US20060101729A1

US20060101729A1 - Hinged panels for construction of a habitable building

Info

Publication number: US20060101729A1
Application number: US10/989,820
Authority: US
Inventors: Michael Waters
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-11-17
Filing date: 2004-11-17
Publication date: 2006-05-18

Abstract

Light weight panels are combined with a hinge structure to form a foldable panel assembly that is suitable for constructing habitable buildings. Such buildings are easily collapsible into a compact package for transport or storage and are readily extendable to an expanded size for use. These buildings may be fitted to a trailer for transport and can remain on the trailer while extended and placed in use, or the building can be off-loaded to a suitable site for extension and use. The hinge structure utilizes flexible membrane elements that are bonded to the edges of adjacent panels.

Description

The present invention relates to structures for providing enclosed functional space for humans and related activities, and more particularly for such structures that are easily collapsible, transportable, and expandable to their original size and shape.

BACKGROUND OF THE INVENTION

Habitable buildings that are easily transportable such as campers and motor-homes are increasingly popular among vacationers and others. There is a consumer demand driving this industry for larger portable living spaces and the manufacturers are attempting to meet this demand and the increasing desires of their customers. However, the allowable width of these campers and motor-homes is limited by the width of the roads and highways that will be used to transport them. There are attempts by some manufacturers to increase the usable habitable space of their products by providing a movable wall or wall-section that is moveable to an extended position. See, for example, U.S. Pat. No. 5,966,956 which issued to Morris et al. on Oct. 19, 1999 and U.S. Pat. No. 5,265,394 which issued to Gardner on Nov. 30, 1993. Typically these types of extendable units, if they extend out more than a few feet, require external support for structural viability, and they are still quite limited in their extension possibilities because they have to be able to be wholly contained in the camper or motor-home for transportation. Additionally, it is difficult to seal out the weather and wind because they usually have components that slide outwardly on cantilevered tracks that sag and, eventually, render weather seals inoperative. Other attempts to increase habitable space are meet by folding panel structures of varying complexity that are difficult to set up and equally difficult to weather seal. See, for example, U.S. Pat. No. 3,302,341 which issued to Konopasek on Feb. 7, 1967 and U.S. Pat. No. 3,653,165 which issued to West on Apr. 4, 1972. One of the problems with providing a suitable foldable panel structure is that in order to hinge two panels together, some kind of framework is required to provide attachment points for the hinges and related hardware. This adds extra unwanted weight to the panels and makes them expensive to produce. Another foldable panel structure shown in U.S. Pat. No. 1,167,070 discloses a pair of solid wood panels pivotally coupled by means of a pair of flexible members attached to adjacent edges of the two panels by means of a series of nails that are driven through the flexible members and into the wood panels. Unfortunately, the depth of the wood material needed to grip and hold the nails in place, adds substantial weight to the assembly. Additionally, the nails provide only point contacts for holding the flexible members in place and result in areas of no support between adjacent nails so that the flexible members can deform under load and eventually fail. This type of hinge is not inherently weatherproof thereby requiring additional sealants where the hinge is exposed to the elements.
What is needed is a foldable panel structure that is extendable outwardly from the camper or motor-home substantially further than heretofore possible with prior art devices. The foldable panels should be very light and yet strong enough to be self supporting, and should automatically seal out the weather along their folding joints. The folding joints should efficiently distribute the loads between adjacent panels and easily support the weight of adjacent panels in the extended position, as well as other normal building loads, and in the retracted position.

SUMMARY OF THE INVENTION

A foldable structure is provided for constructing a building suitable for use as a shelter. The foldable structure includes first and second sandwich-panels. Each sandwich-panel has a core of relatively low density material having two opposite major surfaces and an edge surface. There are two high density tensile-skins, one skin attached to one of the major surfaces of the core and the other skin attached to the other of the major surfaces of the core so that the outer surfaces of the two tensile-skins form opposite first and second outer surfaces terminating at the edge surface. An inside thin flexible member is secured along the edge surface of each of the first and second sandwich-panels. An outside thin flexible member is secured along a portion of the first outer surface of each of the first and second sandwich-panels. The inside and outside flexible members are arranged to pivotally couple the first and second sandwich panels together so they pivot about an axis. The inside flexible member and the outside flexible member are on opposite sides of a plane extending through the axis. The pivotally coupled sandwich-panels are arranged to form walls and a roof of a building having portions that are movable between an extended position for accommodating human occupation and a retracted position for substantially reducing the over all size of the building during transportation and for storage when not in use.
An embodiment of the invention will now be described by way of example with reference to the following drawings:

DESCRIPTION OF THE FIGURES

FIG. 1 is an isometric view of a building in its collapsed state incorporating the teachings of the present invention;
FIG. 2 is a view similar to that of FIG. 1 showing the building in its extended state;
FIG. 3 is an isometric view of a sandwich-panel used in the construction of the building shown in FIG. 1;
FIG. 4 is a partial sectional view, enlarged, of the sandwich-panel taken in the direction of arrow A in FIG. 3;
FIG. 5 is an isometric view of two sandwich-panels joined along adjacent edges by flexible members in accordance with the teachings of the present invention;
FIG. 6 is an end view of the two panels shown in FIG. 5, shown in an intermediate position;
FIG. 7 is a view similar to that of FIG. 6 showing the panels in their retracted position;
FIG. 8 is a view similar to that of FIG. 6 showing the panels in their extended position;
FIG. 9 is an end view of the building shown in FIG. 1 in its retracted position;
FIGS. 10 and 11 are views similar to that of FIG. 9 showing the building in intermediate positions;
FIG. 12 is a view similar to that of FIG. 9 showing the building in its extended position;
FIG. 13 is a side view of the building shown in FIG. 9;
FIG. 14 is a partial cross-sectional view taken along the lines 14-14 in FIG. 10;
FIG. 15 is a partial cross-sectional view taken along the lines 15-15 in FIG. 11;
FIG. 16 is a partial cross-sectional view taken along the lines 16-16 in FIG. 12;
FIG. 17 is a front view of a panel depicting another embodiment of the present invention;
FIG. 18 is a side view of the panel of FIG. 17;
FIG. 19 is an enlarged view taken along the lines 19-19 in FIG. 17;
FIG. 20 is a view similar to that of FIG. 6 showing a variation of the X-Hinge;
FIG. 21 is a front view of a panel depicting another embodiment of the present invention; and
FIG. 22 is an isometric view of a variation of the flexible members shown in FIG. 5.

DESCRIPTION OF AN EMBODIMENT OF THE INVENTION

There is shown in FIGS. 1 and 2 a habitable building 10 carried on a trailer 12 that is used to transport the building to a site where it is to be used. The building 10 is shown in FIG. 1 in its collapsed state for transportation or storage, and in FIG. 2 in its extended state ready for use. The building may be either off-loaded from the trailer, if desired, and placed on a suitable surface that is substantially flat where it will be extended, or it can remain on the trailer 12 and extended as shown in FIG. 2. The building 10 includes a number of foldable sandwich-panels 20 that operate to allow the building to be easily manipulated into either its collapse state or its extended state. This operation and other structural details of the building will be described below.
As shown in FIGS. 3 and 4, each of the sandwich-panels 20 include an interior core 22 of relatively low density material having major outer surfaces 24 and 26, and an edge surface 28. A pair of tensile skins 30 and 32 of relatively high density material are attached to each major surface 24 and 26 of the interior core 22. The skins 30 and 32 may be attached to their respective major surfaces by bonding or any other suitable means whereby the final sandwich-panel 20 has substantial stiffness and strength in tension in the directions parallel to the major surfaces 24 and 26, and has substantial stiffness and strength in a direction perpendicular thereto to resist bending and absorb impact loads. This sandwich structure having outer skins of relatively high tensile material intimately bonded to the entire outer major surfaces of a relatively light interior core yields a superior panel having strength comparable to an H-beam in the direction perpendicular to the major surfaces. The high tensile skins, held rigid by virtue of being bonded to the core, yield very high shear resistance in the direction parallel to the major surfaces. As will be discussed below, the actual density characteristics of the outer tensile skins 30 and 32, and the inner core 22 are selected to provide strength, tensile, shear, bending, and impact resistance to fit the particular application. In general, however, the outer skins 30 and 32 are of a higher density material than is the core 22.
Two panels 20, shown in FIGS. 5 and 6, are pivotally joined along adjacent edges 38 and 40 by means of an inside flexible member or membrane 42 that is continuously bonded to the entire edge surfaces 38 and 40 for the length of the panels 20. An outside flexible member or membrane 44 is continuously bonded to adjacent portions of the skins 30 on each of the two panels 20, for the length of the panels, so that when the two panels are positioned at 90 degrees to each other, as shown in FIG. 6, the two flexible members 42 and 46 form an X having a pivot axis 50 at the center of the X. This hinge or pivot structure will be referred to as an X-hinge 52 when describing various embodiments of the present invention. The two panels 20 are free to pivot about the axis 50 from their retracted position, shown in FIG. 7, through an intermediate position, shown in FIG. 6, to their extended position, shown in FIGS. 5 and 8. It will be understood that the inside and outside flexible members 42 and 44 are shown in the Figures having exaggerated thickness, in the interest of clarity. The actual thickness of these members is in the order of about a few thousands of an inch to about a sixteenth of an inch or greater. The actual thickness is selected to provide the strength and flexibility that is required by the particular application. Specific examples will be provided below. As best seen in FIG. 6, a plane 54 can be drawn through the pivot axis 50 so that the inside flexible member 42 lies on one side of the plane and the outside flexible member 44 lies on the opposite side of the plane 54. This holds true for all positions of the two panels 20 from that shown in FIGS. 6, 7, and 8 as long as the inside flexible member 42 is limited to bonding to the edges 38 and 40. It will be shown below that in certain applications the outer edges of the inside flexible member 42 can wrap around and be bonded to portions of the skins 32. See, for example, FIG. 20.
The building 10 of FIGS. 1 and 2 is shown in FIGS. 9 through 12 illustrating the structure and operation thereof A base unit 60 is arranged on the trailer 12, as shown in FIG. 9, and forms a stable platform to which a roof 62, having two gable ends 64 and two inter-joined panels 20, is pivotally attached so that the roof is pivotable about an axis 66. The roof 62 is pivotable between the retracted position shown in FIG. 9, through an intermediate position shown in FIG. 10 to the extended position shown in FIG. 12. The base unit 60 includes an interior 68 that holds a variety of floor panels, ceiling panels, and interior partitions. The interior 68 can optionally be configured to hold furniture and equipment, not shown, for providing utilities. As best seen in FIGS. 11, 12 and 13, there are a pair of panels 70 and 72 and a comparable opposite pair of panels 74 and 76 which form foldable walls both front and back. Each of the panels 70 through 76 is similar in construction to the sandwich panel 20. An end wall 80, constructed similarly to the sandwich panel 20, extends along the entire end of the building 10. The panel 72 is pivotally coupled to the near end of the end wall 80 by means of an X-Hinge 52 running the entire height of the panel, and the panel 76 is coupled to the opposite end of the end wall 80 in a similar manner, as best seen in FIGS. 14, 15, and 16. The two panels 70 and 72 are pivotally coupled together along common vertical edges, as viewed in FIG. 12, by means of an X-Hinge 52 running the entire height of the panels. Similarly, the two panels 74 and 76 are coupled together by means of an X-Hinge 52. The panel 70 is pivotally coupled to the near wall of the base unit 60, as viewed in FIG. 12, by means of an X-Hinge 52 running the entire height of the panel. Similarly, the panel 74 is coupled to the far wall of the base unit 60 by means of an X-Hinge 52. The X-Hinges 52 are positioned so that the panels 70 through 76 will fold in the manner shown in FIGS. 14, 15, and 16 as the building 10 is moved between its retracted position shown in FIGS. 1 and 9 and its extended position shown in FIGS. 2 and 12. A secondary roof panel 82 is rigidly attached to the end wall 80 by any suitable means and moves along with the end wall as the building 10 moves between its extended and retracted positions. Note that as the building retracts, the secondary roof panel is simply moved into the interior 68. Alternatively, the secondary roof panel 82 may be pivotally coupled to the roof 62 by means of an X-Hinge running the length of the panel 82 along the line 84 as best seen in FIGS. 2 and 12. The base unit 60 and the roof 62 are constructed of material similar to that of the sandwich panel 20, having an inner core of relatively low density material and outer tensile skins bonded to both major surfaces of the inner core. A floor, not shown, is similarly constructed of multiple sandwich panels that are suitably pivotally coupled to each other and to portions of the interior 68 of the base unit 60 by means of multiple X-Hinges 52, and arranged to expand outwardly as the building 10 moves from its retracted position shown in FIG. 9 to its extended position shown in FIG. 12. Additionally, interior partitions may be similarly included to pivot into a desired position as the building 10 extends.
The various materials that may be utilized in the practice of the present invention will be influenced by the application of the sandwich panels and associated X-Hinge. In the present application of a building carried on a trailer for general utility use, the panels 20 have external dimensions of four feet by eight feet having a core thickness of four inches. The tensile skins 30 and 32 are 60T aluminum having a thickness of 0.032 inches and are bonded to the major surface of the core 22 by means of urethane adhesive. There are a variety of heat bond or hot melt adhesives commercially available that are suitable for this application. The core 22 is solid molded foam of approximately one-pound density. This material is sold under the trademark of SNAP_N_LOCK by ______. While many other suitable materials may be used in the practice of the present invention, these materials are by way of example only. The structure disclosed herein renders the various vertical panels of the building 10 extremely strong in the vertical direction, as viewed in FIG. 12. They gain this strength through the tensile skins being held rigidly in parallel planes by being bonded to the surfaces of the core. When fully extended the panel pairs 70 and 72 and the panel pairs 74 and 76 are cantilevered from the base unit 50 forming a beam structure and will easily support their own weight as well as the weight of the roof and a substantial accumulation of snow. The X-Hinge 52 becomes an integral part of the beam structure, efficiently and seamlessly transferring the sheer, tensile, and bending loads from one panel to the next while adding very little weight to the structure. The horizontal panels of the roof 62, secondary roof 82 and the floor (not show) are quite stiff and gain additional strength and stiffness from the X-Hinges 52 that join the individual panels together.
Another embodiment of the present invention is shown in FIGS. 17, 18, and 19. A panel 100 is shown having a central core 102 of a relatively low density material such as a molded foam as used in the core 22 of the panel 20. The two opposite major surfaces of the core 102 are covered with a coating of a relatively dense material such as a two part resin, thereby forming tough outer skins 104 and 106 that provide impact resistance and tensional strength to the panel 100 in a manner similar to the tensile skins 30 and 32 of the panel 20. As with the panel 20, the panel 100 is a sandwich structure having outer skins of relatively high tensile material intimately secured to the entire outer major surfaces of a relatively light inner core which yields a superior panel having substantial strength in the direction perpendicular to the major surfaces. While the relatively high density skins, held rigid by virtue of being intimately secured to the surfaces of the core, yield very high shear resistance in the direction parallel to the major surfaces. The actual density characteristics of the coating that make up the skins, and the inner core 102 are selected to provide strength, tensile, shear, bending, and impact resistance to fit the particular application. The application of such a coating, which may be sprayed on or applied with an applicator such as a brush, is easy to do and is inexpensive. The main requirement for the coating is that it intimately adhere to the surfaces of the core 102 and attain a thickness that will yield the strength required by the application of the panel 100. While certain two part resins are suggested here, it will be understood that other materials may be used to create the outer skins in accordance with the teachings of the present invention. A resin or polymer may achieve the required structural characteristics by the addition of tensile fibers such as Kevlar or fiberglass or by the structural nature of the resin alone depending on the application.
There is shown in FIG. 20 an X-Hinge 110 which is a variation of the X-Hinge 52 shown in FIG. 6. The X-Hinge 110 pivotally couples two sandwich panels 20, 100 together along adjacent edge surfaces 38 and 40 for the length of the panels. An outside flexible member 44 is continuously bonded to adjacent portions of the skins 30, 104 on each of the two panels 20, 100 for the length of the panels. An inside flexible member 112 is continuously bonded to the entire edge surfaces 38 and 40 for the length of the panels 20, 100. In the case of the X-Hinge 110, the inside flexible member 112 includes extensions 114 and 116 that extend beyond the edge surfaces 38 and 40 onto portions of the skins 32, 106. This provides added strength to the X-Hinge 110 when in its retracted position, similar to the position of the panel 20 as shown in FIG. 7. Except for the extensions 114 and 116, the X-Hinge 110 is identical to the X-Hinge 52 in all other respects. As shown in FIG. 20, a plane 54 can be drawn through the pivot axis 50 so that the outside flexible member 44 lies on one side of the plane that all or a substantial portion of the inside flexible member lies on the opposite side of the plane.
There is shown in FIG. 21 a panel 130 illustrating another embodiment of the present invention. In this embodiment an interior core 132 is shown having a honeycomb structure, similar to that used in the aircraft industry. Such honeycomb structures and their manufacture are well know in the art and, therefore, will not be described here. It will be apparent to the skilled art worker that at least a portion of the foam core 22 of the panel 20 could be advantageously replaced with a suitable honeycomb material in the practice of the present invention.
There is shown in FIG. 22 a variation of the joining of the inside and outside flexible members 42 and 44 respectively, prior to bonding to the edges 38 and 40 and the surfaces 30 of the sandwich-panels 20. The two flexible members 42 and 44 are arranged in registry and a line of stitches sewn along the entire length of the material so that the stitches extend through both flexible members and through the axis 50 as shown. The joined flexible members are then bonded to their respective sandwich-panels 20 in a manner similar to that of the X-Hinge 52 shown in FIG. 6. Once the bonding take place the cured adhesive permeates the stitches 140 thereby forming a permanent integral unit. The stitching 140, being embedded in the cured adhesive, has the advantage of adding considerable strength to the hinge joint while adding very little weight.
The building 10 of the present invention, as set forth above, is easily movable from a retracted position shown in FIG. 1 to an extended position shown in FIG. 2. It will be appreciated by those skilled in the art that such movement can be effected by means of a motorized automatic actuating mechanism, not shown, that rotates the roof 62 while extending the end wall 80. The panels 70, 72, 74, and 76 automatically follow the movement of the end wall 80 until they are fully extended as shown in FIG. 16. The same actuating mechanism can fold a floor, not shown, into place and arrange any interior partitions that may be present. The X-Hinge and panel combination of the present invention lends itself to such automation techniques. It will also be understood that other buildings and similar structures may extend in multiple directions from the original base unit 60, including extending vertically to provide a second story to the building. All such structures are considered within the spirit and scope of the present invention.
An important advantage of the present invention is that very strong walls result from the joining of two adjacent sandwich panels by means of the X-Hinge, wherein all of the loading forces are continuously distributed across both panels through the inside and outside flexible members. Having much superior strength over point contact hinges, the X-Hinge yields walls that are self supporting and can be cantilevered from a base unit. Another advantage of the present invention is that no hard-points or frame structure is required for attaching conventional hinges to the panels resulting in cost advantages and lower weight without sacrificing strength and operational effectiveness. This also presents a significant insulative advantage since there are no conductive materials need, such as wood, steel or aluminum frames, to connect the inner and outer sandwich panel surfaces as is required by prior art structures. By dividing the hinge forces into separate tensile and compressive forces, the X-hinge permits the advantageous use of insulative materials such as higher density foams to handle compression loads instead of structural beams or frameworks. The inside and outside flexible members of the X-Hinge are made of a continuous impermeable material that automatically forms a weather tight seal at the joint of the two panels and requires no lubrication as does a conventional hinge. The X-Hinge and panel assembly is relatively easy to fabricate resulting in additional cost savings. Parts count requirements are also greatly reduced over existing sandwich panel connection methods thereby lowering inventory costs.

Claims

1. A foldable structure for constructing a building suitable for sheltering, comprising:

(1) first and second sandwich-panels, each having:

(i) a core of relatively low density material having two opposite major surfaces and an edge surface; and

(ii) two high density tensile-skins, one said skin attached to one of said major surfaces of said core and the other said skin attached to the other of said major surfaces of said core so that the outer surfaces of the two tensile-skins form opposite first and second outer surfaces terminating at said edge surface;

(2) an inside thin flexible member secured along said edge surface of each of said first and second sandwich-panels;

(3) an outside thin flexible member secured along a portion of said first outer surface of each of said first and second sandwich-panels,

wherein said inside and outside flexible members are arranged to pivotally couple said first and second sandwich panels together to pivot about an axis.

2. The foldable structure according to claim 1 wherein said inside flexible member and said outside flexible member are on substantially opposite sides of a plane extending through said axis.

3. The foldable structure according to claim 1 wherein said securing of said inside and outside flexible members to said first and second sandwich panels includes continuous bonding thereof.

4. The foldable structure according to claim 3 wherein said continuous bonding extends for substantially the entire length of said first and second sandwich panels.

5. The foldable structure according to claim 4 wherein said inside and said outside flexible members are joined by a line of stitches sewn through both said flexible members and through said axis.

6. The foldable structure according to claim 1 wherein said inside flexible member is continuously bonded to a portion of said second outer surface adjacent said edge surface of each of said first and second sandwich panels.

7. The foldable structure according to claim 1 wherein said core comprises molded foam.

8. The foldable structure according to claim 1 wherein said core includes a honeycomb structure.

9. The foldable structure according to claim 1 wherein said tensile-skin comprises metal.

10. The foldable structure according to claim 1 wherein said tensile-skin comprises resin.

11. The foldable structure according to claim 1 wherein said core has a density and said tensile-skin has a density that is substantially greater than said core density.

12. The foldable structure according to claim 1 wherein said edge surface has a width of from about one inch to about six inches.

13. A foldable structure for constructing a wall in a habitable building, comprising:

a) a first panel having an interior, and a first major surface and an adjacent edge surface mutually angled and intersecting along a common edge thereof,

b) a second panel having an interior, and a first major surface and an adjacent edge surface mutually angled and intersecting along an edge thereof,

c) a first membrane continuously bonded to a portion of said first surface of each of said first and second panels,

d) a second membrane continuously bonded to said adjacent surface of each of said first and second panels,

wherein said portion of said first surface is of substantially higher density than is the interior of said first and second panels,

wherein said first and second panels are pivotally coupled by means of said first and second membranes and arranged to pivot about an axis.

14. The foldable structure according to claim 13 wherein said first membrane is on substantially one side of a plane extending through said axis and said second membrane is on substantially an opposite side of said plane.

15. The foldable structure according to claim 13 wherein at least one of said first and second panels includes first and second opposing high density tensile-skins separated by a low density material.

16. The foldable structure according to claim 13 wherein said continuous bonding extends for substantially the entire length of said first and second panels.

17. The foldable structure according to claim 16 wherein said first and second membranes are joined by a line of stitches sewn through both said membranes and through said axis.

18. The foldable structure according to claim 13 wherein each of said first and second panels includes a second major surface opposite said first major surface and wherein said second membrane is continuously bonded to a portion of said second major surface adjacent said edge surface of each of said first and second panels.

19. The foldable structure according to claim 13 wherein said interior of said panel comprises molded foam.

20. The foldable structure according to claim 13 wherein said interior of said panel includes a honeycomb structure.

21. The foldable structure according to claim 13 wherein said portion of said first surface comprises metal.

22. The foldable structure according to claim 13 wherein said portion of said first surface comprises resin.

23. The foldable structure according to claim 13 wherein said adjacent surface of each of said first and second panels has a width of from about one inch to about six inches.

24. A foldable building including:

a base unit having an interior space for storing furniture, equipment, and various supplies;

an expandable unit coupled to said base unit and movable between an extended position for accommodating human occupation and a retracted position in close proximity to said base unit for substantially reducing the overall size of said building during transporting and for storage when not in use,

said expandable unit comprising:

(a) at least two roof panels connected along adjacent edges thereof and mutually angled to form a roof;

(b) a front wall and a rear wall, each comprising a pair of panels having a pivotal connection along vertically disposed adjacent edges thereof; each front and rear wall having a pivotal connection to said base unit; and

(c) an end wall having a pivotal connection to both said front wall and said rear wall;

wherein, one of said roof panels is attached by means of a pivotal connection to one of either said base unit or said end wall.

25. The foldable building according to claim 24 wherein only one of said roof panels is pivotally connected to said base unit.

26. The foldable building according to claim 24 wherein said at least two roof panels are rigidly connected along said adjacent edges.

27. The foldable building according to claim 24 wherein when said expandable unit is in said extended position said end wall is spaced from said two roof panels, including a third roof panel having a pivotal connection to one of said end wall or one of said two roof panels and arranged to form a roof between said end wall and said two roof panels.

28. The foldable building according to claim 24 wherein, when moving from said extended position to said retracted position, portions of said front and rear walls are arranged to fold inwardly toward each other while, concurrently, said end wall moves toward said core unit, and said roof pivots about said pivotal connection to one of either said core unit or said end wall so that one of said roof panels is arranged vertically in close proximity and parallel to said end wall when in said retracted position.

29. The foldable building according to claim 24 wherein said front wall and said rear wall are cantilevered from said core unit.

30. The foldable building according to claim 24 in combination with a recreational vehicle of the type to be moved along a highway, either under its own power or towed by another vehicle, while being transported to a site for use.

31. A shelter movable between a compacted state to facilitate transporting said shelter and an extended state having functional space for a human and support materials, and being freely movable therebetween, comprising:

(a) a base unit having an interior;

(b) a plurality of panels, each of which has a pair of opposite major surfaces and an edge surface extending therebetween,

and a pivoted connection along a said edge thereof with a said edge of at least one other of said panels, some of said plurality of panels arranged to form a continuous outer wall circumscribing said functional space, comprising:

(i) a front wall and a rear wall, each comprising a pair of said panels having a pivotal connection along vertically disposed adjacent edges thereof; each front and rear wall having a pivotal connection to said core unit; and

(ii) an end wall having a pivotal connection to both said front wall and said rear wall;

(iii) a roof comprising at least two said panels connected along adjacent edges thereof and arranged to form a roof,

wherein, one of said roof panels is attached by means of a pivotal connection to one of either said base unit or said end wall, and

wherein said front wall and said rear wall are cantilevered from said base unit when in said extended state.

32. The shelter according to claim 31 wherein said pivotal connection of said plurality panels comprises:

(2) an inside thin flexible member secured along said edge surface of each of said panels;

(3) an outside thin flexible member secured along a portion of one of said major surfaces of each of said panels,

wherein said inside and outside flexible members are arranged to pivotally couple two of said plurality of panels together to pivot about an axis.

33. The shelter according to claim 32 wherein said inside flexible member and said outside flexible member are on opposite sides of a plane extending through said axis.

34. The shelter according to claim 33 wherein each said plurality of said panels includes an interior and wherein said portion of one of said major surfaces is of higher density than is said interior.

35. The shelter structure according to claim 32 wherein said inside thin flexible member and said outside thin flexible member are joined by a line of stitches sewn through both said thin flexible members and through said axis.