PROPULSION UNIT FOR AN AIRCRAFT AND METHOD FOR OPENING A MOVABLE COWL OF SAID PROPULSION UNIT

Abstract

A propulsion unit for an aircraft is provided. The propulsion unit includes a stationary unit having at least one cowl pivotally mounted on an axis collinear with a longitudinal axis of the propulsion unit between an operating position or a maintenance position allowing access to the turbojet engine for regular maintenance operations and irregular maintenance operations. The maintenance position for irregular maintenance operations includes an opening angle of the cowl that is greater than the opening angle of the cowl to carry out regular maintenance operations. The propulsion unit further includes at least one cylinder and at least one safety connecting rod secured to the cowl and stationary unit.

Claims

1. A propulsion unit for an aircraft comprising: a stationary unit; at least one cowl pivotally mounted on an axis collinear with a longitudinal axis of the propulsion unit between at least one of a operating position and a maintenance position allowing access to the turbojet engine for regular maintenance operations and irregular maintenance operations, wherein the maintenance position for irregular maintenance operations includes an opening angle of the at least one cowl that is greater than an opening angle of the at least one cowl to carry out regular maintenance operations; at least one cylinder secured to the at least one cowl and secured to the stationary unit by means of a main fitting mounted on the stationary unit; and at least one safety connecting rod secured to the at least one cowl and the stationary unit by means of a main fitting, wherein the cylinder is sized to allow an alternative passage of the at least one cowl between at least one of an operating position and a maintenance position allowing access to the turbojet engine for regular maintenance operations, wherein the safety connecting rod is sized to maintain the at least one cowl in the maintenance position allowing access to the turbojet engine for regular maintenance operations, wherein the main fitting is sized to allow regular maintenance operations, and wherein the main fitting comprises a secondary fitting mounted on the main fitting, the secondary fitting being sized to allow irregular maintenance operations, wherein the secondary fitting supports the at least one cylinder when the at least one cowl is in the maintenance position allowing access to the turbojet engine for irregular maintenance operations.

2. The propulsion unit according to claim 1, wherein the main fitting and the secondary fitting further comprises at least one bore adapted to receive a means for holding the secondary fitting in a position allowing regular maintenance operations or in a position allowing irregular maintenance operations.

3. The propulsion unit according to claim 2, wherein the means for holding the secondary fitting on the main fitting further comprises holding rods adapted to pass at least partially through the at least one bore.

4. The propulsion unit according to claim 1, wherein the at least one safety connecting rod is mounted on the secondary fitting when the secondary fitting is positioned so as to authorize irregular maintenance operations.

5. The propulsion unit according to claim 1, wherein the at least one safety connecting rod is mounted on the stationary unit of the propulsion unit when the secondary fitting is positioned so as to authorize irregular maintenance operations.

6. The propulsion unit according to claim 1, wherein the secondary fitting has a triangular shape.

7. The propulsion unit according to claim 1, wherein the at least one safety connecting rod is mounted on an extension of the secondary fitting.

8. The propulsion unit according to claim 1, wherein the at least one cowl is selected from the group consisting of half-cowl of D-duct type thrust reverser, half-cowl of C-duct type thrust reverser, door for a thrust reverser with doors, half-cowl of fan casing of the turbojet engine, and combinations thereof.

9. A method for opening a movable cowl of propulsion unit, the method comprising: extending the cylinder until opening the cowl in a position adapted for regular maintenance operations; disconnecting the cylinder from the main fitting; positioning the secondary fitting on the main fitting; fixing the cylinder on the secondary fitting so that the cylinder absorbs forces of the cowl; disconnecting the safety connecting rod from the main fitting; and fixing the safety connecting rod on the secondary fitting.

10. The method according to claim 9, the method further comprising: extending the cylinder until opening the cowl in a position adapted for regular maintenance operations; pivoting the secondary fitting so as to at least increase a relative distance between attachment points of the cylinder and the main fitting; disconnecting the safety connecting rod from the main fitting; and fixing the safety connecting rod on at least one of the secondary fitting and the stationary unit of the propulsion unit.

Description

DRAWINGS

[0058] In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which:

[0059] FIG. 1 shows schematically a downstream portion of a propulsion unit of the prior art, in the closed position;

[0060] FIG. 2 shows schematically the downstream portion of the propulsion unit of FIG. 1, in the maintenance position;

[0061] FIG. 3 illustrates the downstream portion of the propulsion unit of the prior art in an isometric view, in which the thrust reverser is shown in the operating position;

[0062] FIG. 4 illustrates a view similar to that of FIG. 3, the thrust reverser is being shown in the maintenance position;

[0063] FIG. 5 shows in an isometric view the propulsion unit according to a first form of the present disclosure, in which the cowl of thrust reverser is in the operating position;

[0064] FIG. 6 is a detailed view of the area VI of FIG. 5;

[0065] FIG. 7 shows in an isometric view the propulsion unit of FIG. 5, in which the cowl of thrust reverser is in the maintenance position enabling access to the turbojet engine for regular maintenance operations;

[0066] FIG. 8 is a detailed view of the area VIII of FIG. 7;

[0067] FIGS. 9a to 9f illustrate the steps of the method according to the present disclosure allowing to pass from a maintenance position of the cowl of thrust reverser enabling access to the turbojet engine for regular maintenance operations to a maintenance position enabling access to the turbojet engine for irregular maintenance operations;

[0068] FIG. 10 shows in an isometric view the propulsion unit of FIG. 5, in which the cowl of thrust reverser is in the maintenance position enabling access to the turbojet engine for irregular maintenance operations;

[0069] FIGS. 11a to 11f relate to a first variant of a second form of the present disclosure; and

[0070] FIGS. 12a to 12f relate to a second variant of the second form of the present disclosure.

[0071] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

DETAILED DESCRIPTION

[0072] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

[0073] It should be noted that in the present disclosure, the terms upstream and downstream refers to the circulation of the airflow inside the propulsion unit formed by the nacelle and the turbojet engine, that is to say from left to right with reference to FIGS. 5 to 12.

[0074] Further, on all the figures, identical or similar references represent identical or similar members or sets of members.

[0075] In the present disclosure, a, stationary unit of the propulsion unit means a region of the propulsion unit which remains immobile during a passage between an operating position and a maintenance position. This region can belong to the turbojet engine or to the nacelle.

[0076] FIGS. 5 to 10 refer to a propulsion unit 101 carried out according to a first form of the present disclosure.

[0077] Reference is made to FIG. 5 showing the propulsion unit 101 in an isometric view, in which the cowl of thrust reverser is in the operating position.

[0078] The propulsion unit 101 comprises a nacelle, in a downstream portion of which is mounted a thrust reverser 107, and a turbojet engine 105 constituting a stationary unit of the propulsion unit.

[0079] The propulsion unit 101 is suspended from a fixed structure of the aircraft, for example under a wing or on the fuselage, by means of a suspension mast 103, fastened to the turbojet engine 105.

[0080] The thrust reverser 107 of the propulsion unit 101 comprises two semi-annular half-cowls 109 surrounding the downstream section of the turbojet engine 105. In FIG. 5, only one of these two half-cowls has been shown.

[0081] The thrust reverser 107 shown in FIG. 5 is of the D-duct type, but the present disclosure also applies to the thrust reversers of the C-duct type.

[0082] The half-cowl 109 of the thrust reverser 107 is mounted on a hinge 117 fixed to the suspension mast 103.

[0083] The thrust reverser 107 of the propulsion unit 101 comprises cylinders 123 called cylinders COS, which can be, for example, hydraulic, electric or pneumatic cylinders as well as safety connecting rods 129 called connecting rods HOR.

[0084] Each cylinder 123 comprises a fixed portion mounted on the main fitting 125, and a movable portion fixed to a fitting 127 mounted on the half-cowl 9 of thrust reverser, while each safety connecting rod 129 is made secured to the turbojet engine and to the movable cowl, in that each connecting rod comprises a first end fixed to the main fitting 125 and a second end fixed to a fitting 131 mounted on the half-cowl 109.

[0085] As shown in more detail in FIG. 6, illustrating an enlargement of the area VI of FIG. 5, the cylinder 123 is secured to the turbojet engine 105 by means of the main fitting 125 mounted on the turbojet engine 105. The cylinder 123 is mounted on the main fitting by means of a holding rod 133, substantially transverse to a side wall 135 of said fitting and passing through the main fitting thanks to a bore 137 passing through the thickness of the fitting 125. The safety connecting rod 129 is in turn pivotally mounted on a holding rod 139, which is also substantially transverse to the side wall 135 of said fitting and passing through the main fitting thanks to a bore 141 passing through the thickness of the fitting 125. The main fitting 125 comprises further a bore 143 passing through the thickness of said fitting.

[0086] According to the present disclosure, the main fitting 125 is sized to allow regular maintenance operations, that is to say that it has mechanical characteristics adapted to support maintenance operations authorizing access to the turbojet engine for regular maintenance operations.

[0087] The passage from an operating position to a maintenance position enabling access to the turbojet engine for regular maintenance operations is carried out by pivoting each half-cowl 109 of the thrust reverser 107 about an axis 119 substantially collinear with a longitudinal axis 121 of the propulsion unit, thanks to the hinges 117.

[0088] The pivoting of each half-cowl 109 of the thrust reverser 107 is obtained by the actuation of the cylinder 123. According to the present disclosure, the cylinder 123 is sized to allow an alternative passage between an operating position and a maintenance position enabling access to the turbojet engine for regular maintenance operations.

[0089] FIG. 7 illustrates the half-cowl 109 in the regular maintenance position, the position in which the half-cowl 109 has pivoted at an angle comprised between about 30 and about 45 degrees relative to its operating position. This maintenance position, called regular maintenance position, authorizes an access to the equipments generally positioned close to the gas generator of the turbojet engine.

[0090] The holding of each half-cowl 109 in the regular maintenance position is reinforced thanks to the safety connecting rod 129, sized to maintain the half-cowl in the maintenance position enabling access to the turbojet engine for regular maintenance operations.

[0091] FIG. 8 is an enlargement of the area VIII of FIG. 7, on which the safety connecting rod 129 has pivoted on the rod 139, relative to the position shown in FIG. 6.

[0092] When an operator desires to carry out irregular maintenance operations, operations concerning equipments of the propulsion unit generally positioned close to the suspension mast of the turbojet engine, and more generally in an area of the propulsion unit having an opening angle of each half-cowl of thrust reverser comprised between about 50 and 60 degrees, the operator proceeds in the following manner, following the method of opening movable cowls of the propulsion unit according to the present disclosure, whose steps are illustrated in FIGS. 9a to 9f to which reference is now made.

[0093] When the half-cowls 9 are in the operating position, that is to say closed, the operator actuates the cylinders 123 in order to extend them (step A of FIG. 9a) until they come into end of stroke abutment and are in a position in which the half-cowls 9 are open in a position allowing regular maintenance operations, the position having typically an opening angle comprised between about 30 and about 45 degrees relative to their operating position. This position is shown in FIG. 9a.

[0094] In this position, the half-cowls 9 are maintained in the regular maintenance position by means of the safety connecting rods 129, which are locked, in abutment. In this position, no force transits through the cylinders 123, and the operator removes the rods 133 on which the cylinders 123 are mounted (step B), which allows to disconnect the cylinders 123 from their main fitting 125, in complete safety. The fixed end of each cylinder 123 is then moved so as to shorten the length of the cylinder (step C), as illustrated in FIG. 9b.

[0095] As shown in FIG. 9c, the operator positions a secondary fitting 145 on the main fitting 125 (step D). The secondary fitting has a substantially triangular shape, having a base 146 and an extension 148, and is sized to allow irregular maintenance operations, and has for this purpose mechanical characteristics and a geometry adapted to support maintenance operations authorizing access to the turbojet engine for irregular maintenance operations.

[0096] The secondary fitting 145 comprises four bores 147, 149, 151, 153, for example passing through the thickness of the fitting, whose positioning in the alignment of some of the bores of the main fitting allows the holding of the secondary fitting on the main fitting, by means of rods passing through said bores. The bores 147, 149 and 151 are carried out at the base 146 of the secondary fitting 145, and the bore 153 is in turn carried out at the extension 148 of the secondary fitting.

[0097] The operator introduces a holding rod 155 passing through the bore 147 of the secondary fitting and the bore 143 of the main fitting, and a holding rod 157 passing through the bore 151 of the secondary fitting and the bore 137 of the main fitting, which provides the holding of the secondary fitting 145 on the main fitting 125. The operator then introduces a holding rod 159 passing through the bore 149 of the secondary fitting 145 and supporting the cylinder 123 (step E). The operator then adjusts the cylinder so as to relieve the safety connecting rod 129, until the cylinder 123 absorbs the forces of the associated half-cowl 9.

[0098] As illustrated in FIG. 9d, the rod 139, on which the safety connecting rod 129 is mounted, is removed (step F), and the connecting rod 129 is disconnected from the main fitting 125. The end of the safety connecting rod 129 is moved in the direction of the bore 153 of the secondary fitting 145 (step G).

[0099] The safety connecting rod 129 is then fixed on the extension 148 of the secondary fitting 145 by means of a holding rod 161 passing through the bore 153 of the secondary fitting 145 (step H).

[0100] FIG. 9f illustrates the propulsion unit according to the present disclosure, equipped with the secondary fitting 145 according to the present disclosure, on which the cylinder COS 123 and the safety connecting rod HOR 129 are fixed. The propulsion unit 101 according to the present disclosure is illustrated in FIG. 10 in the maintenance position allowing carrying out irregular maintenance operations.

[0101] The presence of the secondary fitting 145 has allowed moving the attachment points of the cylinder 123 and of the safety connecting rod 129 by a few centimeters relative to those initially provided on the main fitting 125 to carry out regular maintenance operations. More precisely, the presence of the secondary fitting allows increasing by a few centimeters the relative distance between the attachment point of the cylinder COS and the main fitting, as well as the relative distance between the attachment point of the safety connecting rod HOR and the main fitting. This allows obtaining a more significant stroke of the cylinder COS and a more significant length of the safety connecting rod HOR compared to those obtained when the cylinders COS and the safety connecting rods HOR were positioned on the main fitting. A cylinder stroke and an connecting rod length are then kept identical for regular and irregular maintenance operations, which allows to have cylinders COS and connecting rod HOR with a single stable position and sized for regular maintenance operations, unlike the cylinders COS and to the connecting rods HOR of the prior art, sized to support the irregular maintenance operations having a more significant opening angle of the half-cowls than that for carrying out regular maintenance operations. This then allows to reduce the weight of the propulsion unit in that the weight of the connecting rods HOR, the cylinders COS and the main fitting is less than that obtained according to the prior art in which these parts are more complex, due to the need for two stable positions and their oversizing.

[0102] According to a second form of the present disclosure, the secondary fitting is fixedly mounted on the main fitting, either in such a way as to allow regular maintenance operations or in such a way as to allow irregular maintenance operations. Unlike the first form which plans to mount the secondary fitting on the main fitting when it is desired to carry out irregular maintenance operations, the second form provides for a permanent mounting of the secondary fitting on the main fitting.

[0103] According to a first variant of this second form, shown in FIGS. 11a to 11f, to which reference is now made, the secondary fitting 245 has a substantially triangular shape, having a base 246 and an extension 248.

[0104] The main fitting 225 comprises four bores 263, 265, 267 and 269 (269 shown in FIG. 11c), for example passing through the thickness of the main fitting, and the secondary fitting also comprises four bores 247, 249, 251, 253, for example passing through the thickness of the secondary fitting. The bores 247, 249 and 251 are carried out at the base 246 of the secondary fitting 245, and the bore 253 is in turn carried out at the extension 248 of the secondary fitting.

[0105] When the half-cowls 9 are in the maintenance position to carry out regular maintenance operations, the position shown in FIG. 11a, the bores 247 and 249 of the secondary fitting 245 are positioned respectively opposite the bores 263 and 265 of the main fitting 225. Holding rods 271 and 273, each substantially transverse to a side wall of the main fitting, pass respectively through the bores 247, 263 and the bores 249, 265, which allows the holding of the secondary fitting on the main fitting, both in the maintenance position, shown in FIG. 12a, and in the operating position, not shown.

[0106] In the operating position and in the maintenance position for carrying out regular maintenance operations, the fixed portion of the cylinder 223 is mounted on the secondary fitting 245 thanks to a holding rod 275 passing through the bore 253 of the secondary fitting, and the movable portion of said cylinder is fixed on a fitting mounted on the half-cowl of thrust reverser. In these same positions, the safety connecting rod 229 is in turn linked to the main fitting 225 by means of a holding rod 277 passing through the bore 267 of the main fitting, and to a fitting mounted on the half-cowl of thrust reverser.

[0107] When an operator desires to carry out irregular maintenance operations, he proceeds in the following manner, for each unit comprising the cylinder COS and of the connecting rod HOR.

[0108] The operator removes the holding rod 273 passing through the bores 249 and 265 (step A).

[0109] The operator then performs, manually and without using tools, a rotation of the secondary fitting 245 (step B, FIG. 11b) in the counterclockwise direction when the propulsion unit is viewed from upstream to downstream. By pivoting in this way the secondary fitting 245, the relative distance between the attachment point of the cylinder 223 and the main fitting 225 has been increased by a few centimeters. This allows obtaining a more significant stroke of the cylinder 223 compared to that obtained when the secondary fitting 245 was mounted on the main fitting 225 in its position illustrated in FIG. 11a.

[0110] When the cylinder 223 is in the position shown in FIG. 11c, the holding rod 273 is introduced in the bore 249 of the secondary fitting 245, which is positioned opposite the bore 269 of the main fitting 225 (step C). The rod 277 ensuring the holding of the safety connecting rod 229 on the main fitting 225 is removed from the bore 267 (step D).

[0111] As illustrated in FIG. 11d, the safety connecting rod 229 is disconnected from the main fitting 225, and the end of said connecting rod is moved in the direction of the bore 251 of the secondary fitting 245 (step E).

[0112] The safety connecting rod 229 is then fixed on the extension 258 of the secondary fitting 245 by means of the holding rod 277, passing now through the bore 251 of the secondary fitting 245 (step H).

[0113] FIG. 11f illustrates the propulsion unit according to the present disclosure, equipped with the secondary fitting 245 according to the present disclosure, on which the cylinder COS 223 and the safety connecting rod HOR 229 are fixed.

[0114] The rotation of the secondary fitting 245 has allowed to increase by a few centimeters the relative distance between the attachment point of the cylinder 223 and the main fitting 225, as well as the relative distance between the attachment point of the safety connecting rod 229 and the main fitting, relative to their position in which the cylinder and the safety connecting rod allow to carry out regular maintenance operations. This allows to obtain a more significant stroke of the cylinder 223 and a more significant length of the safety connecting rod compared to those obtained when the secondary fitting 245 was mounted on the main fitting 225 in the position illustrated in FIG. 11a.

[0115] As in the first form, this second form allows having cylinders COS and connecting rods HOR with a single stable position and sized for regular maintenance operations, unlike the cylinders COS and the connecting rods HOR of the prior art, sized to support the irregular maintenance operations having a more significant opening angle of the half-cowls than that to carry out regular maintenance operations. This allows then to reduce the weight of the propulsion unit in that the weight of the connecting rods HOR, the cylinders COS and the main fitting is less than that obtained according to the prior art in which these parts are more complex due to the need for two stable positions and their oversizing.

[0116] According to a second variant of this second form, shown in FIGS. 12a to 12f to which reference is made now, the secondary fitting 345 has a triangular shape.

[0117] The main fitting 325 is identical to the main fitting 225 and comprises four bores 363, 365, 367 and 369 (369 shown in FIG. 12d), for example passing through the thickness of the main fitting. The secondary fitting 345 differs from the secondary fittings 145 and 245 in that it does not have an extension. The secondary fitting 345 comprises three bores 347, 349 and 353, for example passing through the thickness of the secondary fitting.

[0118] When the half-cowls 9 are in the maintenance position to carry out regular maintenance operations, the position shown in FIG. 12a, the bores 347 and 349 of the secondary fitting 345 are respectively positioned opposite the bores 363 and 365 of the main fitting 325. Holding rods 371 and 373, each substantially transverse to a side wall of the main fitting, pass respectively through the bores 347, 363 and the bores 349, 365, which allows the holding of the secondary fitting on the main fitting, both in the maintenance position, shown in FIG. 12a, and in the operating position, not shown.

[0119] In the operating position and in the maintenance position for carrying out regular maintenance operations, the fixed portion of the cylinder 323 is mounted on one of the apexes of the triangle constituted of the secondary fitting 345, thanks to a holding rod 375 passing through the bore 353 of the secondary fitting, and the movable portion of said cylinder is fixed on a fitting mounted on the half-cowl of thrust reverser. In these same positions, the safety connecting rod 329 is in turn linked to the main fitting 325 by means of a holding rod 377 passing through the bore 367 of the main fitting, and to a fitting mounted on the half-cowl of thrust reverser.

[0120] When an operator desires to carry out irregular maintenance operations, he proceeds in the following manner, for each unit consisting of the cylinder COS and the connecting rod HOR.

[0121] The operator removes the holding rod 373 passing through the bores 349 and 365 (step A).

[0122] The operator then introduces a key 379 in a driving square 381 of the secondary fitting 345 (step B, FIG. 12b). This key is of the standard type and allows mounting temporarily a lever arm on the secondary fitting 345. The operator then performs a rotation of the secondary fitting 345 (step C, FIG. 12c) thanks to the key 379 in the counterclockwise direction when the propulsion unit is viewed from upstream to downstream. By pivoting in this way the secondary fitting 345, the relative distance between the attachment point of the cylinder 323 and the main fitting 325 has been increased by a few centimeters. This allows to obtain a more significant stroke of the cylinder 323 compared to that obtained when the secondary fitting 345 was mounted on the main fitting 325 in its position illustrated in FIG. 12a.

[0123] When the cylinder 323 is in the position shown in FIG. 12d, the holding rod 373 is introduced in the bore 349 of the secondary fitting 345, which is positioned opposite the bore 369 of the main fitting 325 (step D).

[0124] As shown in FIG. 12e, the key is removed from the driving square 381, and the rod 377 ensuring the holding of the safety connecting rod 329 on the main fitting 325 is removed from the bore 367 (step E). The safety connecting rod 329 is then disconnected from the main fitting 325 (step F), and the end of said connecting rod is moved at an attachment point (non shown) provided on the turbojet engine, said attachment point being chosen so as to allow an opening of the cowl in the irregular maintenance position, having an opening angle greater than that for a regular maintenance operation.

[0125] FIG. 12f illustrates the propulsion unit according to the present disclosure, equipped with the secondary fitting 345 according to the present disclosure, on which the cylinder COS 323 is fixed, the safety connecting rod HOR 329 not being shown in this Figure.

[0126] The rotation of the secondary fitting 345 has allowed increasing by a few centimeters the relative distance between the attachment point of the cylinder 323 and the main fitting 325, relative to its position in which the cylinder allows to carry out regular maintenance operations. This allows to obtain a more significant stroke of the cylinder 323 compared to that obtained when the secondary fitting 345 was mounted on the main fitting 325 in its position illustrated in FIG. 12a. The safety connecting rod 329 is in turn positioned on an attachment point of the turbojet engine, which is distinct from the secondary fitting. This attachment point is chosen so that the connecting rod allows the holding of the cowl in a position authorizing irregular maintenance operations of the propulsion unit.

[0127] As in the first form and the first variant of the second form, this variant allows having cylinders COS and connecting rods HOR with a single stable position and sized for regular maintenance operations, unlike the cylinders COS and the connecting rods HOR of the prior art, sized to support the irregular maintenance operations having a more significant opening angle of the half-cowls than for carrying out regular maintenance operations. This allows then to reduce the weight of the propulsion unit in that the weight of the connecting rods HOR, the cylinders COS and the main fitting is less than that obtained according to the prior art in which these parts are more complex (two stable positions) and are oversized.

[0128] According to an aspect common to the two forms of the present disclosure, the cables or pipes disposed at the hinge portion of the cowls of thrust reverser and supplying equipments secured to cowls of thrust reverser, are also shortened relative to the prior art, so as to authorize one opening of the cowls of thrust reverser in a regular maintenance position.

[0129] When it is desired to move the propulsion unit in the irregular maintenance position, the parts in the opening hinge area of the cowls are removed in order not to inhibit the opening of the cowls in the irregular maintenance position.

[0130] This allows advantageously to limit also the weight of the propulsion unit, in that all of these pipes and cables are sized to allow the opening of the cowl in the maintenance position authorizing regular maintenance operations.

[0131] The description of the present application refers to cowls of D-duct type thrust reverser. It should be understood that the present disclosure is in no way limited to the half-cowls of D-duct type thrust reverser, but that it encompasses on the contrary all types of movable cowls of the propulsion unit, such as, for example, a half-cowl of a C-duct thrust reverser, a door for a thrust reverser with doors, or even a half-cowl of fan casing of turbojet engine.

[0132] It goes without saying that the present disclosure is not limited to the sole variations of the propulsion unit, described above only by way of illustrative examples, but it embraces, on the contrary, all the variants involving the technical equivalents of the means described as well as their combinations if these are within the scope of the present disclosure.

[0133] The description of the disclosure is merely exemplary in nature and, thus, variations that do not depart from the substance of the disclosure are intended to be within the scope of the disclosure. Such variations are not to be regarded as a departure from the spirit and scope of the disclosure.