Modular Inflatable Structures

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. Provisional Patent Application Ser. No. 63/662,727 filed Jun. 21, 2024.

FIELD OF THE PRESENT INVENTION

The present invention relates generally to structure deriving a significant portion of its structural rigidity from one or more inflatable members and more particularly to connectors for securing inflatable members together or for securing other structural members to an inflatable member.

BACKGROUND OF THE INVENTION

Inflatable structures allow for portability and easy deployment. They feature low weight, rapid deployment, and a small stowage size relative to structure size. They are typically comprised of inflated members that are designed to bear structural loads, including those associated with environmental conditions such as loads rain, snow, and wind. These members could be in the shape of planar panels, tubular cylinders, arches, or other shapes and can be arranged in many configurations for use as emergency shelters, temporary housing or storage, crop protection, greenhouses, and many other uses where portable, temporary, and easy to deploy structures are needed.

Using inflatable members to create structures may require many different components oriented in different arrangements to be joined together. The components could consist of posts, beams, rafters, platforms, walls and roof sections, which can easily be made of inflatable members such as inflatable tubes or inflatable planar panels featuring drop stitch membranes. Moreover, some members could be inflatable while others could be made of non-inflatable materials. Typically, inflatable structures use structural members that are made of an air impermeable rubber-coated fabric like PVC or TPU coated fabrics, and in lighter-weight applications, an air-impermeable, non-reinforced polymer film.

The structural members, which as noted could be either inflatable cylindrical tubes or flat panels, are joined together by airtight seams to form the joints between them. The inflatable members are put into the various orientations necessary and then the seams are taped with an extra layer of air impermeable material, and either hand glued or machine welded to form an airtight seal. These multiple members are joined together for convenience, forming one interconnected inflatable membrane, inflating all at once as the air passes from one member to the next through the sealed joints. This makes inflation and set up very easy, but this one chambered system has inherent flaws.

First, the more structural members that are required, the longer the seam length that is necessary, thus, the more likely a leak in the structure could develop, as each seam presents a far more common failure mode than the surrounding materials. Multiple members originating at one junction require an increasingly complicated seam and thus more seam length and more potential failure points. Secondly, as the structure gets larger or more complex, handling, stowing, and deploying the structure becomes much more difficult as it gets very heavy and bulky. Additionally, but very significant, when there is a leak in a larger structure, it becomes very difficult if not impossible to find, as it could be located anywhere on the surface area of the structure and it is extremely difficult to manipulate a large deflated or partially inflated structure to search for a small leak.

Thus, there is a need to divide the structure into separate components for ease of deployment and long-term management. What is needed is a means to easily attach these inflatable panels or tubes to each other without the need to make or seal a joint of each connection between inflatable members. As described in the following materials, the techniques of this disclosure satisfy these and other needs.

SUMMARY OF THE INVENTION

This disclosure is directed to a modular inflatable structure which includes a structural member, a retention element defining an inner diameter which is secured to the structural member, and an inflatable tube disposed within the retention element. The inflatable tube has a nominal inflated diameter slightly greater than the inner diameter of the retention element and the inflatable tube is secured to the structural member by the retention element when the inflatable tube is inflated.

Still further, this disclosure includes a method for assembling a modular inflatable structure. The method may involve disposing a first deflated inflatable tube within a first retention element of a structural member, wherein the first retention element has an inner diameter and wherein the first inflatable tube has a nominal inflated diameter greater than the inner diameter of the first retention element. The first inflatable tube is secured to the structural member by inflating the first inflatable tube when disposed within the first retention element.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages will become apparent from the following and more particular description of the preferred embodiments of the invention, as illustrated in the accompanying drawing, and in which:

FIG. 1 is a detail view of connections between inflatable tubes of a modular inflatable structure according to an embodiment of the disclosure.

FIG. 2 is a detail view of a structural member configured as a hinge element secured to an inflatable tube according to an embodiment of the disclosure.

FIG. 3 is a detail view of connections between an inflatable tube and an inflatable panel according to an embodiment of the disclosure.

FIG. 4 is a detail view of connections between multiple inflatable tubes of a modular inflatable structure according to an embodiment of the disclosure.

FIG. 5 is a schematic overview of a modular inflatable structure according to an embodiment of the disclosure.

FIG. 6 is a detail view of connections between multiple inflatable tubes with end caps according to an embodiment of the disclosure.

FIG. 7 is a detail view of connections between multiple inflatable tubes with end caps having receptacles according to an embodiment of the disclosure . . .

DETAILED DESCRIPTION OF THE INVENTION

Before describing the present invention in detail, it is to be understood that this invention is not limited to particularly exemplified materials, methods or structures as such may, of course, vary. Thus, although a number of materials and methods similar or equivalent to those described herein can be used in the practice of the present invention, the preferred materials and methods are described herein.

It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments of the invention only and is not intended to be limiting.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one having ordinary skill in the art to which the invention pertains.

Further, all publications, patents and patent applications cited herein, whether supra or infra, are hereby incorporated by reference in their entirety.

As used in this specification and the appended claims, the term “modulus of elasticity” is meant to refer to (Young's) modulus, that is, the stiffness of a material.

As used in this specification and the appended claims, the term “stiffening sheet” is meant to refer to an anisotropic material formed by continuous high modulus fibers saturated with and embedded in a polymer matrix.

As used in this specification and the appended claims, the term “composite anisotropic material” is meant to refer to an anisotropic material formed by continuous high modulus fibers saturated with and embedded in a high modulus polymer matrix that is laminated to a flexible fabric or film.

Finally, as used in this specification and the appended claims, the singular forms “a, “an” and “the” include plural referents unless the content clearly dictates otherwise.

Accordingly, embodiments of this disclosure include a modular inflatable structure formed from inflatable tubes and rigid structural members used to connect the inflatable tubes together in desired orientations and/or to connect the inflatable tubes to other components of the modular structure. These inter-member attachments need to be load and moment-bearing, and durable. They could be interchangeable, and offer a multiplicity of structural arrangements, or modules. According to the techniques of this disclosure, if the inflatable members were individually sealed components, they could be inflated individually and then assembled into a structure one piece at a time instead of an all-at-once inflation. The result would be much less seam length than if each inflatable component was intersected with another seam at each joint. The ends of the components would be sealed with a non-complex seam joint. The modular attachment points could integrate with the component's construction and be made in such a way as to facilitate ease of assembly of the greater structure. Additionally, in one embodiment of a tubular structure, a structural member is secured in a way that transfers loads to the beams adequately by utilizing inflation pressure to hold an attachment point within a radially-oriented retention element, and the secure connection could be done without compromising the associated inflatable members with an additional seam.

To help illustrate aspects of this disclosure, FIG. 1 is a detail view of an inflatable modular structure 10 that includes a structural member 12 that is configured to secure inflatable tubes 14a and 14b together. According to the techniques of this disclosure, structural member 12 features two similar retention elements configured to retain inflatable tubes 14a and 14b. Specifically, in this embodiment, each retention element includes a saddle 16 that is preferably curved to match the profile of the inflated tube, one or more radial webbing loops 18 (two shown in this embodiment) and saddle patch 20. These components define an inner diameter that is substantially noncompliant so that an inflatable tube having a nominal inflated diameter that is slightly greater will be retained and secured upon inflation when disposed within the retention element. The components of each retention element may be flexible, such as the radial webbing loops 18, or relatively rigid such as the saddle 16 and saddle patch 20. More generally, any combination of rigid and/or flexible materials may be employed provided a relatively noncompliant inner diameter is defined to allow the inflatable tubes to be secured when inflated, such as a rigid cylinder or a flexible sleeve. Flanges 22 on saddle 16 allow relatively permanent attachment to structural member 12, such as through the use of nuts and bolts 24 as shown in this embodiment or by any other suitable means. A tensor 26 may be employed as an additional mechanism to distribute loads of the structure when assembled. Here, a webbing strap with D-rings is depicted but it should be appreciated that any equivalent method of adjusting tension may be employed.

Structural member 12 functions as a bracket in the embodiment shown in FIG. 1 to secure inflatable tube 14a to inflatable tube 14b in a desired orientation. Although shown as forming a right angle, any angular orientation may be employed as warranted by the design of the inflatable modular structure. Additionally, brackets having different angles can be swapped between saddle 16 and radial loops 18 or other retention elements. Further, structural members having other functions are within the scope of this disclosure. When using different angular orientations, this is the only component that varies, while all the other components remain the same, thus yielding many structural variations by only changing one simple component. As one non-limiting illustration, FIG. 2 shows an embodiment in which structural member 30 is configured with knuckles 32 to function as a hinge by forming a barrel in cooperation with a complementary hinge piece to receive a hinge pin. Saddle 16, radial loops 18 and saddle patch 20 function in a similar manner as described above.

Examples of suitable materials for the inflatable tubes of this disclosure may be found in U.S. Pat. No. 8,273,427, issued Sep. 25, 2012 (the “'427 patent”), having shared inventorship and incorporated by reference in its entirety. The use of composite reinforced members as is pointed out in '427 patent would allow for more design freedom as these composite reinforced tubes and panels offer far better load and moment bearing capabilities for inflatable tubes and panels. For example, in one embodiment, the forces from the composite reinforced horizontal tubular members can be transferred into adjacent upright tubular members in a suitable way that distributes the loads from these horizontal members to the ground. In one example using tubular members for the horizontal and vertical parts, curved saddles 16 conform substantially to part or all of the tubular members and interact with structural member configured as a bracket, such as structural member 12, that can easily mate with saddles 16, notably accepting the forces from the area where the composite reinforcement within the structural member is located. Since the inner composite material may not be able to extend all the way to the end of the beam due to construction limitations, the described saddle and bracket would need to extend some distance axially along the tubular members to substantially collect the forces from the composite reinforcement, and bring them into the saddle/bracket and then to the vertical member in the same manner. Using radially oriented webbing loops 18 that rely on inflation pressure to capture and hold the saddle in place results in a permanent retention method that includes mating with the inner composite reinforced area and extends around the tube to include the opposite side of the composite reinforced beam thus increasing the ability to sustain high loads.

In such embodiments, the need for a saddle or other attachment that would encompass the entire circumference of the tubular beam is reduced, as the radial webbing loops 18 can bring the loads from the opposite side of the horizontal member to the bracket. Furthermore, the webbing loops 18 can provide for easy placement and adjustment of saddles 16 during assembly, without the need to have them bonded to the tubular member. When the inflatable tube or tubes 14 are fully inflated they are securely held in place. An additional benefit is that by making webbing loops 18 flexible, the retention element can be compressed to a smaller profile for storage or transport.

The structural member may be sufficiently rigid to distribute forces and loads of the modular inflatable structure. Depending on design constraints and desired performance, any suitable material may be used include metals, plastics and natural materials such as wood. In some embodiments, the structural member is formed using any suitable technique, such as injection molding, three-dimensional printing, computer number controlled (CNC) milling and others. As one illustration, composite materials may be used that can optionally be reinforced by embedding components in a binder matrix. For example, the reinforcing components may be formed from fibers, fabrics or the like of any suitable material, including carbon, glass, boron, basalt, Nylon, Kevlar and the like. The binder matrix may be formed from suitable polymeric materials, including polyester and epoxy.

The disclosure outlined here is similar in function to the method of attachment of inflatable members shown in U.S. Pat. No. 12,006,007, issued Jun. 11, 2024 (the “'007 patent”) having shared inventorship and incorporated by reference in its entirety. The method described herein does offer the benefit of a moment-bearing joint by using the radial webbing loops 18 to capture and connect to the opposite side of the cylindrical inflatable tubes 14, and the structural reinforcements within the tubes, allowing for a much better distribution of loads than a simple surface mounted connector. The techniques of this disclosure offer the further benefit that, when deflated, the saddle connectors can be moved radially around the tube easily to allow for different configurations, as they are not mounted to the surface of the inflatable member, but rather statically secured by the inflation pressure acting outward to push the saddle connectors into the radial webbing loops.

Further, the inflatable panels disclosed in the '007 patent may be easily integrated into the modular inflatable structures of this disclosure. For example, FIG. 3 illustrates structural member 40 is configured to secure inflatable tube 14 to planar member 42, which may be a conventional planar structure or may be an inflatable panel as disclosed in the '007 patent. Here, structural member 40 is secured to plate 44, which in turn may be secured to planar member by any suitable means. For example, when planar member 42 is implemented with an inflatable panel, pass through connectors 46 may be employed as described in the '007 patent. Notably, such pass-through connectors engage opposing surfaces of the inflatable panel by passing through the inflatable section of the drop stitch membrane and create one or more seals with the inflatable surface(s) allowing some portion of the connector to be located within the profile established by the surfaces, such that the portion of the connector positioned within the internal volume is exposed to the pressurized internal volume. The connector may be formed from a material that is substantially impermeable to air so that sealing the connector to the surface membranes maintains the integrity of the internal volume and allows it to be pressurized relative to the surrounding atmosphere. As warranted, the connector can be configured to pass through the inflatable member and form seals with the opposing surfaces to have much higher resistance to bending and side loads due to the interaction with the opposite panel surface of the drop stitched inflatable panel. Further performance gains may be realized when employing the composite materials of the '427 patent which allow additional distribution of forces from the opposite side of the panel.

In another aspect, the techniques of this disclosure allow for many different connections to be made among multiple inflatable tubes. To help illustrate, FIG. 4 shows three inflatable tubes 14a, 14b and 14c being secured with two structural members 50. Again, saddle 16, radial loops 18 and saddle patch 20 function in a similar manner as described above, functioning as retention elements for structural members 50 for inflatable tubes 14a and 14b. As shown in this embodiment, a different type of retention element may be used to secure inflatable tube 14c, in the form of receptacle 52. As with the other retention elements of this disclosure, receptacle 52 has an inner diameter that is less than the nominal inflated diameter of tube 14c so that inflation pressure secures tube 14c within the inner diameter. However, in this embodiment it may be desirable for receptacle 52 to be relatively rigid and provide flanges for connection to structural members 50 at a specific angle so that inflatable tubes 14a and 14b are held in a desired orientation with respect to each other as well as to inflatable tube 14c. As will be appreciated, any number of inflatable tubes as well as other components may be secured together in various configurations as warranted by the overall design of the inflatable modular structure.

Yet another non-limiting illustration of the techniques of this disclosure is depicted in FIG. 5, which shows a combination of the inflatable tubes and structural members discussed above being used to form a complete modular inflatable structure 10, which can function as a green house, a shelter or any other type of building. As desired, any number of the components of inflatable structure 10 may be inflatable and may be secured together using the techniques of this disclosure, including wall, roof, floor, door, window, post, column, rafter, joist and other members. Accordingly, the attachment points may be engineered to give the structure load bearing and shear force elements making the structure an integrated unit when fully assembled with connector brackets and other structural members. Furthermore, this system could be used to design and build large structures in a modular fashion, with each particular element capable of being repeated many times over within the same structure. This system would be very easy to manage in production, storage, shipping, deployment, and transport. When there is a leak, it would be very easy to identify the member with the leak, remove it and repair it or replace it with a new member, without deflating the entire structure.

In yet another embodiment, within a tubular structure, the ends of the tubes could be constructed and sealed with a reinforced polymer end cap rather than glued or welded seams that could terminate the end of the inflatable chamber. This end cap could be RF or heat welded to the end of the tube or beam, forming an airtight seal thus minimizing the amount of joints that could leak. Additionally, the end cap could handle loads from the structure and thus contain integrated structural attachment points, like the saddles previously explained, to enable it to interact with other structural members and easily using connector brackets or similar struts or trusses. For example, FIG. 6 schematically illustrates three inflatable tubes 60a, 60b and 60c, each with end cap 62. In this embodiment, end caps 62 are sized to fit closely within structural member 64 that secures the tubes in a desired orientation. As another example, FIG. 7 schematically illustrates three inflatable tubes 70a, 70b and 70c, each with end cap 72. Here, end caps 72 feature a receptacle 74 configured to mate with prongs 76 of structural member 78 to secure the tubes in a desired orientation. In yet another modification, the inflatable tubes could be secured within the end caps by inflation pressure so that the end caps function as retention elements as described above.

Further, the end-capped construction above could include an air pathway that allows it to connect to the joined members for inflation of both, or in turn, many members at once. This pathway could contain a valve, which would allow for inflation all-at-once, or to maintain inflation pressure as a unit, then the valve could be closed which would isolate the joined members and offer the benefits aforementioned of having the ability to see easily where leaks arise and replace leaking members without deflating the entire structure.

Described herein are presently preferred embodiments, however, one skilled in the art that pertains to the present invention will understand that there are equivalent alternative embodiments. In particular, the connectors for inflatable members are particularly suited for recreational products, floating inflatable structures, inflatable flying structures, inflatable home products, inflatable buildings, portable, structural pipes and tubing, aircraft, travel luggage, lightweight, reusable shipping containers and packaging, watercraft, non-inflated structures and buildings and inflatable emergency evacuation chutes.

However, the principles can be used in any suitable application. As such, changes and modifications are properly, equitably, and intended to be, within the full range of equivalence of this disclosure.