BACKGROUND

[0002] Campers and serious hikers strive to minimize the amount of equipment they tote on their journeys in an effort to reduce the volume and weight of their gear. It will be appreciated that minimizing the amount of gear one totes reduces the effort required while on the move during waking hours. In addition to practical considerations, there also exist certain psychological and social considerations. For instance, in certain social circles, the overt toting of a pillow on a canoeing, hiking or camping adventure may invite ridicule from those more inclined to “rough it.”

[0003] Instead of actual pillows, campers sometimes resort to the creation of makeshift pillows from bunched or rolled articles of clothing. Few would deny, however, that propping one's head for sleep on an evenly cushioned surface is more comfortable than setting one's head down on a lumpy bunch or roll of clothing or than going without a headrest of any kind.

[0004] Accordingly, there is a need for a cushion on which to rest one's head for sleep that does not add appreciable weight or volume to one's camping gear when not in use.

SUMMARY

[0005] A typical sleeping bag includes an outer shell joined to an inner lining. The lining and shell combine to form a sleeping bag wall. The sleeping bag wall extends longitudinally between opposed head and foot ends, defined by head and foot edges, and laterally between side edges. The wall is foldable over itself along a longitudinal, bisecting axis such that a contiguous fastener, such as a zipper, can selectively join the two side edges and two portions of the foot edge. The head edge, while folded over, typically remains open. When folded over, lower and upper panels characterize the sleeping bag wall; the lower panel corresponding to the portion of the bag wall upon which a sleeping person's body rests and the upper panel corresponding to the portion of the bag wall that traps heat over a sleeping person's body.

[0006] In a typical embodiment of the invention, an inflatable bladder is retained between the shell and the lining adjacent the head edge of that portion of the sleeping bag wall corresponding to the lower panel. The inflatable bladder comprises at least one flexible, gas tight bladder wall defining a fluid cavity for containing a predetermined volume of gas such as air, for instance. A valve depends from a bladder wall and facilitates the selective communication of fluid (e.g., air) between the cavity and the atmosphere external to the bladder.

[0007] In one version, the bladder is irremovable in the ordinary course of use, being, for instance, inaccessibly incorporated within the sleeping bag wall during manufacture. In another version, a portion of the sleeping bag wall adjacent the head end includes a bladder receptacle or pocket into which, and from which, a bladder can be alternatively inserted and removed. Once inserted, a bladder is removably retained within the bag wall by one or more selectively releasable fasteners which, in alternative illustrative embodiments, include hook and loop fasteners (e.g., Velcro®); one or more snaps or buttons and a zipper, for instance.

[0008] In various versions, the sleeping bag includes a bladder having a valve nozzle accessible through the sleeping bag wall. In such versions, the nozzle facilitates the convenient introduction of gas into the cavity.

[0009] In recognition of the fact that a particular person may prefer to maintain the releasably joined side edges of a sleeping bag to one particular side of his or her body, alternative versions incorporate a bladder, for example, on a particular side of the bisecting fold axis or, in the case of a “reversible” version, on either side of the bisecting fold axis.