Lightweight shelter

A nominally floorless hikers' shelter having a raised, tensioned waterproof canopy supported off the ground by pole supports at the front and rear, in which the canopy has a catenary curved ridgeline tensioned between a higher vertical front support and a lower, outwardly-angled rear arch support. The shelter preferably has a hanging insect netting perimeter, including front and rear door panels and sidewalls, and floor-ready attachment structure for an optional floor to be attached to the support structure in the sleeping area defined by the netting without placing stress on the netting. In a first form the vertical front support is a straight pole; in a second form the vertical front support is a vertical arch. A multiple guyline/single-stake structure for guying out a tensioned shelter edge is also disclosed.

FIELD OF THE INVENTION

The present invention is in the field of tent and tarp type shelters used by hikers and campers.

BACKGROUND OF THE INVENTION

Hikers and campers, especially backpackers, usually require a shelter such as a tent for overnight or multi-night trips. The longer the trip, the greater the need for a shelter of as little packed weight as possible to reduce fatigue, to make room for food and other gear, and to increase the enjoyment of hiking.

Tents tend to be one of the heaviest items in the pack, and many hikers opt for lighter, less-protective tarps or floorless shelters such as nylon pyramids for the weight savings alone. Even “single-wall” tents, with only one layer of waterproof canopy fabric (rather than spaced layers of breathable and waterproof fabric), tend to be heavier than tarps due to the tents' flooring and heavier structural components. Moreover, single-wall tents tend to be known for condensation problems, where exhaled and evaporated moisture from the occupants condenses on the inner surface of the fabric and either drips or runs down the walls onto the floor. Solutions to the condensation problem such as inner wicking surfaces and vents tend to increase weight, and have limits in certain environmental conditions.

Other factors in choosing a tarp shelter over a tent seem to be the preference among many hikers for a more open, airy, close-to-nature experience while sheltering and sleeping outdoors, and the absence of any need to care for an attached floor and keep it clean. The primary drawbacks of tarp shelters are their lack of structural stability in wind, and their lack of insect protection as they are typically floorless and without insect netting.

A hybrid solution to the foregoing problems has been to apply netting in some fashion to tarp style shelters, with mixed success. Detachable netting inserts, defining floored or floorless screened enclosures within the protective tarp canopy, tend to add undesirable weight back into the system. Fixed netting sewn along the tarp perimeter and hanging to the ground provides some protection, but the lack of tensioning and supporting structure in even a well-rigged tarp mitigates some of the benefit. And, finally, tarps simply lack the tent-like structural strength and protection that many hikers find preferable.

An early solution to the foregoing problems was my original Tarptent™ shelter. This combined features of tarps and tents, with a pole-supported, tensioned, tent-style waterproof canopy using lightweight material, and front and rear doors and a sidewall made from insect netting to reduce condensation and provide bug protection.

A second version of the Tarptent™ shelter offered improved structural strength and ventilation using a waterproof canopy raised fully off the ground, a catenary curved ridgeline, and a tensioned, inwardly-angled rear arch pole in place of the previous upright rear pole. The rear arch was staked out with a single stake anchoring three tensioned guylines running from a rear arch awning.

The Tarptent™ shelters were primarily intended as floorless shelters for simplicity and weight savings, with lightweight, removable groundcloths preferably used over the bare-ground “footprint” bounded by the drop-down netting sidewalls and front and rear netting panels. Floors, however, can be optionally added by sewing them to the hanging netting perimeter along the sides and rear.

BRIEF SUMMARY OF THE INVENTION

The invention is an improved structure for nominally floorless canopy shelters, the improved structure including a canopy with a lower, outwardly-angled rear arch support tensioning a catenary ridgeline against a higher, vertical front support. By “nominally floorless” is meant shelters with a raised-off-the-ground, tensioned canopy structure where a floor is either absent, or is attached to but is not structurally a part of the raised, tensioned canopy structure as a whole.

In a first form of the invention the higher, vertical front support is a straight pole. In an alternate form the vertical front support is an arch.

In a further form the invention is an improved guyline arrangement for a raised, tensioned shelter edge, such as the rear arch or its awning, in which a central guyline extending from a center portion of the tensioned shelter edge is secured to an outer guyline extending between two outer anchor points on the tensioned shelter edge. The central guyline can be anchored to a single stake in a manner that simultaneously tensions the outer guyline, and that allows tension to be adjusted across the shelter edge with the central guyline.

In a further form the invention is a floor-ready attachment structure anchored to the support structure for the tensioned canopy portion of the shelter, allowing an optional floor to be securely attached to the netting perimeter of a standard floorless shelter without placing stress on the netting. In a further form the floor-ready attachment structure provides forward-tensioning of an added floor to reduce shifting and bunching of the floor while sleeping or entering/exiting the shelter.

In yet a further form the invention is an improved front awning structure for the front door, where the awning is coextensive with the front edge of the canopy, and in its extended state is releasably tensioned to the front guyline.

These and other features and advantages of the invention will become apparent from further reading of the specification in light of the accompanying drawings.

DETAILED DESCRIPTION OF THE INVENTION

Referring first toFIG. 1, a shelter10according to the invention has a waterproof canopy12made from a lightweight material commonly used for tents and tarps such as coated or treated nylon or polyester. While a waterproof material is preferred for such shelters, it will be understood by those skilled in the art that the degree of waterproofness can vary, and that for some uses water-resistant, wind-resistant, or sun-blocking materials that are not fully waterproof may be useful. The term “waterproof” will be used to include both waterproof and other weather-protective materials useful for such shelters. In the illustrated embodiment the canopy material is a lightweight siliconized nylon of known type, weighing less than two ounces per square yard.

Shelter10has a front end14defined generally by front edge14aof canopy12, a rear end16generally defined by rear canopy edge16a, a ridgeline17, sidewalls18ending at canopy side edges18a, a front awning or beak20, and a rear awning or beak21. The front and rear awnings are preferably made from the same material as canopy12.

The front end of the canopy is raised and tensioned at the peak of ridgeline17on a vertical support22, the tip of the support resting for example in a grommet or a reinforced pocket of canopy12. The rear end of the canopy is raised and tensioned on a cantilevered arch support26centered at the ridgeline. Canopy tension and structure are maintained by guying out the front and rear supports22and26, in the illustrated embodiment with a guyline24secured at or near the tip of support22at the front, with multiple guylines28,29at the rear, and with a guyline attached to a loop or pullout point30at each lower front corner of canopy12. The guylines are preferably secured to the ground with stakes32, although they can also be secured to shrubs, trees, rocks and other available anchor points in known manner.

In the illustrated embodiment, vertical support22and rear arch26are lightweight, hollow, flexible aluminum poles of a type commonly used for tents, preferably collapsible into joined sections for compact carry. Rear arch pole26may be formed with some or all of its sections pre-curved. It will be understood that other materials and structures can be used for the front and/or rear supports, one known alternative being fiber-resin composite rods or poles, although hollow aluminum poles are currently believed to be the most practical and economical.

Once canopy12is supported and tensioned on poles22and26, it forms a stable, taut, floorless shelter structure with its front, rear, and side edges raised off the ground. The falling catenary ridgeline17, dropping from the canopy's peak at front end14to the lower, rearwardly-angled arch at rear end16, causes the ridgeline and sidewalls to be evenly tensioned and essentially wrinkle-free, giving the shelter strength, sag resistance, and wind-shedding ability. Canopy12therefore floats above the ground with stability more like that of a tent or a rigid structure than a tarp. Ridgeline17is a true catenary curve, defined by the well-known hyperbolic catenary curve equation created to describe the curve naturally taken by a homogeneous cable suspended by its ends. Unlike many tarp shelters, the side edges preferably run straight, offering better weather protection and in most conditions not needing additional staking for stability. For high side winds, one or more extra pullout points or guylines can be spaced along canopy side edges18aand used as needed.

The spacing of canopy12above the ground when properly erected can vary. In the illustrated embodiment the preferred spacing of the sidewall edges from the ground is about eight inches. The peak height at the front end in the illustrated embodiment is about 42″ (inches), at the apex of the rear arch about 21.5″ (inches). The width of the illustrated shelter in front is about 80″ (inches), at the rear arch about 51″ (inches), and the overall length is about 93″ (inches). It will be understood that these dimensions are for the particular two-man ultralight model shown in the illustrated embodiment, and that they can vary relative to one another or overall, depending on the desired size of the shelter, the premium placed on light weight versus space and headroom, and other factors that will be recognized by those skilled in the art. The dimensions and proportions of the illustrated embodiment are preferred in part in part for function and in part for the sleek, aesthetically pleasing appearance of the shelter.

Referring toFIGS. 1 through 3, canopy12is provided with a drop-down netting perimeter for insect protection, and additionally for protection against blowing rain, sand and snow. Netting sidewalls34hang from canopy sidewalls18to the ground, a netting end panel36(FIG. 3) hangs from rear canopy edge16ato the ground, and a netting door38hangs from front canopy edge14ato the ground. Door38is preferably divided or otherwise opened or parted, for example with a zipper39(FIG. 2) for ease of entry and exit. End panel36can be fashioned as a secondary door, if desired, although the low height of rear end16makes this less convenient. The netting is preferably attached by sewing to the front, rear, and side edges of the canopy, although other methods could be used. The netting is preferably attached at the very edges of the canopy, but could also be set back.

Shelter10is designed to be nominally floorless, as shown, with the ground-engaging netting perimeter defining a bare-ground footprint under the canopy (FIGS. 2 and 5) for sleeping and gear storage. The netting may be designed to hang just to the ground at an optimum canopy height, or can be provided with extra length to permit canopy height adjustment while maintaining insect protection. In the preferred embodiment illustrated, the lower edge of the netting perimeter forms a horizontal flap along the sidewalls and rear panel designed to extend inwardly on the ground for several inches to provide a place to anchor the free-hanging netting with rocks, gear, sleeping bags, stakes, and such; or to allow a removable groundcloth to be overlapped with the netting for increased insect protection; or to provide an attachment point for an optional floor.

FIGS. 3 and 3Aillustrate the details of the rear arch support and awning structure, and of a novel guyline arrangement allowing three spaced guylines from a tensioned shelter edge to be staked out with a single stake in a single step. Rear edge16aof canopy12has a pole-securing structure in the form of a continuous sleeve16bfor pole26, the pole being removably inserted in the sleeve in known fashion, and long enough that its ends protrude from each end of the sleeve once inserted. A lateral tension strap27is spaced from and connected to the ends of the sleeve with short connector straps27a(and optionally straps27b), each end of tension strap27having a pole-receiving structure such as grommet27c. When the ends of pole26are inserted in the grommets, the tension from the curve of the pole and the rear edge of the canopy pull strap27to its maximum width, locking pole26and the rear of the canopy into its arched structure. Vertical short connector straps27bprovide both a visual indicator that main strap27is not twisted during setup, and serves as a failsafe connection between the pole sleeve and strap27should the end of pole26come loose.

It will be understood that while a continuous pole sleeve is the preferred way to secure the pole to the canopy, other methods such as discontinuous sleeves and clips are possible.

Rear awning21is connected to the rear edge of the canopy, for example at sleeve16bby sewing, extending along at least a major portion of the arch (and preferably coextensive with the rear end of the canopy as shown) to overlie at least a major portion of rear netting panel36, which is connected to and hangs down from the inside of the rear edge of the canopy. Awning21has an acute downward angle relative to the plane of the arch. Awning21extends a greater distance from the canopy at its center, and is preferably tapered inwardly toward the sleeve ends on either side, generally following the sweep of the arc of pole26. Three guylines extend from the rear edge of awning21, converging to a single stakeout point as shown inFIG. 3.

Guylines28are formed by a single loop of cord secured at either end to the opposite sides of rear awning21, and bisected by shorter, straight center guyline29attached to the center of awning21at one end and to the middle of cord28. In the preferred embodiment illustrated, center line29is slidably connected to cord28, for example with a simple knotted loop29aas shown, or with a sliding clip, hook, or the like. Referring toFIG. 3A, the length of center line29is longer than the maximum tensioning distance from the center edge of awning21to the apex of the “V” of fully tensioned cord28. Staking out and tensioning the guylines is accordingly accomplished in a single step by hooking or looping an intermediate portion of center line29and staking it down rearwardly beyond the sliding junction of center line29with cord28, as shown. Tension can be adjusted left and right on the awning by sliding center line29along cord28, and back and forth simply by moving the single stake toward or away from the tent.

It will be understood that the guyline structure28,29ofFIGS. 3 and 3Acan be used for other tensioned shelter edges in the illustrated shelter or even in different shelters, where a raised canopy edge needs to be staked out with a minimum number of stakes and evenly tensioned along its length.

FIG. 4shows the pattern for canopy12superimposed in phantom over the erected shelter, and in particular shows that catenary ridgeline17is a true ridgeline, formed by the joinder of two separate, generally trapezoidal fabric panels18along a center seam, in the illustrated embodiment a sewn seam. Each panel18has a catenary seam edge18bthat in the flat condition curves inwardly from the panel ends, away from the opposite panel's seam edge. The ends18cand18dof each panel are angled inwardly toward one another relative to seam edge18b, with front ends18cbeing essentially straight and rear ends18dpreferably having a mild convex curvature and a length requiring a short outwardly-angled shoulder18ewhere side edge18ajoins rear end18d. This configuration results in a shelter having a vertical front end and an outwardly-cantilevered rear arch when the shelter is erected with tension sufficient to make ridgeline17taut. This configuration also allows the rear edges18dto be folded over and sewn or otherwise secured to form a straight sleeve for arched pole26, and further allows rear awning21to evenly tension the canopy through the multiple guyline arrangement shown inFIGS. 3 and 3A. The preferred angle for the rear arch in the illustrated embodiment is about 12° (degrees) from vertical. It will be understood by those skilled at setting up tents that minor variations will occur with respect to the vertical orientation of the front support and the outward cant of the rear arch among different users and even for the same user, and that although true vertical for the front support and a twelve degree outward cant for the rear arch are the ideal, variations due to “eyeballing” the shelter setup in real life conditions will occur. The shelter will be most taut and weather-worthy when the ideal is achieved on setup.

Referring toFIGS. 1,2and4, front awning20can be a partial awning as shown in solid lines, or can be extended to be coextensive with the front edge14aof the canopy as shown in phantom inFIGS. 1 and 4. Illustrated awning20is a non-structural part of the canopy, providing weather protection for the front door of the shelter but not forming part of the tensioned canopy structure. In the illustrated embodiment, front awning20is attached to the front edge of the canopy on one side of pole22(the left side inFIG. 2), for example by sewing. On the other side it is preferably removably attached to the front edge of the canopy, for example with strips of hook-and-loop closure20alocated on the underside of the awning and on the upper side of the canopy edge. In fair weather the awning can be detached from the canopy on one side and rolled up on the other, secured for example with tie-offs20bin known fashion.

To prevent flapping in high winds, the front point of the awning can be tensioned to guyline24, for example with a short length of elastic cord20cextending from the awning edge to a clip connection with a loop24ain the guyline.

Referring next toFIG. 5, the netting perimeter of shelter10is shown in a preferred floorless version of the shelter, where the drop down netting is sufficiently long for several inches or more to be extended inwardly toward the open sleeping area40as horizontal ground flaps34a,36a,38a. The ends of netting sidewall panels34and rear and front end panels36and38are sewn or otherwise joined at their ends at the corners of the shelter to create a full netting perimeter around the lower edge of the canopy. The corners of the netting make a convenient place to put rocks or gear to weight the netting down. People using the shelter can place their sleeping gear directly on the ground in area40, or can use a removable groundsheet in sleeping area40overlapping the netting ground flaps34a,36a, and38a, or can request that an optional floor be added between the flaps during manufacturing.

An optional floor can simply be attached to the netting perimeter, for example by sewing to sides34aand rear flap36a. However, a floor attached in such fashion can place considerable stress on the netting, and tends to bunch as people move around in the shelter. This problem is solved in the illustrated embodiment with floor-ready attachment structure that can be supplied unobtrusively on a standard floorless shelter but readily receives an optional floor.

Referring toFIGS. 6 and 6A, the rear corner netting seams35are provided with a reinforcement35a, preferably in the form of a strip of flat nylon webbing sewn to the netting, connected to lateral tension strap27at one end and with the other end available to be attached (for example by sewing) to the corner of an attached floor50at the inside edge of the netting. Reinforcement35aconnects the floor to strap27, which is part of the arch support structure, to isolate stress on the floor both from the relatively delicate netting and from the tensioned canopy. The floor side edges50aand rear edge50bare sewn directly to the netting flaps34aand36a.

Referring toFIGS. 6 and 6B, the front corners of the floor are connected at50cwith elastic cords52to loops54or other convenient connection points at the forward raised corners of the canopy above the netting. The use of an elastic attachment for the forward part of the floor is preferred, tensioning the floor forwardly to reduce bunching of the floor as people use the shelter. In the illustrated embodiment, elastic cords52are attached to canopy12at or near the points where the forward corners of the canopy are guyed out, thereby transferring forces on the floor to the guyline and minimizing stress on the canopy.

If a shelter with the above-described floor-ready attachment structure never receives a floor, elastic cord52can simply be omitted or removed, while reinforcements35ain the rear corners help hold the netting down and give some shape to the corners.

Referring next toFIGS. 7 and 8, an alternate embodiment of a shelter according to the invention is generally illustrated at100, with a raised, tensioned canopy112having both front and rear ends114and116supported and structured by arched poles122and126in a manner similar to that described above for the rear arched end of shelter10. It is preferred that the rear end116of shelter100is structurally identical to rear end14of shelter10, including the guyline and staking arrangement. Front end114, however, uses a larger arch, a vertical arch orientation, and a more weather-resistant and versatile awning structure.

Like canopy12in shelter10, the front end114of canopy112in shelter100is raised and tensioned at the forward end of a catenary ridgeline117on a vertical support (pole122), and the rear end116of the canopy is raised and tensioned on a lower, outwardly-angled cantilevered arch support (pole126). Canopy tension and structure are maintained by guying out the front and rear arch support poles122and126, in the illustrated embodiment through a front awning120with spaced parallel guylines124, and through rear awning121with a three-to-one converging guyline structure128at the rear. The need for a stakeout point or guyline at the front corners of canopy112is eliminated. The guylines are preferably secured to the ground with stakes32, although they can also be secured to shrubs, trees, rocks and other available anchor points in known manner.

Because the front arched end114of shelter100includes a lateral tension strap127anchoring the ends of arch pole122similar to the rear strap and arch structure described above, the forward corner seams of the netting panels can be reinforced and anchored to strap127near the pole ends in the same manner as rear corner netting seams35inFIGS. 6A and 6B. Forward-tensioning structure such as elastic cord52and loops54can still be used, but is less necessary to prevent bunching of the floor when the forward end of the floor is anchored to the forward arch strap127.

It will be apparent to those skilled in the art that the foregoing preferred embodiments of a shelter according to the invention are examples only, and that shelters within the scope of the invention as defined by the claims below may vary in their construction details, materials, dimensions and other respects and equivalents from these examples that I have used to disclose the invention.