WO2005051230A2 - Low profile, high pressure textile bladder system - Google Patents

Abstract

An inflatable pipe tube fabric assembly for G-suits and medical appliances consisting of a continuously woven core fabric [32] separated at a first point in one yarn direction by weaving methods into two fabric layers [38] to form a flexible fabric tube between adjacent sections of the core fabric; this process is repeated progressively to form an ssembly of multiple, adjacent fabric tubes from a single core fabric weaving process. A manifold connects the fabric tubes for increased user support when selected criteria are met.

Description

LOW PROFILE, HIGH PRESSURE TEXTILE BLADDER SYSTEM Inventors: Charles A. Howland William Halbedel Mark A. Hannigan

[0001] This application relates and claims priority to pending U.S. application ser. no. 60/524275 filed 11/21/2003.

Field of Invention:

[0002] The invention relates to a fabric constructed with multiple woven tubes which are impermeable to a pressurization fluid, and more particularly to a mechanical pressurization device consisting of a unitary fabric layer configured with multiple tubular pressure envelopes utilizing a gas or liquid filler to achieve a restricted inflation height or thickness, relative to the overall size of the inflated device.

Background:

[0003] For the purpose of this disclosure, including the claims, the following definitions are offered, and intended to be plainly interpreted in the context in which they are used. Fabric is a cloth produced by joining fibers by knitting, weaving or felting. A coated fabric is a fabric to which a coating has been applied to provide or improve its liquid or gas retention properties. A fabric bladder is an inflatable hollow structure consisting of two layers of coated fabric joined at the perimeter or about the circumference of the hollow structure so as to retain liquid or gas under pressure. A textile pipe bladder is an inflatable hollow structure consisting of a single layer of fabric incorporating tubular woven sections. Acceleration protection includes devices, garments in particular, used to counteract the effects of G- forces (inertial forces affecting a mass during a change of velocity in r direction and/or magnitude) including on the human body such as blood movement from upper extremities to lower extremities during high, positive G, aircraft maneuvers. [0004] Many of today's military aircraft accelerate so quickly and turn so rapidly that they meet or exceed the physical limits of their pilots. A new generation of higher-performance jets promises to worsen the problem, exposing the human body to 6, 8, or 12 times the normal force of gravity during flight. The human body cannot deal with these forces without the assistance of pressurization devices used to ensure the proper distribution and flow of blood to prevent impaired vision, or worse, loss of consciousness which can prove fatal if occurring in flight.

[0005] Blood pressure in the vascular system is based upon the resistance to flow. The relationship of these variables is the same as that of the analogous variables found in electrical circuitry, as defined by Ohm's law, where resistance, R, is equal to pressure (E) divided by flow (I).

[0006] Soft tissue in the lower extremities, specifically the gluteal, quadricep and gastrocnemius muscle groups provide ample reservoir space for blood to be drawn rapidly from the anterior and posterior muscle groups of the upper body due to the gravity multiples. Rapid movement of blood must be prevented to ensure stable blood pressure and blood flow back to the upper extremities. Blood flow is controlled by restricting the rate of expansion of the soft tissue, hence preventing a rapid drop in blood pressure. [0007] Traditional anti-gravitational, or "G" suits as they are called, resist tissue expansion using air-inflatable bladders in a coverall type trouser. Prior to bladder inflation, a majority of the slack in fit for these materials is taken up by a corset construction along the length of the trouser. Once the corset is properly tightened, the bladders are inflated by air to provide the tissue pressurization.

[0008] The un-inflated bladder is a flat and thin two-layer structure typically attached along its perimeter via a heatseal method. The fabrics used to make traditional G-suit bladders are coated woven nylon fabrics. These coated woven nylon fabrics have some, but relatively low, stretch characteristics compared to elastomeric materials (i.e. high stretch rubber). Whereas under inflation, the elastomeric materials continue to expand with a relatively small amount of increased pressure; the coated fabric bladders, once taught, maintain a relatively constant volume excluding fabric elongation by exchanging vertical displacement (separation of the fabric layers of the tubular envelope so as to increase the total height of the fabric envelope) for planar contraction (shrinkage of the width of the tubular envelope in the plane of the bladder fabric).

[0009] When the bladder is inflated and the fabric layers separate to produce a significant bladder height, the low stretch materials force the bladder to contract inward in the bladder plane, reducing its perimeter, to allow for the expanded height. The three dimensional change in the bladder geometry is used to apply tension to the enclosing trouser fabric and subsequently apply pressure to the soft tissue areas of concern.

[0010] A bladder system made from an elastomeric material can be configured as a floating system, where the bladder is not attached to the inside of the garment. This is feasible because the elastomer materials can conform to the available space between the trouser layers. Elastomer bladders tend not to be used, however, due to the risk of puncture.

[0011] A bladder system made from low stretch coated nylon fabrics cannot infinitely conform to the available space between the trouser layers. Such a system, if used in a floating manner, would use only one of the three dimensional changes of the bladder (bladder height). Hence a floating woven fabric bladder is not used due to the loss in pressurization efficiency. To maximize the efficiency of the woven fabric bladder system, the bladder must be attached to the garment along the perimeter of the bladder to leverage the planar contraction of the bladder. The planar contraction in these devices is significant, estimated at 35% as shown in Table I. This level of contraction is sufficient to convert an acceptably loose fit garment to a custom fitting garment under pressure. However with a two-layer single cavity bladder system, large inflation heights, typically 4-5 inches in trousers, are required to achieve this level of contraction. This degree of spatial invasion into the limited confines of an aircraft cockpit severely compromises the pilot mobility and can dangerously interfere with control devices in the cockpit.

[0012] Alternatives such as the Libelle suit, a suit using a liquid pressurization fluid, are not considered practical for large-scale implementation due to the limitations in flight duration. Optimized function of the Libelle suit rarely lasts more than 1 hour where in current warfare situations pilots must endure mission lengths in air of 8-10 hours. In addition, the cost of these custom fit suits, required to function properly are prohibitive to implement on a large scale. Lower cost air or liquid inflatable bladder systems with self limiting inflation height at inflation is highly desirable.

[0013] Fabric elongation has been excluded thus far for its contribution to the high inflation height of the bladder. Elongation in the shell fabric or bladder fabric will increase the height of the bladder and proportionately reduce the amount of contraction. A simulation of a 4" fabric based membrane was developed using a bubble inflation method to determine the biaxial response of different fabrics, comparing fiber type, fabric weight, fabric construction as well laminate products. Despite significant changes in fabric stiffness, reductions in inflation height from the baseline 4.5 oz nomex fabric were less than 50%>. In addition to the short-comings, the stiffer fabrics do not appear to be sufficiently compliant to be quiet, comfortable and easy to assemble [0014] Other alternatives are desirable which provide the necessary contraction to tighten the garment while limiting the total height of the bladder to preserve pilot comfort and function.

Summary of the Invention

[0015] The invention encompasses a specialty woven fabric and inflation distribution systems that allow a controlled, very low bladder inflation height with sufficient bladder length contraction to provide at high bladder pressure. In this invention, the bladder is separated into multiple bladder tube sections where the elongation per tube is limited by the available elongation of the fiber length over the tube perimeter. By using multiple smaller bladders linked in a continuous fabric, the bladder height can be controlled to the diameter of the tube set by the initial fabric geometry plus fiber stretch occurring due to inflation pressure. This creates a pressurized bladder tube (pipe) height significantly less than the conventional inflation bladders with equal or greater actual contraction. [0016] The loss of inflation height does not result in a loss of contraction. Standard 8" span bladders can contract a maximum of 36% if inflated to a full circular cross section. This produces an inflation height of approximately 5" in a bladder with an initial.8" span. [0017] Using the pipe bladder fabric technology, multiple bladder pipe sections are woven together, side by side to provide a continuous coverage around the soft tissue areas. As the bladder pipe is inflated by an inflation device, the width of the tube contracts by 30-35% as the tube converts from a flat strip to an elliptical or circular tube cross section. The amount of contraction over a similar span is theoretically equivalent to the traditional bladder inflated to full circular cross-section while limiting inflation height to the tube diameter which can be less than one inch. In practice, the pipe bladder may exceed the actual pressure applied to soft tissue due to the formability around soft tissue and the ability to get to circular cross section. [0018] Below in Table 1 is a summary of the planar bladder contraction for a traditional continuous span bladder, comparing the bladder length (edge to edge in the plane of the bladder heatseal) at various length (a) to height (b) ratios (assuming an elliptical shape) where the formula: a/b=inf [0019] represents a flat, un-inflated bladder where a/b is basically infinite (inf), and the formula: a/b = l [0020] represents a circle. From this analysis it is shown that independent of the tube diameter, the same planar contraction of about 35% is available for each design with the major difference being the maximum height of the bladder is reduced from about 5 inches for a prior art example to less than one inch for a 3 inch pipe circumference.

Table 1

Bladder / Pipe Number of Ellipse ratio Circum - Bladder / Bladder / Tubes / Bladder % (a/b) ference Pipe Height Pipe Width Pipes length Contraction

Traditional Inf 16 0.286 7.996 1.0 8.00 0%

Bladder 7 16 1.111 7.778 1.0 7.78 -3%

Max Height 3 16 2.394 7.183 1.0 7.18 -10%

5" 2 16 3.303 6.606 1.0 6.61 -17% 1 16 5.093 5.093 1.0 5.09 -36%

Pipe Bladder Inf 2 0.036 1.000 7.3 7.73 0% Max Height 7 2 0.139 0.972 7.3 7.54 -3% < 0.7" Height 3 2 0.299 0.898 7.3 6.99 -10% 2 2 0.413 0.826 7.3 6.47 -16% 1 2 0.637 0.637 7.3 5.09 -34%

Pipe Bladder Inf 3 0.054 1.499 5.0 7.80 0% Max Height 7 3 0.208 1.458 5.0 7.59 -3% < 1.0" Height 3 3 0.449 1.347 5.0 7.03 -10% 2 3 0.619 1.239 5.0 6.49 -17% 1 3 0.955 0.955 5.0 5.07 -35%

Brief Description of the Figures

[0021] Fig. 1 is a graph of displacement versus inflation pressure for several four inch fabric samples.

[0022] Fig. 2 is a cross section illustration showing the comparison of a traditional bladder partially inflated compared to an inflated pipe bladder.

[0023] Fig. 3 is a cross section microphoto image of a polyester pipe bladder fabric with bladder wall sections supported by wooden dowels to approximate inflated form.

[0024] Fig. 4 is a close up cross section illustration of the pipe bladder fabric of Fig. 3, illustrating the warp yarn interweaving by which the bladder pipes are interconnected.

[0025] Fig. 5 is the close up cross section illustration of the pipe bladder fabric of Fig. 4, further illustrating tube liners within the bladder pipes.

Description of Preferred Embodiment

[0026] The invention is susceptible of many embodiments. What is explained and • illustrated here are merely preferred embodiments reflecting the best mode known to the inventor for practicing the invention. The preferred embodiments and other examples described and illustrated should be interpreted as illustrative and not limiting of the invention. Application of this technology is not limited in any way to a single fiber type. For example, flame resistant fibers or fibers treated to provide flame resistance are preferred for aviation applications due to pilot safety concerns. Fiber material examples include: Meta-aramid (Nomex™, Conex™); Para-aramid (Kevlar™, Twaron™, Technora™); Liquid Crystal Polymer (Vectran™); Melamine (Basofil™); Acrylic fibers and their derivatives including carbon fibers; Polyester and its variants including fire retardant and low shrink versions; Nylon and it^'s variants including low shrink; Polypropylene; and UHMW Polyethylene (Spectra™, Dyneema™). [0027] Applicant makes no claim to the trademarks referenced here and elsewhere; references are provided as examples of brand names well-known in the industry, which are associated with the related materials.

[0028] The application for pipe bladder fabrics includes any inflatable devices for anti- gravitational applications for space and aviation, medical applications for improving circulation, stabilizing or bracing all areas of the body such as an arm, leg, foot, torso, neck, head, etc destabilized by injury, disease or surgical events. Other applications include body armor protection for law enforcement and corrections operations, riot control. Further pipe bladders have application in impact sports such as football, soccer, or hockey including padding for forearm, shin, shoulder, chest, back, elbow, knee and head protection. Other applications in flexible composite materials for various inflated or inflatable structures, inflatable craft, storage tanks, floatation devices, and protective devices intended to reduce proximity and limit or prevent exposure to shock and vibration. [0029] In addition there is broad application in apparel goods including outerwear, innerwear, glove and footwear to improve protection, comfort and thermal or even electrical insulation and isolation. While the bladder pipes of the G-suit application would normally be running lengthwise of the associated body part so that spanwise contraction of the bladder assembly is used to constrict the enclosed body part, there may be areas or applications where a degree of pipe axis flexing or bending to permit conformance of the pipe bladder device to the object is required.

[0030] This disclosure is therefore directed to a material system that can be tailored and applied to any of these and similar products. This disclosure is intended to cover the use of this material system in these and related products and hybrids. This disclosure is intended to include the integration of these fabrics into these products by means of stitching, adhesives, lamination, calendaring, mechanical assembly, molding by pressure and/or heat in single part and/or multipart molds or mandrels or by autoclaving or other known means. The inventors are well aware of the application of these technologies to produce the listed products and provide the listed utility and functionality.

The most visible aspect of the invention is the distinction between cross sections of a typical embodiment pipe bladder and a conventional one-cell bladder. Referring to Fig. 2, a cross section illustration shows the comparison of a traditional bladder 21, partially inflated, compared to an inflated pipe bladder 22, embodiment of the invention. While both have approximately the same span at the same state of inflation, the respective heights and volumes of the inflated bladders are dramatically different.

[0031] The invention in all embodiments contains a continuous fabric material constructed as a single woven fabric, sheet or web which is separated intermittently into two layers, sheets, or webs at even or uneven spacing via the weaving process such that the intermittent attachment is comprised at least of the warp yarns common to the area of attachment or single layer, referred to here as the base fabric, being divided to become the warp yarns of the two individual fabric layers, sheets or webs. The separation of the base fabric into two individual membrane layers of fabric, and the subsequent reattachment of the two membrane layers as base fabric, allows for the creation of a membrane fabric envelope or enclosure between areas of attachment. These envelopes may take the form of a hollow tube, with a cross-section formable as by inflation to fit the needs of the application. The cross section may be circular, elliptical, square, triangular or other depending on the application, and in particular on the configuration of the tubular fabric assembly and its mating inflation device hardware.

[0032] The principles of the invention have been put into practice with several different fabric materials using tube spacing ranging from 0.5" to 6" (inches), center to center. A preferred embodiment includes a woven aramid fabric with a tube perimeter of 4" producing a circular tube diameter of about 1.25", with tube spacing being slightly larger than tube diameter to accommodate the attachment area between adjacent tubes. This tube diameter allows ample space for practical inflation devices and adequate air flow for rapid inflation as needed in quickly applied and sustained high G-force applications. Similar fabrics may be made of fiber blends to optimize overall fiber properties related to flame, tear, tensile, abrasion, and chemical resistance.

[0033] Referring to Fig. 1, a chart illustrates the relative inflation heights for four inch diameter membrane fabric samples inflated at increasing pressure from 2 psi to 12 psi (pounds per square inch). Fabric variations include 3.0 oz nomex, 4.75 oz nomex, 5 oz PBI blend, 4.0 Vectran laminate, 7.0 oz Turtleskin Sport and 10 oz Vectran OceanWeave. The 4.0 oz Vectran laminate and the 7.0 oz Turtleskin Sport have the same characteristics. [0034] It should be noted that a general range of pipe or tube diameter from about 1/4 inch to 1.5 inches provides for scaling of the invention to fit a wide range of other applications as disclosed above, while still offering adequate space for practical inflation devices, associated plumbing, and adequate airflow. Tube diameters smaller and larger than this range, typically using respectively smaller and larger yarn sizes, may be useful in particular cases, but may require special provisions for inflation and/or fabric sealing. [0035] Fig. 3 is a close up cross section photo image of a polyester pipe bladder fabric 30 with base section 32 interwoven by warp yarns 34 around fill yarns 36 to bladder wall sections 38 supported by wooden dowels 39 to approximate inflated form. [0036] Fig. 4 is a cross section illustration of the pipe bladder fabric of Fig. 3, illustrating more closely the interweaving of warp yarns 34 of the two bladder wall sections 38, about fill yarns 34 by which the bladder pipes of the fabric are interconnected. [0037] It should be noted that the fill yarns in the membrane section and in the base fabric may be the same, as is illustrated in Figs. 3 and 4. In other words, the fill yarns are not necessary additive in the base fabric, as are the warp yarns, but may be varied in the weaving process as between sections of base fabric and sections of membrane fabric. While Figs. 3 and 4 illustrate a preferred base fabric width of at least three fill yarns, the fill yarn end count can be as low as 1, or it can be higher. Also, the weave pattern in the base section, in addition to having the sum of the warp yarns of the two membrane sections, can be varied from that of the membrane section if desired. [0038] The tubes may also be used for many other functions including cooling, heating, and electrical connectivity for e-textile applications; as a flexible, incrementally inflatable, geometrically sequenced, volumetric adjuster acting within a contained area of fixed volume to incrementally change the shape and the effective volume of an enclosure; or as an inflatable divider of pre-calculated displacement acting to further separate two fluid mediums. The tubes may be further configured with calibrated leakage to either or both side of the fabric through discrete openings or areas of greater porosity for limited or gradual expulsion of the tube fluid or filler for special purposes such as lubrication, aeration, mixing, catalytic reaction or other special treatment of the contact surfaces or mediums on one or both sides of the pipe tube fabric assembly device. [0039] Anyone skilled in the art of weaving and informed by this enabling disclosure can create such a fabrics. Fabric finishing may or may not include a scouring and heat setting process to clean and thermally stabilize the fabric. Fabric finishing may or may not include the application of adhesion promoters such as silanes or RFLs or other coatings determined appropriate to the application. Anyone skilled in the art of finishing and informed by this disclosure can create such fabric properties with standard finishing equipment. Fabric coating and lamination may or may not be applied to enhance the functionality of the fabric including but not limited to air holding capability for direct inflation. [0040] The application of the preferred embodiment to anti-gravitational suits is significant for several reasons, particularly for reducing profile height of the suit and improving the pressure distribution of the bladder across the soft tissue sections. The tube spacing and diameter can be tailored to specific sections of the body to provide a higher contact area between the bladder and the skin to improve pressurization distribution.

System Implementation

[0041] The use of pipe bladder fabrics requires complementary components which provide for the necessary air holding and distribution to make the inflatable bladder operational. [0042] Air holding methods can be implemented in a variety of ways via secondary devices such as elastomeric tubing liners, including tubing made from butyl rubber, latex rubber, polyurethane and/or silicone polymers. Referring to Fig. 5, there is illustrated a close up cross section of the same polyester pipe bladder fabric 30 with base section 32 interwoven by warp yarns 34 around fill yarns 36 to bladder wall sections 38; where the pipes formed by bladder wall sections 38 are configured with impermeable tube liners 50. [0043] The tubing components can be inserted into the necessary fabric tube openings and connected to each other via rigid or flexible air manifold devices. Flexible manifold devices are preferred for garment comfort.

[0044] An alternative to discrete liners 50 inserted into the pipe tubes of the fabric as in Fig. 5, is sealing the pipe bladder fabric using laminated films or specialty coatings designed or applicable to this purpose. Sealing the fabric with thermoplastic films, such as urethane, may be a preferable process or method for many applications to limit coating or adhesive migration across the surface of the fabric tube. Such films are readily available and easily applied using methods well known to those experienced in coating and laminating fabrics. Other film types may be used based on the chemical, temperature, and/or light exposure, typically ultraviolet light (UV). Other films include but are not limited to polyester (Mylar), vinyl, aramid (Kapton), and flouro-polymer (Teflon, PVDF) films. The use of laminated films has the practical advantage of lower system weight than tube liner systems and lower processing cost compared to a coated fabric solution for air holding.

[0045] Coating the fabric to be sufficiently durable and air or fluid holding may require denser fabric constructions to permit the coating to seal the fabric interstice while also preventing coating/adhesive migration across the fabric tube section. Adhesive migration across or through the fabric can inadvertently join the opposing sides of a tube or the adjoining sides of an adjacent tube resulting in a deformed or non-functional tube section. Although perfection of such a process in roll to roll processing can be difficult, methods to prevent joining of the tube walls can be employed using low surface energy separator materials such as silicone or flouropolymers. This implementation has the advantage of optimizing the overall weight of the bladder system when compared to the use of elastomer liners or film lamination.

[0046] Bladder systems using coated or laminated fabric also require air distribution devices to provide the inflation. Manifold devices are constructed in various ways using metallic, molded plastic, composite or flexible composite technology. Lighter weight materials are preferred to maximize garment comfort. Flexible manifold technology provides the best opportunity for weight and comfort optimization. [0047] In all embodiments, as will be readily understood and appreciated by those skilled in the art, a control system is herein implied and required for sensing appropriate variables such as G-loads or other biomedical parameters, or simply responding to manual command inputs, to operate the manifold to fill the fabric tubes partially or fully. [0048] The invention is susceptible of many embodiments. For example, there is a pipe tube fabric assembly comprising a continuously woven core fabric separated into two fabric layers by weaving methods and periodically rejoined as the core layer during weaving such that a single or series of hollow fabric tubes are created across either the width or length of the fabric. The fabric may have multiple hollow tubes of cross-sections that are created at equal, unequal or random spacing with equal, unequal or random cross- sectional size. The top layer construction may be made from similar yarns and weave pattern as the bottom layer construction including filament, spun, high modulus, low modulus, high temperature or low temperature fibers. Or the top layer construction may be produced with different yarns than the bottom layer construction including fiber of continuous filament or staple spun or a combination thereof, high or low modulus or a combination thereof, and high or low temperature or a combination thereof. The top layer weave pattern may be different than the bottom layer weave pattern including filament yarns, spun staple yarns, high modulus fiber, low modulus fiber, high temperature fiber or low temperature fibers. The top layer weight and density is different than the bottom layer weave pattern including filament yarns, spun staple yarns, high modulus fiber, low modulus fiber, high temperature fiber or low temperature fibers. The tubes formed by the top and bottom layers may be sealed by a coating or film to allow inflation from any point or points along the length or end of the fabric tube. The fabric and/or the tube portion may be sealed by a urethane based coating or film, by a polyester based coating or film, by an aramid based coating or film, or by a flouropolymer based coating or film. There may be an inflatable device such as a rubber tube liner inserted into one or more of the hollow tube sections to allow the tube sections to be expanded to a size set by the fabric geometry. There may be a flexible or rigid manifold attached by necessary means to allow for inflation of the multiple tubes sequentially or simultaneously. [0049] There are yet other embodiments and examples to be disclosed. For example, there is a pipe tube fabric assembly consisting of a first section of a continuously woven core fabric separated at a first point in one yarn direction by weaving methods into two fabric layers and rejoined at a second point in the same yarn direction as a second section of the core fabric such that the two fabric layers form an flexible fabric tube between adjacent sections of the core fabric. The fabric assembly may consist of multiple fabric tubes interspersed with respective sections of the core fabric. The fabric tubes may be inflatable and substantially impermeable to air. They may be configured with flexible liners that are substantially impermeable to air. The fabric assembly may include a manifold communicating with the fabric tubes and connectible to an air source. The diameter of the fabric tubes may be within the range of about 1/4 inch to 1.5 inches. The yarn direction may be the machine direction, and the sections of the core fabric may include the warp yams of both fabric layers.

[0050] The two fabric layers may be of equal length in the machine direction between adjacent sections of the core fabric. The two fabric layers may be a top layer and a bottom layer, where the top layer has the same yarn and filament type, yarn count, and weave pattern as the bottom layer. Alternatively, at least a portion of the yams of the top layer may be distinguished from at least a portion of the yams of the bottom layer by at least one of the characteristics of fiber type, modulus, and temperature range. Also, the top layer may have a different weave pattern than the bottom layer, and/or the top layer may have a different weight and density than the bottom layer.

[0051] The manifold may be configured for filling all fabric tubes concurrently, or in a desired sequence, to their partial or full volumetric potential. [0052] Furthermore, an inflatable garment incorporating the fabric assembly may be configured as an inflatable medical garment for providing additional circumferential surface area pressure around a selected area of the wearer's body, including any of the chest, abdomen, legs, arms, and neck. Yet further, a pipe tube fabric assembly may have a fabric tube inflatable with a filling fluid such as air or other liquid or gas, where at least one of the fabric layers is configured with a calibrated leakage over all or a selected surface area such that the filling fluid is transmitted at a controlled rate through the fabric layer. [0053] Note also that denser fabric constructions of a fabric assembly suitable for air or fluid holding may require weave densities in the order of 70-100 epi (ends per inch) of warp yams of 40/2 to 80/2 yam size, and 40-80 epi of fill yams of 20/1 to 50/1 fill yam size to permit the coating to seal the fabric interstice while also preventing coating/adhesive migration across the fabric tube section. The preferred coating thickness is 1-3 mils. The coating is inherently adhesive or must be augmented with an adhesive if not.

[0054] Those skilled in the art will recognize other embodiments and examples within the scope of the claims that follow, as interpreted in the context of this disclosure.

Claims

CLAIMS:

We claim: 1. A pipe tube fabric assembly comprising a first section of a continuously woven core fabric separated at a first point in one yarn direction by weaving methods into two fabric layers and rejoined at a second point in the same yarn direction as a second section of said core fabric such that said two fabric layers form an flexible fabric tube between adjacent said sections of said core fabric.

2. A pipe tube fabric assembly according to claim 1, further comprising multiple said fabric tubes interspersed with respective said sections of said core fabric.

3. A pipe tube fabric assembly according to claim 2, said fabric tubes being inflatable and substantially impermeable to air.

4. A pipe tube fabric assembly according to claim 2, said fabric tubes configured with flexible liners, said flexible liners being substantially impermeable to air.

5. A pipe tube fabric assembly according to claim 2, further comprising a manifold communicating with said fabric tubes and connectible to an air source.

6. A pipe tube fabric assembly according to claim 3, the diameter of said fabric tubes being within the range of about 1/4 inch to 1.5 inches.

7. A pipe tube fabric assembly according to claim 3, said yarn direction being the machine direction, said sections of said core fabric comprising the warp yams of said two fabric layers.

8. A pipe tube fabric assembly according to claim 3, said two fabric layers being of equal length in the machine direction between adjacent said sections of said core fabric.

9. A pipe tube fabric assembly according to claim 3, said two fabric layers comprising a top layer and a bottom layer, said top layer having the same yarn and filament type, yam count, and weave pattern as said bottom layer.

10. A pipe tube fabric assembly according to claim 3, said two fabric layers comprising a top layer and a bottom layer, at least a portion of the yarns of said top layer being distinguished from at least a portion of the yams of said bottom layer by at least one of the characteristics of fiber type, modulus, and temperature range.

11. A pipe tube fabric assembly according to claim 3, said two fabric layers comprising a top layer and a bottom layer, said top layer comprising a different weave pattern than said bottom layer.

12. A pipe tube fabric assembly according to claim 3, said two fabric layers comprising a top layer and a bottom layer, said top layer having a different weight and density than the bottom layer.

13. A pipe tube fabric assembly according to claim 3, said fabric tube sealed by a coating.

14. A pipe tube fabric assembly according to claim 13, said coating comprising one from among the group of coatings consisting of urethane based coatings, polyester based coatings, aramid based coatings, and flouropolymer based coatings.

15. A pipe tube fabric assembly according to claim 3, said fabric tube sealed by a film.

16. A pipe tube fabric assembly according to claim 15, said film comprising one from among the group of films consisting of urethane based films, polyester based films, aramid based films, and flouropolymer based films.

17. A pipe tube fabric assembly according to claim 5, configured as an inflatable garment.

18. A pipe tube fabric assembly according to claim 17, said inflatable garment configured as a G-suit for protecting occupants of vehicles including aircraft and spacecraft from excessive G loads during high speed maneuvers.

19. A pipe tube fabric assembly according to claim 5, said manifold being configured for filling all said fabric tubes concurrently.

20. A pipe tube fabric assembly according to claim 5, said manifold being configured for filling said fabric tubes in a desired sequence.

21. A pipe tube fabric assembly comprising a first section of a continuously woven core fabric separated at a first point in the machine direction by weaving methods into two fabric layers and rejoined at a second point in the same direction as a second section of said core fabric such that said two fabric layers form a flexible fabric tube between said sections of said core fabric, said fabric assembly further comprising multiple said fabric tubes interspersed with multiple said sections of said core fabric, said fabric tubes being substantially impermeable to air, said fabric assembly further comprising a manifold communicating with said fabric tubes and connectible to an air source for inflation.

22. A pipe tube fabric assembly according to claim 21, the diameter of said fabric tubes being within the range of about 1/4 inch to 1.5 inches.

23. A pipe tube fabric assembly according to claim 21, said two fabric layers comprising a top layer and a bottom layer, said top layer comprising a different weave pattern than said bottom layer.

24. A pipe tube fabric assembly according to claim 22, said fabric tube sealed by a coating.

25. A pipe tube fabric assembly according to claim 21, said fabric tube sealed by a film.

26. A pipe tube fabric assembly according to claim 21, configured as an inflatable garment, said inflatable garment configured as a G-suit for protecting occupants of vehicles including aircraft and spacecraft from excessive G loads during high speed maneuvers.

27. A pipe tube fabric assembly comprising a first section of a continuously woven core fabric separated at a first point in one yarn direction by weaving methods into two fabric layers and rejoined at a second point in the same yarn direction as a second section of said core fabric such that said two fabric layers form an flexible fabric tube between adjacent said sections of said core fabric, said fabric tube configured as inflatable and impermeable to air by one of the group of configurations consisting of: said fabric layers being woven as substantially impermeable to air; said fabric tube being configured with a flexible liner wherein said flexible liner is substantially impermeable to air; said fabric layers being sealed by an impermeable coating; and said fabric layers being treated by an impermeable film.

28. A pipe tube fabric assembly according to claim 27, the diameter of said fabric tube being within the range of about 1/4 inch to 1.5 inches.

29. A pipe tube fabric assembly according to claim 28, configured as an inflatable garment.

30. A pipe tube fabric assembly according to claim 29, said fabric assembly further comprising multiple fabric tubes interspersed with multiple sections of core fabric, and a manifold communicating with said fabric tubes and connectible to an air source, said inflatable garment configured as an inflatable medical garment for providing additional circumferential surface area pressure around a selected area of the wearer's body.

31. A pipe tube fabric assembly according to claim 1, said fabric tube being inflatable with a filling fluid, at least one of said fabric layers being configured with a calibrated leakage such that said filling fluid is transmitted at a controlled rate through said fabric layer.