Method for making an electroluminescent marking on an exterior wall of an aircraft, marking tape comprising the electroluminescent marking, and aircraft comprising the electroluminescent marking

A method for making an electroluminescent marking on an exterior wall of an aircraft, including a step of superpositioning of layers designed or configured to produce the electroluminescent marking on a first face of a flexible backing distinct from the aircraft to obtain a marking tape and a step of affixing the marking tape to the exterior wall of the aircraft. The disclosure herein also concerns a marking tape for the implementing of the method, a marking device obtained from the method, and an aircraft comprising the marking device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to co-pending French Patent Application FR 16 56112, filed Jun. 29, 2016, the content of which is incorporated by reference herein in its entirety.

TECHNICAL FIELD

The present application relates to a method for making an electroluminescent marking on an exterior wall of an aircraft, a marking tape comprising the electroluminescent marking as well as an aircraft comprising the electroluminescent marking.

BACKGROUND

An exterior wall of an aircraft comprises at least one marking such as a registration number for example. According to one embodiment, this marking is electroluminescent to remain visible at night or when weather conditions are not favorable.

U.S. Pat. No. 8,470,388 proposes one solution for making an electroluminescent marking on a backing which may be an exterior wall of an aircraft. According to this document, the marking process involves a first step of depositing a first insulating layer on the exterior wall of the aircraft, a second step of depositing a second layer of conductive paint, a third step of depositing a third electroluminescent layer, a fourth step of putting in place a power supply electrode positioned on the perimeter of the electroluminescent layer, a fifth step of depositing a fourth transparent conductive layer and a sixth step of depositing a fifth protection layer such as a varnish.

These different steps are carried out one after another on the aircraft. Given the time it takes to make and dry these different layers, this marking process has a major impact on the production sequence of an aircraft.

In order to make the marking so affixed luminescent, the second layer of conductive paint and the power supply electrode are connected by a wire network to an electrical control and power supply system positioned inside the aircraft. For this purpose, the exterior wall of the aircraft comprises at least one orifice, generally two orifices, positioned around or near the electroluminescent marking to allow the passage of the wire network. When the marking is affixed to a surface subject to an air flow (such as a wall of the fuselage), the operation of piercing modifies the surface of the aircraft which is subjected to an air flow and degrades the aerodynamic performance of the aircraft. Likewise, the presence of a wire network on the surface of the aircraft disturbs the movement of the air flow and the performance of the aircraft.

The present disclosure proposes to remedy the drawbacks of the prior art.

SUMMARY

For this purpose, the disclosure herein concerns a method of making an electroluminescent marking on an exterior wall of an aircraft, the exterior wall comprising a panel with an exterior face and an interior face and being bounded by an edge.

According to the disclosure herein, the method involves a step of superpositioning of layers designed or configured to produce the electroluminescent marking on a first face of a flexible backing distinct from the aircraft to obtain a marking tape and a step of affixing the marking tape to the exterior wall of the aircraft.

Unlike the prior art, the electroluminescent marking is made on a flexible backing independent of the aircraft and not directly on the aircraft. Thus, the electroluminescent marking is affixed to the aircraft in a single step of limited duration.

Advantageously, the marking tape comprises a second adhesive face designed or configured to be pasted against the exterior wall and the method involves a step of depositing a protection film against the second adhesive face and a step of removal of the protection film prior to the step of affixing.

Preferably, the method involves a step of affixing at least one connection tape to the exterior face of the panel as far as the edge of the panel to connect the electroluminescent marking to an electrical control and power supply system positioned inside the aircraft.

The disclosure herein likewise concerns a marking device which comprises an electroluminescent marking and which comprises a flexible backing with a first face having a superpositioning of layers designed or configured to produce the electroluminescent marking and a second face designed or configured to be pasted against an exterior face of a panel of an exterior wall of an aircraft.

Advantageously, the second face is adhesive and the marking device comprises a protection film covering the second adhesive face.

Preferably, the marking device comprises an extension designed or configured to extend on the exterior face of the panel as far as one edge of the panel in order to connect the electroluminescent marking to an electrical control and power supply system positioned inside the aircraft.

The disclosure herein also concerns a marking device comprising at least one marking tape according to the disclosure herein.

According to another characteristic, the marking device comprises at least one connection tape for connecting the marking tape to an electrical control and power supply system positioned inside the aircraft, the connection tape being configured to extend on the exterior face of the panel from the marking tape to one edge of the panel.

According to another characteristic, the marking device comprises at least one first and one second connection tape, each of them comprising at least one electrical conductor and a junction tape straddling the first and second connection tapes so as to join the conductor elements of the first and second connection tapes.

Finally, the disclosure herein also concerns an aircraft having a marking device according to the disclosure herein.

DETAILED DESCRIPTION

FIG. 1represents an aircraft10comprising among other things a fuselage12, an airfoil14, an empennage16, and nacelles18.

According to one configuration visible inFIG. 1, the aircraft10comprises an electroluminescent marking20positioned on the empennage16.

Of course, the disclosure herein is not limited to this position for the electroluminescent marking20. Thus, as illustrated inFIGS. 1 and 2, the marking20is affixed to an exterior wall22.

According to one embodiment, the electroluminescent marking20comprises at least one alphanumerical character. According to the example illustrated inFIGS. 1 and 2, the electroluminescent marking20comprises two letters “M” and “L”. Of course, the disclosure herein is not limited to this type of marking, and the electroluminescent marking may be a decoration.

In the rest of the description, an exterior wall22is a wall of the aircraft in contact with an air flow24moving on the outside of the aircraft in flight. This air flow22is represented in the form of an arrow inFIG. 2which indicates the direction of movement of the air flow24.

As an example and without limitation, the exterior wall22may be part of the fuselage12, of the airfoil14, of the empennage16or of one of the nacelles18of the aircraft.

According to one embodiment visible inFIGS. 2 and 3, this exterior wall22comprises at least one panel26with one exterior face26E and one interior face261. This panel26comprises at least one edge28. According to one configuration, the exterior wall22comprises, besides the panel26, at least one structural element30which adjoins the panel26in the area of the edge28. Depending on the case, this structural element30may be another panel, a porthole frame, or something else. The panel26and the structural element30are separated by a gap32.

According to one configuration, the edge28is disposed downstream from the electroluminescent marking20in the direction of movement of the air flow24.

In order to produce the electroluminescent marking20on the exterior wall22, a marking device34is affixed to the exterior face26E of the panel26.

This marking device34comprises at least one marking tape44comprising a flexible backing48with a first face52which bears at least one electroluminescent layer36joined by a first electrical conductor38and a second electrical conductor40to an electrical control and power supply system42positioned inside the aircraft10. The number of electroluminescent layers36and their forms are determined as a function of the desired electroluminescent marking20.

A second face54of the flexible backing48is designed or configured to be pasted against the exterior face26E of the panel26.

The electroluminescent marking20comprises a transparent protection layer65(visible inFIGS. 4 and 5) covering the marking device34and a portion of the exterior face26E of the exterior panel26.

According to one embodiment visible inFIG. 4, the marking tape44comprises, on the first face52, a superpositioning of layers comprising, starting at the first face52:a first conductive layer56;a dielectric layer58;the electroluminescent layer36;at least one power supply electrode60positioned on at least one portion of the perimeter of the electroluminescent layer36;a second transparent conductive layer62; andat least one transparent protection layer64.

As a variant, the tape34comprises at least one decoration layer66positioned on the perimeter of at least one of the electroluminescent layers36and which is inserted between the transparent protection layers64,65or between the transparent conductive layer62and the transparent protection layer64. The decoration layer66has determined forms to bring out the electroluminescent marking20and to camouflage the power supply electrodes60.

According to another variant, a coupling layer may be provided between the flexible backing48and the first conductive layer56.

As a variant, an intermediate layer able to improve the cohesion and the adherence between the other layers of the stack is inserted between the layers56,58,36,62and64of the marking tape.

The conductive layer56, the dielectric layer58, the electroluminescent layer36, the power supply electrode60, the transparent conductive layer62and the transparent protection layer64are not further described, since they may be identical to those set forth in U.S. Pat. No. 8,470,388.

As an illustration, the first conductive layer56, the dielectric layer58and the electroluminescent layer36each have a thickness between 0.02 and 0.05 mm, the second transparent conductive layer62has a thickness less than 0.015 mm and each transparent protection layer64has a thickness of the order of 0.05 mm.

According to the disclosure herein, the method of making an electroluminescent marking20on an exterior wall22of an aircraft comprises a first step of superpositioning of different layers56,58,36,62and64configured to produce the desired electroluminescent marking20on a first face52of a flexible backing48distinct from the aircraft10to produce a marking tape44and a second step of affixing the marking tape44to the exterior wall22. Thus, the different layers56,58,36,62and64, each configured to produce the desired electroluminescent marking20, are affixed to the exterior wall22of the aircraft10in a single step and not successively as in the prior art, which tends to reduce the time of the operation on the aircraft to produce the electroluminescent marking20.

Preferably, the second face54of the flexible backing48is adhesive. In this case, as illustrated inFIG. 6, the marking tape44comprises a protection film50configured to cover the second adhesive face54and to be removed in order to be able to apply the second face54against the exterior wall22of the aircraft. In this case, the method involves a step of depositing the protection film50against the second adhesive face54before or during the first step and a step of removal of the protection film50prior to the second step of affixing.

The fact of having a second adhesive face54makes it possible to simplify the second step of affixing of the marking tape44to the exterior wall22of the aircraft. The protection film50allows for protecting this second adhesive face54from the first step of fabrication of the marking tape44to the second step of affixing. Thus, the marking tape44may be stored and applied to the aircraft in a longer or shorter time after its fabrication.

According to another characteristic of the disclosure herein, the marking device34comprises an extension68in the form of a tape extending, on the exterior face26E of the panel26, from the marking tape44to the edge28of the panel, and on the interior face261of the panel26, from the edge28to a point70offset in relation to the edge28. Thus, the extension68is arranged straddling the interior261and exterior26E faces of the panel26starting from the edge28.

According to one configuration, the extension68is positioned downstream according to the direction of movement of the air flow24in relation to the marking tape44.

As illustrated inFIG. 5, the extension68is present in the form of at least one connection tape72comprising a flexible backing74with a first face76bearing at least one electrical conductor38,40and a second face78configured to be pasted against the exterior face26E of the panel26and a portion of the interior face261of the panel26.

According to one embodiment, the first face76bears the first electrical conductor38and the second electrical conductor40.

The first electrical conductor38comprises a first end joined to the first conductive layer56and a second end joined to the electrical control and power supply system42. The second electrical conductor40comprises a first end joined to the power supply electrode60and/or to the second transparent conductive layer64and a second end joined to the electrical control and power supply system42.

According to the disclosure herein, the extension68allows joining of the electroluminescent marking20to an electrical power supply system42of the aircraft by passing through a gap32provided between the panel26and an adjacent structural element30. Advantageously, the electrical power supply system42is situated in a zone of the aircraft not subjected to the air flow22when the aircraft is moving. Thus, it is not necessary to pierce the exterior wall22of the aircraft in the proximity of the marking (and thus in the air flow) for the electrical powering of the electroluminescent marking20and the aerodynamic performance of the aircraft is not disturbed.

According to one variant embodiment, the extension68is joined to the network of electrical cables of the electrical power supply system42by using a conductor fluid, optionally covered by a protective resin.

According to another variant embodiment, the extension68is joined to the network of electrical cables of the electrical power supply system42by using a connector of crimp type, whose male part is connected to the network of electrical cables and a female part is connected to the extension68.

Advantageously, the second face78is adhesive. Preferably, prior to its affixing to the exterior wall22, the connection tape72comprises a protection film80, as illustrated inFIG. 7, configured to cover the second adhesive face78and to be removed in order to apply the second face78against the exterior wall22of the aircraft.

According to one embodiment visible inFIG. 5, the connection tape72comprises a decoration layer82covered by at least one transparent protection layer84.

According to a first variant, the marking tape44and the connection tape72form one and the same tape. According to this variant visible inFIGS. 2 and 3, the marking device34comprises a single marking tape which comprises a body86having the electroluminescent marking20and an extension68with a determined length so that the extension68extends on the exterior face26E of the panel26from the marking tape44to the edge28of the panel, and on the interior face261of the panel26from the edge28onward.

According to another variant, the marking device34comprises at least one marking tape44and at least one connection tape72disposed to ensure electrical continuity between the different conductor elements of the tapes44and72. These different tapes may be juxtaposed, overlapping, and/or superimposed.

According to another variant visible inFIGS. 8 and 9, the extension68comprises at least two connection tapes72,72′ allowing for a joining of the electroluminescent marking20to the electrical power supply system42.

FIG. 9illustrates one arrangement of three tapes72,72′,88affixed to an exterior wall22of the aircraft and disposed to ensure the electrical continuity.

According to one embodiment, a first connection tape72comprises, from the exterior wall22to the outside, a first flexible backing90, a conductive layer92, a decoration layer94and a transparent protection layer96. A second connection tape72′ comprises, from the exterior wall22to the outside, a first flexible backing90′, a conductive layer92′, a decoration layer94′ and a transparent protection layer96′.

The first connection tape72comprises a first edge89and the second connection tape72′ comprises a second edge89′.

According to one configuration visible inFIG. 9, the first edge89of the first connection tape72covers the second edge89′ of the second connection tape72′.

Regardless of the configuration, the first and second edges89and89′ are close together.

To ensure the electrical continuity, the conductive layer92of the first connection tape72is not covered by the decoration layer94and the transparent protection layer96in the area of the first edge89. Likewise, the conductive layer92′ of the second connection tape72′ is not covered by the decoration layer94′ and the transparent protection layer96′ in the area of the second edge89′.

The third so-called junction tape88is configured to ensure the electrical continuity between the first and second connection tapes72and72′. This junction tape88is disposed straddling the first and second connection tapes72and72′ and it comprises a conductive layer98whose first edge98.1is configured to come into contact with the conductive layer92of the first connection tape72and whose second edge98.2is configured to come into contact with the conductive layer92′ of the second connection tape72′.

Preferably, the thickness of the conductive layer98of the junction tape88(distance separating the first edge98.1from the second edge98.2) is less than or equal to the distance separating the decoration layer94and the transparent protection layer96of the first connection tape72and the decoration layer94′ and the transparent protection layer96′ of the second connection tape72′.

The junction tape88comprises a decoration layer100which covers the conductive layer98having a width ensuring the continuity between the decoration layer94of the first connection tape72and the decoration layer94′ of the second connection tape72′.

The junction tape88comprises a transparent protection layer102which covers the decoration layer100. Preferably, the transparent protection layer102extends beyond the decoration layer100on either side of the decoration layer100in order to cover the transparent protection layer96of the first connection tape72and the transparent protection layer96′ of the second connection tape72′.

More generally, when the marking device34comprises first and second connection tapes72,72′ each of them comprising at least one electrical conductor92,92′, it likewise comprises a junction tape88straddling the first and second connection tapes72,72′ so as to join the conductor elements of the first and second connection tapes72,72′.

Advantageously, each layer as described above is present in the form of a liquid fluid able to be applied by a classical paint application technique, such as spray or brush application.