30 , and connecting to upright support  72 . Lower side cable  64  extends through lower side trace  68  through the intermediate spreader, and then through the second end of the foot end spreader bar  26 , and connecting to upright support  72  (at a lower position than upper cable  62 ). All four cables  58 ,  60 ,  62 ,  64  are under tension. In addition to aiding in maintaining the relative heights of the of the ends and middle of the hammock  10 , these cables also serves to maintain the desired transverse tension in the fabric  12  to provide support to the user, and to prevent the edges of the hammock fabric from collapsing transversely inwardly. The cable traces serve as guide tubes for the cables. However, they also serve to hold the intermediate spreader at its desired longitudinal position on the assembly. 
         [0024]    While the inclusion of lower side cables  60 ,  64  is preferred, they are not necessary for the functioning of the invention. In such a case, the fabric of the hammock provides the tension resistance supplied by the lower side cables. In such a case, the lower side traces  66 ,  68  are not needed as cable conductors. 
         [0025]    The supplemental spreader bar  30  is positioned between upper side cables  58  and  62  in an orientation that is transverse to the body  12  of the hammock  10  and generally parallel to the other two spreader bars  26  and  28 . This bar  30  serves to maintain a wider space for the user&#39;s body to fit between cables  58  and  62 . 
         [0026]    Referring now to  FIG. 3 , a perspective view of the intermediate spreader assembly  32  of the present invention is shown in isolation. The spreader assembly  32  includes a spreader box  34  and flexible spreader strap  52 . The spreader box  34  is a symmetrical support structure constructed of a framework of rigid members, for example, PVC pipes. The box  34  includes a rigid square  40 ,  42  on each end. Each square  40 ,  42  is formed of two spaced upright members  46  and  48  connected at their ends to lower cross member  44  and upper cross member  50 . Each of the upper cross members  50  is preferably hollow so as to allow the side cables  58 ,  62  to extend through the spreader assembly  32 , as discussed above. Extending transversely beneath the hammock body  12  between corresponding bottom corners of upright members  46  and  48  are a pair of rigid transverse members  36 ,  38 . These members  36 ,  38  maintain the proper distance between the two ends  46 ,  48  of box  34 . 
         [0027]    A flexible spreader strap  52  extends between the upper members  50  of ends  46  and  48 . The strap  52  is preferably formed of nylon, canvas or other flexible material having good tensile strength with minimal stretching. The strap  52  is positioned transversely directly under the hammock surface  12  to support the surface and provide a “break” point in the curvature of the hammock  10 . The strap also thus forms a wide, non-rigid positive support in the proper position for the user&#39;s knees. In one embodiment, the tightness of the strap  52  is adjustable by the user using tie down ratchet  54 . 
         [0028]    The spreader assembly  32  provides additional transverse support for the hammock fabric  12  at the intermediate position, serving to keep the edges of the fabric spread apart to reduce the transverse curvature of the hammock fabric, as it would otherwise sag more inwardly in the absence of the spreader assembly  32 . 
         [0029]    A hammock with intermediate support has been described in this disclosure in various exemplary embodiments, but it will be understood by those having ordinary skill in this art that the disclosed invention is not limited by this description. Various modifications and variations of the described embodiments may be made without departing from the scope of this invention.