Patent Application
20250176740
The present invention relates generally to outdoor equipment, and more particularly, to lightweight sleeping pad systems having separable and dissimilar segments, and methods of using those systems.
Ultralight backpacking (“UL backpacking”) is a category of backpacking that emphasizes carrying the lightest and least amount of gear. UL backpacking enthusiasts strive for the lowest reasonable base weight, which is defined as the weight of a loaded pack minus consumables such as food, water and fuel. A low base weight is critical in allowing a backpacker to comfortably cover long distances and to reduce stress on their bodies.
A base weight of less than about 10 lbs. is generally considered to be “ultralight”. In contrast, traditional backpackers typically haul base weights of approximately 15 to 30 lbs., and as much as 55 lbs. or more for winter and/or extended trips, or where special equipment is desired.
Various strategies are employed to decrease base weight, including omitting or sharing equipment, using gear that serves multiple purposes, and/or utilizing specialized lightweight gear. Shelter, sleeping systems and the pack itself are generally considered to be the major items amenable to significant weight reduction. It is important to note that, in UL backpacking, “significant” weight reduction can be measured in ounces and grams.
Sleeping pads are generally considered to be an essential component of a UL backpacker's gear. They provide a layer of cushioning and thermal protection between the backpacker and the ground, thereby promoting comfortable and regenerative sleep.
A typical sleeping pad is a unitary rectangular or mummy-shaped segment of foam or comparable material, generally having dimensions similar to a sleeping bag, and usually weighing around 15 oz., which is significant relative the total base weight threshold of less than 10 lbs. Sleeping pads are also bulky. Backpackers often attach and carry rolled up sleeping pads on the outside of their pack to save space within the pack's carrying compartment. Another disadvantage of conventional sleeping pads is that they don't reasonably lend themselves to multiple purposes, largely because they are too flimsy to be provide mechanical stability yet too large and/or inflexible to be conformed into other articles.
As can be seen, there is a need for an improved sleeping pad system that is suitable for UL backpacking. It is desirable that this system is extremely lightweight, lends itself to multiple purposes, and is easy to use.
A sleep pad system includes an upper segment generally sized and shaped to rest beneath the torso and head of a lying human, a lower segment generally sized and shaped for the human's lower extremities, and a means for attaching the upper segment to the lower segment in an end-to-end orientation. The upper segment and lower segment are separable, with each segment having distinct characteristics and functionality for use without the other segment. In a preferred embodiment the upper segment is constructed of foam, and imparts superior cushioning and warmth properties relative to the foam lower segment upon which the lower extremities rest. The upper segment is preferably configured for accordion-type folding, thereby allowing the upper segment to be transformed into a compact and sturdy article having utility as a structural support, for example as a frame in a frameless ultralight pack. The lower segment, because it is constructed of significantly lighter and/or reduced material than the upper segment, decreases the overall weight of the sleep system. Moreover, it is easily attachable to the outside of the pack making it easily accessible when the upper rigid section is used inside the pack as frame-like support. Further, its compact size and shape lends itself to a variety of purposes including a sitting pad, tent entry mat and/or orderly surface for storing and/or preparing gear and food. The sleep system is configured for use with a variety of auxiliary gear such as pillows, emergency shelters, tents and sun shades.
The following detailed description is of the best currently contemplated modes of carrying out exemplary embodiments of the invention. The description is not to be taken in a limiting sense, but is made for the purpose of illustrating the general principles of the invention.
The following structure numbers shall apply to the following structures among the various FIGS.:
Broadly, the present invention pertains to outdoor equipment, and more particularly, to lightweight sleeping pad systems having separable and dissimilar segments, and methods of using those systems.
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Sleep system 10 may have a longer length embodiment 15 (
Preferably upper segment 20 is approximately 18″-26″ wide thereby allowing for narrow, regular and wide versions as well as differing shapes. The upper segment is preferably approximately 30″-50″ long, approximately ½″ to 1″ thick, weighs approximately 2.5 oz-8.0 oz, and has ˜R value of 1-3. In an alternative embodiment an air or a hybrid air and foam pad could be employed for the upper segment, which would impart a thickness of approximately 1″-3″ and may increase R value to 3-6. Lower segment 40 is preferably 18″-24″ wide by approximately 30″-50″ long, approximately ⅛″ to ½″ thick, weighs approximately 1 oz to 2.5 oz, and has ˜R value of 0.25-2. In an alternative embodiment an air or hybrid pad could be employed for the lower segment, which would impart a thickness of approximately 1″-3″, and may increase R value to 2-4.
Most preferably the longer length sleep system 10 is approximately 20″ wide by approximately 71″ long, and weighs approximately 4.3 oz, while the standard length sleep system is approximately 20″ wide by approximately 61″ long, and weighs approximately 3.5 oz. More specifically, upper segment 20 of the longer length embodiment most preferably measures approximately 20″ wide×41″ long×⅝″ thick, weighs approximately 3.3 oz, and has ˜R value of 2. The standard length upper segment preferably measures approximately 20″ wide×31½″ long×⅝″ thick, weighs approximately 2.5 oz, and has an ˜R value of 2. In both the longer length and standard length preferred embodiments, lower segment 40 measures approximately 20″ wide×31″ long×⅛″ thick, weighs approximately 1.0 oz, and has an ˜R value of 0.5.
Upper segment 20 may be constructed of a variety of materials including polyethylene foam, low density polyethylene foam, ethylene vinyl acetate foam, crosslinked polyethylene foam, irradiated crosslinked polyethylene foam, and combinations thereof. Depending on the specific application and target market the upper section is most preferably constructed of EVAZOTE VA35, a closed cell, cross-linked ethylene vinyl acetate copolymer foam; PLASTAZOTE LD ranging from 15-45 kg/m3 a closed cell, cross-linked polyethylene foam; or SUPAZOTE EM26, a closed cell, cross-linked ethylene co-polymer foam; each from Zotefoams Inc. of Walton, Kentucky. The foam material is preferably formed into a substrate having a recurring pattern of peaks 33 and pits 34, each of which is substantially identical in size and shape. It is noted that each indentation is both a peak and a pit. Said another way, a single indentation is deemed a peak when it gives rise to a convex form on upper segment upper surface 31, and deemed a pit when it gives rise to a concave form on upper segment bottom surface 32 (
Lower segment 40 may be constructed of a variety of materials including polyethylene foam, low density polyethylene foam, ethylene vinyl acetate foam, crosslinked polyethylene foam, irradiated crosslinked polyethylene foam, and combinations thereof. Most preferably the lower segment is constructed of EVAZOTE VA35, a closed cell, cross-linked ethylene vinyl acetate copolymer foam from Zotefoams Inc. of Walton, Kentucky, although similar foams are also within the scope of the invention. The foam material is preferably cut flat without press molding to allow for maximum flexibility.
In a preferred embodiment the upper segment is more rigid and has a higher R value than the lower segment. It is noted, however, that the rigidity and R values don't necessarily correspond with the inherent properties of the foam that the segments are constructed of. By way of example, in a preferred embodiment the upper segment is constructed of SUPAZOTE EM26 which has a density of 26 kg/m3, and the lower segment is constructed of EVAZOTE VA 35 which has a density of 35 kg/m3. The upper segment is constructed of lower density foam, but is thicker, perhaps employing >¼″ of foam which is heated and press molded. Conversely, the lower segment is constructed with only approximately ⅛th inch of foam which is cut flat with no molding. The result is that the upper segment, although constructed of less dense foam, is more rigid and has a higher R value than the bottom segment which is lighter, more flexible and has a lower R value.
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Certain structures and components are disclosed for purposes of describing an embodiment, and setting forth the best mode, but should not be construed as teaching the only possible embodiment. Rather, modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims. Examples of modifications include use of hybrid, newly developed, or natural materials that may decrease weight or increase functionality including rigidity, integrity, comfort, R value, and compactness of size. Other modification may simply enhance the form and look of the system. In addition, one or both upper and lower segments may be adapted for different weather types or seasonal conditions, for example a three season or winter version may change the size, thickness, R value, or materials of the embodiment while maintaining the spirit and scope of the invention. Similarly, the function of the upper and lower segments may change for example the lower section may be more rigid making it useful as structural support, with an upper segment compose of an air or hybrid pad that has flexible characteristics of the said lower segment. In addition, modifications may be made to adapt the pad system for specific user groups for example trail runners, fastpackers, thru-hikers, bikepackers, hunters, military personnel, and other recreational and professional users. For example, in the case of trail runners the upper and lower segments could be modified to serve as a pack like structure and strapping vest themselves removing in part or whole the need for what is traditionally thought of as a stand-alone pack. While separable and dissimilar segments are typical in this invention it does not exclude the use of the same material in both the upper and lower segment. For example, a releasably connected embodiment of identical foam pressed with peaks and pits and with accordion like folds can make more optimal use of each segment compared to an otherwise inseparable embodiment, and in this example having the same upper and lower segment materials could be the best choice for each of the multiple uses that arise when separation with attachment means of the embodiment is allowed. It should be understood that all specifications, unless otherwise stated or contrary to common sense, are +/−10%, and that ranges of values set forth inherently include those values, as well as all increments between. Also, “substantially” as used herein, shall mean generally. By way of example a “substantially planar” surface includes surface imperfections but is generally planar.
