Abstract:
A multipurpose sleeping bag has a shell and liner covering a synthetic-fiber insulator. A head opening located in the center of the multipurpose sleeping bag is provided with a hook-and-loop fastener, which is used to draw the edges of the head opening around one&#39;s neck in an over garment mode of operation. A drawstring when used in the sleeping bag or quilt modes can close the head opening. A foot draft tube extends along the bottom edge to each side. A draw cord extends along the bottom outer end to compress the foot portion and the foot draft tube into a knot-like configuration for the sleeping bag mode. For operations other than the sleeping bag mode, the draw cord is left in place to form a skirt-like configuration. Two separate multipurpose sleeping bags can be joined to give the user a lower temperature sleeping range.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     This invention relates generally to a multipurpose sleeping bag, and more particularly to a sleeping bag that can be converted into an anorak (short coat), cagoule (long coat), poncho, quilt, or vehicle blanket, or be joined to another multipurpose sleeping bag so as to provide a higher degree of warmth.  
         [0003]     2. Description of the Related Art  
         [0004]     Present-day sleeping bags currently available on the market are not designed to be used as an anorak, cagoule, poncho, quilt, or vehicle blanket, or to be joined to another sleeping bag. Currently, people who want the above combination of items must carry them as separate items. The disadvantages of carrying separate items of equipment, such as those stated above, are additional cost and increased weight and bulk.  
       SUMMARY OF THE INVENTION  
       [0005]     Addressing a recognized need, this invention reduces the number of items, as well as the weight and bulk, which must be carried by campers and mountaineers.  
         [0006]     Another object of the present invention is to provide a multipurpose sleeping bag that can be converted into various forms, as stated above, and each of which is well designed to perform its intended function.  
         [0007]     The present invention provides a multipurpose sleeping bag which can be adapted to provide protection from cold weather while walking, riding, sitting, or reclining. The invention provides a single piece of equipment which is lightweight and which can quickly and easily be conversed from one use to another. Specifically, the invention can be configured as a single sleeping bag, long coat, short coat, poncho, quilt, or vehicle blanket, or readily joined with a second multipurpose sleeping bag to make a pair of single sleeping bags.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]      FIG. 1  is a perspective view illustrating the use of the invention as a sleeping bag.  
         [0009]      FIG. 2  is a perspective view with the head and foot ends open, exposing the inside of the multipurpose sleeping bag.  
         [0010]      FIG. 3  is a perspective view of the front side (outside) of the multipurpose sleeping bag.  
         [0011]      FIG. 4  is a perspective view of the bottom side of the multipurpose sleeping bag, showing the collar head opening.  
         [0012]      FIG. 5  is an enhanced fragmentary cross-sectional view illustrating the fastened zippers, the zipper guard and zipper draft tube attachments, the collar hood opening, and the insulation material of a preferred embodiment.  
         [0013]      FIG. 6  is an enlarged fragmentary sectional view taken of the head opening.  
         [0014]      FIG. 7  is an enlarged sectional view taken of the foot end as shown in  FIG. 1 .  
         [0015]      FIGS. 8, 9 , and  10  are perspective views illustrating the manner in which the multipurpose sleeping bag shown in  FIG. 1  may be worn as a long coat, short coat, or poncho, respectively.  
         [0016]      FIG. 11  is a perspective view with the head and foot ends of the inner multipurpose sleeping bag open, illustrating the placement of the second zipper.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0017]     Referring now to the drawings in more detail and particularly to  FIGS. 1 through 6 , it will be seen that the invention, as illustrated in currently preferred embodiments, is a trapezoidal-shaped multipurpose sleeping bag of unitary construction, indicated generally at  10 . Preferably, the multipurpose sleeping bag comprises three flexible layers: an external shell  11 , an internal lining  12 , and insulation material  13 , positioned between the external shell  11  and the internal lining  12  (see  FIG. 5 ). The external shell  11  and the internal lining  12  are preferably made of 70-denier nylon, commonly known as single-ply taffeta. The 70-denier refers to the thickness of the yarn. The actual weave is 86 yarns in one direction and 104 yarns in the other, per square yard. The thickness of the yarn should be chosen to absorb body heat and quickly warm to body temperature, because the faster this warming occurs, the slower will be the rate of conductive heat loss from the body. Further the spaces between yarns in this construction allow the moisture produced by the body to easily escape. Even in a dry climate, the body gives off moisture. Therefore, it is important to allow this moisture easy exit. Indeed, water is extremely efficient at absorbing heat, so one always wants to stay as dry as possible.  
         [0018]     The insulation material or fiberfill  13 , positioned between the external shell  11  and the internal lining  12 , preferably comprises an unbounded, silicone-coated continuous-filament fiber. The silicone coating gives the fiber two very desirable properties. The first is an antistatic property, which allows the fibers to perpetually repel each other; regardless of how tightly the fibers are packed against each other (such as when the invention is compacted in a stuff sack). This property also contributes to the loft always returning after the multipurpose sleeping bag  10  is removed from the stuff sack. The second beneficial property of the silicone treatment is in making the fiber hydrophobic. Water simply does not attach itself to the fiberfill  13 . It is extremely important that the moisture leaving the body be able to pass through the spaces between the yarns of the external shell  11  and the internal lining  12 , and to easily move through the insulation material  13 . Also, it is imperative that the moisture not be able to condense in the insulation material  13 . If this occurs when temperatures are below freezing, frost buildup can severely reduce the thickness of the insulation material  13 , or the moisture may simply freeze as in any other sleeping bag, and thus add weight.  
         [0019]     Even though insulation material  13  is described as a synthetic unbounded, silicone-coated continuous filament fiber, the multipurpose sleeping bag  10  can be made from any other suitable insulation filling.  
         [0020]     By eliminating quilting with laminating the insulation material  13  to the internal lining  12 , the insulation material is prevented from drifting around haphazardly inside the sleeping bag and creating uneven insulation, resulting in cold spots. This laminating procedure also permits less insulation material to be used, which in turn permits a lighter-weight multipurpose sleeping bag.  
         [0021]     In addition, quilting produces a fiberfill that is so densely packed that a wall is created. While this wall of synthetic fiber insulation does not absorb moisture, it inhibits the flow of moisture, which condenses in the sleeping bag.  
         [0022]     The fibers that are touching each other also cause conductive heat loss. When fibers chill, the moist vapor is cooled rapidly, changing it to liquid and then ice, further endangering bodies which dehydrate much more rapidly in extreme cold climates than in hot climates. The insulation material  13 , on the other hand, is quite different with respect to water. Because the fibers are antistatic and repel each other, and are not compacted from a quilting process, the moisture moves more easily through the insulation material  13 . This movement of moisture is further enhanced by the silicone treatment of the fiber. Silicone acts like a lubricant, which allows the moisture to move approximately 16 times more rapidly through the insulation material  13 . In extreme cold conditions, the more rapidly one&#39;s own moisture dissipates, the better off you are.  
         [0023]     The insulation material  13  also allows the body&#39;s thermostat to function more easily. The body&#39;s heating mechanism is constantly turning off and on to compensate for heat loss or heat build up. Thus, the body is continuously generating moisture, which is emitted through the pores of the skin. If the flow of this moisture is blocked or absorbed by the insulation, then that moisture becomes the enemy. If the air temperature is below the freezing point, the moisture trapped in the insulation may freeze. This is especially a problem in extreme cold conditions such as are found in the arctic. Evaluation of many sleeping bags shows an approximate weight gain of five or ten pounds of ice per week. Consequently, body heat is conducted away by the ice forming in the prior art bag. Significantly, one can live a lifetime in a climate with an ambient air temperature of 45 degrees F., but only an hour or so in water that is 45 degrees F. The insulation material  13  of the present invention is a less-restrictive insulation with respect to the flow of moist air.  
         [0024]     All three layers  11 ,  12 , and  13  extend the length and width of the multipurpose sleeping bag and have their entire edge portions joined to each other along their lengths by, e.g., zippers and/or stitching, or other suitable means, as discussed more fully below.  
         [0025]      FIG. 1  shows that the multipurpose sleeping bag  10  includes four sides (right or “east” side  16 , left or “west” side  17 , top or “north” side  18 , and bottom or “south” side  19 ) in the sleeping bag mode of operation. As  FIG. 1  shows, sides  16  and  17  are provided with separable fastener halves  23  and  23   a  (illustratively forming a zipper, in a preferred embodiment). These fasteners preferably form a two-way zipper, with a double slider  23   b ,  23   c  opening the zipper from the top “north” side  18  and bottom “south” side  19 , respectively. By reference to  FIGS. 1 and 2 , it will be seen that fastener halves  23  and  23   a  extend substantially the length of the multipurpose sleeping bag  10 . Hereinafter, fastener halves  23  and  23   a  will be termed “zippers” or “zipper halves”, but the person of ordinary skill will understand that these terms are representative only and not limitative of the invention.  
         [0026]     External shell  11  preferably extends over the top and around the bag, and is sewn together as at  15  along the bottom center portions of the multipurpose sleeping bag  10 . Further, layers  11 ,  12 , and  13  are joined to each other along the length of zipper  23  and by assembly stitching  14  around the radius of the head portion at top or “north” side  18  and the foot portion at bottom or “south” side  19 , and at the head opening slit  40  of the multipurpose sleeping bag  10 . Layers  11 ,  12 , and  13  are also preferably stitched to right or “east” side  16  along with a 1½-inch strip of black webbing, for example, to act as a zipper guard  20 . The zipper guard  20  keeps zipper  23  from getting caught in the internal layer  12 . Zipper guard  20  is inserted on the inside of zipper  23  and layers  11 ,  12 , and  13 , and held by stitching  21 .  
         [0027]     Directly behind zipper  23  (for example, 1½ inches to the left) is placed a zipper draft tube  22 . The zipper draft tube  22  keeps the heat within sleeping bag  10  from escaping through the zipper  23 , and is stitched to layers  12  and  13 . Layers  11 ,  12 , and  13  are further stitched to “west” side  17  along with zipper  23   a.    
         [0028]     Sewn to the foot portion  27  and to the bottom foot edge  28  is a preferably continuous-filament fiber insulation foot draft tube  29 . The foot draft tube  29  keeps the heat within the sleeping bag  10  from escaping through the bottom “south” side  19 .  
         [0029]     Again with reference to  FIG. 1  and  FIG. 2 , when the sleeping bag portions  11 ,  12 , and  13  are sewn together, the sleeping bag hood portion  24  is sewn and forms the hood edge  25 . A hood draw cord sleeve  26  is sewn to hood edge  25 , through which runs a hood cord  26   a  to selectively draw the hood around the head of the wearer when used in the sleeping bag mode. A slide  26   b  is provided to engage each end portion of hood cord  26   a  to retain the hood opening in the desired position.  
         [0030]     Another important feature of the invention is the provision of an open foot portion. Again, when layers  11 ,  12 , and  13  are sewn together, the sleeping bag foot portion  27  and the foot draft tube  29  forms the bottom foot edge  28 . A foot draw cord sleeve  30  is sewn to edge  28  and foot draft tube  29 . The foot draw cord sleeve  30  has a foot draw cord  30   a , similar to  26   a  discussed above. When the multipurpose sleeping bag  10  is zipped into the sleeping bag mode of operation, the foot draw cord  30   a  provides the capability of drawing the bottom portions of layers  11 ,  12 , and  13  together and wrapping the foot draw cord  30   a  around layers  11 ,  12 ,  13  and edge  28  (and foot draft tube  29 ), thereby closing off the open foot portion. This act increases the amount of insulation around the feet of the user and keeps the heat within the bottom “south” side  19  from escaping. Again, a slide  30   b  is provided to engage each end portion of foot draw cord  30   a  to retain the bottom opening to the correct tightness as the user demands in the sleeping bag mode of operation.  
         [0031]     The individual elements for forming the hood collar  40  are illustrated in  FIG. 6 . The hood collar is illustratively formed from two rectangular sheets  41  and  42 , which are made from layers  11 ,  12 , and  13  and sewn together. The locking device to secure sheet  41  to sheet  42 , when using the multipurpose sleeping bag  10  in the sleeping bag mode of operation, is formed by sewing a 1-inch-by-10-inch strip of hook-type fastener  45  to the center position of the external side  11  of  41 , and by sewing a 1-inch-by-10-inch strip of loop-type fastener  46  to the center position of the internal side  12  of  42 . The rectangular sheets  41  and  42  are joined together at  43  and  44 , and are then joined to multipurpose sleeping bag  10  by stitches around the radius of the head opening slit, forming the hood collar  40 . This gives the user the capability of closing the hood collar  40  when using multipurpose sleeping bag  10  in the sleeping bag mode of operation. It is also an important feature that the edges of hood collar  40  may be brought to fit about the wearer&#39;s neck when using the multipurpose sleeping bag  10  in the over garment mode of operation as shown in  FIGS. 8, 9 , and  10 .  
         [0032]     To form the cagoule or long coat as seen in  FIG. 8 , one begins with the multipurpose sleeping bag  10  as formed in  FIG. 1 . The foot draw cord  30   a  is unwrapped around the bottom “south” side  19  and spread out, as seen in  FIG. 3 . Then, zipper  23  is unzipped to below the hood collar  40 , and sides  16  and  17  raised to approximately waist level. By stepping into the bottom “south” side  19  and holding the multipurpose sleeping bag  10  in front with zippers  23  and  23   a  facing the wearer, sheets  41  and  42  are grasped and pulled apart, permitting the wearer to insert his head into the hood collar opening  40 . Then, sides  16  and  17  can be tossed over the head to configure the long coat. If desired, hood draw cord  26   a  can be drawn from one end of hood draw cord sleeve  26  while holding the other end, and tied off into a belt at the waist. Further, excess fabric from layers  11 ,  12 , and  13  can be pushed to the back of the waist for best fit and a neater appearance.  
         [0033]     To form the anorak or short coat as seen in  FIG. 9 , from the long coat mode, the wearer reaches down and under the multipurpose sleeping bag  10 , grabs the ends of bottom or “south” portion  19 , and raises up the ends approximately to waist level. By pulling the ends of foot draw cord  30   a  at the back of the waist, crossing them, and bringing them outside and around to the front of the waist, the ends of foot draw cord  30   a  can be tied off into a belt. Again, excess fabric of layers  11 ,  12 , and  13  can be smoothed out to the back of the waist for best fit.  
         [0034]     To form the poncho as seen in  FIG. 10 , the wearer begins with the multipurpose sleeping bag  10  as formed in  FIG. 3 . The zipper  23  is completely unzipped from zipper  23   a  of multipurpose sleeping bag  10  and laid flat with outside fabric of layer  11  facing the ground. The multipurpose sleeping bag  10  is raised by grasping the sides  16  and  17  from the foot end (bottom or “south” end), and the wearer puts his head through the head opening  40  and flips the hood end (top or “north” end)  18  over the shoulders.  
         [0035]     A compressing stuff sack is preferably provided to compress and carry multipurpose sleeping bag  10 .  
         [0036]      FIG. 11  shows an embodiment in which a second multipurpose sleeping bag is added as an over bag  10   a  to the multipurpose sleeping bag  10  described above, thereby creating a combination system  9  having increased thermal capacity. The over bag  10   a  has elements identical to those of bag  10 , which are indicated by like reference numerals appended by the letter “a”.  
         [0037]     However, the over bag  10   a  can provide even greater versatility for the wearer using insulation material of different weights. For example, the insulation material  13   a  of  10   a  may be around 2.5 to 3 pounds for a temperature rating of +35 degrees F. and up, while insulation material  13  of  10  may have an insulation filling of 4.5 pounds for a temperature rating of +20 degrees F. Thus, when the weather is fairly mild and not expected to be below +35 degrees F., the user who does not wish to carry the complete system formed of the dual multipurpose sleeping bags  10 ,  10   a  simply unzips the multipurpose sleeping bags and takes only bag  10   a . If the temperature is to drop to between +35 degrees F. and +20 degrees F., only sleeping bag  10  is used, but if the temperature is to be colder than +20 degrees F., multipurpose sleeping bag  10  is zipped to multipurpose sleeping bag  10   a , and the system  9  of the two bags  10 ,  10   a  protects down to about −25 degrees F.  
         [0038]     Referring to  FIG. 11 , the system  9  is assembled by placing bag  10  over bag  10   a  so that the external shell  12   a  of bag  10   a  is facing the ground, while the external shell  12  of bag  10  is facing the internal lining  12   a  of  10   a . The zippers  23   d  and  23   e  of bag  10   a  are added to bag  10   a  along both sides  16   a  and  17   a  and next to zippers  23  and  23   a , so that bag  10  can be joined to bag  10   a , thereby forming the combination operational sleep system  9 .  
         [0039]     From the foregoing, it can be seen that the foot end and the hood collar of the present invention, by reason of both their shape and dimensional relationship to the individual user, provides a multipurpose capability for the user not heretofore present in a single sleeping bag. It is also to be understood that the foregoing disclosure describes only the preferred embodiments of the present invention, and that numerous alterations and modifications can be utilized to practice the present invention without departing from the scope and spirit of the invention as defined in the appended claims.