US20130186011A1

US20130186011A1 - Collapsible longeron structures

Info

Publication number: US20130186011A1
Application number: US13/552,544
Authority: US
Inventors: Philip N. Keller; Robert Taylor; Adam Gray; Doug Richardson; Mark Reavis
Original assignee: Composite Technology Development Inc
Current assignee: Composite Technology Development Inc
Priority date: 2006-03-31
Filing date: 2012-07-18
Publication date: 2013-07-25

Abstract

Embodiments of the invention are directed toward rollable and collapsible structures. These structures, for example, can include a plurality of tubular longerons with a slit or gap that extends along the longitudinal length of the longerons. Such longerons can be combined in an arrangement that creates a structure. The structure can be collapsed and the longerons rolled either singularly or as a group into a stowed configuration.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of U.S. patent application Ser. No. 13/036,199, filed Feb. 28, 2011, entitled “Deployable Structures Having Collapsible Structural Members”, and U.S. patent application Ser. No. 13/014,299 filed Jan. 26, 2011, entitled “Collapsible Structures With Adjustable Forms”, the disclosures of which are incorporated by reference in their entirety herein for all purposes.

BACKGROUND

Portable structures that can be deployed and stowed come in a number of configurations and can be used in a number of ways. Tents, for example, can be stowed in a compact form and set up or deployed for a variety of uses.

BRIEF SUMMARY

Embodiments of the invention include tubular longerons that can have a deployed and a stowed state. In the stowed state one or more tubular longerons can be rolled into a single roll. In the deployed state, one or more tubular longerons can be extended and formed into a structure. This longeron structure, for example, can be an A-frame-shaped structure. Embodiments of the invention can provide large, usable structures that can be combined and/or stowed in a small stowed configuration.
The terms “invention,” “the invention,” “this invention” and “the present invention” used in this patent are intended to refer broadly to all of the subject matter of this patent and the patent claims below. Statements containing these terms should not be understood to limit the subject matter described herein or to limit the meaning or scope of the patent claims below. Embodiments of the invention covered by this patent are defined by the claims below, not this summary. This summary is a high-level overview of various aspects of the invention and introduces some of the concepts that are further described in the Detailed Description section below. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used in isolation to determine the scope of the claimed subject matter. The subject matter should be understood by reference to the entire specification of this patent, all drawings and each claim.

BRIEF DESCRIPTION OF THE DRAWINGS

Illustrative embodiments of the present invention are described in detail below with reference to the following drawing figures:

FIG. 1A shows a longeron structure in an unrolled configuration according to some embodiments of the invention.

FIG. 1B shows a longeron structure in a deployed configuration according to some embodiments of the invention.

FIG. 2A shows a longeron structure in an unrolled configuration according to some embodiments of the invention.

FIG. 2B shows a longeron structure in a deployed configuration according to some embodiments of the invention.

FIG. 3A shows another longeron structure in an unrolled configuration according to some embodiments of the invention.

FIG. 3B shows the longeron structure in FIG. 3A in a folded configuration according to some embodiments of the invention.

FIG. 3C shows the longeron structure in FIG. 3A used in a longeron structure according to some embodiments of the invention.

FIG. 3D shows a longeron structure according to some embodiments of the invention.

FIG. 4 shows a tubular longeron being rolled from a deployed to a stowed configuration according to some embodiments of the invention.

FIG. 5A shows a tripod constructed from three longerons according to some embodiments of the invention.

FIG. 5B shows a tripod coupled with a sheet of solar arrays.

FIG. 5C shows three longerons aligned along their longitudinal length and in the process of being rolled into a stowed configuration.

FIGS. 6A, 6B, and 6C show various views of a complex longeron and according to some embodiments of the invention.

FIG. 6D shows a longeron structure formed with complex longeron according to some embodiments of the invention.

FIG. 7 shows a longeron structure with a curved cross-member longeron according to some embodiments of the invention.

FIG. 8 shows a structure with two additional interior legs according to some embodiments of the invention.

FIGS. 9A and 9B are examples of longerons with complex shapes according to some embodiments of the invention.

FIGS. 10A and 10B show a longeron structure with six supporting legs according to some embodiments of the invention.

FIG. 11 shows a longeron structure coupled with a solar array panel according to some embodiments of the invention.

FIG. 12 shows a picture frame longeron structure according to some embodiments of the invention.

FIG. 13 shows a longeron structure with a strap coupled with a bag according to some embodiments of the invention.

DETAILED DESCRIPTION

The subject matter of embodiments of the present invention is described here with specificity to meet statutory requirements, but this description is not necessarily intended to limit the scope of the claims. The claimed subject matter may be embodied in other ways, may include different elements or steps, and may be used in conjunction with other existing or future technologies. This description should not be interpreted as implying any particular order or arrangement among or between various steps or elements except when the order of individual steps or arrangement of elements is explicitly described.
Embodiments of the invention employ various longerons to create longeron structures. These longerons can have a number of configurations. For example, the longerons disclosed herein can be constructed such that they may be flattened and rolled for stowage. The longerons can regain their original cross-section during deployment. The disclosed longerons typically include a long tube with one or more slits or gaps that extend through the longitudinal length of the longeron. The slits may allow the tube to be flattened and rolled. When rolled, the longerons can be stacked or combined and collectively rolled together. The longerons may be constructed from any type of composite material that may, for example, include metal, graphite, or polymer.
Embodiments of the invention include deployable and stowable longeron structures constructed from these longerons. When deployed, these longeron structures can be standalone longeron structures and/or can be used as a tent and/or a longeron structure that is coupled with solar arrays. A plurality or all of these longerons can be embedded within each other and rolled up into a single stowed configuration. In some embodiments, each longeron can be rolled into separate stowed configurations.
For added flexural properties the longerons may have some curvature much like a carpenter's tape. Longerons may also be stiffened by another mechanism such as a sandwich panel that can be collapsed for stowage.
FIG. 1A shows longeron 100 according to some embodiments of the invention. Longeron 100 is a tubular member having first end 110 and second end 140 with gap 120 (or slit) extending along the longitudinal length of the longeron from first end 110 to second end 140. With this slit (or gap) longeron 100 can be referred to as a slit-tube longeron. Generally speaking, longerons described here include a slit or gap unless otherwise specified. Longeron 100 also includes partial slit 112 at first end 110 and partial slit 142 at second end 140. Partial slit 112 separates a portion of longeron 100 at first end 110 into first leg 114 and second leg 116. Partial slit 142 separates a portion of longeron 100 at second end 140 into third leg 144 and fourth leg 146. In some embodiments, longeron 100 can include reinforced material where partial slits 112 and 142 end.
Longeron 100 can include three states: a rolled state, a deployed state, and a resting state. FIG. 1A shows longeron 100 in the resting state. In this state, the longeron is unrolled and unrolled (undeployed). In the rolled state, longeron 100 is flattened and rolled along the longitudinal length of longeron 100 (see FIG. 4, for example).
FIG. 1B shows longeron 100 in the deployed state. In this state, legs 114 and 116 are separated along partial slit 112 and bent (e.g., split, hinged, folded, etc.) to form structural legs. Similarly, legs 144 and 146 are separated along partial slit 142 and bent to form structural legs. Sheer members 122 can be used to keep legs 114, 116, 144, or 146 from returning to the relaxed configuration. These sheer members can be coupled with legs 114, 116, 144, 146 and/or cross member 132. Sheer member 122 can be any type of strap and/or tether comprising, for example, fabric, leather, or composite material. Sheer member 122 may also be compliant to allow rolling and/or unrolling with longerons. The portion of longeron 100 where legs 114, 116, 144, or 146 bend longeron 100 may be reinforced or be more compliant to accommodate such bending. Cross member 132 may or may not be a slit-tube longeron.
FIG. 2A shows another longeron combination that has rolled, unrolled, and/or deployed states. FIG. 2A shows main longeron 200 according to some embodiments of the invention coupled with first longeron 212 and second longeron 214. First longeron 212 and/or second longeron 214 can be coupled with main longeron 200, for example, with a rivet at attachment point 215. First longeron 212 and second longeron 214 can be folded so they extend in the same direction away from attachment points 215. Various other mechanisms may be used to attach the longerons. The longerons can be attached in such a way that first longeron 212 and second longeron 214 can rotate about the attachment point. Moreover, first longeron 212 can be attached with main longeron 200 such that first longeron 212 is substantially aligned with first end 222 of main longeron 200 and second longeron 214 can be attached with main longeron 200 such that second longeron 214 is substantially aligned with second end 224 of main longeron 200. Various techniques can be used to force longeron 214 and longeron 212 to fold in the proper direction.
Main longeron 200 can include three states: a rolled state, a deployed state, and a resting state. FIG. 2A shows main longeron 200 in the resting state. In this state, the longeron is unrolled and undeployed. In the rolled state, main longeron 200 along with first longeron 212 and second longeron 214 is flattened and rolled along the longitudinal length of main longeron 200 (see FIG. 4, for example).
FIG. 2B shows main longeron 200 in the deployed configuration. In this configuration, first longeron 212 and second longeron 214 are rotated and extended as legs along with first end 222 and second end 224. Sheer members 122 can be used to keep first end 222, second end 224, first longeron 212, and second longeron 214 from returning to the relaxed configuration. The portion of main longeron 200, where first end 222 and/or second end 224 bend, may be reinforced with additional or different material (e.g., composite material or adhesive) to accommodate such bending. Similarly, first longeron 212 and second longeron 214 can be reinforced along portions where they bend. Sheer members 122 can be coupled with longerons 212, 214, 222, 224 and/or cross member 132. Cross member 132 may or may not be a slit-tube longeron. In some embodiments, longerons may have portions that are more compliant to accommodate bending. Such portions can have different or less material (e.g., composite material or adhesive) to accommodate such bending.
First longeron 212 and second longeron 214 can be rotated around 215 in either direction along the length of longeron 200 either toward the interior of longeron 200 or away from the interior of longeron 200.
FIG. 3A shows reverse longeron 300 that includes two longerons 310 and 320 conjoined at 330 according to some embodiments of the invention. The two longerons have gaps 311 and 321 on opposite sides of their longitudinal lengths. Reverse longeron 300 flattens out at the portion of the longeron where longerons 310 and 320 are conjoined 330. Longerons 310 and 320 can be conjoined using any technique known in the art. In some embodiments, longerons 310 and 320 can be constructed from composite materials and/or can be conjoined using glues or chemicals similar to those in construction of the composite materials. In some embodiments, conjoined portion 330 of reversed longeron 300 can be reinforced to allow for bending without causing damage to reverse longeron 300.
FIG. 3B shows reverse longeron 300 in a folded configuration. Because longerons 310 and 320 have openings on opposite sides of their longitudinal lengths, reverse longeron 300 can fold upon itself at conjoined portion 330. After being folded, reverse longeron 300 can be rolled along the longitudinal length of the folded reverse longeron into a stowed configuration.
FIG. 3C shows A-frame longeron structure 350 constructed with two reverse longerons according to some embodiments of the invention. A-frame longeron structure 350 includes two reverse longerons 300 coupled with cross member 360, which can also be a tubular longeron with a slit along its longitudinal length. Reverse longerons 300 are folded over at conjoined portion 330. Reverse longerons 300 can be coupled with cross member 360 using any number of coupling techniques including Velcro, snaps, buttons, etc. And, in some embodiments, reverse longerons 300 can be coupled with cross member 360 with sheer members 122.
FIG. 3D shows A-frame longeron structure 380, similar to longer structure 350, but constructed with two non-reverse longerons according to some embodiments of the invention. A-frame longeron structure 380 includes two longerons 385 coupled with cross member 360, which can also be a tubular longeron with a slit along its longitudinal length. When deployed as shown in the figure, longerons 385 are flattened in middle portion 390 and folded as shown. Longerons 380 can be coupled with cross member 360 using any number of coupling techniques including Velcro, snaps, buttons, etc. And, in some embodiments, longerons 380 can be coupled with cross member 360 with sheer members 122.
FIG. 4 shows tubular longeron 400 being rolled from into a stowed configuration. When rolling such a longeron, the tubular walls of longeron 400 can be opened and/or flattened. Then longeron 400 can then be rolled into a stowed configuration. Often portions of the longeron are progressively flattened as the longeron is rolled up. As described previously, multiple longerons can be stacked upon one another or embedded within each other in the tubular or deployed state. The combined longeron stack can then be rolled along the longitudinal length of the longeron into the stowed configuration. In some embodiments, the many tubular longerons that form any of the longeron structures shown in FIGS. 1B, 2B and 3C can be collapsed and rolled into a single stowed roll.
In some embodiments of the invention longeron structures can include multiple longerons like those shown in FIGS. 1A, 1B, 2A, 2B, 3A, 3B and 3C. In some embodiments the various longerons can be rolled together in a single roll, or in multiple rolls. Some rolls may include individual longerons and others may include or two or more longerons rolled together. During deployment the longerons can be unrolled and coupled together, for example, using snaps, pins, hook-and-loop fastener, straps, buckles, etc. Once the longeron structure is deployed or constructed a sheet of solar arrays can be coupled with the structure. During deployment the sheet of solar arrays can be decoupled, the longeron structure taken down by removing the various attachment mechanisms, and the various longerons rolled up either individually and/or collectively.
FIG. 5A show tripod 500 constructed from three longerons 505, 510, and 515 according to some embodiments of the invention. The three longerons 505, 510, and 515 comprise the three legs of tripod 500. Longerons 505, 510, and 515 are coupled together at one end of each longeron to form the tripod longeron structure. FIG. 5B shows tripod 500 with a sheet of solar arrays 520. Various other longeron structures can be coupled with tripod 500. Indeed, tripod 500 can be used in any collapsible and/or mobile longeron structure.
FIG. 5C shows the three longerons aligned along their longitudinal length. The longerons are nested in their deployed configuration 550 and rolled along their longitudinal length. Element 550 show the three longerons nested in their elongated shape. Element 550 shows the longerons flattened and element 560 shows a partially rolled portion of the longerons. In this way, the three longerons are flattened and rolled together. The longerons can be unrolled together as well. The attachment point, where all three longerons are coupled together is configured to allow the longerons to be aligned and/or nested for rolling and stowage. In some embodiments, the longerons can be detachably coupled together. In such embodiments, the three longerons can be nested and rolled together or rolled individually.
FIG. 6A shows a top view of complex longeron 600, FIG. 6B shows the front side of complex longeron 600 and FIG. 6C shows the back side of complex longeron 600. Complex longeron 600 comprises a plurality of longerons coupled together according to some embodiments of the invention. Complex longeron 600 can include cross member longeron 610 and two separate longerons on each end. Cross member longeron 610 can have a diameter that is larger than the diameter of other portions of complex longeron 600. Cross member longeron 610 can have a diameter that is 0.25, 0.5, 0.75, 1.0, 1.25, 1.5, 1.75, 2.0, etc. times larger than the diameter of other portions of complex longeron 600. Cross member longeron 610 can include slit 605 that extends along its longitudinal length. Slit 605 can have any width or thickness.
On both longitudinal ends cross member longeron 610 is coupled with two separates leg longerons: leg longeron 620 and leg longeron 622 on one end as well as leg longeron 624 and leg longeron 626 on the other end. Each leg longeron comprises a slit-tube longeron with a diameter smaller than the diameter of cross member longeron 610 and a slit or gap along the longitudinal length of the leg longeron. In some embodiments slit 605 can correspond with gap 606 that separates the two legs on each end.
In some embodiments, cross member longeron 610 can have portions that have diameters that reduce from the larger diameter of cross member longeron 610 to a smaller diameter. In other embodiments, the leg longerons can have portions that have diameters that increase from the smaller diameter of the leg longeron to a larger diameter to couple with cross member longeron 610.
While complex longeron 600 includes five longerons: cross member 610 and leg longerons 620, 622, 624, and 626; any number of longerons can be used. These longerons can be coupled together using any number of techniques. For example, the longerons can comprise composite materials and can be coupled together using any composite binding techniques known in the art. As another example, the longerons can be fabricated together as a single unitary longeron structure using composite fabrication techniques.
Complex longeron 600 can be flattened and rolled into a stowed configuration; each individual longeron can be flattened and rolled together as a group into a single stowed roll.
FIG. 6D shows a longeron structure formed with complex longeron 600 according to some embodiments of the invention. Leg longerons 620 and 622 can be extended and separated at one end and leg longerons 624 and 626 can be extended and separated at the other end. These leg longerons can support cross member longeron 610. Various straps, connectors, clips, etc. can be used to aide in holding this configuration. The larger diameter of cross member longeron 610 can allow it to support great loads.
FIG. 7 shows longeron structure 700 with curved cross-member longeron 710 according to some embodiments of the invention. Curved cross-member longeron 710 can support greater loads than a straight cross-member and/or can decrease the forces at the joint of legs 720, 722, 724, 726 and cross-member longeron 710. Curved cross-member longeron 710 can be used with any embodiment of the invention. For example, curved cross-member longeron 710 can have a wider the same, a smaller, or a wider diameter cross member than other portions of the longeron structure. As another example, curved cross-member longeron can be coupled with legs of various sizes and/or configurations.
FIG. 8 shows longeron structure 800 with two additional interior legs 823, 825 according to some embodiments of the invention. Interior legs 823 and 825 can be coupled with the other longerons making up longeron structure 800 in any way. For example, interior legs 823 and 825 can be part of a single longeron as shown in FIG. 1A, but with two partial slits that form three longeron shaped legs, one of which can be either or both of legs 823 and 825. As another example, interior legs 823 and 825 can comprise fifth and sixth legs respectively as shown in FIG. 2A. Legs 823 and 825 can be coupled with longeron structure as described above. As another example, longeron structure 800 can have a curved cross-member as shown in FIG. 7 and/or a cross-member with a larger diameter as shown in FIG. 8.
In some embodiments of the invention, longerons can have complex shapes. For example, longerons can have cross-sectional shapes that vary along the length of the longeron. As another example, longerons can have thicknesses that vary along the length of the longeron. FIGS. 9A and 9B are examples of longerons with complex shapes. FIG. 9A shows longeron 900 with middle section 910 that has a wider cross section than other portions of longeron 900. FIG. 9B shows longeron 950 that has a smaller cross section than other portions of longeron 960. Various combinations of wider and/or smaller cross sections can be extended along the longitudinal length of a longeron.
Longeron structures can have any number of cross members and/or legs and can come in a variety of configurations. One example of such a longeron structure is shown in FIGS. 10A and 10B. FIG. 10A shows longeron structure 1000 unrolled. And FIG. 10B shows longeron structure 1000 completely deployed. Longeron structure 1000 includes cross member longeron 1005 and/or six legs 1010, 1012, 1014, 1016, 1018, and 1020. Each longeron may comprise a tubular structure with slit 1006 along the longitudinal length of the longeron. Longeron structure 1000 is similar to longeron structure 200 shown in FIGS. 2A and 2B with the addition of interior legs 1014 and 1016 that can be secured on the interior (inside slit 1006) or exterior of cross member longeron 1005.
FIG. 11 shows longeron structure 1105 coupled with solar array panel 1110 according to some embodiments of the invention. Longeron structure 1105 can be any longeron structure shown in any of the figures and our described in throughout this specification. Solar array panel 1110 can be a sheer member that provides structural strength to longeron structure 1105. The sheer forces in solar array panel 1110 can keep the legs of longeron structure stable.
FIG. 12 shows picture frame longeron structure 1200 according to some embodiments of the invention. Longeron structure 1200 can include longeron 1210 that can be formed into a picture frame shape as shown in the figure. That is, longeron 1210 can be form the perimeter of a polygon (e.g., a rectangle) by bending in certain positions of the longeron. A single longeron can be wrapped and the two ends coupled together with any type of attachment mechanism. Or two or more longerons can have their ends coupled together to form the picture frame. Picture frame longeron structure 1200 can include kick stand longerons 1205 coupled with longeron 1210 to prop up picture frame longeron structure 1200 at an angle. The kick stand longerons can be adjusted to change the angle of the picture frame relative to the sky.
In some embodiments, the various longerons making up a collapsible structure may have different diameters and/or lengths. Moreover, the various longerons can have variable diameters, thickness, etc. These longerons may also be comprised of different material. Moreover, stakes and/or tethers can be sued to secure the structures to the ground.
In some embodiments longeron structures can include feet positioned at the end of any of the longeron structures. These feet can be longerons or other material. In some embodiments the longeron structures can include a grommet that can be used in conjunction with a stake to secure the longeron structure to the ground. The grommet can be disposed with the feet, be part of a strap, or be included in the longeron.
FIG. 13 shows longeron structure 1300 with strap 1305 coupled with bag 1310 according to some embodiments of the invention. Bag 1310 can include a net, pouch, bag, pocket, bucket, etc. that can be filled with weighted material and can be used to hold longeron structure 1300 in place during use. For instance, a user can fill the net with rocks or other material. The length of strap 1305 can be long enough so that bag 1310 rests on the ground or floats above the ground.
Different arrangements of the components depicted in the drawings or described above, as well as components and steps not shown or described are possible. Similarly, some features and subcombinations are useful and may be employed without reference to other features and subcombinations. Embodiments of the invention have been described for illustrative and not restrictive purposes, and alternative embodiments will become apparent to readers of this patent. Accordingly, the present invention is not limited to the embodiments described above or depicted in the drawings, and various embodiments and modifications can be made without departing from the scope of the claims below.

Claims

What is claimed is:

1. A longeron structure comprising:

a tubular longeron having a first end, a second end, and a longitudinal length extending from the first end to the second end, wherein the tubular longeron includes

a gap extending along the longitudinal length of the tubular longeron from the first end to the second end,

a first slit at the first end extending a long a portion of the longitudinal length of the tubular longeron, and

a second slit at the second end extending a long a portion of the longitudinal length of the tubular longeron.

2. The longeron structure according to claim 1, wherein the longeron structure comprises a rolled configuration wherein the tubular longeron is rolled along the longitudinal length of the tubular longeron.

3. The longeron structure according to claim 1, wherein the longeron structure comprises a deployed configuration wherein the tubular longeron is bent at the first slit.

4. The longeron structure according to claim 3, wherein the longeron forms two legs when the tubular longeron is split at the first slit.

5. The longeron structure according to claim 1, wherein the longeron structure comprises a deployed configuration wherein the tubular longeron is split at the second slit.

6. The longeron structure according to claim 5, wherein the tubular longeron forms two legs when the longeron is split at the second slit.

7. The longeron structure according to claim 1, wherein the tubular longeron is curved along the longitudinal length of the longeron.

8. The longeron structure according to claim 1, wherein the tubular longeron comprises a cross section that varies along the longitudinal length of the tubular longeron.

9. A longeron structure comprising:

a main tubular longeron having a first end, a second end, a longitudinal length extending from the first end to the second end, and a gap along the longitudinal length of the longeron from the first end to the second end; and

a first tubular longeron having a first end, a second end, a longitudinal length extending from the first end to the second end, and a gap extending along the longitudinal length of the longeron from the first end to the second end,

wherein the longitudinal length of the first tubular longeron is shorter than the longitudinal length of the main tubular longeron, and

wherein the second end of the first tubular longeron is coupled with the main tubular longeron at a first couple point such that the first tubular longeron can rotate about the couple point.

10. The longeron structure according to claim 9, wherein the longeron structure comprises a rolled configuration wherein the main tubular longeron and the first tubular longeron are rolled along the longitudinal length of the longerons.

11. The longeron structure according to claim 9, wherein the longeron structure comprises a deployed configuration wherein the first tubular longeron and a portion of the main tubular longeron form two legs.

12. The longeron structure according to claim 9, wherein the longitudinal length of the first tubular longeron is less than half the longitudinal length of the main tubular longeron.

13. The longeron structure according to claim 9, further comprising a shear member coupling the first tubular longeron with the main tubular longeron.

14. The longeron structure according to claim 13, wherein the shear member comprises a strap or a photovoltaic sheet.

15. The longeron structure according to claim 9, further comprising:

a second tubular longeron having a first end, a second end, a longitudinal length extending from the first end to the second end, and a gap extending along the longitudinal length of the longeron from the first end to the second end,

wherein the longitudinal length of the second tubular longeron is shorter than the longitudinal length of the main tubular longeron, and

wherein the second end of the first tubular longeron is coupled with the main tubular longeron at a second couple point such that the first tubular longeron can rotate about the couple point.

16. The longeron structure according to claim 15, wherein the longeron structure comprises a rolled configuration wherein the main tubular longeron, the first tubular longeron, and the second tubular longeron are rolled along the longitudinal length of the longerons.

17. The longeron structure according to claim 15, wherein the longeron structure comprises a deployed configuration wherein the second tubular longeron and a portion of the main tubular longeron form two legs.

18. The longeron structure according to claim 15, further comprising a strap coupling the second tubular longeron with the main tubular longeron.

19. A longeron structure comprising:

a first longeron having a first end, a second end, a longitudinal length extending from the first end to the second end, and a gap extending along the longitudinal length of the longeron from the first end to the second end, wherein the first longeron includes a first attachment mechanism near the first end and a second attachment mechanism near the second end;

a second longeron having a first end, a second end, a longitudinal length extending from the first end to the second end, and a gap extending along the longitudinal length of the longeron from the first end to the second end, wherein the second longeron includes a third attachment mechanism positioned between the first end and the second end of the second longeron and configured to couple with first attachment mechanism; and

a third longeron having a first end, a second end, a longitudinal length extending from the first end to the second end, and a gap extending along the longitudinal length of the longeron from the first end to the second end, wherein the third longeron includes a fourth attachment mechanism positioned between the first end and the second end of the third longeron and configured to couple with second attachment mechanism.

20. The longeron structure according to claim 19, wherein the first, second, third and fourth attachment mechanisms comprise a snap, Velcro, carabineers, etc.

21. The longeron structure according to claim 19, further comprising a shear member coupling at least two of the first longeron, the second longeron, and the third longeron.