Abstract:
This invention relates to sleeping bags, more particularly to sleeping bags whose outer shell, liner, and insulation characteristics may be varied through selection of various combinations that are particularly suitable for the planned usage. The sleeping bag of this invention comprises a case constructed from two panels whose sides and one pair of ends are attached to one another and the other pair of ends define an opening into the space between the panels. The sleeping bag further comprises an insulation layer that is sized and configured to be easily removable and replaceable through the opening in the case. At least one fastener attaches the insulating layer to the case. Insulation layers having different thermal ratings may be substituted as needed to obtain adequate protection under varying weather conditions. Being removable from the insulation layer, the case may be cleaned and/or aired separately therefrom. The inner panel includes a closeable opening proximal the longitudinal centerline thereof, to permit easier placement and removal of the insulating layer between the two panels.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to sleeping bags, more particularly to sleeping bags having insulation that can readily be removed and replaced with insulation having a different insulation factor. 
     2. Description of the Prior Art 
     Conventional sleeping bags consist basically of an outer shell, an inner liner and a layer of insulation. The outer shell and liner are sewn together to form a case and insulation is inserted between the outer shell and the liner before the case is stitched closed. The insulation is then sewn in place to prevent the insulation from migrating. The case then may be folded over upon itself so that its opposing edges are aligned. A zipper or other attaching means is attached along the bottom and the longitudinal sides of the case to open and close the sleeping bag. 
     The conventional sleeping bag must be purchased as a unit, leaving little option to the user as to the types of material, the amount of insulation or the color. When the shell or inner lining of a conventional sleeping bag is damaged, the whole sleeping bag frequently must be replaced. When one portion of the sleeping bag becomes soiled, the whole sleeping bag must be cleaned even though the insulation layer may be soiled far less than the shell or the inner liner. 
     Notwithstanding the existence of such prior art sleeping bags, it remains clear that to be able to easily disassemble the sleeping bag into its component parts (shell, inner liner and insulation layer) would enable the user to clean only the soiled part and having these component parts marketed separately would permit the user to replace only the damaged component. There is also a need for easy access to the insulation layer for ease of removal and a need for a means for maintaining the insulation layer properly aligned within the case. 
     SUMMARY OF THE INVENTION 
     The current invention relates to a sleeping bag having an easily removable insulation layer so that insulation layers having different thermal ratings may be substituted as needed to obtain adequate protection under varying weather conditions. The case of the sleeping bag is soiled more easily than the insulation layer and must be cleaned frequently. The case being easily removable from the insulation layer, permits the case to be cleaned as needed without over-washing the insulation layer. 
     The sleeping bag comprises a case constructed of a first panel that has opposing longitudinal sides, a first end and a second end and a second panel also having opposing longitudinal sides, a first end and a second end. The longitudinal sides of the first panel are attached to the juxtaposed longitudinal sides of the second panel and the second end of the first panel is attached to the second end of the second panel, defining a case and creating a compartment between the first panel and the second panel. The first ends of the first and second panels define an opening into the compartment. The attached longitudinal sides of the first panel and the second panel define a first side and a second side of the case, the first ends of the first and second panels define the first end of the case and the attached second ends of the first panel and the second panel define the second end of the case. 
     An insulating layer, having a predetermined insulation factor, is inserted through the opening into the compartment defined between the first panel and the second panel. At least one fastener attaches the insulating layer to the case to restrict movement of the insulating layer within the case. 
     The case is folded upon itself along the longitudinal center line of the case so that the first side of the case is adjacent to the second side of the case. When the case is folded the second end of the case is folded upon itself so that a first portion of the second end of the case is juxtaposed to a second portion of the second end of the case. The longitudinal sides of the case are releasably attachable to one another and the two portions of the second end of the case are releasably attachable to one another. 
     The invention accordingly comprises an article of manufacturer possessing the features, properties, and the relation to elements which will be exemplified in the article hereinafter described, and the scope of the invention will be indicated in the claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings, in which: 
     FIG. 1 is an isometric view of the sleeping bag of this invention; 
     FIG. 2 is a cross-sectional view of the sleeping bag of this invention taken along line  2 — 2  of FIG. 1; 
     FIG. 3 is an unfolded bottom plan view of the sleeping bag of FIG. 1, with portions broken away to illustrate the juxtaposition of the first panel, the insulation layer, and the second panel; 
     FIG. 4 is an unfolded top plan view of the sleeping that of FIG. 1; 
     FIG. 5 is an unfolded bottom plan view of a second embodiment of the sleeping bag of FIG. 1 
     FIG. 6 is an unfolded top plan view of a third embodiment of the sleeping bag of this invention, illustrating the second panel removed from the first panel; 
     FIG. 7 is an unfolded bottom plan view of the insulating layer of the sleeping bag of FIG. 1; and 
     FIG. 8 is a cross-sectional view of the insulating layer taken along line  8 — 8  of FIG.  7 . 
     Similar reference characters refer to similar parts throughout the several views of the drawings. The same parts of different embodiments are identified in increments of 100. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A preferred embodiment for the sleeping bag of this invention is illustrated in the drawing FIGS. 1-4 in which the apparatus is generally indicated as  10 . As seen in FIG. 1, the apparatus  10  is comprised of a case, shown generally as  12 , and as shown in FIG. 2 and 3, an insulation layer shown generally as  38 . 
     As seen in FIG. 3, case  12  comprises a first panel  14  and a second panel  16 . The first panel  14  has a pair of longitudinally extending sides  18  and  20 , a first end  22  and a second end  24 . The second panel  16 , as seen in FIG.  4 ,also comprises a pair of longitudinally extending sides  26  and  28 , a first end  30  and a second end  32 . As clearly seen in FIG. 2, the first panel  14  is juxtaposed to the second panel  16 , so that the longitudinal sides of the first panel are adjacent to the corresponding longitudinal sides of the second panel and the first end  24  of the first panel  14  is adjacent to the first end  30  of the second panel  16 . The longitudinal side  18  of the first panel  14  is attached to the longitudinal side  26  of the second panel and the longitudinal side  20  of the first panel  14  is attached to the longitudinal side  28  of the second panel  16 . Also, the second end  24  of the first panel  14  is attached to the second end  32  of the second panel  16 . In a preferred embodiment, the panels are attached to one another by stitching, or other well-known nonremovable fastening means, so that they are permanently joined together during use. However, the first ends  22  and  30  of the first and second panels respectively, remain unattached defining an opening  34  into the case  12  for access into the compartment  36  between the first and second panels,  14  and  16  respectively. 
     An insulation layer  38 , as seen in FIG. 7, is sized and configured to be receivable within and removal from the compartment  36  through the opening  34 . The insulation layer  38  may be constructed in any well-known fashion, including sewing material  40  together to create a bag like structure to contain loose insulation material  42  or batting. The insulation layer  38  may be sewn along a plurality of lines  44 , or may be quilted (not shown) to maintain the shape of the insulation layer  38  by reducing the migration of the insulation material  42 . The insulation layer  38  may also be a layer of preformed bonded batting material, which is adequately bonded to prevent migration. In the alternative, the insulation layer  38  may be any other suitable insulating material, including but not limited to, a woven or unwoven sheet material. 
     At least one fastener  46  is used to attach the insulation layer  38  to the case  12  to prevent it from shifting within the case  12 . As seen in FIG.  3  and FIG. 7, in a preferred embodiment, the fastener  46  comprises a two-part hook and loop fastener in which one part  46   a  is attached to the first panel  14  and a second part  46   b  is attached to the insulation layer  38 . Also, in this preferred embodiment, there are three fasteners  46  arrayed proximal to the second end  24  of the first panel  14  and the second end  48  of the insulation layer  38 . In other preferred embodiments, one-half of the fastener  46  may be located anywhere on the first panel  14  or on the second panel  16  with the other half on the adjacent area of the insulation layer  38 . In other embodiments, the fastener  46  may comprise a snap, a hook and eye or any other well-known attaching means that would be suitable for the purpose. 
     In a preferred embodiment, the opening  34 , may be closed by at least one hook and loop fastener  50 , with the first part  50   a  of the fastener  50  being attached proximal the first end  22  of the first panel  14  and the second part  50   b  of the fastener  50  being attached proximal the second end  30  of the second panel  16 . As seen in FIG. 3, in a preferred embodiment three fasteners  50  are used. In other embodiments, the opening  34  may be closed by a zipper, snaps or other suitable means. 
     The longitudinally extending sides of the first and second panels,  14  and  16  respectively, define the longitudinally extending sides of the case  12 , and the second ends of the first and second panels define the second end of the case  12 . To form the sleeping bag  10 , the case  12  is folded along the longitudinal centerline A, shown in FIG. 3 so that the longitudinal sides of the case  12  are juxtaposed as seen in FIG.  2 . The second end of the case may be divided into a first portion on one side of the longitudinal centerline and a second portion on the other side of the longitudinal centerline A, so that when the case  12  is folded upon itself the first portion and the second portion of the second end are juxtaposed. The longitudinal sides of the case  12  are releasably attachable to one another and the first portion and the second portion of the second end of the case  12  are releasably attachable to one another. In a preferred embodiment, they are releasably attached to one another by a single zipper  52 , which extends from the point at which the centerline crosses the second end of the case  12  to a point along the longitudinal sides proximal the first end of the case  12 . In other preferred embodiments, hook and loop fasteners, snaps, or other suitable fastening means, may be used in place of the zipper  52  to close the sleeping bag  10 . 
     FIG. 5 illustrates a second embodiment  110  of the sleeping bag  10 . The structure of the sleeping bag  110  is identical to the structure of the sleeping bag  10  with exception of a closeable opening  154  that extends inwardly (in relation to the case) from one end of the case  112  toward the other end of the case  112 . In a preferred embodiment, the opening  154  extends from the first end  122  of the first panel  14  to a point that is proximal to the second end  124  of the first panel  114 . In addition, in this preferred embodiment, the opening extends generally along the longitudinal centerline A. The opening  154  expands the opening  134 , permitting easier insertion of the insulation layer  138  through the expanded opening (comprising the opening  134  and the opening  154 ) into the compartment  136 . The opening  154  is openable and closeable by a zipper  156 . In other preferred embodiments, snaps and hook and loop fasteners may be used in place of the zipper  156 . 
     FIG. 6 illustrates a third embodiment  210  of the sleeping bag  10 . In this embodiment, the first panel  214  is totally separable from the second panel  216 , being releasably attachable to one another by a zipper  258 . Therefore, the longitudinal sides  220  and  218  of the first panel  214  are attached to the respective longitudinal sides  228  and  226  of the second panel  216 , and the second end  224  of the first panel  214  is attached to the second end  232  of the second panel  216 . In this embodiment, the zipper  258  also joins the first end  222  of the first panel  214  to the first end  230  of the second panel  216 . The zipper  258  is attached so that it extends from the comer  260  of the first panel  214  along the longitudinal side  220 , across the second end  224 , along the second longitudinal side  218  and then back along the first end  222  to the corner  260 . This particular positioning of the zipper is to permit opening the first end of the case  212 , while leaving the longitudinal sides and the second end of the case  212  attached to one another. This will permit easy insertion of a back board, air mattress or pillow material. In other embodiments the zipper  258  may end at the corner  260 , leaving the first end of the case  212  open. As in the first embodiment of the sleeping bag  10 , the first end may then be closed by snaps or hook and loop fasteners. 
     The sleeping bag  10  may be constructed from many different materials, providing choices to the consumer. The first and second panels  14  and  16  respectively, may be constructed of various weights of nylon, with 70 denier nylon being a preferred weight for general usage. The panels may also be constructed from nylon tricot, cotton duck, cotton poplin and cotton tricot. Since the first panel comprises the exterior surface or shell of the sleeping bag  10  and the second panel the inner liner, which is in contact with the consumer, a preferred combination of materials may comprise constructing the first panel from 70 denier rip-stop nylon for lightness and wear and constructing the second panel from cotton tricot for comfort. The consumer will also have choices of color, for example, plain colors like green or red, camouflage colors of green or tan, or attractive designs and patterns. 
     The insulation layer  38  may be constructed from various weights of materials that are well-known for their insulation capabilities. In a preferred embodiment the insulation layer  38  is constructed from a batt of polyester fiber which is enclosed in an interfacing cover. The interfacing cover may be a woven or non-woven fabric made from cotton, or various synthetic fibers. The batts may be constructed of various weights, such as, but not limited to, two , three or four pound batts. 
     Having thus set forth a preferred construction for the current invention, it is to be remembered that this is but a preferred embodiment. Attention is now invited to a description of the use of the sleeping bag  10 . The consumer will select a case  12  that is constructed from the particular materials or combination of materials or colors that the consumer finds desirable for the planned usage of the sleeping bag  10 . The consumer may elect to purchase several different cases  12  with different materials and colors. The consumer will also select one or more appropriate insulation layers  38  having different insulation factors needed to provide the necessary warmth for various planned uses. 
     Now, prior to the use of the sleeping bag  10 , the consumer will select the appropriate case  12  and the appropriate insulation layer  38  for the planned use. The consumer will then open the first end of the case  12  and insert the insulation layer  38 . If the consumer purchases the case illustrated as embodiment  112 , as illustrated in FIG. 5, the consumer may then open zipper  156  to expand the opening in the case  112 , thereby easing the installation of the insulation layer  38 . The consumer will ensure that the first part of the fasteners  46   a  that are attached to the case  12  are joined to the second part of the fastener  46   b  that are attached to the insulation layer  38 . This will restrict the movement of the insulation layer  38  within the case  12 . The consumer will then re-fasten the fasteners  50  across the first end of the case  12  to keep case  12  closed about the insulation layer  38  and to prevent dirt from entering the case  12 . 
     The consumer may now fold the bag along its longitudinal centerline A, thereby folding it upon itself so that the zipper  52 , or other closure means, may be engaged attaching the longitudinal sides of the case to each other and the two portions of the second end of the case to each other. The sleeping bag  10  is now ready for use or to be packed for travel. 
     The third embodiment of sleeping bag  210  provides the consumer with many additional choices. The first panel  214  and the second panel  216  may now be sold separately so the consumer may construct a case  212  by selecting from many different. For example, if there were six different first panels  214 , six different second panels  216  and 10 different insulation layers  38 , the consumer could construct 360 different sleeping bags. 
     In addition to the ability to construct a custom sleeping bag, the consumer can disassemble the sleeping bag for cleaning purposes. This enables the consumer to use different cleaning techniques on the different parts and to clean only that part which is soiled. 
     While the foregoing describes several particularly preferred embodiments of the present invention, it is to be understood that numerous variations and modifications of the structure will occur to those skilled in the art. Accordingly, the foregoing description is to be considered illustrative only of the principles of this invention and is not to be considered limitative thereof, the scope of the invention being determined solely by the claims appended hereto.