This invention relates generally to sleeping bags, and more specifically to a sleeping bag that is adjustable in length to accommodate users of different height.
A sleeping bag is a durable overnight covering that provides generally soft padding, heat insulation, and weather-resistance. Sleeping bags are extensively used by backpackers, campers, and many others for portable and inexpensive bedding. Families, scouting troops, tour groups, and individuals use sleeping bags during recreational pursuits or whenever they need temporary bedding.
Ideally, a sleeping bag should be of a length that approximately fits the person using the bag. A property sized bag provides adequate cover and efficient heat insulation. If the bag is too short, an upper portion of the user, possibly including portions of the shoulders, arms, and chest, will not be covered. If the bag is is too long, it may not provide the user with efficient heat insulation around the feet. Specifically, the foot end of the bag will extend beyond the user's feet. As a result, this portion of the bag receives little or no heat from bodily warmth and becomes colder relative to the remainder of the bag. Even a portion of the bag adjacent the user's feet becomes colder since heat energy is lost to the extending foot end portion of the bag. Another drawback inherent to over-long sleeping bags is that the user, particularly a child, may move or shift position while sleeping during the course of a night and slide down further than intended into the interior of the bag. In that situation, the user's head may be inside the bag in a region of low air circulation and decreased oxygen availability.
Aggravating the problem is that sleeping bags are typically fixed in length. Children who have sleeping bags that are child-sized may soon out-grow their bags, making it necessary to buy new bags at considerable expense. Many families and other groups own several bags which they would prefer to be interchangeably useable by different members of the family or group, including members having significantly different height, rather than one bag being dedicated for use by only one individual. Unfortunately, many sleeping bag designs incorporate a one-size-fits-all approach that fails to adequately meet the needs of these users.
Therefore, there is a need for a sleeping bag that will fit, to an approximate extent, users of varying height.