Skin-constrained expandable bellows

Abstract

An augmented assembly skin-constrained expandable bellows system includes a top end cap, a bottom end cap, and a bellows attached to and separating the top and bottom end caps, and configured to retain pressurized fluid between the top and bottom end caps. The system also includes nozzles configured to allow fluid to enter and exit the bellows, and a non-extendable skin attached to each of the top and bottom end caps and to the bellows. When the bellows expands via the nozzles, the top end cap is in a first position, and when the top end cap is adjusted from the first position to a second position, the skin is configured to hold the top end cap in the second position and constrain the bellows into a predetermined rigid three-dimensional shape.

Description

Technical Field

[0001] This invention relates to inflatable structures, and more specifically, to inflatable bellows-type structures, wherein the expanded form of the structure is desired to have stiffness. Inflatable structures typically include an air bladder holding pressurized air or liquid, and a line attached to the opposing inner surface of the air bladder. The line is typically attached to the inner surface of the air bladder. When the air bladder inflates, the pressure within the air bladder causes the air bladder to expand outward, thereby applying tension to the line, which in turn limits the expansion of the air bladder. In addition to limiting the expansion of the air bladder, the line increases the amount of compressive load the air bladder can withstand before the air bladder deforms under compressive loads. Such internally tensioned inflatable structures are used in devices requiring a high compressive strength-to-weight ratio, such as aircraft wings. Background Technology

[0002] While internally tensioned expandable structures have achieved their intended purpose, there is still a need for new and improved expandable structures and their construction methods that maintain or increase the structural capabilities of expandable structures while improving packaging dimensions, providing multi-degree-of-freedom rigid unfolding, having a smooth outer surface that facilitates cleaning, increasing shear resistance, and reducing weight, while maintaining or reducing costs and manufacturing complexity. Summary of the Invention

[0003] According to several aspects of this disclosure, an augmented assembly skin-constrained expandable bellows system includes a top end cap, a bottom end cap, and a bellows attached to and separating the top and bottom end caps, and configured to retain pressurized fluid between the top and bottom end caps. The system also includes nozzles configured to allow fluid to enter and exit the bellows, and a non-extendable skin attached to each of the top and bottom end caps and to the bellows. When the bellows expands via the nozzles, the top end cap is in a first position, and when the top end cap is adjusted from the first position to a second position, the skin is configured to hold the top end cap in the second position and constrain the bellows into a predetermined rigid three-dimensional shape.

[0004] In another aspect of this disclosure, the bellows includes one or more expandable chambers. Each of the one or more expandable chambers is formed by one or more top portions and one or more bottom portions. Each of the one or more top portions is sealed to one of the one or more bottom portions around a peripheral edge, and the peripheral edge defines a radially extending bellows flange.

[0005] In another aspect of this disclosure, one or more top portions and one or more bottom portions define a folded portion of the bellows, the folded portion extending in the axial direction between the peripheral edges of the top end cap and the peripheral edges of the bottom end cap. The folded portion of the bellows includes one or more folds that reduce the bellows stiffness in the axial direction of the skin-constrained expandable bellows system.

[0006] In another aspect of this disclosure, the non-extendable skin is replaceable. Replaceable non-extendable skin-constrained bellows of different shapes are used to define different expansion three-dimensional geometries of a fully expandable skin-constrained expandable bellows system.

[0007] In another aspect of this disclosure, the non-extendable skin includes a plurality of bellows attachment features at predetermined locations, the plurality of bellows attachment features being aligned with one or more of the bellows flanges, as well as a top end cap and a bottom end cap.

[0008] In another aspect of this disclosure, one or more of the radially extending bellows flanges are attached to a non-extendable skin at one or more of a plurality of bellows attachment features.

[0009] In another aspect of this disclosure, each of one or more top portions includes one or more slots, and each of one or more bottom portions includes one or more slots, and the one or more top portions and one or more bottom portions are heat-sealed to each other only around their peripheral edges using a removable mask. The one or more slots in the one or more top portions and bottom portions allow airflow through the one or more top portions and bottom portions while maintaining the shape and structural integrity of the bellows.

[0010] In another aspect of this disclosure, the corrugated tube is formed of one or more materials including silicone, thermoplastic polyurethane (TPU), or TPU-coated fabric. The corrugated tube attachment feature on the non-stretchable skin includes a TPU-impregnated portion of the non-stretchable skin material. The removable mask is formed of one or more materials including paper, cellophane, glycerin, and paper soap. The removable mask is soluble in solvents that do not react with TPU, wherein the solvent includes one or more of water, acetone, and alcohol.

[0011] In another aspect of this disclosure, when the skin-constrained expandable bellows system is fully expanded, the non-extendable skin completely encapsulates the bellows and provides a smooth outer surface.

[0012] In another aspect of this disclosure, a non-extendable skin extends a first axial distance on a first side of the bellows and a second axial distance less than the first axial distance on a second side of the bellows. The second side is opposite to the first side, and when the skin constrains the expandable bellows system to be fully expanded, the rigid three-dimensional shape is constrained by the skin to a non-linear shape.

[0013] In another aspect of this disclosure, a method of producing a skin-constrained expandable bellows includes assembling a top end cap, a bottom end cap, and a bellows attached to and separating the top and bottom end caps. The bellows is configured to hold pressurized fluid between the top and bottom end caps. The method also includes attaching a non-extensible skin to each of the top end cap, the bellows, and the bottom end cap, and using nozzles disposed on one or more of the top and bottom end caps to allow fluid to enter and exit the bellows. When the bellows expands via the nozzles, the top end cap is in a first position, and when the top end cap is adjusted from the first position to a second position, the skin is configured to hold the top end cap in the second position and constrain the bellows into a predetermined rigid three-dimensional shape.

[0014] In another aspect of this disclosure, the method further includes assembling one or more expandable chambers, each of the one or more expandable chambers being formed by one or more top portions and one or more bottom portions. The method includes sealing each of the one or more top portions to one of the one or more bottom portions around a peripheral edge. The peripheral edge defines a radially extending bellows flange.

[0015] In another aspect of this disclosure, the method further includes masking one or more top portions and one or more bottom portions with a removable mask, and as a result of the masking, heat-sealing each of the one or more top portions to one of the one or more bottom portions only around the perimeter edge. Each of the one or more top portions includes one or more slots, and each of the one or more bottom portions includes one or more slots, and the one or more slots in the one or more top portions and bottom portions allow airflow while maintaining the shape and structural integrity of the bellows.

[0016] In another aspect of this disclosure, the method includes folding one or more top portions and one or more bottom portions to define a folded portion of the bellows extending in an axial direction between a peripheral edge of a top end cap and a peripheral edge of a bottom end cap. The folded portion of the bellows includes one or more folds that reduce the bellows stiffness in the axial direction of the skin-constrained expandable bellows system.

[0017] In another aspect of this disclosure, the method includes equipping a non-extendable skin with a plurality of bellows attachment features at predetermined locations aligned with one or more of the bellows flanges and the top and bottom end caps.

[0018] In another aspect of this disclosure, the method includes attaching a non-extendable skin to one or more of a radially extending bellows flange at one or more of a plurality of bellows attachment features.

[0019] In another aspect of this disclosure, the method includes forming a corrugated tube from one or more materials including silicone, thermoplastic polyurethane (TPU), or TPU-coated fabric; forming a corrugated tube attachment feature on a non-stretchable skin material by a TPU-impregnated portion of the non-stretchable skin material; and forming a removable mask from one or more materials including paper, cellophane, glycerin, and paper soap, wherein the removable mask is soluble in a solvent that does not react with the TPU. The solvent includes one or more of the following: water, acetone, and alcohol.

[0020] In another aspect of this disclosure, the method includes completely encapsulating the bellows with a non-extendable skin to provide a smooth outer surface when the skin-constrained expandable bellows system is fully expanded. The non-extendable skin is replaceable, and different shapes of replaceable non-extendable skin-constrained bellows define different expansion three-dimensional geometries of the fully expanded skin-constrained expandable bellows system.

[0021] In another aspect of this disclosure, the method includes producing a skin-constrained expandable bellows of a nonlinear rigid three-dimensional shape by providing an inextensible skin, which extends a first axial distance on a first side of the bellows and extends a second axial distance less than the first axial distance on a second side of the bellows. The second side is opposite to the first side.

[0022] In another aspect of this disclosure, an augmented skin-constrained expandable bellows system includes a top end cap, a bottom end cap, and a bellows attached to and separating the top and bottom end caps, and configured to retain pressurized fluid between the top and bottom end caps. The bellows includes one or more expandable chambers. Each of the one or more expandable chambers is formed by one or more top portions and one or more bottom portions. Each of the one or more top portions is sealed to one of the one or more bottom portions around a peripheral edge. The peripheral edge defines a radially extending bellows flange. Each of the one or more top portions includes one or more grooves, and each of the one or more bottom portions includes one or more grooves, and the one or more top portions and the one or more bottom portions are heat-sealed to each other only around the peripheral edge using a removable mask. The removable mask is formed of one or more materials including paper, cellophane, glycerin, and paper soap. The removable mask is soluble in solvents that do not react with TPU. The solvents include one or more of the following: water, acetone, and alcohol. One or more slots in one or more top and bottom portions allow airflow through one or more top and bottom portions while maintaining the shape and structural integrity of the bellows. One or more top and bottom portions define a folded portion of the bellows extending axially between the peripheral edges of the top and bottom end caps. The folded portion of the bellows includes one or more folds that reduce the axial stiffness of the bellows constrained by the skin-constrained expandable bellows system. Nozzles are configured to allow fluid to enter and exit the bellows. A non-extendable skin is attached to each of the top and bottom end caps and to the bellows. The non-extendable skin includes multiple bellows attachment features at predetermined locations, which align with one or more bellows flanges and the top and bottom end caps. One or more radially extending bellows flanges are attached to the non-extendable skin at one or more of the multiple bellows attachment features. The bellows is formed of one or more materials including silicone, thermoplastic polyurethane (TPU), or TPU-coated fabric. The bellows attachment feature on the non-stretchable skin includes a TPU-impregnated portion of the non-stretchable skin material. When the bellows expands via the nozzle, the top end cap is in a first position, and when the top end cap is adjusted from the first position to a second position, the skin is configured to hold the top end cap in the second position and constrain the bellows into a predetermined rigid three-dimensional shape. When the skin constrains the expandable bellows system to full expansion, the non-stretchable skin completely encapsulates the bellows and provides a smooth outer surface. When the non-stretchable skin extends a first axial distance on a first side of the bellows and a second axial distance less than the first axial distance on a second side of the bellows, the rigid three-dimensional shape is constrained by the skin into a non-linear shape.The non-extendable skin is replaceable, and the different shapes of replaceable non-extendable skins constrain the bellows into different expansion three-dimensional geometries of the fully expandable skin-constrained expandable bellows system.

[0023] Further areas of application will become apparent from the description provided herein. It should be understood that the descriptions and specific examples are intended for illustrative purposes only and are not intended to limit the scope of this disclosure.

[0024] The present invention also includes the following technical solutions.

[0025] Technical Solution 1. A skin-constrained expandable bellows system with added assembly, the system comprising:

[0026] Top end cap;

[0027] Bottom end cap;

[0028] A bellows, which is attached to and separates the top end cap and the bottom end cap, and is configured to hold pressurized fluid between the top end cap and the bottom end cap;

[0029] Nozzles, the nozzles being configured to allow fluid to enter and exit the bellows; and

[0030] A non-extendable skin, said non-extendable skin being attached to each of the top end cap and the bottom end cap and to the bellows; and

[0031] When the bellows expands via the nozzle, the top end cap is in a first position, and when the top end cap is adjusted from the first position to a second position, the skin is configured to hold the top end cap in the second position and constrain the bellows into a predetermined rigid three-dimensional shape.

[0032] Technical Solution 2. The skin-constrained expandable bellows system with added assembly as described in Technical Solution 1, wherein the bellows comprises:

[0033] One or more expandable chambers, wherein each of the one or more expandable chambers is formed by one or more top portions and one or more bottom portions; each of the one or more top portions is sealed to one of the one or more bottom portions around a peripheral edge, and wherein the peripheral edge defines a radially extending bellows flange.

[0034] Technical Solution 3. An augmented skin-constrained expandable bellows system as described in Technical Solution 2, wherein the one or more top portions and the one or more bottom portions define a folded portion of the bellows, the folded portion extending in an axial direction between the peripheral edges of the top end cap and the peripheral edges of the bottom end cap, and wherein the folded portion of the bellows includes one or more folds that reduce the bellows stiffness in the axial direction of the skin-constrained expandable bellows system.

[0035] Technical Solution 4. An augmented assembly of a skin-constrained expandable bellows system as described in Technical Solution 2, wherein the non-extendable skin is replaceable, and wherein different shaped replaceable non-extendable skins constrain the bellows to define different expansion three-dimensional geometries of the fully expandable skin-constrained expandable bellows system.

[0036] Technical Solution 5. An augmented assembly skin-constrained expandable bellows system as described in Technical Solution 4, wherein the non-extendable skin includes a plurality of bellows attachment features at predetermined locations, the plurality of bellows attachment features being aligned with one or more of the bellows flanges, as well as a top end cap and a bottom end cap.

[0037] Technical Solution 6. An augmented skin-constrained expandable bellows system as described in Technical Solution 5, wherein one or more of the radially extending bellows flanges are attached to the non-expandable skin at one or more of a plurality of bellows attachment features.

[0038] Technical Solution 7. An augmented assembly skin-constrained expandable bellows system as described in Technical Solution 5, wherein each of the one or more top portions includes one or more slots, and each of the one or more bottom portions includes one or more slots, and the one or more top portions and the one or more bottom portions are heat-sealed to each other only around the perimeter edge using a removable mask, and wherein the one or more slots in the one or more top portions and bottom portions allow airflow through the one or more top portions and bottom portions while maintaining the shape and structural integrity of the bellows.

[0039] Technical Solution 8. The skin-constrained expandable bellows system with added assembly as described in Technical Solution 6, wherein:

[0040] The bellows is formed of one or more materials including: silicone resin, thermoplastic polyurethane (TPU), or TPU-coated fabric; and

[0041] The corrugated attachment feature on the non-stretchable skin includes a TPU impregnation portion of the non-stretchable skin material, and wherein the removable mask is formed of one or more of the following materials: paper, cellophane, glycerin, and paper soap, wherein the removable mask is soluble in a solvent that does not react with TPU, wherein the solvent includes one or more of the following: water, acetone, and alcohol.

[0042] Technical Solution 9. An augmented assembly skin-constrained expandable bellows system as described in Technical Solution 1, wherein when the skin-constrained expandable bellows system is fully expanded, the non-extendable skin completely encapsulates the bellows and provides a smooth outer surface.

[0043] Technical Solution 10. An augmented skin-constrained expandable bellows system as described in Technical Solution 9, wherein the non-extendable skin extends a first axial distance on a first side of the bellows and extends a second axial distance less than the first axial distance on a second side of the bellows, wherein the second side is opposite to the first side, and wherein, when the skin-constrained expandable bellows system is fully expanded, the rigid three-dimensional shape is constrained by the skin to a non-linear shape.

[0044] Technical Solution 11. A method for producing a skin-constrained expandable bellows, comprising:

[0045] Add a top end cap, a bottom end cap, and a bellows attached to and separating the top end cap and the bottom end cap, the bellows being configured to maintain pressurized fluid between the top end cap and the bottom end cap;

[0046] Attach a non-extendable skin to each of the top end cap, the bellows, and the bottom end cap;

[0047] Fluid is allowed to enter and exit the bellows by means of nozzles disposed on one or more of the top end cap and the bottom end cap, wherein the top end cap is in a first position when the bellows expands via the nozzles, and the skin is configured to hold the top end cap in the second position and constrain the bellows into a predetermined rigid three-dimensional shape when the top end cap is adjusted from the first position to the second position.

[0048] Technical Solution 12. The method for producing a skin-constrained expandable bellows as described in Technical Solution 11 further includes:

[0049] Assemble one or more expandable chambers, wherein each of the one or more expandable chambers is formed by one or more top portions and one or more bottom portions; and

[0050] Each of the one or more top portions is sealed to one of the one or more bottom portions around a perimeter edge, wherein the perimeter edge defines a radially extending bellows flange.

[0051] Technical Solution 13. The method for producing a skin-constrained expandable bellows as described in Technical Solution 12 further includes:

[0052] Mask the one or more top portions and the one or more bottom portions with a removable mask; and

[0053] As a result of the shielding, each of the one or more top portions is heat-sealed to one of the one or more bottom portions only around the perimeter edge, wherein each of the one or more top portions includes one or more grooves, and each of the one or more bottom portions includes one or more grooves, and the one or more grooves in the one or more top portions and bottom portions allow airflow while maintaining the shape and structural integrity of the bellows.

[0054] Technical Solution 14. The method for producing a skin-constrained expandable bellows as described in Technical Solution 13 further includes:

[0055] Folding the one or more top portions and the one or more bottom portions to define a folded portion of the bellows, the folded portion extending in the axial direction between the peripheral edges of the top end cap and the peripheral edges of the bottom end cap, wherein the folded portion of the bellows includes one or more folds that reduce the bellows stiffness in the axial direction of the skin-constrained expandable bellows system.

[0056] Technical Solution 15. The method for producing a skin-constrained expandable bellows as described in Technical Solution 14 further includes:

[0057] At predetermined positions aligned with one or more of the bellows flanges and the top and bottom end caps, the non-extendable skin is equipped with a plurality of bellows attachment features.

[0058] Technical Solution 16. The method for producing a skin-constrained expandable bellows as described in Technical Solution 15 further includes:

[0059] The non-extendable skin is attached to one or more of the radially extending bellows flanges at one or more of the plurality of bellows attachment features.

[0060] Technical Solution 17. A method for producing a skin-constrained expandable bellows as described in Technical Solution 15, wherein:

[0061] The corrugated pipe is formed from one or more of the following materials: silicone resin, thermoplastic polyurethane (TPU), or TPU-coated fabric; and

[0062] The corrugated attachment feature is formed on the non-stretchable skin by a TPU impregnation portion of the non-stretchable skin material; and

[0063] A removable mask is formed from one or more of the following materials: paper, cellophane, glycerin, and paper soap, wherein the removable mask is soluble in a solvent that does not react with TPU, wherein the solvent includes one or more of the following: water, acetone, and alcohol.

[0064] Technical Solution 18. The method for producing a skin-constrained expandable bellows as described in Technical Solution 11 further includes:

[0065] When the skin-constrained expandable bellows system is fully expanded, the bellows is completely encapsulated with the non-extendable skin to provide a smooth outer surface, wherein the non-extendable skin is replaceable, and wherein replaceable non-extendable skins of different shapes constrain the bellows to define different expansion three-dimensional geometries of the fully expanded skin-constrained expandable bellows system.

[0066] Technical Solution 19. The method for producing a skin-constrained expandable bellows as described in Technical Solution 18 further includes:

[0067] A skin-constrained expandable bellows of a nonlinear rigid three-dimensional shape is produced by providing a non-extendable skin, which extends a first axial distance on a first side of the bellows and extends a second axial distance less than the first axial distance on a second side of the bellows, wherein the second side is opposite to the first side.

[0068] Technical Solution 20. An assembled skin-constrained expandable bellows system, the system comprising:

[0069] Top end cap;

[0070] Bottom end cap;

[0071] A bellows, attached to and separating the top end cap and the bottom end cap, and configured to maintain pressurized fluid between the top end cap and the bottom end cap; wherein the bellows comprises:

[0072] One or more expandable chambers, wherein each of the one or more expandable chambers is formed by one or more top portions and one or more bottom portions; each of the one or more top portions is sealed to one of the one or more bottom portions around a peripheral edge, wherein the peripheral edge defines a radially extending bellows flange;

[0073] Each of the one or more top portions includes one or more grooves, and each of the one or more bottom portions includes one or more grooves, and the one or more top portions and the one or more bottom portions are heat-sealed to each other only around the perimeter edge using a removable mask, wherein the removable mask is formed of one or more materials including paper, cellophane, glycerin, and paper soap, wherein the removable mask is soluble in a solvent that does not react with TPU, wherein the solvent includes one or more of the following: water, acetone, and alcohol.

[0074] One or more slots in one or more top portions and bottom portions allow airflow through one or more top portions and bottom portions while maintaining the shape and structural integrity of the bellows;

[0075] Wherein, the one or more top portions and the one or more bottom portions define a folded portion of the bellows, the folded portion extending in an axial direction between the peripheral edge of the top end cap and the peripheral edge of the bottom end cap;

[0076] The folded portion of the bellows includes one or more folds, which reduce the bellows stiffness in the axial direction of the skin-constrained expandable bellows system.

[0077] A nozzle configured to allow fluid to enter and exit the bellows;

[0078] A non-extendable skin is attached to each of the top end cap and the bottom end cap and to the bellows, wherein the non-extendable skin includes a plurality of bellows attachment features at predetermined locations, the plurality of bellows attachment features being aligned with one or more of the bellows flanges and the top end cap and the bottom end cap.

[0079] One or more of the radially extending bellows flanges are attached to the non-extendable skin at one or more of the plurality of bellows attachment features.

[0080] The corrugated pipe is formed of one or more of the following materials: silicone resin, thermoplastic polyurethane (TPU), or TPU-coated fabric.

[0081] The corrugated attachment feature on the non-stretchable skin includes a TPU impregnation portion of the non-stretchable skin material; and

[0082] Wherein, when the bellows expands via the nozzle, the top end cap is in a first position; when the top end cap is adjusted from the first position to a second position, the skin is configured to hold the top end cap in the second position and constrain the bellows into a predetermined rigid three-dimensional shape; wherein, when the skin constrains the expandable bellows system to full expansion, the non-extendable skin completely encapsulates the bellows and provides a smooth outer surface; and wherein, when the non-extendable skin extends a first axial distance on a first side of the bellows and extends a second axial distance less than the first axial distance on a second side of the bellows, the rigid three-dimensional shape is constrained by the skin into a non-linear shape.

[0083] The non-extendable skin is replaceable, and the replaceable non-extendable skins of different shapes constrain the bellows into different expansion three-dimensional geometries of the fully expanded skin-constrained expandable bellows system. Attached Figure Description

[0084] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of this disclosure in any way.

[0085] Figure 1A This is a perspective partial cross-sectional view of a skin-constrained expandable bellows system in an unexpanded state according to aspects of this disclosure.

[0086] Figure 1B It is in a state of partial expansion according to aspects of this disclosure. Figure 1A A perspective partial cross-sectional view of a skin-constrained expandable bellows system.

[0087] Figure 1C shows a fully expanded state according to aspects of this disclosure. Figure 1A and Figure 1B A perspective partial cross-sectional view of a skin-constrained expandable bellows system.

[0088] Figure 1D Figure 1C is a perspective partial cross-sectional view of a portion of a skin-constrained expandable bellows system according to an aspect of this disclosure, showing further details of the bellows flange and skin attachments.

[0089] Figure 2 This is an exploded view of an added component of a skin-constrained expandable bellows system according to aspects of this disclosure;

[0090] Figure 3This is a partial cross-sectional view of a portion of an additional component of a skin-constrained expandable bellows system according to aspects of this disclosure;

[0091] Figure 4A This is a partial cross-sectional side view of a nonlinear skin-constrained expandable bellows system in a partially expanded state according to aspects of this disclosure; and

[0092] Figure 4B This is a partial cross-sectional side view of a nonlinear skin-constrained expandable bellows system in a fully expanded state according to aspects of this disclosure. Detailed Implementation

[0093] The following description is exemplary in nature and is not intended to limit this disclosure, application, or use.

[0094] Some devices, such as aircraft wings, are designed to change shape during operation. Such devices typically include complex rigid mechanisms that enable this change of shape during operation. These rigid mechanisms increase the cost, weight, and storage size of the device.

[0095] The skin-constrained expandable bellows system 10 according to the invention can be incorporated into a device to change the shape of the device during operation without significantly increasing the cost, weight and storage size of the device.

[0096] refer to Figure 1A , Figure 1B Figure 1C illustrates a skin-constrained expandable bellows system 10 in various configurations. Specifically, Figure 1A A skin-constrained expandable bellows system 10 is depicted in either a retracted or unexpanded position. Figure 1B Figure 1C depicts a skin-constrained expandable bellows system 10 in a partially retracted or partially expanded position, and Figure 1C depicts a skin-constrained expandable bellows system 10 in a fully deployed or fully expanded position. The skin-constrained bellows system 10 includes a top end cap 12, a bottom end cap 14, a bellows 16, a nozzle 18, and a skin 20.

[0097] Each of the top end cap 12 and the bottom end cap 14 is a rigid structure with a peripheral edge 22. A bellows 16 is attached to the peripheral edges 22 of the top end cap 12 and the bottom end cap 14 and is configured to hold a pressurized fluid, such as air, between the top end cap 12 and the bottom end cap 14. A nozzle 18 is operable to allow fluid to enter and exit the bellows 16. A skin 20 is coupled to the top end cap 12 and the bottom end cap 14. When the bellows 16 expands, the skin 20 constrains the movement of the top end cap 12 relative to the bottom end cap 14, and thus limits the number and type of degrees of freedom of the expandable structure 10.

[0098] In the expandable structure described herein, it is assumed that the bottom end cap 14 is stationary or fixed in space, and the movement of the top end cap 12 is constrained only by the bellows 16 and the skin 20. However, in various embodiments, the top end cap 12 may be stationary or fixed in space, and the movement of the bottom end cap 14 may be constrained only by the bellows 16 and the skin 20 connecting the top and bottom end caps 12 and 14 to each other. In other embodiments, neither the top end cap 12 nor the bottom end cap 14 is stationary or fixed in space, and the movement of the top and bottom end caps 12 and 14 may be constrained only by the bellows 16 and the skin 20 connecting the top and bottom end caps 12 and 14 to each other.

[0099] Top end cap 12 and bottom end cap 14 provide rigid attachment points for the skin 20. The materials and geometries of top end cap 12 and bottom end cap 14 are selected to ensure that they do not bend when a load or pressure is applied to either top end cap 12 or bottom end cap 14. Top end cap 12 and bottom end cap 14 may be made of rigid materials such as acrylonitrile butadiene styrene, Delrin®, acetal, etc. Top end cap 12 and bottom end cap 14 are sealed to bellows 16. Therefore, fluid is only allowed to enter or exit bellows 16 through nozzle 18.

[0100] Bellows 16 is configured to contain a pressurized fluid, such as a gas (e.g., air, helium, etc.) or a liquid, between a top end cap 12 and a bottom end cap 14. Bellows 16 may be made of a flexible, non-stretchable material. For example, bellows 16 may be made of silicone, thermoplastic polyurethane (TPU), and / or TPU-coated fabric. The geometry and / or material of bellows 16 are chosen to ensure that bellows 16 does not impede the movement of the expandable structure 10. Ideally, bellows 16 is flexible in the axial direction 24 of the expandable structure 10 and rigid in all radial directions of the expandable structure 10, including radial direction 26.

[0101] In several aspects, the bellows 16 defines one or more expandable chambers 28. Each of the expandable chambers is formed by a top portion 30 and a bottom portion 32. The top portion 30 and the bottom portion 32 are connected to each other via known thermal, chemical, or mechanical means for impermeably adhering segments of silicone, TPU, or TPU-coated fabric together. More specifically, each of the top portion 30 and the bottom portion 32 of the expandable chamber 28 is completely sealed around the peripheral edge of the expandable chamber 28 to define a bellows flange 34. The bellows flange 34 creates an airtight bellows 16 structure but increases the overall unfolded and retracted width.

[0102] In some examples, nozzle 18 extends through bottom end cap 14 and is adjustable between an open position and a closed position. When nozzle 18 is in the open position, it allows fluid to enter or exit bellows 16. When nozzle 18 is in the closed position, it prevents fluid from entering or exiting bellows 16. Nozzle 18 may be a mechanically controlled valve (e.g., Schrader valve, Presta valve, etc.) or an electronically controlled valve.

[0103] Now for reference Figure 1D And continue to refer to Figure 1A As shown in Figure 1C, the bellows flanges 34 define the radially outermost portion of each of the expandable chambers 28. In some examples, a skin 20 is attached to each bellows flange 34 to reduce the coverage area size of the skin-constrained expandable bellows system 10 in its unexpanded state. That is, because the skin 20 is attached to some or all of the bellows flanges 34, when the bellows 16 expands, the skin 20 causes the bellows flanges 34 to fold against the skin 20. This reduces the overall width of the skin-constrained expandable bellows system 10 by approximately twice the width of the bellows flanges 34. Furthermore, because the skin 20 is attached to some or all of the bellows flanges 34, the bellows 16 prevents the skin 20 from significantly expanding radially outward from the bellows 16 when the skin-constrained expandable bellows system 10 is contracted or in its unexpanded state. When the system 10 is in its unexpanded state, the bellows flanges 34 lie flat. To facilitate precise deployment, expansion, and smoothing of the outer surface 36 of the skin-constrained expandable bellows system 10, the skin 20 is attached only to one of the top portion 30 or the bottom portion 32 of the expandable chamber 28. Therefore, when the skin-constrained expandable bellows system 10 reaches Figure 1C and... Figure 1D In the fully expanded position shown, the bellows flange 34 remains attached to the skin 20 and bends to allow the skin 20 to be taut on the expandable bellows 16.

[0104] Turn now Figure 2 And continue to refer to Figures 1A to 1DThe portion of the skin 20 is shown in more detail. More specifically, the skin-constrained expandable bellows system 10 is shown in an exploded top view. The skin 20 has an upper end 38 coupled to the top end cap 12 and a lower end 40 coupled to the bottom end cap 14. The skin 20 is a sheet of non-stretchable material, such as nylon, cotton, etc. Nylon, cotton, or other such non-stretchable materials may also be impregnated or coated with materials that provide desired properties, such as watertightness, airtightness, or predetermined permeability. Similarly, the non-stretchable material and / or the substance impregnated in the non-stretchable skin 20 may be given color, texture, etc., without departing from the scope or intent of this disclosure. The skin 20 may provide a smooth outer surface for the expandable structure. A smooth outer surface can improve the aerodynamic quality of the expandable structure and facilitate cleaning. In some examples, the skin 20 may be removed or partially removed from other parts of the expandable structure to facilitate cleaning, or for wear replacement or aesthetic reasons. Similarly, various materials can be used for the skin 20, allowing for different aesthetic and physical properties to be produced or used in different applications or uses. The material strength of the skin is sufficient to withstand a predetermined load applied to the expandable structure 10. Applying a load greater than the predetermined load to the expandable structure 10 will cause the bellows 16 to bend.

[0105] The length of the bellows 16 (i.e., its dimension in the axial direction 24) may be greater than the length of the skin 20 to ensure that the skin 20 is taut and may slacken when it expands. In the example shown, the bellows 16 includes a folded portion 42 that extends in the axial direction 24 below the peripheral edge 22 of the bottom end cap 14 and folds over itself. In several aspects, the skin 20 extends in the axial direction 24, which is substantially perpendicular to the top end cap 12 and the bottom end cap 14. If the skin 20 extends in a direction other than the axial direction 24 when the bellows 16 expands, the length of the bellows 16 may be greater than the effective length of the skin 20. The effective length of the skin 20 is the distance the skin 20 extends in the axial direction 24 between the top end cap 12 and the bottom end cap 14. In several aspects, for a skin-constrained expandable bellows system 10 having a generally linear solid shape, the skin 20 is formed of one or more generally rectangular non-stretchable sheets of material, which, as described herein, are connected or otherwise attached to the bellows 16. However, it should be understood that the skin-constrained expandable bellows 16 may have various shapes other than those of a linear solid without departing from the scope or intent of this disclosure.

[0106] Turn now Figure 3 And continue to refer to Figures 1A to 2The skin 20 is coupled to the top end cap 12, the bottom end cap 14, and the bellows 16 via one or more bellows attachment features 44. The bellows attachment features 44 may define any of a variety of permanent, semi-permanent, or removable attachment devices. In several examples, the bellows attachment features 44 may include heat-sealable attachments, adhesives, mechanical fasteners such as hook-and-loop fasteners, tongue-and-groove fasteners, or similar fasteners, without departing from the scope or intent of this disclosure. Similarly, the bellows flange 34 may have features that interact directly or indirectly with the bellows attachment features 44 of the skin 20 to ensure that the skin 20 and the bellows 16 are properly positioned relative to each other and attached to each other. In certain non-limiting examples, the bellows attachment features 44 define a heat-sealable TPU strip that is sealed or otherwise bonded to the skin 20 during assembly at a specific location aligned with the bellows flange 34. The width of the TPU strip is substantially equal to the width or radial extent of the bellows flange 34. Additional bellows attachment features 44 extend along the upper end 38 and lower end 40 of the skin 20. Further bellows attachment features 44 may be located at other locations on the skin 20, such as along the vertical edge 50 of the skin 20, and may be attached to the bellows 16, other portions of the skin 20, etc. In several aspects, the gaps between the bellows attachment features 44 on the skin 20 vary in size, such that the gaps between the TPU strips at the lower end 40 are larger than the gaps near the upper end 38, to allow the flange 34 to fold upwards during expansion.

[0107] The skin 20 can be fabricated with pre-patterned TPU strip bellows attachment features 44. Pre-patterning enables attachment when a stack of skin-constrained expandable bellows system 10 components is fabricated. The spacing between the bellows attachment features 44 also prevents unwanted attachments to the bellows 16 when the bellows 16 are thermo-pressed to the skin 20 during assembly. The skin-constrained expandable bellows system 10 of this disclosure can be assembled using an augmented construction approach. The patterning of the bellows attachment features 44 on the skin allows the skin 20 to be sealed to the bellows flange 34 while the bellows 16 layers are fabricated. This augmented construction ensures the formation of a sealed bellows 16, and the skin 20 is augmented to the bellows 16 to form the entire stack of the bellows 16 and skin 20 components.

[0108] In the example where the skin 20 has a TPU corrugated tube attachment feature 44, the first additional manufacturing step includes placing the material used for the skin 20 on or in a hot press. More specifically, the two skin panels 20A and 20B are positioned such that the lower ends 40 are positioned parallel to each other and nearly in contact. A strip of cellophane 52, slightly wider than the range of the top portion 30 and bottom portion 32 of the corrugated tube 16 material, is placed at the center where the two skin panels 20A and 20B meet. The cellophane strip 52 prevents the corrugated tube 16 itself from being sealed to the TPU of the skin 20 in an undesirable location.

[0109] The bellows 16 may be composed of a series of bellows sections 16A, 16B…16N. A first TPU layer (TPU1) with a large groove 54 is placed on top of a cellophane strip 52, followed by an inner mask 56 and an intermediate TPU layer (TPU2). TPU1 and TPU2 are then sealed using a hot press at a predetermined temperature for a predetermined time. In some examples, TPU1 and TPU2 are heated to approximately 300°F for approximately 75 seconds. The large groove 54 in TPU1 allows air or other pressurized fluid to pass through TPU1 and fill the bellows section 16.

[0110] Another bellows section 16B can be constructed and sealed to the first bellows section 16A. An outer mask 58 is placed on top of TPU 2, and then another intermediate TPU layer (TPU 3) is placed on top of the outer mask 58. A thermopressor can then be used to seal TPU 2 and TPU 3 as described above. The above process can then be repeated by placing another inner mask 56 on TPU 3, followed by another intermediate TPU layer 4, and then sealing them together by heating as described above, thereby forming additional bellows sections 16B…16N. The inner mask 56 and the outer mask 58 prevent the different TPU layers from adhering to each other during assembly. In several examples, the inner mask 56 and the outer mask 58 are removed from the bellows 16 during post-assembly. Depending on the specific application, the inner mask 56 and the outer mask 58 can be removed in various ways. In some examples, the inner mask 56 and the outer mask 58 are removed from the bellows 16 via mechanical means, via solvents or other chemical means, etc. In certain examples, the inner mask 56 and the outer mask 58 are made of water-soluble materials, such as paper, glycerin, cellophane, paper soap, etc. In some examples, the inner mask 56 and the outer mask 58 are made of materials soluble in substances such as alcohol, acetone, or other solvents that do not react with TPU.

[0111] As shown in the figure, TPU2, TPU3, and TPU4 include multiple slots 60. It should be understood that although only two locations of the slots 60 are shown on each of TPU2, TPU3, and TPU4, there may be more than two slots 60 or fewer than two slots 60 without departing from the scope or intent of this disclosure. However, it should also be understood that each of TPU1, TPU2, TPU3, TPU4, etc., provides radial confinement for the bellows 16. Therefore, if multiple adjacent bellows portions 16A, 16B, 16C, 16D, etc., include intermediate TPU layers TPU1, TPU2, TPU3, TPU4, etc., each with only a single large slot 54, the bellows 16 may not be properly radially confined and may expand radially outward in an undesirable shape, or result in a lack of structural stability in the overall structure of the skin-constrained expandable bellows system 10.

[0112] The skin 20 seals to the bellows flange 34 at each of the bellows attachment features 44. More specifically, the skin 20 is folded onto the TPU 4 and then folded back, such that the bellows attachment features 44 in the skin 20 lie flat on the bellows flange 34 of the TPU 4. A hot press is then activated to attach the bellows attachment features 44 to the bellows flange 34 of the TPU 4. In some examples, an additional heating process may be used to increase the integrity of the seal between the skin 20 and the bellows 16. The assembly process of the bellows 16 can be further continued by applying an outer mask 58 to the TPU 4, applying another intermediate layer TPU 5 on the outer mask 58, and hot pressing under the aforementioned settings. The bellows 16 can be completed by placing another inner mask 56 on the TPU 5, another intermediate layer TPU 6, and then hot pressing, and the skin 20 can then be resealed to the bellows flange 34. Each of the inner mask 56 and the outer mask 58 prevents the TPU layers from sealing each other over the covered areas of the inner mask 56 and the outer mask 58.

[0113] It should be understood that the above-described construction process of the bellows 16 can be repeated any number of times to create bellows 16 with various heights for different applications. That is, for a given application, the process can be repeated as needed, using the inner mask 56 and the outer mask 58 to further seal the bellows portion 16N, and then folding the skin 20 to attach the skin 20 to the bellows portion 16N. In the construction of five bellows 16, this process should be completed a total of three times, such that the skin 20 is folded and sealed to the TPU layer three times. After the third repetition, the outer mask 58 is placed on the TPU 8, and the intermediate layer TPU 9 is placed on top of the outer mask 58. These layers are then heat-pressed. The inner mask 56 is placed on the TPU 9, and the TPU bellows 16 with the large groove TPU 10 is placed on top of the inner mask 56. These layers are then heat-pressed to ensure proper sealing and complete the fabrication process.

[0114] Subsequently, a hot press is used to attach the skin 20 to each of the top end cap 12 and the bottom end cap 14. More specifically, the bellows attachment feature 44 is heated in a manner that ensures the TPU strip melts into the top end cap 12 and the bottom end cap 14. The top end cap 12 and the bottom end cap 14 are thus sealed to the bellows 16. The bottom end cap 14 is placed within the large groove 54 of the TPU 10, with the TPU side of the bottom end cap 14 facing away from the rest of the bellows 16. The height of the hot press is adjusted to account for the thickness of the bottom end cap 14, and then it is heated as described above. The process is similarly repeated at the opposite ends of the bellows 16, such that the top end cap 12 is inserted through the large groove 54 of the TPU 10, with the TPU side of the top end cap 12 facing away from the rest of the bellows 16, and then heat-sealed as previously described.

[0115] While other materials can be used for the bellows 16 and the bellows attachment features 44 on the skin 20, the use of TPU simplifies the assembly process. This is because TPU seals well with other TPU materials, but not well with nylon, cotton, or other non-stretchable materials that constitute the skin 20 itself. Therefore, embedding TPU strips into the skin 20 is an effective way to ensure that the bellows flange 34 seals to the skin 20 only at the predetermined desired location. If the entire skin 20 were impregnated with TPU, the assembly of the bellows 16 would be more complex, as the bellows flange 34 would be difficult to position precisely on the skin 20. Furthermore, the gaps between the bellows attachment features 44 on the skin 20 ensure that the skin 20 does not adhere to or seal itself when folded over the bellows flange 34 during assembly.

[0116] When both the skin 20 and the bellows flange 34 are flat within the hot press, the skin 20 is attached to the bellows flange 34 with its length parallel to the bellows flange 34, allowing the skin 20 to fully extend during expansion. If the skin 20 is attached to the bellows 16 after the bellows 16 is sealed, there is a risk that the attachment of the bellows flange 34 to the skin will not be parallel to the long axis of the skin 20. In this case, the skin 20 may be undesirably pulled upward or downward on one side of the bellows 16.

[0117] Therefore, attaching the skin 20 to the bellows 16 during the sealing process is a simpler and more precise manufacturing method compared to attaching the skin 20 to the bellows 16 after it has been sealed. Although the masking material is located between each layer of the bellows 16, there is no risk of improperly sealing the layers of the bellows 16 together or puncturing the bellows 16. Furthermore, by combining the assembly of the skin 20 with the sealing of the bellows 16, the process becomes more efficient and more suitable for mass production.

[0118] Multiple skin panels 20A and 20B can be combined to completely enclose and effectively seal the bellows 16. Skin panels 20A and 20B are attached to each other to completely surround all sides of the bellows 16. Skin panels 20A and 20B can be attached to each other by known methods including fabric adhesive, hook and loop fasteners, stitching, heat sealing, etc. In a further example, additional skin panels 20C…20N can be used to surround the bellows 16. In a particular example, four skin panels 20A, 20B, 20C, and 20D respectively cover each of the vertical wall portions of the straight solid formed by the bellows 16. Extending skin panels 20A, 20B…20N beyond the ends of the bellows 16 allows the fully assembled skin 20 to enclose the bellows 16 and connect to the other skin panels 20A…20N. Because the skin 20 is on all sides of the bellows 16, none of the bellows 16 is directly exposed. Conversely, when the bellows 16 is fully expanded, the smooth outer surface 36 is formed by the skin.

[0119] Now go to Figure 4A and Figure 4B This shows a non-linear skin-constrained expandable bellows system 10. Figure 4A The system 10, which is in a partially inflated state, is depicted, and Figure 4B The system 10 is depicted in a fully expanded state. More specifically, a non-linear skin 20 is used to constrain the vertically expanding uneven structure of the bellows 16 by preventing expansion at one end of the bellows 16 while gradually expanding towards the other end. That is, embedded TPU strips forming the bellows attachment feature 44 on the non-linear skin can be arranged radially from the non-expanding point on the bellows 16. This allows the skin 20 to attach to the flange of the bellows 16 as the bellows 16 expands. The radial placement of the embedded TPU strips provides a non-linearly expanding skin constraining the structure of the expandable bellows system 10. This allows for structural expansion with varying heights from one end of the bellows 16 to the other end. Such non-linear shapes can be used in aerodynamic devices such as spoilers, chin spoilers, diffusers, side skirts, or steps attached to the side skirts of certain motor vehicles. Furthermore, the skin-constrained expandable bellows system 10 of this disclosure is suitable for a variety of applications in terms of size, shape, and stiffness, including but not limited to: expandable storage boxes, expandable quarter-circles on truck cabs, expandable motor vehicle bumper extensions, expandable vertical side skirts, expandable cargo dividers, etc. It should be understood that, although... Figure 4A and Figure 4B The skin-constrained expandable bellows system 10 shown has a generally sector-shaped cross-section, and Figures 1A to 3The skin-constrained expandable bellows system 10 shown elsewhere in the text has a substantially linear solid shape, but variations in shape and degrees of freedom are intended to be within the scope of this disclosure. That is, the skin 20 constrains the unfolded or expanded shape of the bellows 16 and generally defines the unfolded shape of the skin-constrained expandable bellows system 10.

[0120] In some examples, the skin 20 is removable or replaceable. Therefore, different skin 20 shapes and sizes can be used with the same underlying bellows 16 to produce a variable three-dimensional skin-constrained expandable bellows system 10 shape. That is, the expansion geometry of the skin-constrained expandable bellows system 10 can be changed by exchanging the skin 20. In such examples, the skin 20 and the bellows flange 34 are attached to each other via temporary or replaceable means, such as hook-and-loop fasteners, tongue-and-groove fasteners or other mechanical fasteners, temporary heat-sealable attachments, adhesives, etc.

[0121] Compared to a similar bellows 16 structure without an outer skin 20, the skin 20 of the skin-constrained expandable bellows system 10 significantly increases shear resistance. Experiments have shown that a skin 20 completely covering all four sides of the bellows 16 increases shear resistance by approximately 1.4 times compared to a bellows 16 with a skin 20 only on two parallel sides. Furthermore, experiments have determined that even when the bellows 16 is equipped with a skin 20 only on two parallel sides, the shear resistance of the bellows 16 is approximately 4.6 times that of a completely unconstrained bellows 16, and its resistance to vertical compression is approximately 3.3 times greater.

[0122] The skin-constrained expandable bellows system 10 disclosed herein offers several advantages. These include expandable structures and methods of construction thereof that maintain or increase the structural capabilities of expandable structures while improving packaging dimensions, providing multi-degree-of-freedom rigid deployment, having a smooth outer surface that facilitates cleaning, increasing shear resistance, and reducing weight, while maintaining or reducing costs and manufacturing complexity.

[0123] The description of this invention is merely exemplary in nature, and variations that do not depart from the spirit of this disclosure are also intended to be within the scope of this invention. Such variations should not be considered as departing from the spirit and scope of this disclosure.

Claims

1. An assembled skin-constrained inflatable bellows system, the system comprising: a top end cap; a bottom end cap; a bellows attached to and separating the top end cap and the bottom end cap and configured to hold pressurized fluid between the top end cap and the bottom end cap; a nozzle configured to allow fluid to enter and exit the bellows; and an inextensible skin attached to each of the top end cap, the bottom end cap, and to the bellows; and wherein, when the bellows is inflated via the nozzle, the top end cap is in a first position, and when the top end cap is adjusted from the first position to a second position, the skin is configured to hold the top end cap in the second position and constrain the bellows into a predetermined rigid three-dimensional shape. the bellows comprises: one or more inflatable chambers, wherein each of the one or more inflatable chambers is formed by one or more top portions and one or more bottom portions; each of the one or more top portions is sealed to one of the one or more bottom portions around a perimeter edge, and wherein the perimeter edge defines a radially extending bellows flange.

2. The increased assembled skin-restrained inflatable bellows system of claim 1, wherein, the one or more top portions and the one or more bottom portions define a folded portion of the bellows that extends in an axial direction between a perimeter edge of the top end cap and a perimeter edge of the bottom end cap, and wherein the folded portion of the bellows comprises one or more folds that reduce a bellows stiffness in the axial direction of the skin-constrained inflatable bellows system. the inextensible skin is replaceable, wherein different shapes of replaceable inextensible skin constrain the bellows to define different inflated three-dimensional geometries of a fully inflated skin-constrained inflatable bellows system.

3. The assembled skin-restrained inflatable bellows system of claim 2, wherein, the inextensible skin comprises a plurality of bellows attachment features at predetermined locations that align with one or more of the bellows flanges and the top end cap and the bottom end cap.

4. The increased assembled skin-restrained inflatable bellows system of claim 2, wherein, one or more of the radially extending bellows flanges are attached to the inextensible skin at one or more of the plurality of bellows attachment features.

5. The assembled skin-restrained inflatable bellows system of claim 4, wherein, each of the one or more top portions comprises one or more slots and each of the one or more bottom portions comprises one or more slots, and the one or more top portions and the one or more bottom portions are heat sealed to each other only around the perimeter edge using a removable mask, and wherein the one or more slots in one or more top and bottom portions allow airflow through the one or more top and bottom portions while maintaining the shape and structural integrity of the bellows.

6. The assembled skin-restrained inflatable bellows system of claim 5, wherein, 8. The assembled skin-constrained inflatable bellows system of claim 7, wherein:

7. The increased assembled skin-restrained inflatable bellows system of claim 5, wherein, the bellows is formed from a material comprising one or more of: silicone, thermoplastic polyurethane, or thermoplastic polyurethane-coated fabric; and ​ ​ The bellows attachment feature on the non-extensible skin includes a thermoplastic polyurethane impregnated portion of the non-extensible skin material, and wherein the removable mask is formed of a material including one or more of: paper, cellophane, glycerin, and paper soap, wherein the removable mask is soluble in a solvent that does not react with the thermoplastic polyurethane, wherein the solvent includes one or more of: water, acetone, and alcohol.

9. The increased assembled skin-restrained inflatable bellows system of claim 1, wherein, When the skin-constrained inflatable bellows system is fully inflated, the non-extensible skin fully encapsulates the bellows and provides a smooth outer surface.

10. The assembled skin-restrained inflatable bellows system of claim 9, wherein, The non-extensible skin extends a first axial distance on a first side of the bellows and a second axial distance on a second side of the bellows that is less than the first axial distance, wherein the second side is opposite the first side, and wherein when the skin-constrained inflatable bellows system is fully inflated, the rigid three-dimensional shape is skin-constrained to a non-linear shape.

11. A method of producing a skin-constrained inflatable bellows, comprising: assembling a top end cap, a bottom end cap, and a bellows attached to the top end cap and the bottom end cap and separating the top end cap and the bottom end cap, the bellows configured to hold a pressurized fluid between the top end cap and the bottom end cap; attaching a non-extensible skin to each of the top end cap, the bellows, and the bottom end cap; utilizing a nozzle disposed on one or more of the top end cap and the bottom end cap to allow fluid to enter and exit the bellows, wherein the top end cap is in a first position when the bellows is inflated via the nozzle, and the skin is configured to hold the top end cap in a second position and constrain the bellows to a predetermined rigid three-dimensional shape when the top end cap is adjusted from the first position to the second position.

12. The method of producing a skin-constrained inflatable bellows of claim 11, further comprising: assembling one or more inflatable chambers, wherein each of the one or more inflatable chambers is formed from one or more top portions and one or more bottom portions; and sealing each of the one or more top portions to one of the one or more bottom portions around a perimeter edge, wherein the perimeter edge defines a radially extending bellows flange.

13. The method of producing a skin-constrained inflatable bellows of claim 12, further comprising: masking the one or more top portions and the one or more bottom portions with a removable mask; and as a result of the masking, heat sealing each of the one or more top portions to one of the one or more bottom portions around the perimeter edge only, wherein each of the one or more top portions includes one or more slots and each of the one or more bottom portions includes one or more slots, and the one or more slots in one or more of the top portions and the bottom portions allow airflow while maintaining the shape and structural integrity of the bellows.

14. The method of producing a skin-constrained inflatable bellows of claim 13, further comprising: folding the one or more top portions and the one or more bottom portions to define a folded portion of the bellows, the folded portion extending in an axial direction between a perimeter edge of the top end cap and a perimeter edge of the bottom end cap, wherein the folded portion of the bellows includes one or more folds that reduce a bellows stiffness of the skin-restrained inflatable bellows system in an axial direction.

15. The method of producing a skin-restrained inflatable bellows of claim 14, further comprising: equipping the non-extensible skin with a plurality of bellows attachment features at predetermined locations aligned with one or more of the bellows flanges and the top and bottom end caps.

16. The method of producing a skin-restrained inflatable bellows of claim 15, further comprising: attaching the non-extensible skin to one or more of the radially extending bellows flanges at one or more of the plurality of bellows attachment features.

17. The method of producing a skin-restrained inflatable bellows of claim 15, wherein: the bellows is formed from a material comprising one or more of: silicone, thermoplastic polyurethane, or thermoplastic polyurethane coated fabric; and the bellows attachment features are formed on the non-extensible skin from a thermoplastic polyurethane impregnation of the non-extensible skin material; and the removable mask is formed from a material comprising one or more of: paper, glassine, glycerin, and paper soap, wherein the removable mask is soluble in a solvent that does not react with thermoplastic polyurethane, wherein the solvent comprises one or more of: water, acetone, and alcohol.

18. The method of producing a skin-restrained inflatable bellows of claim 11, further comprising: fully encapsulating the bellows with the non-extensible skin to provide a smooth outer surface when the skin-restrained inflatable bellows system is fully inflated, wherein the non-extensible skin is replaceable, and wherein different shapes of replaceable non-extensible skin constrain the bellows to define different inflated three-dimensional geometries of the fully inflated skin-restrained inflatable bellows system.

19. The method of producing a skin-restrained inflatable bellows of claim 18, further comprising: producing a non-linear rigid three-dimensional shape of a skin-restrained inflatable bellows by providing a non-extensible skin that extends a first axial distance on a first side of the bellows and a second axial distance on a second side of the bellows that is less than the first axial distance, wherein the second side is opposite the first side.

20. An assembled skin-restrained inflatable bellows system, the system comprising: a top end cap; a bottom end cap; a bellows attached to and separating the top end cap and the bottom end cap and configured to hold a pressurized fluid between the top end cap and the bottom end cap; wherein the bellows comprises: a plurality of radially extending bellows flanges; and one or more top portions and one or more bottom portions. one or more inflatable chambers, wherein each of the one or more inflatable chambers is formed by one or more top portions and one or more bottom portions; each of the one or more top portions is sealed to one of the one or more bottom portions around a perimeter edge, wherein the perimeter edge defines a radially extending bellows flange; wherein each of the one or more top portions includes one or more slots and each of the one or more bottom portions includes one or more slots, and the one or more top portions and the one or more bottom portions are heat sealed to each other only around the perimeter edge using a removable mask, wherein the removable mask is formed from a material including one or more of: paper, cellophane, glycerin, and paper soap, wherein the removable mask is soluble in a solvent that does not react with the thermoplastic polyurethane, wherein the solvent includes one or more of: water, acetone, and alcohol, and wherein the one or more slots in the one or more top portions and bottom portions allow airflow through the one or more top portions and bottom portions while maintaining the shape and structural integrity of the bellows; wherein the one or more top portions and the one or more bottom portions define a folded portion of the bellows that extends in an axial direction between the perimeter edge of the top end cap and the perimeter edge of the bottom end cap; wherein the folded portion of the bellows includes one or more folds that reduce the bellows stiffness in an axial direction of the skin constrained inflatable bellows system; a nozzle configured to allow fluid to enter and exit the bellows; an inextensible skin attached to each of the top end cap, the bottom end cap, and to the bellows, wherein the inextensible skin includes a plurality of bellows attachment features at predetermined locations that align with one or more of the bellows flanges and the top end cap and bottom end cap; wherein one or more of the radially extending bellows flanges are attached to the inextensible skin at one or more of the plurality of bellows attachment features; wherein the bellows is formed from a material including one or more of: silicone, thermoplastic polyurethane, or thermoplastic polyurethane coated fabric; the bellows attachment features on the inextensible skin include a thermoplastic polyurethane impregnated portion of the inextensible skin material; and the bellows attachment features on the inextensible skin include a thermoplastic polyurethane impregnated portion of the inextensible skin material; and wherein, when the bellows is inflated via the nozzle, the top end cap is in a first position, when the top end cap is adjusted from the first position to a second position, the skin is configured to hold the top end cap in the second position and constrain the bellows into a predetermined rigid three-dimensional shape, wherein, when the skin constrains the fully inflated expandable bellows system, the non-extensible skin fully encapsulates the bellows and provides a smooth outer surface, and wherein, when the non-extensible skin extends a first axial distance on a first side of the bellows and a second axial distance on a second side of the bellows that is less than the first axial distance, the rigid three-dimensional shape is constrained by the skin into a non-linear shape, wherein the non-extensible skin is replaceable and different shapes of replaceable non-extensible skin constrain the bellows into different inflated three-dimensional geometries of the skin-constrained expandable bellows system.

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