The subject matter of the present application is in the field of portable tent and tarp shelters for hikers, backpackers, and campers.
Modified versions of the classic A-frame tent or tarp shelter are known, and include both floored and floorless styles. Modern shelters of this type commonly use a weatherproof nylon or polyester fabric “fly” (canopy) supported by two spaced upright poles, for example adjustable length hiking or “trekking” poles. The main body of the canopy defines a lengthwise, generally rectangular main floor plan or “footprint” between the poles, under which hikers can shelter and sleep, with semi-pyramidal vestibule end portions of the canopy staked down outwardly of the poles. One or both of the vestibule ends usually includes a door. The canopy may be used alone as a floorless shelter, or in combination with an attached floor or inner tent made from varying fabrics.
Two poles erected at the peak ends of the canopy ridgeline support the ridgeline, while ground-level edges of the canopy are secured to the ground directly or through guy lines, using stakes or other fixed supports. The walls of the canopy generally slope directly toward the ground from the ridgeline and peaks, without vertical wall portions, and thus limit the interior useable space. Increasing the pole height and canopy slope angle for a given footprint increases useable space relative to the footprint, but can reduce the shelter's stability in wind and increase its weight. Generally available trekking poles limit practical maximum height to 145 cm/57 in or lower, absent separate trekking pole tip extenders.
As a practical matter, useable space is space where the canopy walls are high enough above the ground so that the occupants and their gear are not pressing against or distorting the canopy walls while inside. Although preferences will vary, I prefer to define useable space as the interior volume where all canopy fabric is 12″ (inches) or more above the ground. This allows room for feet and heads to be clear of the canopy fabric while sleeping.
I have invented a modified A-frame tent shelter, comprising a fabric canopy with a main canopy defining or overlying a generally rectangular footprint or floor with longer sides and shorter ends. The main canopy includes two peaks adapted to be supported above the ground/footprint by two upright poles, adjacent the sides of the main canopy and spaced from the ends of the main canopy. The peaks are spaced in opposite directions from the midpoints of their respective sides of the main canopy, defining a canopy ridgeline that crosses the main canopy (and the footprint) diagonally from one side to the other side. Two lower corners of the canopy farthest from their respective (same-side) peaks, and generally orthogonal to the ridgeline, are adapted to be raised and tensioned on short struts that create a sidewall effect across the ends of the main canopy over the head and foot ends of the main canopy when the canopy is erected.
The main canopy includes tensioning points at the corners adapted to tension and secure the canopy against the upright poles and struts with guy lines and/or stakes or other anchors secured to the ground.
The main canopy is essentially coextensive with the rectangular footprint, meaning that it covers an essentially rectangular area corresponding to the footprint when erected at its peaks on poles and at its orthogonal-to-the-ridgeline corners on struts. The erected main canopy also defines two quadrilateral side openings to the footprint area, in the shape of a trapezoid (two parallel edges) or trapezium (no parallel edges) depending on the angle at which the corner struts are tensioned.
In a further form, the canopy includes fabric vestibule portions extending from the sides of the main canopy beyond the footprint. The vestibule portions may slope from the main canopy to ground level, where they can be secured with stakes or equivalent.
In a further form, the main canopy and vestibule portions comprise substantially triangular panels of fabric defining a faceted hexagonal configuration sloping to the ground from the peak ends and ridgeline. The triangular fabric panels may be defined by actual seams, a bias cut in the fabric, and/or the natural tension lines in the fabric when the canopy is erected on poles and struts and secured to the ground.
In further form, doors are provided in one or both vestibule portions of the canopy.
The footprint may be the covered area under the main canopy, or a fabric floor located under the main canopy, for example as part of an inner tent attached to or supported under the canopy. “Footprint” can accordingly include a virtual floor defined by the ground area covered by the main canopy when erected, or an actual floor made from fabric.
These and other features and advantages of the invention will become apparent from the detailed description below, in light of the accompanying drawings.
Referring first to
Main canopy 20 has longer sides 20a, and shorter ends 20b. Footprint 30 has longer sides 30a and shorter ends 30b. The sides and ends of main canopy 20 correspond approximately to the sides and ends of footprint 30, meaning that when shelter 10 is erected with the main canopy tensioned above the ground/footprint, the ground-level (straight-line) distance between corners 20c along the sides 20a of the canopy is equal to or greater than the distance between corners 30c along the sides 30a of the footprint, and the ground-level distance between corners 20c along the ends 20b of the canopy is equal to or greater than the distance between corners 30c along the ends 30b of the canopy. The result is that the rectangular area defined under main canopy 20 in its erected configuration is equal to or greater than the rectangular area of footprint 30.
It will be understood that when relative fabric dimensions and shapes are discussed herein, reasonable variations should be taken into account. Such known variations include approximations as to the non-rigid shape of structures formed largely from fabric; fabric tolerances; fabric finishing details (tie-out points, catenary cuts, rounded edges, bathtub floors); fabric tension variations under different weather conditions; deformation of the shelter from the ideal shape when set up on irregular terrain; and variations in set up and tensioning by people of different skill levels. Terms of shape, size, and orientation such as rectangular, orthogonal, upright, triangular, equal length and similar should be given reasonable interpretation due to such factors.
Main canopy 20 includes two peaks 22 adapted to receive the ends of upright support poles, for example adjustable-length hiking or “trekking” poles 50. For this purpose peaks 22 may be shaped and reinforced with heavier or different fabric or other material, or may include pole-receiving structure such as grommets or cups. Peaks 22 are joined by a ridgeline 24, which may be a straight- or catenary-cut seam, or a bias line in the canopy fabric when the shelter is erected. Peaks 22 may be provided with vents 22a.
The peaks of an A-frame type shelter can also be supported by suspending them in tension from an overhead support, such as a tree branch or poles braced in a V-shape over the peak. This is usually accomplished by running lines from grommets (not shown, but known) on the exterior of the peaks to the overhead support. Shelter 10 could also be supported in this fashion, and this manner of support should be included in the definition of pole-supported.
The peaks 22 are spaced in opposite directions from the midpoints M of their respective sides 20a and 30a of the main canopy and footprint (the midpoint of the main canopy as a whole), defining a canopy ridgeline 24 that crosses the footprint 30 diagonally (at an acute angle rather than orthogonally) from one side 30a to the other side 30a. Peaks 22 are also spaced from the nearer or non-strut corners 20c, 30c on their respective sides of the main canopy. Peaks 22 and any upright poles 50 supporting them are adjacent the sides 20a of the canopy and 30a of the footprint, lying either within, on, or outside of the actual side edges of the canopy and footprint depending on their relative dimensions and the desired placement of the pole bottom ends.
To give an idea of scale, a typical peak height for a shelter 10 designed to accommodate two sleeping people in footprint 30 would be in the range of forty to fifty inches or so off the ground, using a typical pair of adjustable trekking poles 50 for support. The dimensions of shelter 10 can vary depending on the number of occupants for which footprint 30 is sized, and the desired ratios between interior room, height, weight and weather-worthiness (the latter dependent in part on the angle and tension of the canopy walls). These and other factors will be understood by those skilled in the art of portable tent and tarp shelters.
The canopy of illustrated shelter 10 includes optional but preferred fabric vestibules 40 that extend weather protection beyond main canopy 20 and footprint 30. Vestibules in tent shelters are commonly floorless, providing dry storage and increased ventilation when the canopy is closed down for weather protection. Vestibules 40 may be permanently attached to the main canopy, as by sewing or as fabric extensions thereof, or may be detachable from the main canopy. Illustrated vestibules 40 include first smaller panels 42 and second larger panels 44, at least one of which is at least partially separable from an adjacent panel or adjacent edge of the main canopy 20 to function as a door flap. In the illustrated example, all panels 42 and 44 can be separated sufficiently from each other and/or from the main canopy to roll or zip them aside to provide doors on each side of shelter 10.
A further feature of illustrated vestibules 40 is the use of faceted triangular panels for 42 and 44, resulting in semi-pyramidal vestibule volumes and an overall hexagonal shape (in plan view) for shelter 10 when vestibules 40 are staked in place. In the illustrated example, smaller first panels 42 are isosceles triangles (preferred for stable, symmetrical tensioning of peaks 22 and ridgeline 24), and larger second panels 44 are scalene triangles.
Shelter 10 is erected by securing at least the four corners 20c of the main canopy 20 to the ground, for example with stakes and/or guy lines 80 and 90, and by inserting upright poles 50 into peaks 22. The corners of canopy 20 are provided with tie-out points of known type, which may include grommets, tabs, loops, pre-installed guy lines, or other known options for securing the corners to the ground.
If the main canopy 20 is not provided with vestibules such as 40, or if vestibules 40 are rolled up or removed, then the staked corners 20c should be supplemented with guy lines 82 (
Still referring to
The sidewall 20d created across canopy end 20b by the strut at corner 21 has the form of a mildly twisted plane or curved panel, highest and most vertical at strut corner 21 and gradually returning toward the natural slope of canopy 20 at the other (same-side, non-strut) corner 20c. In this sense, sidewall 20d can be considered a virtual sidewall, or a sidewall effect, since it need not (although it could) be formed in the canopy fabric as a separate panel, and since its geometry gradually changes across canopy end 20b from strut corner 21 to non-strut corner 20c.
The curvature and gradual reduction of the sidewall effect 20d across canopy end 20b is mitigated by the offset of peaks 22 and poles 50 from the midpoints of the shelter. This pole offset toward the non-strut corners 20c creates a steeper slope angle for the fabric in non-strut corners 20c, helping to maintain the verticality and height of the sidewall 20d created by strut 60 at the other corner.
Where shelter 10 includes a vestibule 40 as part of the overall canopy, the strut structure may be used to create and/or tension a similar generally vertical sidewall 44d in vestibule panel 44 adjacent corner 21, with similar results along the lower edge of panel 44.
The height at which strut-supported corners 21 are supported above the ground can vary, but in the illustrated example a height of 13″ (inches) has been found useful to provide a vertical sidewall 20d along at least a portion of the ends 20b of main canopy 20. In general the height at which strut-supported corners 21 are supported above the ground should be at or above the minimum useable interior height determined for that shelter.
The structure of struts 60 may vary, and can be as simple as single straight pieces of substantially stiff material such as aluminum tent pole tubing and other known equivalents. In the illustrated example, struts 60 and the strut-supported corners 21 are the inverted V-shaped struts and fabric corner structure described in my U.S. Pat. No. 7,841,356 issued Nov. 30, 2010, the entirety of whose disclosure is hereby incorporated by reference.
Referring now to
Strut legs 62 can be made from any known material commonly used for tent poles and struts, for example short lengths of aluminum tubing, carbon-fiber rods, fiberglass rods, stiff plastic rods, etc. It will also be understood that while a cylindrical tube or rod shape is preferred, non-cylindrical or non-tubular shapes such as flat slats or battens can be used. The important thing is that the struts 62 be relatively rigid and stiff enough to provide support and tension to the fabric walls formed in the canopy at corner 21. The lower ends of the struts 62 are connected by a flexible strap such as 66 to positively limit the distance they can be spread apart in tension by the canopy fabric when the shelter is staked out. By forming the struts 60 as separate legs 62 joined only by a flexible strap 66, they can be collapsed and rolled up with the shelter 10. Therefore this is the preferred, but not the only, way to form the strut structures 60. For example, the strut structure 60 could use a rigid, removable connector leg instead of a strap to join the lower ends of strut legs 62 when the tent shelter is erected. Alternately, the struts 60 may be integrated with the canopy fabric in a manner making them easily removed when taking the shelter down.
It will be understood that while it is highly preferred that the lower ends of struts 62 are connected as shown to positively limit their spread, it is also possible to leave them unconnected, provided that the lower ends of the struts 62 are secured in place in their spread apart position. For example, the lower ends of strut legs 62 could be secured to a tent floor using grommets, or could be staked into the ground, or could be jammed into the ground or snow.
Strut legs 62 can be sealed permanently in sleeve(s) 64 by sewing or other means, or the ends of sleeve(s) 64 could be left open, or provided with a removable cover or flap, so that strut legs 62 can be removed and replaced as needed.
Still referring to
Referring again to
The upper end of corner 21 is reinforced with a patch of strong fabric 21a, such as vinyl or heavy nylon, to better secure the upper pullout loop 21b to the relatively thin fabric of the tent body, and to provide a reinforced sewing attachment point for the upper end of strut sleeve 64. The lower pullout loop 21c can be sewn or otherwise fastened directly into the tent body material, or provided with its own reinforcement patch (not shown). While guyline 80c is shown as a double-ended line secured in the middle by stake 90 and tied or clipped at each end to the upper and lower ends of corner 21, it will be understood that a single guyline with a single attachment point to the upper end of corner 21 could be used (with the bottom end of the corner secured in some other fashion, for example by staking directly to the ground), or that multiple guylines with multiple attachment points could be used, although the illustrated two-point corner attachment with a single guyline connected to upper and lower portions of the corner is preferred.
Upper and lower pullout loops 21b and 21c are preferably provided with guy line tighteners of known type, to independently tension and adjust the upper and lower portions of fabric corner 21 through guy line 80c. As shown in the Figures, the optimal adjustment results in the upper end of V strut 60 being angled outwardly, while the fabric corner 21 remains more vertical due to the tension exerted by the guy line 80c on the lower portion of the corner through lower pullout loop 21c. Both the strut 60 and the fabric corner 21 can be considered substantially vertical, for example being generally less than forty-five degrees from vertical.
It will be understood that while the strongest fabric-supporting and tensioning structure is achieved when the lower ends of strut legs 62 are spread to their maximum as shown in the Figures, it is possible to adjust the spacing of their lower ends for different effects on the height and tension of the canopy fabric.
In a shelter 10 with canopy vestibule portions 40, a first leg of strut 60 is secured to a portion of panel 44 adjacent corner 21, and the second leg of strut 60 is secured to a portion of canopy end 20a adjacent corner 21. In a shelter 10 without vestibule portions 40, the first leg of strut 60 may be omitted, moved to a vertical connection with the vertical portion of corner 21, or secured or connected to the adjacent side edge 20a of main canopy 20; or, a different style of strut could be used, including a short straight upright strut.
Referring to
It will be noted in all Figures above that the shelter canopy 11 (comprising main canopy 20 and vestibules 40) is composed of triangular panels in a faceted hexagonal configuration having six main stakeout points. Main canopy 20 is composed of four triangular faceted panels 26 (see
It will be understood that the disclosed embodiments represent presently preferred examples of how to make and use the invention, but are intended to enable rather than limit the invention. Variations and modifications of the illustrated examples in the foregoing written specification and drawings may be possible without departing from the scope of the invention. It should further be understood that to the extent the term “invention” is used in the written specification, it is not to be construed as a limiting term as to number of claimed or disclosed inventions or discoveries or the scope of any such invention or discovery, but as a term which has long been conveniently and widely used to describe new and useful improvements in science and the useful arts. The scope of the invention supported by the above disclosure should accordingly be construed within the scope of what it teaches and suggests to those skilled in the art, and within the scope of any claims that the above disclosure supports, whether the claims are made in this provisional application or in a non-provisional application claiming priority to this provisional application.
This application claims the benefit of U.S. Provisional Application No. 61/513,827, filed Aug. 1, 2011 by the same inventor (Shires), the entirety of which provisional application is incorporated herein by reference.
Number | Name | Date | Kind |
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2263867 | Barnard | Nov 1941 | A |
3043320 | Moss | Jul 1962 | A |
3468321 | Thompson | Sep 1969 | A |
3741224 | Clelland | Jun 1973 | A |
3943952 | Marquart et al. | Mar 1976 | A |
5477876 | Moss | Dec 1995 | A |
7841356 | Shires | Nov 2010 | B2 |
20080302403 | Stewart | Dec 2008 | A1 |
Entry |
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Trailspace, Nemo Meta 2P, Three-Season Tent reviews, Aug. 1, 2010, 3 pages, www.trailspace.com, U.S. |
Black Diamond, Betamid, “Gear” section of manufacturer website, Mar. 12, 2006, 1 page (supplemented by 2pages of add'tl photos, specs), www.bdel.com, U.S. |
Number | Date | Country | |
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61513827 | Aug 2011 | US |