Patent Description:
In the event of an emergency landing, aircraft typically have one or more evacuation assemblies, such as inflatable evacuation slides, that can be deployed to facilitate safe evacuation of passengers and crew. Qualification and development testing for aircraft systems, such as evacuation slides, typically includes high wind angle determination. High wind angle is typically defined as the wind angle at which the evacuation slide experiences an increased, and/or its greatest, lateral toe end displacement, head end twisting, and/or toe end gap (i.e., space between the toe end the exit surface). Approximately <NUM>% of tests conducted during qualification and development are wind deployment tests to determine the high wind angle and/or to stabilize the deployment characteristics of the evacuation slide under high wind conditions.

Head end twist and toe end displacement are generally dependent on a stiffness of the joining region of evacuation slide to a girt bar, as the joining region is the location where the hinging/pivoting of the evacuation slide occurs. In this regard, the angle of twist and/or lateral displacement of the evacuation slide, during wind testing, is driven by the stiffness of the joining region. Current joining regions typically include a fabric girt sleeve. The girt sleeve is joined at one end to head end tube(s) of the evacuation slide and is connected (e.g., wrapped around) at the other end to the girt bar, which is coupled to the aircraft fuselage. The girt sleeve exhibits very little resistance to bending or torsion, thereby allowing the girt sleeve to twist and/or buckle in response to twisting and lateral loads applied during the wind testing. Twisting and/or buckling of the girt sleeves allows the evacuation to twist and/or translate laterally, thereby creating high displacements and possible failure of the wind qualification tests. <CIT> relates to evacuation systems for an aircraft. <CIT> relates to an evacuation system with an extendable head end.

An evacuation slide is provided in claim <NUM>. The evacuation slide comprises a sliding surface, an inflatable rail extending around a perimeter of the sliding surface, and an inflatable girt. The inflatable rail includes a head end tube, a toe end tube longitudinally opposite the head end tube, a first longitudinal tube extending between the head end tube and the toe end tube, and a second longitudinal tube extending between the head end tube and the toe end tube. The inflatable girt is coupled to the head end tube.

The inflatable girt is fluidly coupled to the head end tube. The inflatable girt comprises a sleeve section defining a plurality of first inflatable chambers, an upper section coupled to the sleeve section and defining a plurality of second inflatable chambers, and a lower section coupled to the sleeve section and the upper section and defining a plurality of third inflatable chambers.

The upper section, the lower section and the sleeve section meet at a junction. The upper section extends from the junction to the sliding surface. The lower section extends from the junction to an underside surface opposite the sliding surface. The sleeve section extends from the junction away from the head end tube.

In various embodiments, an end of the sleeve section opposite the junction forms a bar loop. In various embodiments, the plurality of second inflatable chambers is fluidly connected to the head end tube.

In various embodiments, the sleeve section includes a first fabric panel forming a first exterior surface and a first interior surface of the sleeve section, a second fabric panel forming a second exterior surface and a second interior surface of the sleeve section, and a plurality of sleeve section seams bonding the first fabric panel to the second fabric panel.

In various embodiments, the upper section includes a first outer fabric panel forming a first upper exterior surface and a first upper interior surface of the upper section, a first inner fabric panel forming a second upper exterior surface and a second upper interior surface of the upper section, and a plurality of upper section seams bonding the first outer fabric panel to the first inner fabric panel.

In various embodiments, the lower section includes a second outer fabric panel forming a first lower exterior surface and a first lower interior surface of the lower section, a second inner fabric panel forming a second lower exterior surface and a second lower interior surface of the lower section, and a plurality of lower section seams bonding the second outer fabric panel to the second inner fabric panel.

An evacuation assembly is also disclosed herein. In accordance with various embodiments, the evacuation assembly may comprise a compressed fluid source, an evacuation slide in fluidly coupled to the compressed fluid source, and an inflatable girt coupled a head end of the evacuation slide.

In various embodiments, an end of the sleeve section forms a bar loop.

A more complete understanding of the present disclosure, however, may best be obtained by referring to the detailed description and claims when considered in connection with the drawing figures.

The detailed description of exemplary embodiments herein makes reference to the accompanying drawings, which show exemplary embodiments by way of illustration. While these exemplary embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosures, it should be understood that other embodiments may be realized.

With reference to <FIG>, an aircraft <NUM> is shown. Aircraft <NUM> includes a fuselage <NUM> having plurality of exit doors, including an exit door <NUM>. Aircraft <NUM> includes one or more evacuation systems positioned near a corresponding exit door <NUM>. For example, aircraft <NUM> includes an evacuation system <NUM> positioned near exit door <NUM>. In the event of an emergency, exit door <NUM> may be opened by a passenger or crew member of aircraft <NUM>. Evacuation system <NUM> may deploy in response to exit door <NUM> being opened and/or in response to another action taken by a passenger or crew member such as, for example, depression of a button or actuation of a lever. While evacuation system <NUM> is disclosed as deploying from exit door <NUM>, it is further contemplated and understood that evacuation system <NUM> may deploy from other locations. For example, evacuation system <NUM> may deploy from a wing of aircraft <NUM>.

With reference to <FIG>, evacuation system <NUM> is illustrated in a deployed position. In accordance with various embodiments, evacuation system <NUM> includes an inflatable evacuation slide <NUM>. Evacuation slide <NUM> may be deployed from an aircraft, such as aircraft <NUM> in <FIG>. Evacuation system <NUM> may further include a compressed fluid source <NUM>. Compressed fluid source <NUM> is fluidly coupled to evacuation slide <NUM>. Compressed fluid source <NUM> is configured to provide a pressurized gas to inflate evacuation slide <NUM>.

The evacuation slide <NUM> includes a head end <NUM> and a toe end <NUM>. Toe end <NUM> is disposed longitudinally opposite the head end <NUM> such that a longitudinal axis of the evacuation slide <NUM> extends from the head end <NUM> to the toe end <NUM>. As used herein, the "lateral" direction refers to directions approximately perpendicular to the longitudinal axis of the evacuation slide <NUM>. As used in the previous context only, "approximately perpendicular" means ± <NUM>° from perpendicular.

Upon deployment of evacuation slide <NUM>, toe end <NUM> translates away from the head end <NUM> and the aircraft <NUM> (<FIG>) and contacts an exit surface <NUM>. Exit surface <NUM> may a ground surface or exit surface <NUM> may be a water surface in the event of a water landing. Evacuation slide <NUM> includes a sliding surface <NUM> and an underside surface <NUM> opposite sliding surface <NUM>. Sliding surface <NUM> extends from head end <NUM> to toe end <NUM>. During an evacuation event, underside surface <NUM> is oriented generally towards exit surface <NUM> and sliding surface <NUM> is oriented generally away from exit surface <NUM>. Evacuation slide <NUM> includes a first (or upper) rail <NUM>. First rail <NUM> may extend generally around a perimeter of sliding surface <NUM>. In this regard, first rail <NUM> may define sliding surface <NUM>. First rail <NUM> includes a first longitudinal tube <NUM>, a second longitudinal tube <NUM>, a head end tube <NUM>, and a toe end tube <NUM>. Head end tube <NUM> forms head end <NUM> of evacuation slide <NUM>. Toe end tube <NUM> forms toe end <NUM> of evacuation slide <NUM>. First and second longitudinal tubes <NUM>, <NUM> each extend between head end tube <NUM> and toe end tube <NUM>. In various embodiments, evacuation slide <NUM> may also include a second (or lower) rail <NUM>. Second rail <NUM> is located generally between first rail <NUM> and exit surface <NUM>, upon deployment of evacuation slide <NUM>.

The evacuation slide <NUM> includes an inflatable girt <NUM>. Inflatable girt <NUM> is coupled to head end <NUM> of evacuation slide <NUM>. Inflatable girt <NUM> is also coupled to (e.g., wrapped around) a girt bar <NUM>. Girt bar <NUM> is attached to an aircraft structure (e.g., the fuselage, a door frame, etc.) of aircraft <NUM>, in <FIG>. In this regard, inflatable girt <NUM> is coupled to the aircraft structure via girt bar <NUM>. Evacuation slide <NUM> is coupled to the aircraft structure via its attachment to inflatable girt <NUM>.

With reference to <FIG>, additional details of inflatable girt <NUM> are illustrated. The inflatable girt <NUM> includes an upper section <NUM>, a lower section <NUM>, and a sleeve section <NUM>. Upper section <NUM>, lower section <NUM> and sleeve section <NUM> meet one another at a junction, or seam, <NUM>. Upper section <NUM> extends from junction <NUM> and from lower section <NUM> and sleeve section <NUM> to sliding surface <NUM>. Lower section <NUM> extends from junction <NUM> and from upper section <NUM> and sleeve section <NUM> to underside surface <NUM>. Sleeve section <NUM> extends from junction <NUM> and from upper section <NUM> and lower section <NUM> away from head end tube <NUM>. Upper section <NUM> and lower section <NUM> may be coupled to head end tube <NUM>. For example, upper section <NUM> and lower section <NUM> may be bonded to head end tube <NUM>. In various embodiments, upper section <NUM> and lower section <NUM> may form a tube loop <NUM> through which head end tube <NUM> is located.

An end <NUM> of sleeve section <NUM> forms a bar loop <NUM> configured to receive girt bar <NUM>. In this regard, inflatable girt <NUM> and evacuation slide <NUM> are coupled to the aircraft structure by locating girt bar <NUM> through bar loop <NUM>. In various embodiments, bar loop <NUM> is maintained by a lace or cord <NUM>. Cord <NUM> may be in a daisy chain or speed lacing configuration. In this regard, cord <NUM> may be configured in a series of loops, with each loop extending through an opening in sleeve section <NUM> and through an adjacent loop in the series. After a plurality of loops have been threaded together in this manner, a pin, or other securement structure, <NUM> may close the daisy chain. The cord <NUM> unlaces in response to removal, or an uncoupling, of the pin <NUM> from cord <NUM>. In other words, pulling (i.e., removing) the pin <NUM> from the final loop releases cord <NUM>, thereby opening bar loop <NUM>. The opening of bar loop <NUM> releases girt bar <NUM> from sleeve section <NUM>. Stated differently, releasing cord <NUM> uncouples the inflatable girt <NUM> and the evacuation slide <NUM> from the aircraft structure.

As described in further detail below, each of upper section <NUM>, lower section <NUM> and sleeve section <NUM> define a plurality of inflatable chambers. In accordance with various embodiments, the inflatable chambers may be fluidly connected to the head end tube <NUM>. In this regard, inflatable girt <NUM> is configured to be inflated during inflation of evacuation slide <NUM>. Stated differently, inflatable girt <NUM> may be inflated via the fluid provided by compressed fluid source <NUM>, in <FIG>. In the inflated state, the pressure within inflatable girt <NUM> tends to resist bending and/or twisting loads, and in particular, tends to prevent twisting of head end <NUM> about the longitudinal axis of evacuation slide <NUM> and/or lateral displacement of toe end <NUM> (<FIG>) during high wind conditions and/or during wind qualification tests. While evacuation slide <NUM> is illustrated as a single lane slide, it is contemplated and understood that inflatable girt <NUM> may be employed on any type of evacuation slide. In this regard, inflatable girt <NUM> may be used with a dual, or multi, lane slide and/or on an over wing slide. For example, an over wing slide may include a slide section and a ramp section extending between the head end of the slide section and the exit door, and inflatable girt <NUM> may be coupled between the aircraft structure and the end of the ramp section, proximate the exit door.

<FIG> illustrates inflatable girt <NUM> in an inflated state. <FIG> illustrates inflatable girt <NUM> in a deflated state. <FIG> illustrates a cross-section view, taken along the line 4C-4C in <FIG>, of sleeve section <NUM> of inflatable girt <NUM>, with inflatable girt <NUM> in the inflated state. <FIG> illustrates a cross-section view, taken along the line 4D-4D in <FIG>, of upper section <NUM> of inflatable girt <NUM>, with inflatable girt <NUM> in the inflated state. <FIG> illustrates a cross-section view, taken along the line 4E-4E in <FIG>, of lower section <NUM> of inflatable girt <NUM>, with inflatable girt <NUM> in the inflated state. With combined reference to <FIG>, <FIG>, in accordance with various embodiments, sleeve section <NUM> defines a plurality of first inflatable chambers <NUM> (<FIG>), upper section <NUM> defines a plurality of second inflatable chambers <NUM> (<FIG>), and lower section <NUM> defines a plurality of third inflatable chambers <NUM> (<FIG>).

With particular reference to <FIG>, and <FIG>, first inflatable chambers <NUM> may be formed by a first fabric panel <NUM> and a second fabric panel <NUM>. First fabric panel <NUM> and second fabric panel <NUM> generally form sleeve section <NUM>. In this regard, first fabric panel <NUM> forms a first exterior surface <NUM> and a first interior surface <NUM> of sleeve section <NUM>, and second fabric panel <NUM> forms a second exterior surface <NUM> and a second interior surface <NUM> of sleeve section <NUM>. First exterior surface <NUM> is opposite and oriented away from first interior surface <NUM>. Second exterior surface <NUM> is opposite and oriented away from second interior surface <NUM>. First interior surface <NUM> is oriented toward second interior surface <NUM>. First interior surface <NUM> and second interior surface <NUM> may include an impermeable coating. For example, a polyurethane or other air retentive material may be applied to first interior surface <NUM> and second interior surface <NUM>. First fabric panel <NUM> is bonded to second fabric panel <NUM> at sleeve section seams <NUM>. Sleeve section seams <NUM> define, at least, a portion of each first inflatable chamber <NUM>. In this regard, sleeve section seams <NUM> separate adjacent first inflatable chambers <NUM>. Each sleeve section seam <NUM> may form an airtight seal (e.g., a hermetic barrier) between adjacent first inflatable chambers <NUM>. The bar loop <NUM> (<FIG>) and the openings for cord <NUM> (<FIG>) may be formed on the opposite side of the sleeve section end seam <NUM>END from first inflatable chambers <NUM>. In this regard, first inflatable chambers <NUM> remain airtight after release of cord <NUM>.

With particular reference to <FIG>, and <FIG>, second inflatable chambers <NUM> may be formed by a first outer fabric panel <NUM> and a first inner fabric panel <NUM>. First outer fabric panel <NUM> and first inner fabric panel <NUM> generally form upper section <NUM> of inflatable girt <NUM>. In this regard, first outer fabric panel <NUM> forms a first upper exterior surface <NUM> and a first upper interior surface <NUM> of upper section <NUM>, and first inner fabric panel <NUM> forms a second upper exterior surface <NUM> and a second upper interior surface <NUM> of upper section <NUM>. First upper exterior surface <NUM> is opposite and oriented away from first upper interior surface <NUM>. Second upper exterior surface <NUM> is opposite and oriented away from second upper interior surface <NUM>. First upper interior surface <NUM> is oriented toward second upper interior surface <NUM>. First upper interior surface <NUM> and second upper interior surface <NUM> may include an impermeable coating. For example, a polyurethane or other air retentive material may be applied to first upper interior surface <NUM> and second upper interior surface <NUM>. In various embodiments, first outer fabric panel <NUM> may be integral with first fabric panel <NUM>. In this regard, first outer fabric panel <NUM> and first fabric panel <NUM> may be part a single panel of fabric material. First outer fabric panel <NUM> is bonded to first inner fabric panel <NUM> at upper section seams <NUM>. Upper section seams <NUM> define, at least, a portion of each second inflatable chamber <NUM>. In this regard, upper section seams <NUM> separate adjacent second inflatable chambers <NUM>. Each upper section seam <NUM> may form an airtight seal (e.g., a hermetic barrier) between adjacent second inflatable chambers <NUM>.

With particular reference to <FIG>, and <FIG>, third inflatable chambers <NUM> may be formed by a second outer fabric panel <NUM> and a second inner fabric panel <NUM>. Second outer fabric panel <NUM> and second inner fabric panel <NUM> generally form lower section <NUM> of inflatable girt <NUM>. In this regard, second outer fabric panel <NUM> forms a first lower exterior surface <NUM> and a first lower interior surface <NUM> of lower section <NUM>, and second inner fabric panel <NUM> forms a second lower exterior surface <NUM> and a second lower interior surface <NUM> of lower section <NUM>. First lower exterior surface <NUM> is opposite and oriented away from second lower interior surface <NUM>. Second lower exterior surface <NUM> is opposite and oriented away from second lower interior surface <NUM>. First lower interior surface <NUM> is oriented toward second lower interior surface <NUM>. First lower interior surface <NUM> and second lower interior surface <NUM> may include an impermeable coating. For example, a polyurethane or other air retentive material may be applied to first lower interior surface <NUM> and second lower interior surface <NUM>. In various embodiments, second outer fabric panel <NUM> may be integral with second fabric panel <NUM>. In this regard, second outer fabric panel <NUM> and second fabric panel <NUM> may be part a single panel of fabric material. In various embodiments, second inner fabric panel <NUM> may be integral with first inner fabric panel <NUM>. In this regard, second inner fabric panel <NUM> and first inner fabric panel <NUM> may be part a single panel of fabric material. Second outer fabric panel <NUM> is bonded to second inner fabric panel <NUM> at lower section seams <NUM>. Lower section seams <NUM> define, at least, a portion of each third inflatable chamber <NUM>. In this regard, lower section seams <NUM> separate adjacent third inflatable chambers <NUM>. Each lower section seam <NUM> may form an airtight seal (e.g., a hermetic barrier) between adjacent third inflatable chambers <NUM>.

With reference to <FIG>, <FIG>, in various embodiments, first inflatable chambers <NUM> are fluidly connected to second inflatable chambers <NUM> and/or to third inflatable chambers <NUM>. In this regard, one or more fluid paths may be formed between first inflatable chambers <NUM> and at least one second inflatable chamber <NUM> and/or between first inflatable chambers <NUM> and at least one third inflatable chamber <NUM>. In various embodiments, the flow path(s) may be formed at junction <NUM>. With additional reference to <FIG>, second inflatable chambers <NUM> are fluidly coupled to head end tube <NUM> such that fluid flows from head end tube <NUM> into second inflatable chambers <NUM>. In various embodiments, third inflatable chambers <NUM> are also fluidly coupled to head end tube <NUM> such that fluid flows from head end tube <NUM> into third inflatable chambers <NUM>. In various embodiments, third inflatable chambers <NUM> may be fluidly coupled to head end tube <NUM> via second inflatable chambers <NUM> and/or via first inflatable chambers <NUM>. In this regard, in response to deployment of evacuation slide <NUM>, fluid from compressed fluid source <NUM> (<FIG>) flows into head end tube <NUM> and from head end tube <NUM> into second inflatable chambers <NUM> and then from second inflatable chambers <NUM> into first inflatable chambers <NUM> and third inflatable chambers <NUM>. The various fluid paths between first inflatable chambers <NUM>, second inflatable chambers <NUM>, and third inflatable chambers <NUM> may be formed at junction <NUM>. In this regard, the bonding between the interior surfaces of the various fabric panels may be non-continuous along junction <NUM>. The locations along junction <NUM> where the fabric panels are not bonded together define orifices through which fluid may flow to inflate the first, second, and third inflatable chambers <NUM>, <NUM>, <NUM>. Stated differently, first, second, and third inflatable chambers <NUM>, <NUM>, <NUM> may be in fluid communication. For example, in various embodiments, first, second, and third inflatable chambers <NUM>, <NUM>, <NUM> may be part of one, interconnected fluid path, which is fluidly connected to head end tube <NUM>. The fluid connection to head end tube <NUM> causes first, second, and third inflatable chambers <NUM>, <NUM>, <NUM> to inflate in response to deployment of evacuation slide <NUM>. While first, second, and third inflatable chambers <NUM>, <NUM>, <NUM> are illustrated as extending in a generally longitudinal direction, it is contemplated and understood that one or more of first, second, and third inflatable chambers <NUM>, <NUM>, <NUM> may extend in a generally lateral direction. In this regard, inflatable girt <NUM> may be formed with one or more of first, second, and third inflatable chambers <NUM>, <NUM>, <NUM> oriented <NUM>° from the position shown in any of <FIG>, <FIG>, <FIG>.

The pressure within first, second, and third inflatable chambers <NUM>, <NUM>, <NUM> is configured to resist buckling, bending, and/or twisting of inflatable girt <NUM>. In this regard, inflatable girt <NUM> tends to make evacuation slide <NUM>, with momentary additional reference to <FIG>, less susceptible to lateral displacement of toe end <NUM>, to twisting of head end <NUM> about the longitudinal axis of evacuation slide <NUM>, and/or to separation of toe end <NUM> from exit surface <NUM> (i.e., toe gap). The pressurized inflatable girt <NUM> acts as a beam section with increased moment of inertia and torsional stiffness to reduce the bending and twist. For example, simulations have shown then when subjected to the same wind load, a slide having a standard, non-inflatable girt exhibited a <NUM>° head end twist and a lateral toe end deflection of <NUM> inches (<NUM>), while the same evacuation slide with an inflatable girt, as disclosed herein, coupled thereto experienced a <NUM>° head end twist and a toe end deflection of <NUM> inches (<NUM>).

The scope of the disclosure is accordingly to be limited by nothing other than the appended claims.

Systems and apparatus are provided herein. In the detailed description herein, references to "one embodiment", "an embodiment", "various embodiments", etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic.

Claim 1:
An evacuation slide (<NUM>), comprising:
a sliding surface (<NUM>);
an inflatable rail (<NUM>) extending around a perimeter of the sliding surface (<NUM>), the inflatable rail including a head end tube (<NUM>), a toe end tube (<NUM>) longitudinally opposite the head end tube (<NUM>), a first longitudinal tube (<NUM>) extending between the head end tube (<NUM>) and the toe end tube (<NUM>), and a
second longitudinal tube (<NUM>) extending between the head end tube (<NUM>) and the toe end tube (<NUM>); and
an inflatable girt (<NUM>) coupled to the head end tube (<NUM>), wherein the inflatable girt (<NUM>) is fluidly coupled to the head end tube (<NUM>); characterized in that
the inflatable girt (<NUM>) comprises:
a sleeve section (<NUM>) defining a plurality of first inflatable chambers (<NUM>);
an upper section (<NUM>) coupled to the sleeve section (<NUM>) and defining a plurality of second inflatable chambers (<NUM>); and
a lower section (<NUM>) coupled to the sleeve section (<NUM>) and the upper section (<NUM>) and defining a plurality of third inflatable chambers (<NUM>); and
wherein the upper section (<NUM>), the lower section (<NUM>) and the sleeve section (<NUM>) meet at a junction (<NUM>), wherein the upper section (<NUM>) extends from the junction to the sliding surface (<NUM>), wherein the lower section (<NUM>) extends from the junction to an underside surface opposite the sliding surface (<NUM>), and wherein the sleeve section (<NUM>) extends from the junction away from the head end tube (<NUM>).