An expandable shelter having an expanded configuration and a collapsed configuration in which the shelter has the approximate dimensions of a standard International Organization for Standardization (ISO) freight container. The expandable shelter includes first and second substantially parallel corner posts disposed at a first end of the shelter. The expandable shelter also includes a ramp coupled with hinges at the first end of the shelter and is configured to fit securely on the interior of the first and second corner posts when in a closed configuration in which the ramp is disposed between the first and second corner posts. The expandable shelter has sufficient strength to withstand the forces of at least eight similar shelters stacked on top of the shelter.

[0001]    The present application claims the benefit of U.S. Provisional Patent Application 61/358,120; filed Jun. 24, 2010. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    The work resulting in this invention was supported in part by the U.S. Army Medical Material Development Agency (USAMMDA) under Contract No. W81XWH08-C-0060. The U.S. Government has certain rights in the invention. 
     
    
     BACKGROUND 
       [0003]    1. Field of Invention 
         [0004]    The present application relates to a shelter system, and more particularly, to an expandable shelter system. 
         [0005]    2. Related Art 
         [0006]    Deployable shelter systems generally provide self-contained shelters for use in a variety of environments. Deployable shelter systems are known which are configured to be in the size and shape of a standard ISO (International Organization for Standardization) shipping container. In this way, the shelters may be shipped by commercial means, such as by railway, boat or aircraft, including military aircraft. Such a shelter may be deployed at a remote location. These shelters typically are expandable from the size of an ISO container to a larger size. Such shelters may be used for a variety of purposes, such as medical, temporary housing, disaster recovery, meeting space, office space, or laboratory space. 
       SUMMARY 
       [0007]    In accordance with one aspect of the present invention, an expandable shelter is provided. The expandable shelter has an expanded configuration and a collapsed configuration in which the shelter has the approximate dimensions of a standard International Organization for Standardization (ISO) freight container. The shelter comprises first and second substantially parallel corner posts, the first and second corner posts are disposed at a first end of the shelter. The first and second corner posts have first and second ends. The shelter also comprises an upper frame support extending between the first ends of the first and second corner posts. The shelter additionally comprises a lower frame support extending between the second ends of the first and second corner posts. The shelter also comprises a wall support attached to the first and second corner posts and the upper frame support. The shelter further comprises a displaceable panel hinged at the first end of the shelter and configured to fit securely on the interior of the first and second corner posts when in a closed configuration in which the displaced panel is disposed between the first and second corner posts, wherein the shelter has sufficient strength to withstand the forces of at least eight similar shelters stacked on top of the shelter. 
         [0008]    In accordance with another aspect of the present invention, an expandable shelter is provided. The expandable shelter has an expanded configuration and a collapsed configuration in which the shelter has the approximate dimensions of a standard International Organization for Standardization (ISO) freight container. The shelter comprises first and second substantially parallel corner posts disposed at a first end of the shelter. The shelter also comprises a ramp coupled with hinges at the first end of the shelter and configured to fit securely on the interior of the first and second corner posts when in a closed configuration in which the ramp is disposed between the first and second corner posts, wherein the shelter has sufficient strength to withstand the forces of at least eight similar shelters stacked on top of the shelter. 
         [0009]    In accordance with a further aspect of the present invention, an expandable shelter is provided. The expandable shelter has an expanded configuration and a collapsed configuration in which the shelter has the approximate dimensions of a standard International Organization for Standardization (ISO) freight container. The shelter comprises first and second substantially parallel corner posts, the first and second corner posts are disposed at a first end of the shelter. The first and second corner posts have first and second ends. The shelter also comprises an upper frame support extending between the first ends of the first and second corner posts. The shelter additionally comprises a lower frame support extending between the second ends of the first and second corner posts. The shelter also comprises a wall support attached to the first and second corner posts and the upper frame support. The shelter additionally comprises a fabric connector connected to the wall support. The shelter further comprises a displaceable panel hinged at the first end of the shelter and configured to fit securely on the interior of the first and second corner posts when in a closed configuration in which the displaced panel is disposed between the first and second corner posts, wherein the shelter has sufficient strength to withstand the forces of at least eight similar shelters stacked on top of the shelter. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0010]    The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures is represented by a like descriptor. For purposes of clarity, not every component may be labeled in every drawing. 
           [0011]    The advantages and features of this invention will be more clearly appreciated from the following detailed description, when taken in conjunction with the accompanying drawings, in which: 
           [0012]      FIG. 1  is a perspective view of multiple, stacked deployable, expandable, shelters; 
           [0013]      FIG. 2  is a front, perspective view of a single deployable, expandable, shelter in a retracted condition; 
           [0014]      FIG. 2A  is a schematic, cross-sectional end view taken along the line  2 A- 2 A of  FIG. 2 ; 
           [0015]      FIG. 3  is a front, perspective view of a single deployable, expandable, shelter of this invention; 
           [0016]      FIG. 3A  is a schematic, cross-sectional end view taken along the line  3 A- 3 A of  FIG. 3  showing a first floor panel being lowered; 
           [0017]      FIG. 4  is a front, perspective view showing the floor panel in a lowered condition; 
           [0018]      FIG. 4A  is a schematic, cross-sectional end view taken along the line  4 A- 4 A of  FIG. 4  showing one section in a deployed condition; 
           [0019]      FIG. 5  is a rear perspective view of the deployable, expandable shelter of this invention in a deployed condition; 
           [0020]      FIG. 5A  is a schematic, cross-sectional end view taken along the line  5 A- 5 A of  FIG. 5 ; 
           [0021]      FIG. 6  is a rear perspective view illustrating the ramp of this invention in a lowered position; 
           [0022]      FIG. 6A  is a schematic, cross-sectional plan view taken along the line  6 A- 6 A of  FIG. 6 ; 
           [0023]      FIG. 7  is a rear perspective view illustrating the ramp transition panel of this invention; 
           [0024]      FIG. 8  is a rear perspective view of the deployable, expandable shelter of this invention in a deployed condition with a fabric portico; 
           [0025]      FIG. 9  is a front elevational view of the deployable, expandable shelter of this invention in a deployed condition; 
           [0026]      FIG. 10  is a rear elevational view of the deployable, expandable shelter of this invention in a deployed condition; 
           [0027]      FIG. 11  is a fragmentary side view of one end of the deployable, expandable shelter of this invention as seen along line  11 - 11  of  FIG. 10 ; 
           [0028]      FIG. 12  is a fragmentary plan view of the ramp of  FIG. 11  as seen along line  1212  of  FIG. 11 ; 
           [0029]      FIG. 13  is a perspective view of the ramp transition panel of  FIG. 11  in a folded position; 
           [0030]      FIG. 14  is a schematic end view of the ramp as seen along line  14 - 14  of  FIG. 12 ; 
           [0031]      FIG. 15  is a schematic cross-sectional view of the skirt taken along line  15 - 15  of  FIG. 12 ; 
           [0032]      FIG. 16  is a front perspective view of a corner post showing a jack in a stowed position; 
           [0033]      FIG. 17  is a front perspective view of the post of  FIG. 16  showing the jack in a deployed position; 
           [0034]      FIG. 18  is a cross-sectional side view taken along the line  18 - 18  of  FIG. 16 ; 
           [0035]      FIG. 19  is a cross-sectional plan view taken along the line  19 - 19  of  FIG. 18 ; 
           [0036]      FIG. 20  is a fragmentary, rear perspective view, partially cut-away, of a hinge assembly of  FIG. 18 ; 
           [0037]      FIG. 21  is a cross-sectional side view taken along the line  21 - 21  of  FIG. 17 ; 
           [0038]      FIG. 22  is a cross-sectional plan view taken along the line  22 - 22  of  FIG. 21 ; 
           [0039]      FIG. 23  is a fragmentary, rear perspective, partially broken-away view of a hinge assembly of  FIG. 21 ; and 
           [0040]      FIG. 24  is a cross-sectional front view of a foot mounted to a ram taken along line  24 - 24  of  FIG. 21 . 
       
    
    
     DETAILED DESCRIPTION 
       [0041]    The present invention relates to a deployable, expandable, shelter which may be expanded from a collapsed condition in which it has the size and shape of a standard ISO container to a condition in which it is about three times its original, collapsed size. The collapsed shelter of the present invention can be stacked nine units high for shipping or storage. The shelter of the present invention, when deployed, may be used for hospital or medical purposes, laboratory space, disaster recovery, temporary housing, meeting or office space, or other like purposes. 
         [0042]    In one embodiment, the deployable, expandable shelter may be transported along with other standard ISO shipping containers by cargo aircraft, military aircraft, rail, truck and container ship. For example, two such shelters can be accommodated in a military C-130 aircraft. The shelters may be stacked one on top of the other to a height of nine for shipping on the deck of a container ship or for storage. These shelters are built to structural standards for shipping containers and to comply with ISO 1496/1 test requirements. 
         [0043]    One end of the shelter may be provided with a panel which forms the end wall of the shelter in a collapsed condition and which may be pivoted downwardly about a bottom hinge to form a ramp. A portico may be attached to the shelter by a fabric connector on a wall support when the ramp is lowered. The wall support provides strength and rigidity to that end of the shelter. The portico permits the maintenance of a controlled environment, or a sterile environment in the interior of the shelter. The ramp end may be provided with stabilizers. 
         [0044]    The end of the ramp may be provided with a flexible transition panel. The transition panel provides a transition from the ramp end to the ground or to another ramp, and is flexible to accommodate an uneven ground surface. This permits easy movement of wheeled objects to and from the interior of the shelter through, for example, a portico. 
         [0045]    Corner posts are provided at each corner of the shelter. These posts are load-bearing, and are reinforced to permit stacking of the shelter. The corner posts may be provided with jacks that may pivot outwardly from the post. Typically the jacks are provided with feet, such as sand feet, which assist in stabilizing the shelter. The jacks in the posts level the shelter. These jacks may be either manually operated, or, if access to power is provided, there is a self-leveling system which automatically levels the shelter. Each of the expanded modules of the shelter are also provided with stabilizers having feet which permit leveling of those portions of the shelter. 
         [0046]    In one embodiment, panels which serve as the side panels to the shelter when collapsed are pivoted downwardly and serve as floor panels for first and second modules on either side of the shelter when in an expanded condition. The side walls and top walls of the modules on either side of the shelter may be rolled or slid outwardly along rails disposed on the floor panels. Each floor panel may be lowered by a winch, which could be manually operated or power operated. 
         [0047]    One embodiment of shelter  10  of this invention will now be described with respect to  FIGS. 1 and 2 .  FIGS. 1 and 2  illustrate a typical shelter  10  in a collapsed configuration. When in a collapsed configuration, shelter  10  may have the configuration of a standard ISO container, which is typically twenty feet long, eight feet wide, and eight feet high. As shown in  FIG. 1 , shelter  10  may be stacked on top of other shelters  10 , or ISO containers with which it is compatible. In this manner, a shelter  10  or multiple shelters  10  can be shipped by means of cargo aircraft, military aircraft, rail, truck or container ship to a desired location. In one example, two such shelters  10  may be accommodated in a C-130 aircraft for deployment. Moreover, the shelters  10  may be stacked in a storage facility along with ISO containers. In one embodiment, shelters  10  are configured so as to be able to be stacked nine high, as illustrated in  FIG. 1 , which shows containers  10   a  through  10   i  in a stacked configuration. Shelters  10   a - i  preferably are built to satisfy ISO 1496/1 test requirements. 
         [0048]    Shelter  10  includes a main section  12  which has a first end  14 , a second end  16 , a roof  152 , a floor panel  118  having a floor surface  116 , panel  62 , panel  82 , and four corner posts  20 . As shown in  FIG. 2A , shelter  10  may further include a first expandable module  60  and a second expandable module  80 . When in a collapsed condition, modules  60  and  80  are fully disposed within main section  12 . The side of section  12  includes upper structural frame members  17 , lower structural frame members  138  and side structural frame members  13 . Upper and lower frame members  17  and  138  may extend between posts  20  on both sides of section  12 . Side frame members  13  may be affixed to posts  20  on either side of panels  62  and  82 . Frame members  17 ,  138  and  13  may be formed of aluminum or other suitable materials. Ends  14  and  16  may include upper frame supports  21  and lower frame supports  23 , which may be formed of steel or aluminum or the like. 
         [0049]    Corner post  20  will now be described with particular reference to  FIGS. 16-23 . There are four corner posts  20  which are the main support elements of shelter  10 . Corner posts  20  may be made of heavy gauge, welded steel. Gusset plates  29  (see  FIG. 2A ) may be provided at the top and bottom ends of posts  20  to provide greater strength and rigidity. Each corner post typically has a connection block  50  attached such as by welding to its top and bottom ends. Each block  50  typically has holes  52  formed in the top and bottom surfaces thereof to allow a standard container connector  54  to be inserted therein. Connectors  54  may be used to clamp shelters  10  together vertically. Holes  56  formed on the sides of blocks  50  may be used for interfacing with a crane, forklift or other like mechanism for movement of shelter  10  from one place to another. 
         [0050]    In one embodiment, each post  20  contains a jack  22 .  FIG. 16  shows a jack  22  in a stowed or normally retracted position, while  FIG. 17  shows a jack  22  in a deployed condition. Jack  22  typically includes a ram  24  for leveling of shelter  10 . Typically, each jack  22  is disposed within a housing  264 . Housing  264  may be disposed within an interior cavity of post  20  in the retracted position. A cover plate  260  may be disposed on the front of housing  264 . In one embodiment, cover plate  260  may have integral cross bolts  274  that may lock the cover plate  260  and jack  22  in a stowed position as seen in  FIG. 19 . A bracket  276  may be attached to the front of cover plate  260  and may be used to manually pull the jack  22  out of the post  20  and swing it into its deployed condition. There may also be a manual access knob  278  that permits access to a socket for a hand crank that can be used to manually crank down the ram  24  of jack  20 , for leveling of shelter  10  in the absence of any power. Alternatively, or in addition, ram  24  may be driven by an electromechanical motor. Electrical power and sensor wires  280  may be attached at connectors at the top end of housing  264 . The bottom end of ram  24  may be filled with a stabilizing foot  36 . 
         [0051]    Foot  36  may have a base plate  38  with flanges  40  and reinforcing ribs  42 . Foot  36  may include a post  34  which is attached at a bottom end to the base plate  38 . The top end of post  34  may include a spherical head  32 . The bottom end of each ram  24  may be fitted with a spring ball connector  26  which is shown in  FIG. 24 . Connector  26  may be a block which is attached to the bottom of ram  24  and which has a central socket  30  with two spring balls  28 . When foot  36  is aligned with and moved upwardly toward spring balls  28 , head  32  will snap into place between spring balls  28  to retain foot  36  in a pivoting relationship with respect to the end of ram  24 . 
         [0052]    A hinge  44  having arms  272  may be attached to pins  266  on housing  264 . Hinge arms  272  may be fitted onto pins  268  on spacers  269  which are attached to the inside of post  20 . Hinges  44  permit pivoting of jack  22  outwardly with respect to post  20 . A stop  270  may be attached at  271  to the hinge arms  272 . When jack  22  is in a stowed position, stop  270  abuts the inside of post  20  and when jack  22  is in a deployed condition, stop  270  abuts housing  264 , preventing further outward pivoting or movement of jack  22 . As shown in  FIG. 17 , in one embodiment, cross bolt guides  48  may be attached to the rear of housing  264 . When jack  22  is deployed, a cross bolt  46  may be inserted into guides  48  until stop  47  hits housing  264 . The cross bolt  46  spans the opening to the post  20  and blocks the jack  22  and prevents it from pivoting back into a stowed position under load. 
         [0053]    Panel  62  may form a side panel of section  12  when in a collapsed condition, but may form a floor panel of first expanded module  60  when in an expanded condition as will be described. Similarly, panel  82  may form a side panel of section  12  when in a collapsed condition, but may form a floor panel of the second expandable module  80  when in an expanded condition. Locking bars  140  hold panels  62  and  82  in place in a collapsed condition. Locking bars  140  are conventional, and may include cam  142  at one end which may be inserted into a receiver  144 . The cam  142  is rotated into a locking position by handle  146  which, when the locking bar is fully locked, is flush with the outer surface of panel  62  or  82  and may be held in place with clamp  147 . 
         [0054]    The first end  14  containing a first end wall  154  may include a door  156 . Door  156  may contain a latch  160  and is mounted on hinges  162 . A window  158  may be provided in door  156 . Second end  16  may include a wall support  186 , a frame  188  and an opening  180  for a ramp  18  which pivots downwardly, as will be described. Ramp  18  may include a door  202  having a handle  204  mounted on hinges  206 . 
         [0055]    First expandable module  60  will now be described with particular reference to  FIGS. 2-4A . As previously noted, panel  62  which forms the outer wall of section  12  when in a collapsed condition, is pivoted downwardly, as shown in  FIG. 4 , to form a floor panel for the first expandable module  60 . First expandable module  60  also includes a side wall  64 , a first end wall  66  and a second end wall  68 , a ceiling  70  and a floor surface  72  which is disposed on the inside surface of the panel  62 . Panel  62  is pivotally attached to lower frame member  138  of section  12  at hinges  114  ( FIG. 5A ). When pivoted downwardly, panel  62  may be supported by two support arms  100 , one at each side of panel  62 . Typically, although not necessarily, each support arm  100  is formed of two rigid links, an upper link  102  and a lower link  104 , which are connected at hinge  106 . 
         [0056]    Each support arm  100  typically is anchored at an upper end at anchor point  110  to an adjacent side frame member  13  of section  12 . The lower end of each support arm  100  typically is attached to panel  62  at an anchor point  112 . Typically, although not necessarily, turnbuckles  108  are provided at the upper and lower end of each support arm  100  at anchor points  110  and  112  to adjust the length of the support arm to equalize the length on both sides, and to ensure that when deployed, panel  62  is substantially horizontal. 
         [0057]    Panel  62  is typically lowered by a cable  306  which is attached to a winch  176 . Winch  176  may be mounted to any suitable interior surface of main section  12 , such as panel  14  or side frame member  13 , on a surface thereof facing the inside of section  12 . Winch  176  may be manually operated. In another embodiment, winch  176  may be operated using a tool such as a drill D as shown in  FIG. 3A , which is coupled to a drive socket  302  on the winch  176 . Winch  176  includes a reel  304 . Cable  306  may pass from reel  304  through side frame member  13  over a pulley block  310 . Cable  306  may extend from pulley block  310  along end wall  66  to pulleys  312  on one side of panel  62  and over pulley  314 . Cable  306  may extend along the outside surface of panel  62  through cable guide  316 , as shown in  FIG. 3 , to pulleys  312 ,  314  on the side of panel  62  opposite winch  176 . Cable  306  may extend along end wall  68  to anchor  318  mounted on side frame member  13 . By passing cable  306  across the entire outside surface of panel  62 , panel  62  is adequately supported during the deployment phase, and any torque or twisting of panel  62  during deployment is minimized. 
         [0058]    Panel  62  may contain an outer lip  63  which abuts an upper frame member  17  when in a collapsed condition. Panel  62  may also be provided with a flange  78  that extends about the free, outer perimeter of panel  62  to act as a stop to protect panel  62  when in the collapsed condition. Flange  78  may include a gasket to seal the interior of shelter  10  when in a deployed condition. 
         [0059]    Rails  74  disposed on floor surface  72  of panel  62  and rails  120  disposed on floor surface  116  of section  12  accommodate slides or rollers  76  on the bottom of walls  66  and  68  to allow module  60  and associated walls  64 ,  66  and  68  and ceiling  70  to be slid or rolled outwardly away from section  12  in its collapsed condition to an expanded position as shown in  FIG. 4A . Flange  78  may limit the movement of first expandable module  60  outwardly as it is pulled from its collapsed position. Typically two handles  124  may be provided, one at each end of panel  62 , to allow two people to pull wall  64  and walls  66 ,  68  and ceiling  70  outwardly to deploy first expanded module  60 . 
         [0060]      FIG. 4A  shows first expandable module  60  in its fully deployed condition. Module  60  is open at the end facing into the interior of section  12 . A flange  126  may be provided on ceiling  70  to abut against an interior surface of section  12  to limit outward movement of module  60  and/or to minimize any twisting of the module resulting from downward tilting of module  60  with respect to section  12 . Ceiling  70  of first expandable module  60  may include a light  150 , such as flat LED lights or other lights that are recessed or do not project sufficiently far downwardly from ceiling  70  to interfere with movement of the modules  60  and  80  or with the head room within shelter  10 . 
         [0061]    Second expandable module  80  will now be described with particular reference to  FIGS. 4A ,  5 ,  5 A and  6 A. The second expandable module includes a floor panel  82 , a sidewall  84 , first end wall  86 , a second end wall  88 , and a ceiling  90 . As can be seen, in one embodiment, ceiling  90  is spaced below ceiling  70  of module  60  to allow ceiling  70  to pass above ceiling  90  when the modules are in their collapsed position in section  12 . Similarly, end walls  86  and  88  are positioned so as to be located inside end walls  66  and  68  when in a collapsed position. Thus, module  80  is somewhat smaller than module  60  to permit collapse of shelter  10 . It is to be understood, however, that these positions could be reversed, so that ceiling  70  is positioned below ceiling  90  and walls  86  and  88  are outside walls  66  and  68  during the collapsed condition of the modules. Expandable module  80  is deployed in much the same fashion as first expandable module  60 . Panel  82 , which serves as a side wall of the container when in a collapsed condition is pivoted downwardly about hinges  114  to serve as a floor panel of module  80 . Panel  82  may include a flange  98  to protect panel  82  when in the collapsed condition. Flange  98  may include a gasket to seal the interior of shelter  80  when in a deployed condition. Panel  82  may be connected to shelter  10  by support arms  100  which may have upper links  102  and lower links  104  which are coupled at hinge  106 . Support arms  100  may be attached to panel  82  at anchor point  112  and to shelter  10  at anchor point  110  on side frame member  13 . Turnbuckles  108  may be provided at each end of arm  100 . Cable  306  allows deployment of panel  82  in a fashion similar to panel  62  of the first expandable module  60 . Cable  306  may extend from reel  304  of a winch  178 , through pulley blocks  310 , over pulleys  312  and  314 , along the outside end wall  86  and may pass along the outside of side wall  84  through a cable guide  316 , to another set of pulleys  312  and  314  at the other side of wall  84 . Cable  306  may extend along end wall  88  to anchor  318  on side frame member  13 . 
         [0062]    Winch  178  may be manually operated, or connected to a drill or other power device through a socket  302 . Winch  178  may be fixed to the wall like winch  176 , or, in one embodiment, it may be mounted on rails or slides  308  to be movable to allow the winch  178  to be stowed out of the way of wall  66  when the shelter is collapsed. In particular, as shown in  FIGS. 3A and 6A , slides or rails  308  may allow winch  178  to be moved toward first end  14  out of alignment with end wall  66  of first expandable module  60 . In this way, when shelter  10  is collapsed, wall  66  may abut the inner wall of section  12  to allow module  60  to be collapsed as far as possible without interference from winch  178 . Winch  176  is already out of alignment with any of the walls of first and second expandable modules  60  and  80 , and therefore may be permanently mounted in position on the wall of section  12 , if desired. 
         [0063]    Like the first expandable module  60 , the inside surface of panel  82  forms the floor surface  92  of second expandable module  80 . Rails  94  are provided on surface  92  and rails  122  are provided on floor surface  116  to accept slides or rollers  96  on the bottom of walls  86  and  88  to permit the expansion of module  80 . Flange  98  may limit movement of walls  86 ,  88  and  84  outwardly. A flange  126  may be provided on ceiling  90  to abut against an interior surface of section  12  to limit outward movement of module  80  and/or to minimize any twisting of module  80  resulting from downward tilting of module  80  with respect to section  12 . Handles  124  may also be provided on sidewall  84  to permit manual expansion of module  80 . Like module  60 , module  80  may be provided with lights  150 , such as flat LED lights or other lights that are recessed or that do not interfere with movement of modules  60  and  80  or with sufficient head room within shelter  10 . 
         [0064]    Stabilizers  148  may be provided adjacent the unsupported corners of panel  62  of module  60  and panel  82  of module  80 . Typically, two such stabilizers  148  are provided for each panel  62  and  82 . However, more stabilizers  148  may be utilized if necessary. Stabilizers  148  are attached to respective panels  62  and  82  at points  149  of the outer edge thereof, such as by means of a lip disposed beneath the edges of panels  62  and  82 . Stabilizers  148  preferably are provided with an enlarged, flat foot on which they are mounted to provide stability. Stabilizers  148  may be provided with spring loaded ratchets which are adjustable in height to accommodate an uneven ground surface and which may be urged upwardly against the edges of panels  62  and  82 . 
         [0065]    The structure at second end  16  will now be described with reference to  FIGS. 6-11 . As noted, second end  16  may include a ramp  18  in opening  180  which is connected to the floor panel  118  of section  12  such as by a hinge  182 . Ramp  18  may extend the entire distance between spaced posts  20  at second end  16 . Ramp  18  may contain a door  202  mounted on hinges  206  ( FIG. 5 ) which is flush with ramp  18 . Door  202  may include a recessed latch  204  on the exterior or underside of ramp  18 . Door  202  may be used as an access to the interior of section  12  for storing items, when ramp  18  is in an upright position. Ramp  18  may be provided with a smooth, flush surface  208  on the interior or top side of the ramp to allow movement of cargo or the like thereover. When in an upright position, ramp  18  is held in place by, for example, locking bars  140 . Four such bars are illustrated in  FIG. 10 . These locking bars are conventional and may have cam heads  142  that are urged into a snug relationship with receivers  144  when the handles are pivoted against the ramp by handles  146 , as shown in FIG.  5 ,. Clamps  147  may be provided for retention of the handles  146  in a stowed position. 
         [0066]    Typically, extending around the perimeter of ramp opening  180 , there is a peripheral wall support  186 . Wall support  186  provides the required rigidity and strength to second end  16  and permits ramp  18  to extend from post  20  to post  20  to provide the widest ramp possible without sacrificing strength or rigidity. Wall support  186  may be formed of steel. Wall support  186  is attached to posts  20 . Bumpers, such as rubber bumpers  184 , may be provided on wall support  186  at the upper end of the opening  180  for ramp  18  to allow the ramp to be drawn snugly into an upright position against the outer surface of wall support  186 . Wall support  186  may have affixed thereto a fabric connector  190 . Connector  190  is clamped to wall support  186  such as by a retainer  192 . (See  FIGS. 5A ,  6 A and  10 ). Fabric connector  190  may have one fabric layer  194  or two fabric layers  194  and  196 . Layers  194  and  196  each have a connecting device, such as zipper  198 , which can be attached to a structure or structures  350  which may form a portico when the ramp is in a down or deployed condition as shown in  FIGS. 8 and 10 . Layer  194  may be attached to, for example, a biological barrier, while layer  196  may be attached to, for example, an environmental barrier. When ramp  18  is in an upright position, connector  190  may be rolled up and stowed using straps  200 . 
         [0067]    In another embodiment, a structure forming a portico  350  may be provided. Portico  350  may be formed of two layers. For example, one layer may form an environmental barrier and another layer may form a biological barrier. Each layer may be selectively attached by a connecting device, such as zipper  356 , to a connecting device, such as zipper  198 , on a respective layer  194  or  196 . Other known connecting devices such as VELCRO® hook and loop fasteners, snaps or the like may be used. Portico  350  may be of any desired structure. In one embodiment, air beams (not shown) are used to support the portico structure. Any type of conventional air beam may be used. Air beams typically are tubes of fabric or plastic or the like which are inflated and have a pre-configured shape to provide structural support. Portico  350  may have a door  352 , such as a fabric door, at an end spaced from opening  180 . Door  352  may be opened or closed using zippers  354 . Rings  212 , such as D-rings, may be provided on ramp  18 , and strap  358  along the bottom and side edges of portico  350  may be tied to rings  212  or the like on the ramp  18  to hold the portico in position. Portico  350  may be stowed within section  12  when shelter  10  is in a collapsed condition and ramp  18  is upright. 
         [0068]    When ramp  18  is in a down or deployed condition, it may be supported by stabilizers, such as the two stabilizers  216  shown in  FIG. 7 . Stabilizers  216  are conventional stabilizers which are affixed to the end of ramp  18  in a conventional manner to support ramp  18 . Stabilizers  216  typically have enlarged feet. Stabilizers  216  may be adjusted by the use of spring loaded ratchets to different heights to accommodate an uneven ground surface, and to provide the desired spacing between the end of ramp  18  and the underlying ground. 
         [0069]    As shown in  FIG. 11 , ramp  18  may be raised and lowered by use of a winch  320  which may be either manually operated or motor-driven. Typically, winch  320  is attached to a corner post  20  by rails  322 . A pulley arm  334  may be attached to post  20  by hook  336  that passes through a hole  56  in corner block  50 . The pulley arm  334  is aligned within guide blocks  338 . A clamping member  340  may be attached to post  20  through a flange on pulley arm  334  by use of a screw together with a threaded hole on post  20 . A spool  326  on winch  320  may reel cable  328  out through rollers  330  and through pulley  332  on arm  334 . A snap hook  342  on the end of cable  328  may be attached to a ring  210  on the exterior of the ramp  18 . To lower ramp  18 , handles  146  are removed from clamps  147  and the locking bars  140  are released by turning handles  146 . Cam  142  is then withdrawn from receiver  144 . Ramp  18  then can be lowered by winch  320 , using crank arm  324 , if manually operated. As the ramp  18  approaches ground level, stabilizers  216  may be attached to the end of the ramp by inserting pins  218  through holes  214 . The stabilizers  216  are urged upwardly against the end of ramp  18  to provide a solid support independent of the winch  320  and cable  328 . 
         [0070]    In another embodiment, as shown in  FIGS. 12-15 , a transition panel  230  may be attached to the end of ramp  18 . Panel  230  provides a smooth transition from ground level to ramp  18  or from ramp  18  to another ramp or the like. Panel  230  allows wheeled vehicles and the like to be rolled onto or off ramp  18 . Typically, panel  230  is segmented as shown in  FIGS. 12 and 13  to accommodate any unevenness in the ground. That is, panel  230  is comprised of hinged segments or fingers  244 . Fingers  244  may be spaced from one another by small gaps, or they may be immediately adjacent one another. 
         [0071]    Preferably, panel  230  extends across the width of ramp  18 . In one embodiment, panel  230  is attached to sections  232  and  234 , which may be angled structures for strength. Holes  236  in sections  232  and  234  may pass over posts  218  on stabilizers  216 . A locking sleeve retainer  220  may pass over posts  218  to lock the panel  230 , ramp  18  and stabilizers  216  together as shown in  FIGS. 7 ,  11  and  12 . It is understood, of course, that panel  230  may be attached in other ways to ramp  18  and that this embodiment illustrates only one possible way of attachment. 
         [0072]    When panel  230  is stored, sections  232  and  234  may be folded together so that panel  230  can be inserted within the interior of shelter  10 . In one embodiment, sections  232  and  234  are connected together by hinge  238 . During storage, a storage fixture, such as a pin  224  may be inserted through holes  236  in sections  232  and  234  and a locking sleeve  220  may be attached at one end of pin  224 . 
         [0073]    Each of fingers  244  may be attached to a sealed tubing spacer  240  by an associated hinge  242 . In one embodiment, tubing spacers  240  are welded or otherwise attached to the front of sections  232  and  234 . Fingers  244  may be tapered at the end attached to hinges  242  and also at a second end  248 . Each finger  244  floats or moves independently of the other fingers  244 . Fingers  244  additionally may each have downwardly bent tabs  250  that have holes  252 . Fingers  244  typically are joined together on their underside by a rod or rods  254  which pass through holes  252  in tabs  250 . A pin  256  may be inserted in each end of rod  254  to prevent movement of rod  254 . The holes  252  are oversized to allow a certain amount of sliding movement of rod  254 . This arrangement permits a predetermined amount of individual movement of the fingers  244  with respect to one another. This flexibility or movement is illustrated in  FIGS. 14 and 15 . Each finger  244  may rotate about axis  258  by an angle equal to about  30 ° above and below a median position. 
         [0074]    Typically, each panel, such as panel  62 , wall  64 , wail  66 , wall  68 , panel  82 , wall  84 , wall  86 , wall  88 , ramp  18 , ceiling  70  and ceiling  90 , is formed of a structural panel  130  as illustrated in  FIG. 2A . Each panel  130  may include a framework of tubing  132  with a honeycomb support  134  filling the voids. The honeycomb support may be formed of any type of material, such as a polymer. One example is NOMEX™. Insulation material may be inserted into the honeycomb support  134 . A sheet metal skin  136 , such as an aluminum skin, typically covers this structure. 
         [0075]    When in a retracted or collapsed configuration as shown in  FIG. 2 , the corner posts  20  provide bearing members which support loads above shelter  10  and provide the necessary strength to allow the shelters  10  to comply with ISO 1496/1. Also, loads are transferred from frame members  17  to frame members  15  through locking bars  140  by way of panels  62  and  82 . At end  16 , wall support  186  provides load support as well as locking bars  140 , through ramp  18 . At ends  14  and  16 , upper frame supports  21  and lower frame supports  23  provide load bearing support. To comply with the racking requirements of ISO 1496/1, typically four equally-spaced locking bars  140  are used for each panel  62  and  82 . Wall support  186  also helps maintain the required rigidity, as do frame supports  21  and  23 . 
         [0076]    First end wall  154  may be provided with a power and communications panel  164  which typically is flush with wall  154 . A leveling bubble may also be provided for manual leveling of the shelter  10 . Preferably, however, the shelter is self-leveling. A self-leveling control panel  168  allows the shelter to level itself through the use of built-in sensors and software. Control panel  168  may be in any suitable location, such as on the inside surface of wall  154 . A typical self leveling unit employs an inclinometer and electric motors and gear reducers to operate rams  24  of jacks  22  in a known manner to level shelter  10 . One exemplary, suitable self-leveling unit is leveling support model  287 A, manufactured by Hetek Hebetechnik GmbH, Treffurt, linter den Linden, Germany. 
         [0077]    Power may be provided by line  400  to connector  402  ( FIG. 3 ) from a source, such as a peripheral mechanical module to power communications panel  164 . Heating, ventilation and air conditioning may be provided through supply and return ducts  406  and  408  ( FIG. 8 ) which may connect to adapter plates  410  and  412 , respectively, in complexing panel  414  ( FIG. 4 ), when the shelter is in an expanded condition. Communication lines (not shown) may connect with connectors  404  on panel  164 . Clean and waste water lines  416  and  418 , respectively, ( FIG. 8 ) may be connected to adapter plate  420  which is interchangeable with other adapter plates at port  422  in wall  86 . ( FIGS. 6A and 9 ). Panel  164  may be integrated with internal panel  166 . Power from panel  166  may be supplied to panel  167  to supply power to outlet strips (not shown) and lights  150 . Power from panel  166  may also be supplied to panel  168 . 
         [0078]    It should be appreciated that various embodiments may be formed with one or more of the above-described features. The above aspects and features may be employed in any suitable combination as the present invention is not limited in this respect. It should also be appreciated that the drawings illustrate various components and features which may be incorporated into various embodiments. For simplification, some of the drawings may illustrate more than one optional feature of the feature or component. However, the invention is not limited to the specific embodiments disclosed in the drawings. It should be recognized that the invention encompasses embodiments which may include only a portion of the components illustrated in any one drawing figure, and/or may also encompass embodiments combining components illustrated in multiple different drawing figures. 
         [0079]    It should be understood that the foregoing description of various embodiments is intended merely to be illustrative thereof and that other embodiments, modifications, and equivalents are within the scope of the invention recited in the claims appended hereto.