Patent Publication Number: US-6711763-B2

Title: Backpacker&#39;s hammock and ground bivy

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to an ultra lightweight hammock and ground bivy for backpackers and camping enthusiasts. More specifically, this invention relates to an ultra lightweight hammock for safe and secure suspension between a pair of supports. 
     Conventional hammocks possess several desirable features for the camper. They certainly provide comfortable sleeping accommodations. They also are particularly advantageous where the terrain is uneven, rocky, or inhabited by various ground dwellers such as insects and reptiles. 
     On the other hand, conventional hammocks include a variety of undesirable features which have limited their widespread use by camping enthusiasts. Weight and stability are key drawbacks. It has been long known to provide a horizontal, rigid cross member at either or both ends of the hammock in order to improve stability. A typical example of such feature is illustrated in U.S. Pat. No. 4,686,720 of Newell. The added bulk and weight of these stiffening members, however, renders the hammock unsuitable for camping equipment generally. Serious backpackers, being extremely conscious of bulk and weight, would not even consider construction of the type illustrated in Newell. 
     Reduced weight for a hammock has been achieved, but at the sacrifice of stability. Examples are found in U.S. Pat. No. 5,913,772 of Clark and U.S. Pat. No. 6,185,763 of Hennessy. Both eliminate the rigid support members of the type as required by Newell and similar constructions, but both are suspended at each end by a rope. One end of the rope is connected to the hammock itself (typically, to a metal ring) and the opposite end is tied to a tree or similar upright support. This results in a somewhat precarious construction where the hammock tends to roll, tip or twist along the axes of the rope lines at each end. The user must be extremely careful when using such a hammock, particularly when entering or exiting the construction, or risk being dumped to the ground. The Hennessy patent provides that the sides of the hammock can be staked to the ground intermediate the hammock ends for stability. This, of course, assumes that the terrain is suitable for secure staking. 
     In addition to the potential danger associated with the instability of rope ties on each end of a hammock, the user must possess some skill in knot tying in order to effectively secure the hammock to an adjacent tree. And lastly, this method of attachment typically scars or otherwise marks the bark of the tree from which a hammock is suspended. This is unacceptable to environmentally conscientious campers and backpackers who follow the socially responsible wilderness directive to “leave only your footprints.” 
     The need remains in the camping and backpacking industry for an extremely lightweight hammock and ground bivy which provides both a safe and stable construction suspendible from trees in an environmentally responsible manner. The primary objective of this invention is to meet this need. 
     SUMMARY OF THE INVENTION 
     More specifically, an object of the invention is to provide an ultra lightweight hammock of durable construction which may be folded and packed in a minimal space. 
     Another object of the invention is to provide an ultra lightweight hammock which may be suspended in a stable condition between two adjacent trees in order to resist the tipping and rolling motion heretofore associated with conventional hammocks. 
     Yet another object of the invention is to provide an ultra lightweight hammock which may be safely and stably suspended between two adjacent trees without special knowledge or skill in knot tying techniques. 
     An additional object of the invention is to provide an ultra lightweight hammock which may be suspended between two adjacent trees without marring or otherwise damaging the tree bark. 
     A further object of the invention is to provide an ultra lightweight hammock of the character described which can also double as a ground bivy. 
     In summary, an ultra lightweight hammock for suspension between two trees includes a rectangular top panel joined along at least three side and end edges to a bottom panel. An elongate opening permits access between the top and bottom panels. Tubular sleeves form each end of the hammock and receive elongate webs which extend from the ends of the tubular sleeves around an adjacent tree to be secured by an adjustable buckle attachment. An option pocket may be formed in the bottom panel to receive a sleeping pad. 
     Other and further objects of the invention, together with the features of novelty appurtenant thereto, will appear in the description of the drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the following description of the drawings, in which like reference numerals are employed to indicate like parts in the various views: 
     FIG. 1 is a perspective view of a hammock constructed in accordance with a first preferred embodiment of the invention shown suspending between a pair of trees; 
     FIG. 2 is an enlarged fragmentary view of one end of the hammock taken along line  2 — 2  of FIG. 1 in the direction of the arrows; 
     FIG. 3 is a top plan view of the hammock prior to suspension between a pair of supports; 
     FIG. 4 is a side sectional view of the hammock taken along line  4 — 4  of FIG. 3 in the direction of the arrows; 
     FIG. 5 is a sectional plan view of the hammock taken along line  5 — 5  of FIG. 4 in the direction of the arrows; 
     FIG. 6 is a top plan view of a hammock constructed in accordance with a second preferred embodiment of the invention shown prior to suspension between a pair of supports; and 
     FIG. 7 is a sectional view of the hammock taken along line  7 — 7  of FIG. 6 in the directions of the arrows. 
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     Referring to the drawings in greater detail, attention is first directed to FIG.  1 . which illustrates a first preferred embodiment of a hammock construction of the invention, designated generally by the numeral  10 , suspended between a pair of spaced apart trees  11  &amp;  12  or similar upright supports. 
     The construction of the hammock  10  can be understood with reference to FIGS. 3-5. The hammock  10  includes a generally rectangular, bottom panel  14  (FIGS. 4 &amp; 5) having a width and a length appropriately sized to accommodate the user. The bottom panel  14  has longitudinal side edges  14   a  &amp;  14   b  which extend along the length of the panel and lateral end edges  14   c  &amp;  14   d  which extend along the width of the panel. 
     The hammock  10  also includes a generally rectangular, top panel  16  (FIGS. 3 &amp; 4) which covers the bottom panel  14  and which has a width and a length substantially corresponding to those dimensions of the bottom panel  14 . Accordingly, the top panel  16  has longitudinal side edges  16   a  &amp;  16   b  which extend along the length of the top panel  16  and correspond respectively to the longitudinal side edges  14   a  &amp;  14   b  of the bottom panel  14 . Similarly, the top panel  16  has lateral end edges  16   c  &amp;  16   d  which extend along the width of the top panel  16  and correspond respectively to the lateral end edges  14   c  &amp;  14   d  of the bottom panel  14 . 
     More particularly, in the construction of the first embodiment of hammock  10 , the longitudinal side edges  14   a  &amp;  14   b  of the bottom panel  14  are integrally formed with or securely connected to the corresponding longitudinal side edges  16   a  &amp;  16   b  of the top panel  16 . In like manner, the lateral end edges  14   c  &amp;  14   d  of the bottom panel  14  are integrally formed with or securely connected to the corresponding lateral end edges  16   c  &amp;  16   d  of the top panel  16 . 
     The top panel  16  has a longitudinal slit or opening  18  intermediate the longitudinal side edges  16   a  &amp;  16   b  thereof which may extend the substantial length of the top panel  16  to provide access to the space defined by the top panel  16  and the bottom panel  14 . Fasteners  20 , such as Velcro or hook and loop tabs, may be spaced along the opening  18  to selectively open or close the opening  18  as desired. 
     Secured at least to each end edges  14   c  &amp;  14   d  of the bottom panel  14  are tubular sleeves  22  &amp;  24  which extend substantially the width of the bottom panel  14 . The tubular sleeves  22  &amp;  24  may also be secured to the end edges  16   c  &amp;  16   d  of the top panel  16 . 
     Received respectively within the tubular sleeves  22  &amp;  24  are web or belt members  26  &amp;  28 . Each web  26  &amp;  28  has a width substantially greater than its thickness. Connected to the webs  26  &amp;  28  are a corresponding adjustable buckles  30  &amp;  32 . Preferably each buckle  30  &amp;  32  includes a takeup adjustment known to those skilled in the fastener arts such that when the buckle is closed, the tag end of the web may be pulled to effectively tighten the encircled region of the web. 
     As shown in FIGS. 4 &amp; 5, an interior panel  34  is secured to the bottom panel  14  to form an interior pocket  36 . Generally, the width and length dimensions of the interior panel  34  are less that the corresponding width and length of the bottom panel  14 . As shown in FIG. 5 the interior panel  34  is joined, as by stitching, along each longitudinal side and one end thereof to the bottom panel  14 . However, any three edges of the interior panel  34  may be selected for being secured to the bottom panel  14  so as to provide a pocket  36  of sufficient size to accommodate a backpacker&#39;s foam sleeping pad or air mattress as necessary. 
     For the true minimalist in lightweight backpacking gear, an alternative embodiment of the invention is illustrated in FIGS. 6 &amp; 7. The hammock, generally designated by the numeral  40 , includes a generally rectangular, bottom panel  42  having a width and a length appropriately sized to accommodate the user. The bottom panel  42  has longitudinal side edges  42   a  &amp;  42   b  which extend along the length of the panel and lateral end edges  42   c  &amp;  42   d  which extend along the width of the panel. 
     The hammock  40  also includes a generally rectangular, top panel  44  which covers the bottom panel  42  and which has a width and a length substantially corresponding to those dimensions of the bottom panel  42 . Accordingly, the top panel  44  has longitudinal side edges  44   a  &amp;  44   b  which extend along the length of the top panel  44  and correspond respectively to the longitudinal side edges  42   a  &amp;  42   b  of the bottom panel  42 . Similarly, the top panel  44  has lateral end edges which extend along the width of the top panel  44  and correspond respectively to the lateral end edges  42   c  &amp;  42   d  of the bottom panel  42 . 
     More particularly, in the construction of the second embodiment of hammock  40 , only the longitudinal side edge  42   a  of the bottom panel  42  is integrally formed with or securely connected to the corresponding longitudinal side edge  44   a  of the top panel  44 . Similar to the construction of the first embodiment, however, the lateral end edges  42   c  &amp;  42   d  of the bottom panel  42  are integrally formed with or securely connected to the corresponding lateral end edges of the top panel  44 . 
     So constructed, therefore, the longitudinal side edge  42   b  of the bottom panel  42  and the corresponding, but unjoined, longitudinal side edge  44   b  of the top panel  44  form an elongate slit or opening  46  to provide access to the space defined by the top panel  44  and the bottom panel  42 . 
     Secured at least to each end edges  42   c  &amp;  42   d  of the bottom panel  42  are tubular sleeves  48  &amp;  50  which extend substantially the width of the bottom panel  42 . The tubular sleeves  48  &amp;  50  may also be secured to the end edges of the top panel  44 . 
     Received respectively within the tubular sleeves  48  &amp;  50  are web or belt members  52  &amp;  54  of which only a portion is shown in FIG. 6 because the construction is the same as previously described for the first embodiment. Likewise, it will be understood that each web  52  &amp;  54  is fitted with a buckle fastener (not shown). Keeping with the desire to minimize weight, the alternative embodiment shown in FIGS. 6 &amp; 7 does not include an interior panel to form a sleeping foam pocket. 
     In terms of materials of construction, the various panels and tubular sleeves of the hammock  10  or  40  may be fabricated from a tightly woven, flexible fabric. For example, ripstop nylon is strong and durable for this application. Various weight grades of fabric may be selected as appropriate for the tradeoff between the advantages of lightweight versus greater durability. Likewise, the fabric may be coated or waterproofed as desired assuming the added weight of such treatment is acceptable. The web members may be nylon belting material of at least ¾ inch width fitted with buckles preferably made of lightweight polymer material. 
     With the exception of the buckles themselves, the rest of the hammock construction is of relatively flexible material which may be readily folded, stuffed or otherwise packed in a small space within a backpack or stuff sack. 
     In operation, the user simply removes the hammock  10  from storage and selects appropriately spaced apart trees  11  &amp;  12  from which to suspend the hammock. The web or belt  26  extending from each end of the tubular sleeve  22  is caused to encircle the tree  12  and the buckle fastener  30  is closed. If too much slack exists in the belt  26 , then the tag end may be pulled to snug the belt around the tree. It is important that the webbing material pass directly from the end of the tubular sleeve  22  around the tree  12  without the ends of the belt  26  twisting or crossing on itself. This permits the fabric of the tubular sleeve  22  to bunch together on the web so as to span a distance at least about ten percent of the overall width of the hammock when the top and bottom panels  16  &amp;  14  still have a rectangular form (i.e., before suspension from the tree). Thus the bunching of the tubular sleeve  22  on the web  26 , the diameter of the tree  12  itself, and, most importantly, the resistance to torsion of the web  26  all combine to provide a stable hammock suspension. 
     In like manner, the opposite belt  28  in tubular sleeve  24  may be secured by buckle  32  around the opposite tree  11 . The resultant hammock suspension is extremely resistant to the tipping and rolling motions heretofore associated with conventional hammocks. The installation can be quickly accomplished without special knowledge or skill in knot tying techniques, and without marring or otherwise damaging the tree from which the hammock is suspended. 
     From the foregoing it will be seen that this invention is one well adapted to attain all the ends and objects hereinabove set forth, together with the other advantages which are obvious and which are inherent to the invention. 
     It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims. 
     Since many possible embodiments may be made of the invention without departing from the scope thereof, it is understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense. 
     NUMERALS 
     hammock  10   
     trees  11  &amp;  12   
     bottom panel  14   
     longitudinal side edges  14   a  &amp;  14   b    
     lateral end edges  14   c  &amp;  14   d    
     top panel  16   
     longitudinal side edges  16   a  &amp;  16   b    
     lateral end edges  16   c  &amp;  16   d    
     slit or opening  18   
     fasteners  20   
     tubular sleeves  22  &amp;  24   
     web or belt members  26  &amp;  28   
     buckles  30  &amp;  32   
     interior panel  34   
     interior pocket  36   
     hammock  40   
     bottom panel  42   
     longitudinal side edges  42   a  &amp;  42   b    
     lateral end edges  42   c  &amp;  42   d    
     top panel  44   
     longitudinal side edges  44   a  &amp;  44   b    
     lateral end edges 
     elongate slit or opening  46   
     tubular sleeves  48  &amp;  50   
     web or belt members  52  &amp;  54