Patent Description:
Evacuation systems for aircraft typically include an inflatable device that helps passengers disembark from the aircraft in the event of an emergency or other evacuation event. The inflatable device (e.g., inflatable slide or inflatable raft) may deploy from a door sill or a side of the aircraft fuselage. The evacuation systems generally include an inflation assembly for inflating the inflatable device. The inflation assembly may include an aspirator, a pressurized cylinder, and other hardware (e.g., pressure release valves). The inflation assembly adds to the envelope size and overall weight of the evacuation system. Inflation assemblies are disclosed in <CIT> and <CIT>. <CIT> discloses a dual stage inflator for modulating the inflation rate of an air bag at between either a first or a second rate and the inflation amount between either a first or a second peak upon detection of rapid vehicle deceleration.

<CIT> discloses a multiple stage air bag inflator for protecting vehicle occupants has primary combustion chamber containing fuel and inflation gas, with pressure sensitive rupture disks allowing gas flow into surrounding annular secondary chamber before exiting through outer wall ports.

<CIT> discloses a dual chamber gas generator for inflating a vehicle inflatable restraint cushion.

<CIT> discloses an evacuation system used in aircraft, comprising an evacuation slide, and a reactant packet disposed within inflatable portion of chemically reactive material configured to react to produce gas and inflate the evacuation slide.

An inflation assembly and system for an inflatable device is provided as defined by claim <NUM>.

An evacuation system is also provided as defined by claim <NUM>.

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

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 exemplary embodiments of the disclosures, it should be understood that other embodiments may be realized and that logical changes and adaptations in design and construction may be made in accordance with this disclosure and the teachings herein. Thus, the detailed description herein is presented for purposes of illustration only and not limitation.

Also, any reference to attached, fixed, connected or the like may include permanent, removable, temporary, partial, full and/or any other possible attachment option. Surface cross hatching lines may be used throughout the figures to denote different parts but not necessarily to denote the same or different materials.

Throughout the present disclosure, like reference numbers denote like elements. Accordingly, elements with like element numbering may be shown in the figures, but may not be necessarily be repeated herein for the sake of clarity.

System program instructions and/or controller instructions may be loaded onto a tangible, non-transitory, computer-readable medium (also referred to herein as a tangible, non-transitory memory) having instructions stored thereon that, in response to execution by a controller, cause the controller to perform various operations. The term "non-transitory" is to be understood to remove only propagating transitory signals per se from the claim scope and does not relinquish rights to all standard computer-readable media that are not only propagating transitory signals per se.

Evacuation systems according to the present disclosure may include an inflatable device, for example, an evacuation slide or a life raft, and an inflation assembly configured to inflate the inflatable device. In accordance with various embodiments, the inflation assembly may include a series of pyrotechnic inflators fluidly coupled to a manifold. The gas from the pyrotechnic inflators may be output to a turbine fan fluidly coupled to the inflatable device. In accordance with various embodiments, the pyrotechnic inflators may be configured to fire sequentially. Ignition of the pyrotechnic inflators may be controlled to regulate a deployment of the inflatable. In accordance with various embodiments, a controller may be configured to send ignite signals to the pyrotechnic inflators, using a predetermined sequence, or based on sensor readings at different environmental conditions. Evacuation systems employing pyrotechnic inflators may have a decreased size and/or reduced weight as compared to traditional evacuation systems employing a charge cylinder. Additionally, inflation systems having pyrotechnic inflators may reduce or eliminate a need for inspections of the evacuation systems and, in particular, inspections of the charge cylinder, which tends to increase time between service intervals and reduce costs.

With reference to <FIG>, an exemplary aircraft <NUM> is shown, in accordance with various embodiments. Aircraft <NUM> may comprise a fuselage <NUM> having plurality of exit doors, including an exit door <NUM>. Aircraft <NUM> may include one or more evacuation systems positioned near a corresponding exit door. 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>. In various embodiments, evacuation system <NUM> may deploy in response to exit door <NUM> being opened or in response to another action taken by a passenger or crew member such as depression of a button, actuation of a lever, or the like.

With reference to <FIG>, evacuation system <NUM> is illustrated in accordance with various embodiments. Evacuation system <NUM> includes an inflatable device <NUM>. In various embodiments, inflatable device <NUM> is an evacuation slide. In <FIG>, inflatable device <NUM> (referred to hereinafter as evacuation slide <NUM>) is in the inflated, or "deployed," position. In accordance with various embodiments, evacuation slide <NUM> includes a head end <NUM> and a toe end <NUM> opposite head end <NUM>. Head end <NUM> may be coupled to an aircraft structure (e.g., fuselage <NUM> in <FIG>). In various embodiments, evacuation slide <NUM> may be employed as a life raft 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>. In response to an evacuation event (i.e., in response to deployment of evacuation slide <NUM>), underside surface <NUM> may be oriented toward an exit surface, for example, toward the ground or toward a body of water. While evacuation slide <NUM> is illustrated as a single lane slide, it is contemplated and understood that evacuation slide <NUM> may include any number of lanes.

In accordance with various embodiments, evacuation system <NUM> further includes an inflation assembly <NUM>. Inflation assembly <NUM> is configured to inflate evacuation slide <NUM> in response to deployment of evacuation system <NUM>. Inflation assembly <NUM> includes a plurality of inflators <NUM> and a manifold <NUM>. Manifold <NUM> is fluidly coupled to a turbine fan <NUM> of inflation assembly <NUM> via a conduit <NUM>. Turbine fan <NUM> is configured to pump ambient air into evacuation slide <NUM> in response to receiving fluid from conduit <NUM>. For example, turbine fan <NUM> may include one or more sets of impeller blades. The fluid from conduit <NUM> is directed in the interior and toward the impeller blades of turbine fan <NUM>. The impeller blades rotate in response to receiving fluid from conduit <NUM>. Rotation of the impeller blades causes one or more sets of fan blades within turbine fan <NUM> to rotate. Rotation of the fan blades draws ambient air into the turbine fan, the ambient air, along with the fluid from conduit <NUM>, is output into the evacuation slide <NUM>.

With reference to <FIG>, a cross-section view of an inflator <NUM> of inflation assembly <NUM> is illustrated. In various embodiments, inflator <NUM> is a pyrotechnic inflator. In this regard, inflator <NUM> includes a solid gas generator material configured to produce a gas in response to ignition of an ignitor of inflator <NUM>. In accordance with various embodiments, inflator <NUM> may include a housing <NUM> and a cylinder <NUM> located within housing <NUM>. Cylinder <NUM> includes a pressurized gas <NUM>. Pressurized gas <NUM> may be nitrogen, carbon dioxide, helium, argon, or any other suitable pressurized gas. Inflator <NUM> includes a nozzle <NUM> and an igniter <NUM>. Nozzle <NUM> may be located at a first end <NUM> of inflator <NUM>. Igniter <NUM> may be located generally at a second end <NUM> of inflator <NUM>, which is opposite first end <NUM>. Igniter <NUM> may be electrically coupled to a link <NUM>. Igniter <NUM> is configured to ignite (i.e., fire) in response to receiving an electrical signal via link <NUM>. A solid gas generating material <NUM> is located within a vessel <NUM> of inflator <NUM>, proximate second end <NUM>. Solid gas generating material <NUM> may comprise sodium azide (NaN<NUM>), ammonium perchlorate (NH<NUM>ClO<NUM>), perchloric acid (HClO<NUM>), potassium perchlorate (KClO<NUM>), sodium perchlorate (NaClO<NUM>), sodium chlorate (NaClOa), potassium chlorate (KClO<NUM>), lithium chlorate (LiClO<NUM>), and/or any suitable solid gas generating material.

Solid gas generating material <NUM> is thermally coupled to igniter <NUM>, such that firing, or ignition, of igniter <NUM> generates a chemical reaction (e.g., combustion or exothermic reduction) of solid gas generating material <NUM>, thereby generating gas <NUM>. Gas <NUM> may flow from vessel <NUM> into cylinder <NUM>. Gas <NUM> increases a pressure within cylinder <NUM>. The increased pressure may break a seal <NUM> located between cylinder <NUM> and nozzle <NUM>, thereby fluidly coupling nozzle <NUM> and cylinder <NUM>. In other words, in response to seal <NUM> breaking (or being otherwise removed from between nozzle <NUM> and cylinder <NUM>), a mixture <NUM> of pressurized gas <NUM> and gas <NUM> flows from cylinder <NUM> into nozzle <NUM>. The mixture <NUM> then exits inflator <NUM> via nozzle <NUM> and flows into an interior volume <NUM> of manifold <NUM>, with momentary reference to <FIG>.

With additional reference to <FIG>, inflation assembly <NUM> includes a series of inflators <NUM>, such as inflators <NUM><NUM>, <NUM><NUM>, <NUM><NUM>,. <NUM>N (collectively referred to as inflators <NUM>). Inflators <NUM> are fluidly coupled to interior volume <NUM> of manifold <NUM>. Manifold <NUM> includes an outlet nozzle <NUM>. Outlet nozzle <NUM> fluidly couples interior volume <NUM> to conduit <NUM> (<FIG>). In various embodiments, manifold <NUM> includes a pressure release valve <NUM>. Pressure release valve <NUM> is configured to open in response to a pressure within interior volume <NUM> exceeding a threshold pressure, thereby allowing fluid to exit interior volume <NUM> and causing the pressure within interior volume <NUM> to decrease. In various embodiments, pressure release valve <NUM> is a burst disk, comprising a thin metallic film that is configured to burst (i.e., break) open in response to a pressure within interior volume <NUM> exceeding a threshold pressure.

In accordance with various embodiments, inflation assembly <NUM> includes a controller <NUM>. Controller <NUM> is configured to control the ignition of inflators <NUM>. In this regard, inflators <NUM> may be operationally coupled to controller <NUM>. Controller <NUM> may be electrically coupled to inflators <NUM> via links <NUM>. Links <NUM> may represent a wired connection, a wireless connection, a mechanical connection (e.g., a shaft, rod, lever, conduit, cord, etc.), or any other link capable of operably coupling controller <NUM> to the igniters <NUM> (<FIG>) of inflators <NUM>. Inflators <NUM>, manifold <NUM>, and controller <NUM> may be positioned on evacuation slide <NUM> or anywhere on aircraft <NUM>. Controller <NUM> is configured to send electrical signals to the igniters <NUM> of inflators <NUM>, thereby causing the igniters to ignite and fluid mixture <NUM> to flow into interior volume <NUM>. Controller <NUM> is configured to send the signals to igniters <NUM> in response to deployment of evacuation system <NUM>.

Controller <NUM> includes one or more processors and one or more tangible, non-transitory memories <NUM> and is capable of implementing logic. The processor can be a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or a combination thereof. Controller <NUM> may control the deployment of evacuation slide <NUM> by controlling an ignition sequence of inflators <NUM>. For example, in various embodiments, controller <NUM> may control the timing of the ignite signals based on a predetermined time delay. For example, controller <NUM> may send a first ignite signal to inflator <NUM><NUM> and a second ignite signal to inflator <NUM><NUM>. Controller <NUM> may send the second ignite signal a predetermined time delay (e.g., <NUM> seconds <NUM> seconds, <NUM> seconds, etc.) after sending the first ignite signal to inflator <NUM><NUM>. Controller <NUM> may send a third ignite signal to inflator <NUM><NUM> a predetermined time delay (e.g., <NUM> seconds <NUM> seconds, <NUM> seconds, etc.) after sending the second ignite signal to inflator <NUM><NUM>.

With combined reference to <FIG> and <FIG>, the time delay between ignite signals is selected to maintain a desired pressure within interior volume <NUM> and a desired flowrate thru conduit <NUM>. The time delay is configured such that the flowrate thru conduit <NUM> generates a desired rotation per minute (RPM) of the fan in turbine fan <NUM>. In this regard, if the optimal, or desired, RPM of turbine fan <NUM> is achieved at an operating pressure of <NUM> pounds per square inch gauge (psig) (<NUM> MPa) in turbine fan <NUM>, the timing of the ignition signals will be selected such that fluid output from each newly fired inflator <NUM> maintains the pressure within interior volume <NUM> at about <NUM> psig (<NUM> MPa). As used in the previous context only, the term "about" means ± <NUM>%. The time delay and controlled pressure may also protect the downstream components from bursting due to too high an increase in sudden pressure.

In various embodiments, controller <NUM> may determine how many inflators will be ignited based on environmental conditions and/or a condition of aircraft <NUM>. In various embodiments, inflation assembly <NUM> includes one or more sensors <NUM> operably coupled to controller <NUM>. Stated differently, sensors <NUM> are in communication with controller <NUM>. Sensors <NUM> may be configured to measure environmental conditions. Sensors <NUM> may include, for example, temperature sensor(s) configured to output environmental temperature measurements to controller <NUM>, wind speed sensor(s) configured to output windspeed measurements to controller <NUM>, and/or sill height sensor(s) configured to output sill height measurements to controller <NUM>. In various embodiments, sensors <NUM> may include sill height sensors configured to determine a sill height of exit door <NUM> (with momentary reference to <FIG>) by measuring a distance between the sill of exit door <NUM> and an exit surface on which aircraft <NUM> is supported. In various embodiments, sensors <NUM> may include sill height sensors configured to determine a sill height of exit door <NUM> based on a roll and/or a pitch of aircraft <NUM>.

In various embodiments, inflation assembly <NUM> may include one or more pressure sensor(s) <NUM> operably coupled to and in communication with controller <NUM>. Pressure sensors <NUM> are configured to measure a pressure of evacuation slide <NUM>. Pressure sensors <NUM> may be located at various locations along evacuation slide <NUM>.

In accordance with various embodiments, controller <NUM> may be pre-implemented with multiple ignition (i.e., firing) sequence configurations. Controller <NUM> may choose the desired, or optimal, ignition sequence for inflators <NUM> based on output from sensors <NUM> and sensors <NUM>. In various embodiments, controller <NUM> may determine a number of inflators <NUM> to ignite (i.e., fire) based on the measurements received from sensors <NUM> and sensors <NUM>. For example, if, based on output from sensor <NUM>, controller <NUM> determines the sill height measurement is less than a predetermined threshold sill height, controller <NUM> may ignite a first number of inflators <NUM> configured to inflate evacuation slide to a first length. If controller <NUM> determines the sill height measurement is greater than the predetermined threshold sill height, controller <NUM> may ignite a second, greater number of inflators configured to inflate evacuation slide <NUM> to a second length that is greater than the first length. In various embodiments, if, based on temperature measurements output from sensor <NUM>, controller <NUM> determines the temperature measurement is greater than a threshold temperature, controller <NUM> may ignite fewer inflators <NUM> (e.g., inflators <NUM><NUM> - <NUM><NUM>), as compared to if controller <NUM> determines the temperature measurement is less than the threshold temperature. Controller <NUM> may also determine the number of inflators <NUM> to ignite based on pressure measurements from pressure sensors <NUM>. For example, if the pressure measurement is greater than a predetermined threshold pressure, controller <NUM> may ignite a first number of inflators <NUM>. If the pressure measurement is less than the predetermined threshold pressure, controller <NUM> may ignite a second, greater number of inflators. In various embodiments, controller <NUM> may continue sending ignite signals until a desired pressure measurement is achieved. In this regard, based on the measurements from sensors <NUM> and/or from pressure sensors <NUM>, controller <NUM> may choose how many inflators <NUM> to ignite to inflate evacuation slide <NUM> to a desired pressure.

Controlling the amount of fluid provided to evacuation slide <NUM> may allow for a reduction or elimination of pressure relief valves along evacuation slide <NUM>. Reducing the number of valves may decrease weight and/or a cost of the evacuation slide. Further, inflators <NUM> may be associated with longer intervals between inspection, maintenance, and overhaul as compared to charged cylinders. Longer intervals between inspection, maintenance, and overhaul tends to reduce aircraft downtime and/or decreases the costs of maintenance and replacement.

With reference to <FIG>, an inflator <NUM> is illustrated. In accordance with various embodiments, inflation assembly <NUM>, with momentary reference to <FIG>, may include one or more inflators <NUM> in place of one or more inflators <NUM>. Igniters <NUM> of inflators <NUM> may be operationally and/or electrically coupled to controller <NUM> via links <NUM>. Igniter <NUM> may be configured to ignite (i.e., fire) in response to receiving an electrical signal (e.g., an ignite signal) from controller <NUM> via link <NUM>.

In accordance with various embodiments, inflator <NUM> is a pyrotechnic inflator. In this regard, inflator <NUM> may include a solid gas generator material configured to produce a gas in response to ignition of an ignitor of inflator <NUM>. In accordance with various embodiments, inflator <NUM> includes a housing <NUM>. A solid gas generating material <NUM>, similar to solid gas generating material <NUM> in <FIG>, is located within housing <NUM>. The solid gas generating material <NUM> is thermally coupled to an igniter <NUM>. The firing, or ignition, of igniter <NUM> causes a chemical reaction (e.g., exothermic reduction or combustion reaction) of solid gas generating material <NUM>, thereby generating a gas <NUM>. In various embodiments, inflator <NUM> may include an enhancer <NUM>, for example, a powder propagator, located between igniter <NUM> and solid gas generating material <NUM>. In various embodiments, ignition of igniter <NUM> ignites enhancer <NUM>. Ignition of enhancer <NUM> causes a chemical reaction (e.g., exothermic reduction or combustion reaction) of enhancer <NUM>, which ignites solid gas generating material <NUM>, thereby causing a chemical reaction (e.g., exothermic reduction or combustion reaction) that generates gas <NUM>. Gas <NUM> may exit inflator <NUM> via orifices <NUM>. In various embodiments, gas <NUM> may flow through a filter <NUM> configured to decrease a temperature of gas <NUM>. In various embodiments, filter <NUM> may be located between solid gas generating material <NUM> and orifices <NUM>.

It should be noted that many additional functional relationships or physical connections may be present in a practical system.

Claim 1:
An inflation assembly for an inflatable device configured to be positioned, in use, at an exit door of an aircraft for deployment of the inflatable device out of the exit door and a system for controlling ignition of the inflation assembly, the inflation assembly comprising: a manifold (<NUM>) defining an interior volume (<NUM>);
a turbine fan (<NUM>) comprising a fan;
a conduit (<NUM>) to fluidly couple the manifold to the turbine fan (<NUM>);
a plurality of inflators (<NUM>) fluidly coupled to the manifold, wherein each inflator of the plurality of inflators includes:
a solid gas generating material; and
an ignitor configured to ignite in response to receiving an ignite signal, wherein the solid gas generating material is configured to generate a gas in response to an ignition of the ignitor;
the system comprising:
a controller (<NUM>); and
a tangible, non-transitory memory (<NUM>) configured to communicate with the controller, the tangible, non-transitory memory having instructions stored thereon that, in response to execution by the controller, cause the controller to perform operations comprising:
selecting by the controller, a time delay between each of a plurality of ignite signals to maintain a desired pressure within the interior volume (<NUM>) of the manifold (<NUM>) and a desired flow rate through the conduit (<NUM>) to generate a desired rotation per minute of the fan in the turbine fan (<NUM>) fluidly coupled to the manifold (<NUM>); and
sending, by the controller, a plurality of ignite signals to the plurality of inflators, each ignite signal in the plurality of ignite signals delayed by a respective time delay to maintain the desired pressure within the interior volume (<NUM>) of the manifold (<NUM>) and the desired flow rate through the conduit (<NUM>) to generate the desired rotation per minute of the fan in the turbine fan (<NUM>) fluidly coupled to the manifold (<NUM>).