Patent Abstract:
A portable, insulated shelter consists of flexible inner and outer layers, lightweight fabric panels located therebetween, and connected to each other, a suitable support frame, and a system, such as a HVAC unit and a suitable connector, for actively controlling the interior environment of the shelter. The shelter may be used to protect and provide livable conditions in harsh, remote locations. Methods of selectively installing and removing the fabric panels are also provided, along with methods of setting up and disassembling the shelter.

Full Description:
BACKGROUND 
     Although a number of shelters, tents and insulation systems are known or have been suggested in the art, they all have or would have disadvantages. Japanese Patent No. 2004-132006 (Kawahara), for example, discloses a heat-insulating layer for a tent. An air layer D is formed between the tent 3 and a canopy sheet 5. As shown in FIG. 4 of Kawahara, cylindrical members 4 are attached to the exterior cover 5 by staple-shaped elements 8. The Kawahara tent requires a device f for forcing air through a duct d, which would waste energy, and the Kawahara tent is unduly complicated and unreliable, and it would be difficult to transport and set up, especially in remote, harsh environments. 
     U.S. Patent Application Publication No. 2009/0188539 (Hollinger) refers to the use of inert gas or low pressure within hollow or airtight tubes 901, 911 (FIGS. 9A, 9B) to provide insulation within a multi-layer tent. The Hollinger tent would require a source of inert gas, which would be impracticable, or inflation/deflation of the tubes, and the tubes would be subject to puncturing and damage, or additional construction expense would be required to make them sufficiently rugged. The Hollinger tent is unduly complicated and unreliable, and would be difficult to transport and set up, especially in remote, harsh environments. 
     Japanese Patent No. 2006-265849 to Shimizu discloses a fabric shelter (FIG. 14), and other shelters known in the art are shown in U.S. Pat. No. 4,102,352 (Kirkham), U.S. Pat. No. 4,607,655 (Wagner et al.), and U.S. Pat. No. 7,178,483 (Wu). 
     SUMMARY 
     The disadvantages of the prior art can be overcome to a great extent by a portable, insulated shelter that has flexible inner and outer layers, and lightweight fabric insulation panels located between the inner and outer layers. The shelter may be used, for example, to shelter human occupants in harsh, remote environments. In a preferred embodiment, the inner layer provides the inner surfaces of the shelter, and provides a living space by surrounding the occupants above and on all sides thereof. 
     The fabric panels may be connected together to provide thermal insulation for the shelter, by surrounding the flexible inner layer above and on all sides thereof. The outer layer may be used to protect the fabric panels (or the inner layer/liner when the fabric panels are not installed) from wind, rain, ice and snow. The flexible outer layer is preferably located outside of the fabric panels, and the shelter has only three layers, such that the fabric panels are sandwiched between the inner layer and the outer layer. 
     In a preferred embodiment of the invention, the fabric panels each include multiple layers of materials sandwiched together, and the fabric panels are removably connected to each other, and to the frame, by hook and loop fasteners. 
     In a preferred embodiment of the invention, the shelter may be supported by an exterior frame, made up, for example, of aluminum poles that can be disassembled. The invention is not limited, however to the preferred embodiments. The shelter may be supported by an interior frame made of arches and purlins, in a Quonset but configuration, and/or by other suitable support structures. 
     In a preferred embodiment of the invention, an HVAC unit is used to provide heat and/or cooling for the shelter occupants. The unit may be powered by electricity, liquid hydrocarbon fuel, or other suitable power sources. In a preferred embodiment, the shelter may be designed to maintain an interior temperature of about seventy degrees Fahrenheit, for outside ambient temperatures in the range of from about minus twenty-five degrees to plus one hundred and twenty-five degrees Fahrenheit, with significant reduction in energy power requirements compared to conventional shelters. 
     The disadvantages of the prior art may also be overcome to a great extent by using a portable, insulated shelter to protect human occupants in a harsh, remote environment, where the shelter has a liner and an outer layer, and a fabric insulation layer located between the flexible inner and outer layers. According to this aspect of the invention, the flexible inner layer provides the inner surfaces of the shelter, surrounding the occupants above and on all sides thereof, and the fabric insulation panels are installed and/or removed after the inner and outer layers of the shelter are provided. 
     When the fabric panels are installed, they are sandwiched between the inner and outer layers, and thereby provide thermal insulation for the shelter. In a preferred, especially compact and convenient embodiment of the invention, the top and side walls of the shelter do not have any layers other than the inner and outer layers and the fabric insulation panels. 
     In a preferred embodiment of the invention, the shelter is convenient and easy to set up. Although a six-foot ladder may be used during assembly, the shelter otherwise can be installed without any special tools. 
     According to one aspect of the invention, when insulation is desired, the fabric panels are located between the inner and outer layers of the shelter, such that the inner layer of the shelter is provided by the same element in both insulated and non-insulated configurations. The shelter can be changed from a non-insulated to an insulated configuration without changing the interior space of the shelter. In other words, since there is an inner wall located inside the insulation, the shelter has a comfortable, finished configuration, even when the insulation panels are installed, and the inner layer is always located inside the frame elements, even when the insulation panels are not installed. Thus, the insulation system described herein is particularly well suited for providing livable interior conditions in harsh climates, using portable fabric shelters, tents and other soft-walled structures. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1A  is a perspective view of a shelter constructed in accordance with a preferred embodiment of the present invention, in a non-insulated configuration. 
         FIG. 1B  is a perspective view of the shelter of  FIG. 1A , in an insulated configuration, with insulation panels located between an outer cover and an inner liner. 
         FIG. 2  is another perspective view of the shelter of  FIGS. 1A and 1B , looking into the shelter from the front to the back, with the front of the shelter removed, and with the liner removed. 
         FIG. 3  is an enlarged view of portion  3  of  FIG. 2 , showing a purlin-arch connection. 
         FIG. 4  is a perspective view of a portion of the shelter of  FIGS. 1A and 1B , viewed from inside the shelter, with the liner removed, and with two insulation panels connected to respective arches. 
         FIG. 5  is a front perspective view, like  FIG. 2 , with all of the insulation panels installed, and with one of the liner sections partially re-installed. 
         FIG. 6  is an enlarged view of portion  3  of  FIG. 2 , showing two liner sections surrounding the purlin-arch connection. 
         FIG. 7  is an enlarged view of a portion of the shelter of  FIG. 1B , showing a hook and loop connection between a fifth insulation panel and a sixth arch. 
         FIG. 8  is a perspective view of a front portion of the shelter of  FIG. 1B , viewed from inside the shelter. 
         FIG. 9A  is a cross-sectional view taken along line  9 A of  FIG. 1A , showing the liner and the outer cover. 
         FIG. 9B  is a cross-sectional view taken along line  9 B of  FIG. 1B , showing the liner, the insulation layer, and the cover. 
     
    
    
     DETAILED DESCRIPTION 
     Turning now to the drawings, where like reference numerals designate like elements, there is shown in  FIG. 1A  an exemplary shelter  10  constructed in accordance with a preferred embodiment of the present invention. The shelter  10  has a front wall  12 , a back wall (not shown), a roof  14 , and side walls  16 . The right side wall (not shown) is the mirror image of the left side wall  16 . The front and back walls  12 , the roof  14 , and the side walls  16  are supported by a suitable frame made of aluminum, steel, wood or the like, which has, by way of example, six arches  18 ,  20 ,  22 ,  24 ,  26 ,  28 , three longitudinally-extending purlins  30 ,  32 ,  34  ( FIG. 2 ), and suitable floor-frame members  36 ,  38 ,  40 ,  42 . Depending on expected wind and other conditions, the shelter  10  may be tied to the ground by suitable wires or ropes (not shown). The shelter  10  may have, for example, a Quonset but configuration, and may be, for example, about twenty feet wide and about thirty two and one-half feet long. 
     The front and back walls  12  of the shelter  10  may have a semi-circular configuration, and are secured to the frame  18 ,  28 ,  36 ,  40  along their peripheries (that is, along the edges of the front and back walls  12 ). If desired, a door  50  ( FIGS. 1A ,  1 B) and windows  52 ,  54  may be located in the front wall  12 . The roof and side walls  14 ,  16  may be formed of one or more rectangular, flexible pieces that extend flexibly from the ground on the right side of the shelter  10 , over the top of the shelter  10 , and to the ground on the left side of the shelter  10 . The front and back walls  12 , the roof  14 , and the side walls  16  are secured together along their peripheries (that is, seamed along all of their adjoining edges) to form a secure, weather-proof enclosure, such that the shelter  10  provides a comfortable interior space for the occupants (not shown), with interior surfaces (not shown in  FIG. 1 ) that do not need to be changed or covered even when the shelter  10  is collapsed and taken down for transport to another location. 
     In a non-insulated configuration, the front and back walls  12 , and the roof and side walls  14 ,  16 , across essentially their entire extents, have the two-layer configuration illustrated in  FIGS. 1A and 9A . There is an inner fabric liner  70  with an inner surface  71  that faces inwardly toward the occupants (or storage space) inside the shelter  10 . The liner  70  is formed of five rectangular panels  72 ,  74 ,  76 ,  78 ,  80  that together are essentially coextensive with the roof and the sidewalls  14 ,  16 . As such, the liner  70  covers essentially the entire living space (and/or storage space) provided by the shelter  10 . The liner  70  may be supported by the purlins  30 ,  32 ,  34 , as discussed in more detail below. 
     As shown in  FIGS. 1B and 9B , an insulation layer  84  may be installed (and, if desired, removed from) between the liner  70  and the outer layer  86  of the shelter  10 . The insulation layer  84 , in the illustrated embodiment, is made up of five rectangular insulation panels  90 ,  92 ,  94 ,  96 ,  98 , only two of which can be seen in  FIG. 1B , and only one of which ( 94 ) is shown, partially installed, in  FIG. 2 . To install the insulation layer  84 , that is, to change the shelter configuration from that of  FIG. 1A  ( 9 A) to that of  FIG. 1B  ( 9 B), the inner layer  70  (all five liner panels  72 ,  74 ,  76 ,  78 ,  80 ) is completely removed, such that the inside of the shelter  10  is as shown in  FIG. 2 . Then, a central insulation panel  94  is threaded between the outer layer  86  and the purlins  30 ,  32 ,  34 . In operation, the central insulation panel  94  is laid out on the floor of the shelter  10  and aligned with the center bay  106 . Then the panel  94  is lifted up and placed in position, by running the panel  94  over the three purlins  30 ,  32 ,  34  in the center bay  106 . In the installed configuration ( FIG. 1B ), the center insulation panel  94  is sandwiched between the purlins  30 ,  32 ,  34  and the outer cover  86  of the shelter  10 . 
     As shown in  FIG. 3 , the front edge  114  of the center insulation panel  94  overlaps the third arch  22 , except where purlin cutouts  116  are provided to make room for purlin-arch connections  118 . The front edge  114  has one cutout  116  for each of three purlin-arch connections  118 , since there are three purlins  30 ,  32 ,  34  in the illustrated shelter  10 . The front edge  114  of the center insulation panel  94  also has hook and look tabs  120  that wrap around the third arch  22  to secure the panel  94  in the insulated configuration. The insulation panel  94  may be located so that any side windows (not shown) open down and toward the inside of the shelter  10 . The length of the insulation panel  94  is slightly longer than the length of the arches  22 ,  24 , such that the ends  122  ( FIG. 2 ) of the panel  94  overlap the floor frame  38 ,  42 . 
     The other four insulation panels  90 ,  92 ,  96 ,  98  are essentially identical to the center panel  94 , and they are threaded, one at a time, between the cover  86  and the purlins  30 ,  32 ,  34 , and their front edges are connected to the respective first, second, fourth and fifth arches  18 ,  20 ,  24 ,  26  by the same arrangement of hook and look tabs  120  and purlin cutouts  116 . Hook and loop inner seams  124  ( FIG. 4 ) that run essentially the entire lengths of the back edges  126  of the first four insulation panels  90 ,  92 ,  94 ,  96  are then connected to corresponding hook and loop outer seams  128  that run along essentially the entire lengths of the front edges of the second through fifth insulation panels  92 ,  94 ,  96 ,  98 . Each pair of seams  124 ,  128  is interrupted in three places by the purlin cutouts  116 , to accommodate the purlin-arch connections. The overlapped seams  124 ,  128  provide a sealed thermal barrier between the outside and the inside surfaces of the insulation layer  84 . In the insulated configuration, the arches  20 ,  22 ,  24 ,  26  are located mostly outside of the insulation layer  84 . That is, the arches  20 ,  22 ,  24 ,  26  are located between (1) the flexible seams  124 ,  128  of the insulation layer  84  and (2) the flexible outer cover  86 . 
     Then, after the five insulation panels  90 ,  92 ,  94 ,  96 ,  98  are installed, connected to the respective arches, and seamed together, the liner panels  72 ,  74 ,  76 ,  78 ,  80  are returned to their original positions.  FIG. 5  shows the center liner panel  76  being returned to its original position in the center bay  106 . The liner panels  72 ,  74 ,  76 ,  78 ,  80  are seamed together by, for example, hook and loop seams along their edges  134 ,  136  ( FIG. 6 ), with suitable purlin cutouts  130  being provided to accommodate the purlin-arch connections  118 . 
     Liners for the front  12  and back of the shelter  10  may also be removed to permit installation of insulation. The front and back insulation layers and liners may be connected to the outer cover  86  and the first and sixth arches  18 ,  28  and the front and back floor-frame members  36 ,  40  by suitable zippers or hook and loop seams. Liners for the front and back of the shelter  10  may be installed as shown in  FIG. 8 . When the door  50  is made of a flexible material, the liner  70  may be connected to the door  50  by a zipper. When the door is solid (not flexible), the liner  70  may be connected to the door by a suitable adhesive (not illustrated). 
     The outer layer  86 , which may be made of polyvinyl chloride (PVC), is essentially coextensive with the inner layer  70  (and therefore essentially coextensive with the front and back walls  12 , the roof  14  and the side walls  16 ). The inner layer (liner)  70  may be made of a lightweight polyethylene material. The outer fabric layer  86  completely surrounds the shelter  10  and thereby provides an outer fabric shell which operates as a noise barrier, and which protects all elements inside the outer layer  86 , including the frame elements, from wind, rain, snow and the like and which prevents insects and other pests from entering the shelter  10 . 
     Each insulation panel  90 ,  92 ,  94 ,  96 ,  98  may be made of lightweight, flexible material, and may be constructed of multiple layers  162 ,  164 ,  166  sandwiched together, as shown in  FIG. 9B . 
     An HVAC unit  200  ( FIGS. 1A ,  1 B) can be provided to supply heated, cooled, humidified and/or dehumidified air to the interior of the shelter  10  via suitable tubing  202  and sealed openings  204  through the shelter  10 . If desired, one of the insulating panels  98  may be provided with a pre-cut hole (not shown) to conveniently accommodate the tubing  202  without providing space for air drafts and/or pests to enter the shelter  10 . The HVAC unit  200  may be electric (and connected to a liquid-fueled generator) or may itself be fueled by gasoline, diesel fuel or the like. In a preferred embodiment of the invention, two stovepipe-type openings may be provided. 
     It can be very expensive to transport liquid fuel to remote locations. Consequently, an important advantage of the present invention is that it can provide an efficient insulating system, forming a three-layer shell around the occupants (or the storage space provided by the shelter  10 ), that reduces overall fuel consumption and that is also lightweight, and convenient to handle and install, and that provides a livable interior space without disrupting the inner surfaces of the interior space when the insulation pieces  90 ,  92 ,  94 ,  96 ,  98  are removed and installed. The insulation panels can be affixed in the space  212  ( FIGS. 9A ,  9 B) between the inner and outer layers  70 ,  86  when desired. 
     The invention is not limited to the structures, methods and instrumentalities described above and shown in the drawings. Among other things, the invention is not limited to the particular Quonset but configuration shown in the drawings, nor is it limited to the particular number or arrangement of illustrated frame elements. The invention may be implemented, for example, in a Gable-type shelter, and in a wide variety of other configurations. The invention is defined by the claims set forth below.

Technology Classification (CPC): 4