ASSISTANCE DEVICE FOR AN EMERGENCY OPENING MECHANISM FOR AIRCRAFT DOORS PROVIDED WITH IMPROVED CONTROL MEANS

Abstract

The present invention relates to an assistance device for the emergency opening of aircraft doors, comprising a helical ejection spring (R) mounted between a fixed flange (F1) and a movable flange (F2) taking up the compression forces of the spring (R) and connected together by at least two longitudinal rods (T) housed in a sliding manner in guide tubes (G) and fixed to the movable flange (F2) and to the fixed flange (F1) where they are provided with a retaining bolt (B) formed of separable coaxial parts (b), characterized in that it comprises a control ring (1) mounted on the fixed flange (F1) and carrying retractable elements (2) coming, in the extended position, to bear against the bolts (B) to ensure their locking by securing said parts (b) and the compression of the spring (R) and allowing, in the retracted position, the separation of said parts, the synchronized unlocking of the bolts and the relaxation of the spring.Figure for abstract: Figure 1.

Description

Title of the invention: DEVICE FOR ASSISTANCE OF AN EMERGENCY OPENING MECHANISM FOR AIRCRAFT DOORS PROVIDED WITH IMPROVED CONTROL MEANS Technical field

[0001] The invention relates to the field of aeronautics and is more particularly concerned with mechanisms ensuring the emergency opening of aircraft cabin evacuation doors using an assistance device provided with means for accumulating mechanical energy of elastic origin and control means allowing its release in the event of emergency opening.

[0002] Current devices for assisting in the emergency opening of aircraft doors use a pressurized gas such as nitrogen as an energy source. This energy is transformed into a mechanical actuating force when the gas is expanded in a system consisting, in particular, of a cylinder and a piston. Triggering the ejection of the door with such a device is then easily obtained via the opening of a valve or the rupture of a diaphragm. For this purpose, a lever driven by the door opening mechanism generates either the opening of the valve or the rupture of the diaphragm.

[0003] However, the use of compressed nitrogen generates significant maintenance costs because the risks of leaks are problematic from a safety point of view. Consequently, such an embodiment of the opening control device requires regular monitoring and checks of the equipment used as well as frequent topping up of the nitrogen tank.

[0004] There are other solutions which make it possible to simplify the maintenance operations of the assistance device. These other solutions consist of using a source of mechanical energy consisting of a cylindrical envelope spring which, in a normal situation, is kept in compression by means of a locking mechanism and whose relaxation, thanks to the unlocking of the mechanism, in an emergency situation, results in the immediate ejection of this door.

[0005] However, these other solutions require having space available in the central part of the spring to accommodate means capable of ensuring, at the same time, the maintenance of the spring in compression and the exertion of the necessary and sufficient forces to produce an instantaneous triggering of the opening via the relaxation of this spring.

[0006] A control device implementing these spring solutions associated with expanding locking bolts is described in patent FR3113028. Furthermore, Patents FR3098490 and FR3113028 describe spring control devices held by breakable cables.

[0007] However, the integration of bolts or cables in the ejection control device as provided in these documents requires the mounting of additional members and, in particular, anchoring elements which clutter the structure of these devices, in particular, around the spring.

[0008] Furthermore, with these devices, it is not possible to use metal cables whose breaking, which is necessary for the relaxation of the spring, would require excessive shear forces. Cables made of a polymer material (for example, of the Dyneema, Kevlar, Vectran, etc. type) could prove satisfactory in terms of mechanical strength and ease of breaking but nevertheless have a tendency to kink which is not admissible in the envisaged application.

[0009] Therefore, in the case where the central part of the spring does not offer free space, it has therefore been envisaged, within the framework of the invention, to maintain the spring in compression from its external environment. This option nevertheless requires providing at least two recovery elements mounted as diametrically opposed and locked in order to ensure the compression of the spring without creating a bending moment. In addition, these two recovery elements must be unlocked simultaneously to ensure the complete relaxation of the spring and the immediate triggering of the opening of the door.

[0010] To this end, the invention is concerned with a door ejection assistance device comprising, in particular, two wedging flanges, respectively, a fixed flange and a movable flange, mounted on either side of the spring and intended to take up the compression forces. These flanges are connected to each other by at least two longitudinal rods housed in a sliding manner in guide tubes. The ends of each of these rods, which project from the outside of the fixed flange, are integral with bolts consisting of the joining of three separable parts. In the locking position, the constituent parts of these so-called "expandable" bolts are integral and ensure the retention of the rods and the compression of the spring. When unlocking, these parts are capable of separating to release the rods and thus allow the spring to release.

[0011] With this embodiment of an assistance device, the expansion bolts, which are locked in a normal situation, must be unlocked in an emergency situation to release the rods and allow the spring to relax.

[0012] The problem that the invention aims to solve then lies in the dual objective of allowing, on the one hand, easy locking of the bolts not requiring complex adjustment to guarantee adequate locking of each of them, and on the other hand, instantaneous and simultaneous unlocking of all the bolts.

[0013] This objective is achieved, according to the invention, by means of a device for assisting an emergency opening mechanism for aircraft doors, comprising a helical ejection spring connected to said mechanism and mounted between two wedging flanges, respectively, a fixed flange and a movable flange intended to take up the compression forces of the spring and connected together by at least two longitudinal rods housed in a sliding manner in guide tubes, one of the ends of said rods being fixed to the movable flange and the other end projecting from the outer face of the fixed flange where it is provided with a retaining bolt consisting of the joining of separable coaxial parts, characterized in that it further comprises a control ring for said assistance device mounted on the outer face of the fixed flange and carrying retractable elements coming, in the extended position,pressing against the bolts to ensure their locking by securing said parts and maintaining the spring in compression and allowing, in the retracted position, the separation of said parts, the synchronized unlocking of the bolts and the relaxation of the spring.

[0014] According to a preferred embodiment of the assistance device of the invention, the retractable elements are formed of needles mounted transversely on radial tabs extending at the periphery of said control ring and coupled to return springs. Preferably, these needles are housed in sleeves forming slides.

[0015] According to a specific embodiment of the invention, the assistance device comprises three longitudinal rods extending around the spring and spaced apart by approximately 120°, each of these rods being provided with a retaining bolt coupled to a retractable locking / unlocking element.

[0016] According to an advantageous characteristic of the assistance device of the invention, the inner wall of the guide tubes is provided with a sliding washer intended to facilitate the sliding of the rods.

[0017] According to another advantageous characteristic of the assistance device of the invention, the periphery of the control ring comprises an anchoring lever for an engagement spring intended to be connected to the fixed flange and to ensure that the retractable elements press against the retaining bolts.

[0018] This lever has an interface with the door opening mechanism intended to cause the rotation of the control ring.

[0019] According to yet another characteristic of the device of the invention, the control ring is mounted in free rotation on the outer face of the fixed flange, coaxially with the helical ejection spring.

[0020] According to another variant embodiment of the invention, the periphery of the control ring has two plates each carrying a pin intended to come into abutment on either side against a lug arranged on the outer face of the fixed flange so as to limit the angular displacement of said ring.

[0021] According to yet another characteristic of the assistance device of the invention, the movable flange is provided with an interface with the door opening mechanism.

[0022] Another object of the invention is an aircraft door equipped with an emergency opening mechanism provided with the assistance device as defined above.

[0023] The door opening mechanism assistance device according to the invention ensures a uniform distribution of the locking forces at the interface between all the retaining bolts and the rods keeping the ejection spring compressed without obstructing its internal volume. Thanks to the control ring, the invention thus guarantees both the maintenance of strong axial compression and a quasi-instantaneous relaxation producing optimal kinetic energy to allow the automatic and safe ejection of the door.

[0024] The invention also allows precise and easy adjustment of the opening assistance device as well as the implementation of simple and rapid maintenance operations. PRESENTATION OF THE FIGURES

[0025] Other characteristics and advantages of the invention will emerge from the non-limiting description which follows, with reference to the appended drawings in which:

[0026] [Fig.l] is an overall perspective view of a device for assisting in the emergency opening of an aircraft door equipped with a preferred embodiment of the control means according to the invention in the locking position.

[0027] [Fig.2] is a partial perspective view of the assistance device of [Fig.l] in the locking position of the control means in normal conditions.

[0028] [Fig.3] is a partial perspective view of the assistance device of [Fig.l] in the unlocking position of the control means after emergency opening of the door.

[0029] [Fig.4] is a partial front view of the assistance device of [Fig.l] in the locking position of the control means in normal situation.

[0030] [Fig.5] is a partial front view of the assistance device of [Fig.l] in the unlocking position of the control means after emergency opening of the door.

[0031] [Fig.6] is a perspective view of the control ring of the device assistance according to the invention in the locking position

[0032] [Fig.7] is a partial exploded perspective view of the control means of the emergency opening assistance device according to the invention.

[0033] For clarity, identical or similar elements are indicated by identical reference signs in the following description and in the figures. Natu- Therefore, the embodiments of the invention illustrated schematically by the figures presented above and described below are given only as non-limiting examples. It is explicitly provided within the scope of the invention that different embodiments can be proposed and combined to propose others. DETAILED DESCRIPTION

[0034] The invention relates to aircraft doors and is more particularly concerned with an opening assistance device intended to be integrated into the door ejection mechanism in an emergency situation and equipped with improved control means.

[0035] The invention aims to apply to a specific assistance device comprising, as illustrated by [Fig.l], a helical ejection spring R connected to the door opening mechanism via an interface A (shown schematically and partially in [Fig.l]). The spring R is mounted in compression between two wedging flanges, respectively, a fixed flange F1 and a movable flange F2 which are intended to take up the forces of the spring R. The interface A of the assistance device is mounted here on the movable flange F2.

[0036] The two flanges are connected to each other by at least two rods, and in the embodiment shown here, by three longitudinal rods T. These rods are housed in a sliding manner in guide tubes G and extend around the spring R parallel to its axis, being spaced apart by approximately 120°. Preferably, the inner wall of the guide tubes G is provided with a sliding washer (not visible in the figures) intended to facilitate the sliding of the rods T. One of the ends t2 of the rods T is permanently fixed to the movable flange F2 while their other end t1 projects onto the outer face of the fixed flange F1 where it is provided with a retaining bolt B.

[0037] In the specific embodiment to which the invention is intended to apply, the bolts B are made up of the union of separable coaxial cylindrical parts b. Bolts of this type, called "expandable", are marketed in particular by the company Soterem (registered trademark) and are already used in the space sector. In the absence of constraints allowing them to be held together, the parts b can separate to automatically unlock the bolts B.

[0038] The invention consists in proposing improved control means for this assistance device intended to ensure, on the one hand in the normal position, the locking of the bolts B and, on the other hand in an emergency situation, their unlocking to release the rods T and thus allow the spring R to relax and actuate, via the interface A, the door opening mechanism.

[0039] These complementary means are produced, according to the invention, in the form of a control ring 1 mounted on the outer face of the fixed flange F1 and carrying retractable elements 2 for locking / unlocking the bolts B. The ring 1 is mounted in free rotation on the outer face of the fixed flange Fl and coaxially with the helical spring R for assisting ejection.

[0040] More precisely, the retractable elements 2 come, in the extended position, to bear against the bolts B to ensure their locking by securing the parts b and thus guarantee the maintenance of the spring R in compression. When they retract, the elements 2 release the parts b which separate automatically, causing the synchronized unlocking of the bolts B. The rods T no longer being fixed to the fixed flange F1, the helical spring R is no longer maintained in compression and is released. The relaxation of the spring R of the assistance device then drives the movable flange F2 and the rods T in translation in the guide tubes G and jointly actuates the door opening mechanism.

[0041] In the embodiment of the invention shown here in the drawings, the retractable elements 2 are formed of three needles 21 mounted transversely on radial tabs 11 extending at the periphery of the control ring 1. Each of these needles 21 is coupled to a return spring 22, as illustrated by [Fig. 5] and in detail by [Fig. 7]. Preferably, the needles 21 are housed in sleeves 20 forming slides and facilitating their translational movement through the tabs 11 between their extended and retracted positions. A nut 30 screwed onto a threaded rear portion of the sleeve 20 secures the assembly to the tab 11. A clip 31 prevents the needle 21 from being disengaged from the sleeve 20.

[0042] The periphery of the control ring 1 comprises a lever 12 for anchoring an engagement spring 5 intended to be connected to the fixed flange F1 and to ensure that the retractable needles 21 press against the bolts B for retaining the rods T. The ring 1 is also provided at its periphery with two radial plates 10 carrying pins 3a, 3b intended to come into abutment on either side against a lug E arranged on the outer face of the fixed flange F1 so as to limit the angular displacement of the ring 1, as illustrated in FIGS. 5 and 6. Preferably, at least one of the pins 3a is adjustable in length so as to adjust the stroke and the pressing force of the needles 21 on the bolts B.

[0043] The lever 12 comprises, for its part, a pin 12a intended to interface the control coming from the door mechanism. In this configuration, an axial support contact with the pin 12a causes the rotation of the ring 1 and makes available the assistance force on the door opening mechanism.

[0044] The invention is not limited to a number of rods, expanding bolts and retractable elements as described above and shown in the drawings. Indeed, it is possible to provide, according to alternative embodiments of the invention not shown, to adapt and increase this number according to needs and, in particular, the dimensional and mechanical characteristics of the spring of the assistance device used to ensure emergency opening of the door.

Claims

Claims

1. Device for assisting an emergency opening mechanism for aircraft doors, comprising a helical ejection spring (R) connected to said mechanism and mounted between two wedging flanges, respectively, a fixed flange (F1) and a movable flange (F2) intended to take up the compression forces of the spring (R) and connected together by at least two longitudinal rods (T) housed in a sliding manner in guide tubes (G), one of the ends (t2) of said rods being fixed to the movable flange (F2) and the other end (t1) projecting from the outer face of the fixed flange (F1) where it is provided with a retaining bolt (B) consisting of the joining of separable coaxial parts (b), characterized in that it further comprises a ring (1) for controlling said assistance device mounted on the outer face of the fixed flange (Fl) and carrying retractable elements (2) coming, in the extended position,bearing against the bolts (B) to ensure their locking by securing said parts (b) and maintaining the spring (R) in compression and allowing, in the retracted position, the separation of said parts, the synchronized unlocking of the bolts and the relaxation of the spring.,

2. Device according to claim 1, characterized in that said retractable elements (2) are formed of needles (21) mounted transversely on radial tabs (11) extending at the periphery of said control ring (1) and coupled to return springs (22).

3. Device according to the preceding claim, characterized in that said needles (21) are housed in sleeves (20) forming slides.

4. Device according to one of the preceding claims, characterized in that it comprises three longitudinal rods (T) extending around the spring (R) and spaced apart by approximately 120°, each of these rods being provided with a retaining bolt (B) coupled to a retractable locking / unlocking element (2).

5. Device according to one of the preceding claims, characterized in that the inner wall of the guide tubes (G) is provided with a sliding washer intended to facilitate the sliding of the rods (T).

6. Device according to one of the preceding claims, characterized in that the periphery of said control ring (1) comprises an anchoring lever (12) of an engagement spring (5) intended to be connected to the fixed flange (Fl) and to ensure that the retractable elements (2) are supported against the retaining bolts (B).

7. Device according to the preceding claim, characterized in that the lever (12) comprises an interface (12a) with the door opening mechanism intended to cause the rotation of the control ring (1).

8. Device according to one of the preceding claims, characterized in that said control ring (1) is mounted in free rotation on the outer face of the fixed flange (F1), coaxially with the helical ejection spring (R).

9. Device according to one of the preceding claims, characterized in that the periphery of said control ring (1) has two plates (13) each carrying a pin (3a, 3b) intended to come into abutment on either side against a lug (E) arranged on the outer face of the fixed flange (F1) so as to limit the angular displacement of said ring.

10. Device according to one of the preceding claims, characterized in that said movable flange (F2) is provided with an interface (A) with the door opening mechanism.

11. Aircraft door equipped with an emergency opening assistance device according to one of the preceding claims.

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