Abstract:
A lightweight base frame including connectable frame members. The members are advantageously extensible. A thicker central portion of each member advantageously provides sturdiness and stability to the base frame. A cloth is suspended taunt across the frame. Once assembled, the base frame and cloth form the floor of the shelter as well as a cot. Attachable adjustable-height legs with high-traction feet further enable the user to lie comfortably and level above grade on a wide range of ground surfaces, even on rugged or sloping terrain. In a preferred embodiment, built-in leveling bubbles in the end and side frame components help adjust the base frame to level. A shelter primarily in the nature of a tent is then erected up from the base frame.

Description:
TECHNICAL FIELD OF THE INVENTION 
     This invention relates generally to the temporary shelter, outdoor recreation and camping arts, and more specifically to a collapsible all-terrain shelter and frame for use in such environments. 
     BACKGROUND OF THE INVENTION 
     Generally, tents and similar outdoor shelters are restricted to being placed and anchored to the ground. That is, the character of the floor in such structures is dictated by the underlying ground. Although modem technology provides tents that are relatively inexpensive and lightweight compared to tents of a decade ago, these tents do not protect the occupant(s) from the discomforts of wet or rocky ground. In addition, even the most modem tents provide little comfort on sloping ground. 
     To be sure, a cot provides to the relief to the user regarding wet or rocky ground. However, the cot is of no aid to the user when dealing with sloping terrain. Furthermore, commercial one-camper tents are too small to comfortably enclose a cot. Similarly, two-camper tents are too small to hold two cots. Just taking the one-camper instance, even if the tent was large enough to comfortably accommodate the cot, the bulk and weight of the separate tent and cot would preclude them from being easily carried by the camper, let alone fitting into the camper&#39;s backpack. 
     There is, therefore, a need for an apparatus that provides the comfort and safety of a cot within a shelter. Such an inventive apparatus will be level and stable on soft, rough or sloping terrain, will have the structural design to comfortably accommodate one or more sleeping adults, will require no special training or tools to assemble and disassemble, will be well-ventilated, will provide ample storage, and will be able to be carried inside a personal backpack. 
     SUMMARY OF THE INVENTION 
     These and other objects, features and technical advantages are achieved by my invention, which comprises a lightweight base frame including connectable frame members. The members are advantageously extensible. A thicker central portion of each member advantageously provides sturdiness and stability to the base frame. 
     After extending the frame members, the user can easily connect them by locking their ends into rounded corner brackets to assemble the base frame. A cloth is suspended taunt across the frame. Once assembled, the base frame and cloth form the floor of the shelter as well as a cot. Attachable adjustable-height legs with high-traction feet further enable the user to lie comfortably and level above grade on a wide range of ground surfaces, even on rugged or sloping terrain. In a preferred embodiment, built-in leveling bubbles in the end and side frame components help adjust the base frame to level. 
     A shelter primarily in the nature of a tent is then erected up from the base frame. The shelter comprises further advantageous features as will be described in detail later on. 
     It is therefore a technical advantage of the present invention for the inventive shelter and cot to be collapsible and portable. For easy storage and transport, the frame sides and ends advantageously extend from their centers. 
     A further technical advantage is that the invention is lightweight, easy to assemble, and durable. In a preferred embodiment, the shelter canopy is advantageously constructed from 70-denier ripstop nylon supported by crossed flexible hoop arches constructed from plastic or fiberglass. 
     Another technical advantage is that in most cases, the invention obviates the need for ground stakes and guy ropes. Except in the most severe conditions, the inventive assembly is freestanding and does not need to be stabilized by anchors to the ground. This freestanding feature frees the user from carrying tools, ground stakes and rope unless severe conditions are anticipated. 
     A still further technical advantage is that the invention is adaptable to alternative service. In appropriate conditions, the invention may be used as a traditional “on-the-ground” shelter. This can be accomplished by using the canopy and adjustable hoop arches without attaching them to the base frame and adjustable-height legs. Alternatively, in a medical emergency, the base frame and the unsupported canopy can be used as a stretcher. 
     The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which: 
     FIG. 1 shows a perspective view of the inventive shelter in a one-user embodiment. 
     FIG. 2 shows a top view of the collapsible base frame in a one-user embodiment. 
     FIG. 3 shows an elevation view of FIG.  2  and illustrates the adjustable height legs. 
     FIG. 4 is a perspective view of the two ply floor surrounded by the base frame assembly. 
     FIG. 5 is an exploded view of the two-ply floor. 
     FIG. 6 shows a top view of the assembly in a one-user embodiment. 
     FIG. 7 shows a perspective view of the one-user embodiment from the rear. 
     FIG. 8 illustrates the optional cellar storage compartment. 
     FIG. 9 shows a perspective view of the inventive shelter in a two-user embodiment. 
     FIG. 10 shows a top view of the collapsible base frame in a two-user embodiment. 
     FIG. 11 shows a side view of the front and rear entrances in a two-user embodiment. 
     FIG. 12 shows a detailed view of the base frame locking button assembly in a preferred embodiment. 
     FIGS. 13 shows a detailed view of attachment by the floor sleeves to the base frame in a preferred embodiment. 
     FIGS. 14A and 14B show a detailed side views of the collapsible hoop arches in the folded and extended positions. 
     FIG. 15 illustrates a preferred embodiment of the floor having corner grommets to receive the hoop arch ends. 
     FIG. 16 shows a detailed top view of the screen mesh dome in a preferred embodiment. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIGS. 1,  2  and  3  illustrate a perspective view of a first embodiment operable for a single user. A substantially planar base frame comprises two extensible side frame components  1  and two extensible end frame components  2 . The side frame components and end frame components extend and fit into rounded corner brackets  3 . An independently adjustable height leg  4  connects to each of the lower sections of the four rounded corner brackets such that the legs extend in a common direction orthogonal to the plane of the planar base frame. The lower end of each adjustable height leg is fitted with a pivoting foot  5  that stabilizes the apparatus on soft or uneven terrain. Foot  5  is advantageously high-traction. 
     It will be understood that the frame components, legs and feet are advantageously constructed from a lightweight but structurally strong material such as aluminum or a fiber-reinforced plastic composite, for example. The invention is not limited in this regard, however. Moreover, although FIGS. 1 through 16 herein depict embodiments in which four corner brackets  3  are employed, it will be appreciated that other embodiments of the invention may employ any sized polygonal frame having at least three corner brackets and at least three adjustable legs. 
     Although not illustrated, it will be further appreciated that frame components  1 ,  2  may also advantageously be thicker in a central portion to provide additional sturdiness and stability to the assembled frame. 
     With further reference to FIG. 1, cover  7  is a double layer flap consisting of a screen mesh interior flap and a waterproof nylon exterior flap. Both of the flaps advantageously have a vertical zipper  8  and a horizontal zipper  9  running the length of the base of the opening. These zippers provide easy access and secure the front entrance flaps. When opened, one or both flaps can be rolled back and held in place by loop ropes. 
     Optional front vestibule  10  provides additional undercover storage by extending the vestibule canopy to the ground and securing it to the ground with, for example, ground stakes. The canopy is advantageously equipped with a diagonal zipper opening  11  for easy access. Note, however, that if optional front vestibule  10  is used, the inventive shelter will no longer be free-standing. 
     FIG. 1 also shows a dome mesh screen  12  with a protective rain flap  13  that provides ventilation. The protective rain flap  13 , when not in use, can be rolled and tied for storage, as depicted in FIG.  1 . Cross ventilation is achieved by side screened windows  14  equipped with horizontal and vertical flaps  15  to cover them during cold or wet weather. (The protective flap is shown to be rolled back in FIG. 1.) Additional cross ventilation can be achieved by opening the rear screen window  30  (see FIG. 7) and using the front screen opening  7 . 
     Next, to examine the base frame in a one-user embodiment in more detail, refer to FIG. 2, which is a top view of the collapsible base frame. Assembling the base frame is begun by extending the side frame components  1  and end frame components  2 . All of the frame components advantageously extend from the center and this extensible mechanism allows the base frame components to be of a manageable size for storage and transport. Once the user has extended the base frame components  1  and  2  and has fed them through the tent floor sleeves, the base frame assembly is completed by inserting the component ends into the horizontal openings of each of the rounded corner brackets  3 . Locking button  16  assembly secures the side  1  and end  2  components in place. Refer to FIG. 12 for a detailed illustration of the base frame locking button assembly  16 , in which a spring loaded hemisphere  34  engages with  35  at the selected adjustable length, as is known in the art. 
     Referring now to FIG. 3, it will be seen that leveling of the apparatus is accomplished by adjusting the height of each adjustable height leg  4  by pulling or pushing the leg into the bottom portion of the rounded corner bracket  3  the desired distance such that the frame sets level on the terrain. Leg  4  is then advantageously locked into corner bracket  3  using locking button mechanism  16  as described above with reference to FIG.  12 . Leveling bubbles  17  built into the end frame components  1  and the side frame components  2  further advantageously aid in leveling the shelter on sloping terrain. 
     With continuing reference to FIG. 3, the shelter is further leveled and secured by placing the movable foot  18  into a desired position. A hinge mechanism  19  on the bottom of the adjustable height leg allows the foot to be pivoted through a wide range of angles. Furthermore, the movable foot is wide so to provide stability in soggy ground, and is equipped with a high-traction surface  20 , such as a rubber tread, for improved traction on sloping surfaces. 
     FIG. 4 illustrates a perspective view of the base frame assembly and the shelter floor surface. The floor surface is created when the camper feeds the base frame components  1  and  2  through the tent floor sleeves  24 . As further illustrated on FIG. 13, the floor sleeves  24  are constructed from layering and sewing the edges of the upper ply  21  and the lower ply  22  of the floor so that the frame components  1  and  2  can be fed through next to seam  40 . 
     FIG. 5 depicts the two plys  21 ,  22  of the floor separated for the purposes of illustration. The floor is comprised of an upper ply floor  21  and a lower ply floor  22  sewn together along the outer edge. In a preferred embodiment, the upper ply floor  21  comprises 1000 denier fine mesh polyester pulled tightly across the base frame. The bottom ply  22  of the floor is constructed from 70-denier ripstop nylon that adds strength to the floor and insulation from wet and cold. 
     FIG. 6 depicts a top view of the shelter. Collapsible hoop arches are fully extended and are fed through the canopy tent sleeves  25  sewn into the canopy of the shelter. Refer to FIGS. 14A and 14B for folded and extended details of the collapsible hoop arches. FIGS. 14A and 14B illustrate the collapsible hoop arches as provided in four exemplary sections A, B, C and D, as may be found in the art. Returning to FIG. 6. A dome shape results by bending the hoop arches and inserting the hoop arch ends into the grommets  26  sewn into the floor  21  and  22  of the shelter. Refer to FIG. 15 for a detailed illustration of a preferred embodiment of the grommets. 
     FIG. 6 also depicts the screen mesh dome  27 . Advantageously, the shelter is equipped with an attached rain flap  28  and zipper pocket  29 . In FIG. 6, the rain flap is shown to be rolled and stored. The rain flap can be easily unrolled from the zipper pocket and secured into place by a series of snaps and hooks in case of wet or cold weather. FIG. 16 provides a more detailed illustration of the dome hook  42  and hook ring  43  arrangement. 
     FIG. 7 depicts a rear view of the one-user embodiment. Rear window  30  provides ventilation when the outer entrance flap is rolled back leaving the inner flap (screen) in place. Rear window  30  is equipped with an attached rain cover  31  that can be rolled up along the edge of the window when not in use. In FIG. 7, the rain flap is shown rolled and stored. 
     FIG. 7 also depicts interior side storage compartments  32  that are sewn into the tent canopy on both sides of the interior. The top of the compartment contains a zipper opening  32   a  for easy access. 
     FIG. 8 shows the optional additional storage available under the floor  21 / 22 . FIG. 8 illustrates this storage with the floor of the shelter removed, for clarity of illustration. Cellar storage compartment  33  consists of a removable nylon bag with a zipper opening  33   a  equipped with binding lines  33   b  that secure the storage compartment to the rounded corner brackets. The binding lines allow the cellar storage compartment to be suspended on the underside of the shelter floor. 
     FIG. 9 depicts a perspective view of a two-user embodiment. This two-user embodiment is a substantially similar, but enlarged version of the one-user embodiment. As will be appreciated from FIG. 9, the two-user embodiment has many of the same features as the one-user embodiment. The vestibule enclosure/storage system is expanded under the two-user embodiment in that a rear vestibule  39  and rear entrance  38  may optionally be provided according to FIG.  11 . The additional vestibule and entrance, when provided, also allows improved ventilation and access. 
     Of course, the base frame end components will be likely to be longer in the two-user embodiment. The two-user embodiment also advantageously comprises an additional intermediate set of adjustable height legs to help stabilize the structure. FIG. 10 illustrates the base frame according to a two-user embodiment. Rather than having one extensible end frame piece as in the one-user embodiment, the two-user embodiment advantageously comprises two separate end frame pieces that connect in the center to a proximal “T” bracket  36 . The “T” bracket  36  also advantageously contains a further built-in leveling bubble  17 . A longitudinal support bar  37  extends horizontally from the proximal “T” bracket  36  and inserts into a distal “T” bracket fitting  36  connecting the opposite end frame components  2 . This longitudinal support bar  37  provides additional lateral support to the base frame and further compartmentalizes the floor space. 
     Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.