Patent Description:
In aircraft, floors in passenger cabins are often carpeted for comfort and noise reduction. For passengers and crew moving about within such a space, movement across the carpet can cause electrostatic charge to build up on the carpet. If the carpet is not conductive (as is generally the case), the charges cannot flow to the surrounding aircraft structure. Passengers and crew members moving about the cabin on the carpet thus may become charged. In environments with low humidity, such as an aircraft cabin, electrostatic charge build-up can be especially prevalent. Passengers and crew then risk discharging themselves when touching conductive surfaces within the cabin.

Such electrostatic discharge (ESD) can generate an electrical field reaching several kV/m. In addition to being physically uncomfortable for a person experiencing the discharge, damage to electronic systems contacted during discharge within the cabin can occur. Unless otherwise protected against ESD, the functionality of such a system contacted during discharge within the cabin (e.g. computers, cell phones, electrical operational systems of the cabin, etc.) can be temporarily inhibited or even permanently damaged or destroyed.

Various solutions have been proposed to decrease electrostatic charge build-up on cabin carpeting. For example, this issue has been addressed by application of anti-static treatments (generally spray) to carpets. While the anti-static treatment prevents electrostatic charge build-up on the carpet, regular cleaning of the carpet can reduce the efficacy of the anti-static treatment or even remove the anti-static treatment from the carpet completely. As the carpeting of aircraft is likely to undergo regular, vigorous cleaning, the anti-static treatment will need to be re-applied regularly in order to prevent ESD effects over the long-term. As the anti-static treatment is often a chemical product in spray form, application of the anti-static treatment may face environmental constraints. This is thus not generally an economical, nor ecological solution. Prior art document <CIT> describes a web-shaped textile flooring with or without a backing of any type. The flooring comprises an effective layer capable of leading off electrostatic charges and earthed electric conductors arranged in the form of a network, characterized in that the network formed by conductors being in direct contact with each other is in direct continuous contact with the effective layer and a broader conductor strip extends in longitudinal web direction contacting the conductors of the conductor network.

Consequently, there is a desire for a solution which aids in preventing or reducing electrostatic discharge within an aircraft cabin but without at least some of the above drawbacks.

It is an object of the present technology to ameliorate at least some of the inconveniences present in the prior art.

According to the invention, there is provided an aircraft including a fuselage defining a cabin therein; and a pair of oppositely disposed wing assemblies connected to the fuselage. The fuselage includes a conductive structure; and a flooring arrangement for the cabin, the flooring arrangement including at least one insulating layer for insulating the cabin; a wire mesh disposed above the at least one insulating layer; a carpet layer disposed above the wire mesh, the carpet layer and the wire mesh being in electrically conductive contact; and at least one resistive element connected to the wire mesh, the wire mesh being electrically connected to a conductive structure of the fuselage through the at least one resistive element, characterized in that the at least one resistive element includes a first resistor electrically connected at a first location on the wire mesh, and a second resistor electrically connected at a second location on the wire mesh, the first location and the second location being disposed on opposite sides of the wire mesh.

In some embodiments, the at least one resistive element is adapted to: allow transmission, from the wire mesh to the conductive structure, of electrostatic charges developed on the carpet layer, and impede transmission, from the conductive structure to the wire mesh, of high current events experienced by the aircraft.

In some embodiments, the conductive structure includes at least portions of the fuselage.

In some embodiments, the first location and the second location are diametrically opposing corners of the wire mesh.

In some embodiments, the at least one resistive element has a resistance of at least about one mega-ohm.

In some embodiments, the at least one resistive element has a resistance equal to or less than about five mega-ohms.

As used herein, the term "about" in the context of a given value or range refers to a value or range that is within <NUM>% of the given value or range.

Embodiments of the present technology each have at least one of the above-mentioned object and/or aspects, but do not necessarily have all of them. It should be understood that some aspects of the present technology that have resulted from attempting to attain the above-mentioned object may not satisfy this object and/or may satisfy other objects not specifically recited herein.

Additional and/or alternative features, aspects and advantages of embodiments of the present technology will become apparent from the following description and the accompanying drawings.

It should be noted that the Figures are not drawn to scale, unless otherwise noted.

The present technology will now be described in connection with one or more embodiments. The discussion of any one particular embodiment or associated feature is not intended to be limiting of the present invention. To the contrary, the discussion of particular embodiments and features is intended to illustrate the breadth and scope of the present invention. There are numerous variations that fall within the scope of the claims and that will be made apparent from the discussion that follows.

With respect to various features that are discussed in connection with specific embodiments, it is noted that the features are not intended to be exclusive of one another. To the contrary, as should be apparent to those skilled in the art, several of the features may be combinable in arrangements that differ from the specific embodiments described below. Those combinations are contemplated to fall within the scope of the present invention.

The present technology will be described with respect to aircraft, but it is contemplated that all or some of the aspects of the technology could be applied to other passenger vehicles, including but not limited to: trains, automobiles, and ships. It should also be noted that the term "passenger" as used herein is meant to refer to any person traveling within an aircraft or other vehicle, including but not limited to, any traveler, rider, driver, pilot, operator, staff or crew member, and the like.

<FIG> shows a top view of a fixed-wing jet aircraft <NUM> according to the present technology. The aircraft <NUM> includes a fuselage <NUM> (the body of the aircraft <NUM>). Connected to the fuselage <NUM> are two oppositely disposed wing assemblies <NUM>, also referred to herein as wings <NUM>. The wings <NUM> produce lift and therefore flight of the aircraft <NUM> during operation. The illustrated aircraft <NUM> is simply an example of an aircraft implementing an embodiment of the present technology; it is not meant to be limiting.

The fuselage <NUM> is partially formed from a frame structure <NUM>, schematically illustrated in <FIG> as a shell structure of the fuselage <NUM>. The frame structure <NUM> provides part of the structural integrity of the fuselage <NUM> and the aircraft <NUM>. The frame structure <NUM> is formed from aluminum, although different conductive materials could be used, including but not limited to composite materials. As the frame structure <NUM> is a relatively large conductive structure <NUM>, extending along the length of the fuselage <NUM> and being made of a conductive material, the frame structure <NUM> generally serves as electrical grounding for various systems in the aircraft <NUM>. It is contemplated that grounding could be provided by a signal or current return network in embodiments where the aircraft <NUM> is formed from a composite material.

Within the fuselage <NUM> is defined a passenger cabin <NUM>, also referred to as a cabin <NUM>, portions of which are illustrated in <FIG>. There are a plurality of passenger seats <NUM> in the cabin <NUM>. The number and relative orientations of the seats <NUM> depend on the specific embodiment, and are not limited to the arrangement illustrated in the Figures. The fuselage <NUM> includes a plurality of windows <NUM> extending through to the passenger cabin <NUM> (<FIG>). The cabin <NUM> could include more or fewer windows <NUM> than is illustrated in the Figures, depending on the specific embodiment of the aircraft <NUM>.

The cabin <NUM> includes a plurality of storage bins <NUM> disposed generally above the passenger seats <NUM>. The number and form of the storage bins <NUM> depend on the specific embodiment, and are not limited to the arrangement illustrated in the Figures. In some embodiments, the storage bins <NUM> could be omitted.

Depending on the specific embodiment, the cabin <NUM> could further include additional features, including but not limited to: tables, passenger service items such as window shades, lighting systems, air control systems, sound systems, crew communication systems, and entertainment or media systems.

According to the present technology, the cabin <NUM> further includes a flooring arrangement <NUM>. With further reference to <FIG>, the flooring arrangement <NUM> provides a floor surface on which passengers can walk about the cabin <NUM>, as well as a plurality of insulating layers for insulating the cabin <NUM> from noise produced below the cabin <NUM> and outside the fuselage <NUM>. While only one flooring arrangement <NUM> is described as providing flooring in the cabin <NUM>, it is contemplated that a plurality of flooring arrangements <NUM> could be included in any given cabin <NUM>.

The flooring arrangement <NUM> includes a carpet layer <NUM>, with which passengers' feet in the cabin <NUM> are in contact. The carpet layer <NUM> is a top-most layer of the flooring arrangement <NUM>. The carpet layer <NUM> includes a carpet fabric layer <NUM> on top side of the carpet layer <NUM> and a carpet backing <NUM> to provide stiffness and durability to the carpet fabric layer <NUM>.

The carpet fabric layer <NUM> is formed from a mixture of natural and artificial fiber materials, specifically wool and nylon. Depending on the specific embodiment, the carpet fabric layer <NUM> could be made from one or a mixture of different materials, including but not limited to wool and nylon. The carpet backing <NUM> is a flame retardant synthetic latex mesh to which the carpet fabric layer <NUM> is weaved. Depending on the embodiment, the carpet backing <NUM> could instead be glued or otherwise attached to the carpet fabric layer <NUM>. It is contemplated that the carpet backing <NUM> could be made from one or more different materials, depending on the embodiment. It is further contemplated that the carpet fabric layer <NUM> and the carpet backing <NUM> could be integrally connected, where the carpet fabric layer <NUM> is fused to and extends upward form the carpet backing <NUM>.

The flooring arrangement <NUM> includes several insulating and protective layers between the carpet layer <NUM> and the structural surface of the fuselage <NUM> extending under the cabin <NUM>. As is mentioned above, the insulating layers aid in insulating the interior space of the cabin <NUM> from noise below the cabin <NUM> and from outside of the fuselage <NUM>. It is contemplated that the flooring arrangement <NUM> could include more or fewer insulating layers than is described below for the present embodiment.

According to the illustrated embodiment schematically displayed in <FIG>, the flooring arrangement <NUM> includes, in descending order from beneath the carpet layer <NUM>: a wire mesh <NUM>, an underlay composition <NUM>, a water-proof membrane <NUM>, and a damping layer <NUM>. It is contemplated that the flooring arrangement <NUM> could include additional layers depending on the specific embodiment. It is also contemplated that details of the underlay composition <NUM>, the water-proof membrane <NUM>, and/or the damping layer <NUM> could vary depending on the embodiment. It is also contemplated that the order of the various layers <NUM>, <NUM>, <NUM> could vary depending on the embodiment. The wire mesh <NUM>, disposed immediately below the carpet layer <NUM>, will be described in more detail below.

The underlay composition <NUM> provides cushioning under the carpet layer <NUM> for comfort of the passengers, as well as vibrational and acoustic isolation from the structure of the fuselage <NUM> below the cabin <NUM> and from the exterior of the aircraft <NUM>. In the present embodiment, the underlay composition <NUM> is formed from three non-conductive layers: two underlay layers <NUM> and a vinyl isolator layer <NUM> sandwiched therebetween. The underlay layers <NUM> are fabricated from silicone foam, but different embodiments could use one or more different materials.

Immediately below the underlay composition <NUM> is the waterproof membrane <NUM>. The flooring arrangement <NUM> includes the water-proof membrane <NUM> to aid in impeding water infiltrations or condensation from below the flooring arrangement <NUM>. In some cases, the waterproof membrane <NUM> could aid in preventing condensation occurring on the damping layer <NUM> from reaching the carpet layer <NUM> and seeping into the cabin <NUM>. Similarly, the water-proof membrane <NUM> aids in impeding water spills or infiltrations from within the cabin <NUM> from reaching areas of the fuselage <NUM> under the flooring arrangement <NUM>.

In the present embodiment, the waterproof membrane <NUM> is formed from a thin sheet of polyurethane, although this is simply one non-limiting example. It is contemplated that other membranes could be used, depending on the specific embodiment. In some embodiments, it is also contemplated that the water-proof membrane <NUM> could be omitted. In some cases, another layer of the flooring arrangement <NUM> could be water-proof or could integrally include a water-proof membrane or material. While the layer <NUM> is specifically water-proof in the present embodiment, it is contemplated that the layer <NUM> included in the flooring arrangement <NUM> could have a different resistance to water or liquid penetration. For instance, the layer <NUM> could be water-resistant and/or water-repellent.

The damping layer <NUM> is disposed immediately beneath the water-proof membrane <NUM>. The damping layer <NUM> is included for aiding in reducing noise and structural vibration from being transmitted into the cabin <NUM> through the floor arrangement <NUM>. In the present embodiment, Deltane <NUM> is used as the damping layer <NUM>. It is contemplated that other materials or products could be used, depending on the specific embodiment.

The wire mesh <NUM> of the flooring arrangement <NUM> will now be described in more detail with further reference to <FIG>, where the wire mesh <NUM> is illustrated schematically. While referred to herein simply as the "wire mesh", it is also known as welded wire mesh, wire screen, and welded wire fabric In an example that does not fall within the scope of the claims, the wire mesh <NUM> could be implemented using metal grating. Alternatively, the wire mesh <NUM> could be implemented using ermetal mesh sheet for example. In examples that do not fall within the scope of the claims, the wire mesh <NUM> could be weaved into the carpet fabric layer <NUM> or integrated into the carpet backing <NUM>. It is further contemplated that the wire mesh <NUM> could be implemented in the form of a conductive sheet disposed immediately below the carpet layer <NUM>, depending on the specific embodiment. The specific form of the conductive layer <NUM> could depend on various factors, including but not limited to: material of the layer <NUM>, materials present in the carpet layer <NUM>, and weight concerns for the overall flooring arrangement <NUM>.

The wire mesh <NUM> is formed from metal wires loosely woven and welded together to form a sheet-like structure. While illustrated as being formed from wires oriented in two orthogonal directions, it is contemplated that the wire mesh <NUM> could have a variety of weave or overlay patterns. In the present embodiment, the metal wires are fabricated from anodized aluminum, but it is contemplated that the wire mesh <NUM> could be formed from one or different materials, including but not limited to: copper, plated nickel, and other low resistance materials treated to prevent corrosion. In the interest of minimizing weight added to the overall aircraft <NUM> by the wire mesh <NUM>, the wires forming the wire mesh <NUM> are thin wires forming a <NUM> by <NUM> grid form in the present embodiment. It is contemplated that the grid formed by the wire mesh <NUM> could include a spacing of greater or less than <NUM> between wires. This is simply one non-limiting example, however, and larger wires or conductive material could be used in different embodiments.

The wire mesh <NUM> is disposed immediately below the carpet layer <NUM>, between the carpet layer <NUM> and the cushioning and insulating layers <NUM>, <NUM>, <NUM>. The wire mesh <NUM> forms a conductive layer in direct contact with the carpet layer <NUM>, such that electrostatic charges that build up on the carpet layer <NUM> can conduct into the wire mesh <NUM>. As charges cannot generally conduct laterally across the carpet layer <NUM>, the wire mesh <NUM> contacts a bottom side of the carpet layer <NUM> across at least a majority of the width and length of the carpet layer <NUM>.

The flooring arrangement <NUM> further includes electronic circuitry <NUM> for electrically connecting the wire mesh <NUM> to a conductive structure of the aircraft <NUM>. In the present embodiment, the electronic circuitry <NUM> connects the wire mesh <NUM> to the conductive frame structure <NUM>. In different embodiments, it is contemplated that the wire mesh <NUM> could connect to a different conductive structure, for instance metal structures extending under the flooring arrangement <NUM>. The electronic circuitry <NUM> includes two resistive elements, specifically two resistors <NUM>, <NUM>, electrically connected between the wire mesh <NUM> and the frame structure <NUM> of the fuselage <NUM>. The resistive elements <NUM>, <NUM> allow flow of electric charge from the wire mesh <NUM>, while preventing the free flow of rapid charges, as will be discussed in greater detail below.

The electronic circuitry <NUM> also includes a plurality of conductive wiring for connecting the resistors <NUM>, <NUM> to the wire mesh <NUM> and to the conductive frame structure <NUM>, including at least one disconnectable bonding strap for installing the flooring arrangement <NUM> in the aircraft <NUM>. The conductive wiring, which generally form short conductive paths for connecting the wire mesh <NUM> to the conductive frame structure <NUM>, are sometimes referred to as one or more jumpers. It is contemplated that the electronic circuitry <NUM> could include additional elements, depending on the particular embodiment, such as additional wiring, semiconductor elements, additional resistors, etc. It is also contemplated that one or both of the resistive elements connecting the wire mesh <NUM> to the conductive frame structure <NUM> could be replaced with different electronic elements depending on the embodiment, including but not limited to: resistor assemblies such as Wheatstone bridges, rheostats, capacitors, and diodes. It is also contemplated that additional resistive elements could be implemented depending on the embodiment.

The resistors <NUM>, <NUM> are electrically connected to different extremities of the wire mesh <NUM>. In the embodiment illustrated, one resistor <NUM> is connected to a front, right corner of the wire mesh <NUM> and the other resistor <NUM> is connected to a rear, left corner of the wire mesh <NUM>. Locating the resistors <NUM>, <NUM> at diametrically opposing corners aids in distributing the potential more uniformly across an entirety of the wire mesh <NUM>, but this is simply one example embodiment. It is contemplated that the resistors <NUM>, <NUM> could be disposed at the opposite corners, or in a different arrangement depending on the embodiment.

In the present embodiment, each resistor <NUM>, <NUM> has a resistance of no more than about <NUM> mega-ohms (MΩ), such that electrostatic charge accumulated by the wire mesh <NUM> from the carpet layer <NUM> can dissipate, through the resistors <NUM>, <NUM>, away from the wire mesh <NUM> to the conductive frame structure <NUM>. While lower resistance would allow accumulated charges to more rapidly dissipate away from the wire mesh <NUM>, it would be disadvantageous to allow discharge from the conductive frame structure <NUM> to the wire mesh <NUM>, especially for incidents of high current events and/or rapid electric impulses, i.e. lightning strikes on the aircraft <NUM> that may conduct through the conductive frame structure <NUM>. In order to impede current flow due to electric impulses from the conductive frame structure <NUM>, in the present embodiment each resistor <NUM>, <NUM> has a resistance of at least about <NUM> MΩ. As such, incidents of high current, short electric impulse, such as lightning strikes, that impact the aircraft <NUM> are impeded from propagating from the conductive frame structure <NUM> to the wire mesh <NUM>.

While in the present embodiment of the aircraft <NUM>, the resistance of the resistive elements <NUM>, <NUM> is limited to between about <NUM> and <NUM> MΩ, it is contemplated that this range may change depending on various details of a given embodiment. Several factors of the design of specific embodiments could impact the particular resistances to be used, including but not limited to: material composition of the wire mesh <NUM>, material composition and/or arrangement of the frame structure <NUM>, material composition of the carpet layer <NUM>, and details related to the specific equipment risks of a given embodiment. In some embodiments, for example, each resistive element could have a minimum resistance of a few micro-ohms (mΩ), and in some embodiments a maximum resistance of up to about <NUM> MΩ.

It should be noted that in some embodiments of the aircraft <NUM>, the frame structure <NUM> may be non-conductive (i.e. fabricated from non-conductive material). In such a case, it is contemplated that the wire mesh <NUM> and the resistive elements <NUM>, <NUM> could be connected to another conductive or grounding structure of the aircraft <NUM>.

Claim 1:
An aircraft (<NUM>) comprising:
a fuselage (<NUM>) defining a cabin (<NUM>) therein; and
a pair of oppositely disposed wing assemblies (<NUM>) connected to the fuselage (<NUM>),
the fuselage (<NUM>) comprising:
a conductive structure (<NUM>); and
a flooring arrangement (<NUM>) for the cabin (<NUM>), the flooring arrangement (<NUM>) comprising: at least one insulating layer for insulating the cabin (<NUM>);
a wire mesh (<NUM>) disposed above the at least one insulating layer;
a carpet layer (<NUM>) disposed above the wire mesh (<NUM>), the carpet layer (<NUM>) and the wire mesh (<NUM>) being in electrically conductive contact; and
at least one resistive element (<NUM>, <NUM>) connected to the wire mesh (<NUM>),
the wire mesh (<NUM>) being electrically connected to the conductive structure (<NUM>) of the fuselage (<NUM>) through the at least one resistive element (<NUM>, <NUM>), characterized in that the at least one resistive element (<NUM>, <NUM>) comprises:
a first resistor (<NUM>) electrically connected at a first location on the wire mesh (<NUM>); and
a second resistor (<NUM>) electrically connected at a second location on the wire mesh (<NUM>),
the first location and the second location being disposed on opposite sides of the wire mesh (<NUM>).