IMPROVEMENT OF THE LOCKING / UNLOCKING MECHANISM OF AN AIRCRAFT DOOR WITH SIDE EMERGENCY OPENING OF THE RETAINING SYSTEM

Description

TECHNICAL FIELD

[0001] The invention relates to the field of aeronautics and, more particularly, aircraft doors known as "side-exhaust" doors, and focuses on an improvement of their integrated locking and unlocking mechanisms.

[0002] An aircraft typically has several openings in its fuselage to provide access to the cabin or cargo holds. These openings are fitted with doors whose locking / unlocking mechanism must ensure secure locking and a watertight seal during flight. Furthermore, the doors must be easy and quick to open for flight crew, either from inside the aircraft or from outside by emergency personnel. Resistance to the pressure differential between the inside and outside of the cabin is achieved using stops installed around the perimeter of the door leaf and its frame. PREVIOUS ART

[0003] Aircraft doors already exist that include: an opening comprising a door structure, an external wall fixed to this structure and door stops; a fixed part comprising a door frame intended to be fixed to the fuselage of the aircraft and having frame stops; a support arm connected to the opening part and having an end pivotally mounted on the door frame, this support arm and the opening part being movable between a closed position in which the opening part closes the door frame, the door stops being then locked against the frame stops, an intermediate unlocking position in which the door stops are clear of the frame stops and an open position in which the opening part is clear of the door frame.

[0004] Such a door described in patent application US2001 / 0070416 is equipped with a locking / unlocking mechanism adapted to control the transition from the closed position to the unlocked position and vice versa.

[0005] This locking / unlocking mechanism comprises, for its operation, an internal lever or handle and an external lever or handle which are mounted on the door structure and are movable between a locked position and an unlocked position.

[0006] According to certain door opening and closing kinematics, as described in US patent 4,720,065, the door opens and closes according to a circular translation, the door being thus kept parallel to the frame.

[0007] The present invention relates more particularly to aircraft doors that unlock through lateral movements of the opening sash allowing the door stops to be released from the frame stops without resorting to vertical movements of the opening sash, as described in US patent application 2021 / 0387713. These lateral movements are defined here as movements along a longitudinal direction parallel to the longitudinal axis of the aircraft.

[0008] WO 2020 / 253986 describes such an aircraft door in which the locking / unlocking mechanism comprises: a control shaft extending along a substantially vertical axis and mounted on the door structure by means of a pivot joint around the axis of the control shaft, the internal lever and the external lever being connected transversely to the control shaft so that an action on one of the levers causes the control shaft to rotate around its axis; a guide track attached to the opening and extending along a plane substantially orthogonal to the control shaft and having an opening at its end; an actuating finger fixed on the support arm and adapted to cooperate with the guide track; a mechanical transmission adapted to cause a movement of the actuating finger when the control shaft is actuated in rotation.

[0009] This specific locking / unlocking mechanism has two configurations, respectively, an actuation configuration corresponding to the angular stroke of the levers between their locking position and their unlocking position and in which the rotation of the control shaft then causes a movement of the actuating finger along the guide track, and; a release configuration in which the levers are in the unlocking position and in which the actuating finger is movable between a first position where it is positioned at the opening of the guide track and a second position where it is outside the guide track, the opening then being in the open position.

[0010] In this locking / unlocking mechanism, the mechanical transmission includes a fork positioned opposite the guide track and connected to the control shaft.

[0011] This fork extends along a plane substantially orthogonal to the control shaft and is pivotally mounted on the door structure around an axis substantially parallel to the control shaft. The fork has two actuating arms and an opening at its end.

[0012] In the release configuration, the fork opening is positioned opposite the guide track opening.

[0013] In the actuation configuration, the actuating finger is inserted both into the guide track and into the fork such that pivoting the fork causes the actuating finger to move along the guide track.

[0014] For this purpose, the actuating finger is, on the one hand, mounted on an actuating arm which is integral with the support arm and which is positioned between the fork and the guide track and includes, on the other hand, a double roller extending transversely on either side of the actuating arm.

[0015] Furthermore, the mechanical transmission includes a cam fixed in rotation to the control shaft and a connecting rod linking the cam to the fork and adapted to drive the pivoting of the fork when the cam and the control shaft rotate. DESCRIPTION OF THE INVENTION

[0016] It so happens that natural phenomena, such as freezing rain or supercooled water encountering a cold obstacle (zero degrees Celsius or below), result in the formation of a layer of ice covering the fuselage and the door. This layer of ice, potentially present when the doors are opened, creates a mechanical barrier between the door and the frame, preventing the door from unlocking.

[0017] Current so-called "semi-plug" doors use an upward vertical movement to disengage the stops, and this kinematic requires sufficient space between the top of the door and the fuselage.

[0018] If such a door is covered with ice, it is then necessary to break it by pulling in the lower part of the door (which requires only small efforts), to shear the ice present on the sides which, on the other hand, requires significant efforts but compatible with a classic door mechanism and also to break the ice in compression in the upper part which normally requires very significant efforts but the use of a seal closing the door in its upper part makes the ice fragile in this area.

[0019] However, a door with lateral escape of the stops is achieved through a combination of translations in longitudinal and transverse planes and a rotation about a vertical axis. This kinematic approach has the advantage of allowing the fuselage skin to be cut very close to the door skin without additional clearance, thus reducing the size of the opening in the fuselage while maintaining equivalent passage dimensions.

[0020] But, with such a door, any horizontal movement of the door parallel to the fuselage will be impossible since on one or the other of its lateral edges, the door will come into compression against the ice and will be blocked, which is problematic both ergonomically and in terms of safety.

[0021] On the other hand, moving one of these edges towards the inside of the cabin will break the ice on that edge and then on the other by dynamic effect because the ice offers little resistance to a transverse force.

[0022] But it is necessary that this force exerted on the opening and directed inwards be produced directly by the locking / unlocking mechanism because the use of a ramp placed on the fuselage would require prior lateral movement to generate this inward movement.

[0023] Furthermore, current technical certification standards mandate a minimum opening force once the pressure differential between the inside and outside of the fuselage reaches a specified value to prevent accidental opening. Therefore, this pressure must exert a greater force on the lever during opening than the specified minimum.

[0024] The invention therefore aims to improve aircraft doors known in the prior art with lateral escape of the stops and, in particular, to modify their locking / unlocking mechanism to incorporate means for breaking the glass possibly present between the opening and the door frame during a preliminary phase of the door opening.

[0025] In this context, the invention aims to provide an improvement to the mechanical transmission means ensuring a preliminary movement of the door oriented transversely inwards to break the glass and allow the subsequent action of the unlocking mechanism, thus ensuring the conformity of the door to the certification standards in force.

[0026] This objective is achieved by means of a locking / unlocking mechanism designed to control the movement of a side-exhaust aircraft door from the stops from the closed position to the unlocked position and vice versa, said mechanism comprising: an internal lever and an external lever mounted on the door and movable between a locked and an unlocked position; a control shaft extending along a substantially vertical axis, mounted on the door by means of a pivot joint, the internal and external levers being connected transversely to the control shaft such that an action on one of the levers causes the control shaft to rotate about its axis; a guide track extending in a plane substantially orthogonal to the control shaft and having an opening at its end; an actuating finger fixed on a support arm, this actuating finger being adapted to cooperate with the guide track; a mechanical transmission adapted to cause movement of the actuating finger when the control shaft is rotated.said transmission comprising a fork disposed opposite the guide track and connected to the control shaft and comprising two actuating arms and an opening at its end such that, in an actuation configuration corresponding to the angular stroke of the levers between their locking position and their unlocking position, the pivoting of the fork causes a displacement of the actuating finger along the guide track and, in a release configuration where the levers are in the unlocking position, the opening of the fork is disposed opposite the opening of the guide track,characterized in that the two actuating arms of the fork meet opposite its opening in a loop which is offset transversely with respect to the longitudinal axis of the arms, and in that the closed end of the guide track opposite its opening is provided with a loop of enlarged diameter whose wall, together with the actuating finger in the closed position of the door, defines a gap whose compensation allows a force to be exerted on the door inwards during a preliminary phase of unlocking.

[0027] According to an advantageous feature of the invention, the mechanism includes a cam that is rotationally fixed to the control shaft.

[0028] According to another feature of the mechanism of the invention, the fork is driven in rotation by a shaft which is itself driven in rotation by the mechanical transmission.

[0029] In addition, the vertical axis of the fork loop is offset from the shaft axis in order to produce a mechanical driving effect.

[0030] According to a specific embodiment variant, the mechanical transmission comprises a belt mounted, on the one hand, around said shaft and, on the other hand, on an intermediate mechanical linkage in contact with a roller inserted in a path made in said cam.

[0031] According to yet another feature of the mechanism of the invention, in its actuation configuration, the actuation finger is inserted both in the guide track and in the fork.

[0032] Preferably, this actuating finger has a double roller.

[0033] The invention provides that, in the release configuration of the mechanism, the opening of the fork is arranged opposite the opening of the guide track.

[0034] Furthermore, the actuating finger is never positioned in the fork loop regardless of the mechanism's position.

[0035] Another object of the invention is an aircraft door with side exit from the stops equipped with a locking / unlocking mechanism as defined above.

[0036] The mechanism of the invention makes it possible to generate an initial displacement of an edge of the opening towards the interior of the cabin before starting the unlocking phase, which ensures the breaking of the glass around the door and then provides the movement necessary for the complete release of the stops.

[0037] To this end, the invention uses the fork to ensure the inward movement and the cam is designed to allow this movement even if the door is blocked in the longitudinal direction by the glass.

[0038] Another advantage of the invention is that this inward movement of the door helps to prevent accidental opening because the force to be exerted on the lever (or handle) to open the door is greater than 300 lbs as soon as the pressure differential is above 2 psi.

[0039] Other advantages of the invention include the reduction in the dimensions of the fuselage opening, the elimination of the flap, the reduction of the fuselage ramps, the reduction of the energy expenditure of opening in normal conditions and the improved compactness of the locking / unlocking mechanism. PRESENTATION OF THE FIGURES

[0040] Other features and advantages of the invention will become apparent from the following non-limiting description, with reference to the accompanying drawings in which: [ Fig.1 ] is a side perspective view of a preferred embodiment of the locking / unlocking mechanism of the invention equipping a door with lateral escape stops. Fig.2 ] is a perspective view from below of the locking / unlocking mechanism of the figure 1 . [ Fig.3 ] is a partial view from below of the mechanism of the figure 1 , in the locked position. Fig.4 ] is a detailed view of the locking mechanism of the invention in the position of the figure 3 and illustrating the cooperation between the guide track and the actuating finger. Fig. 5 ] is a partial view from below of the mechanism of the figure 1 and illustrates the first step in a door unlocking sequence designed to break the ice. Fig. 6 ] is a partial view from below of the mechanism of the figure 1 and illustrates a second step in a door unlocking sequence. Fig. 7 ] is a partial view from below of the mechanism of the figure 1 and illustrates a third step in a door unlocking sequence. Fig. 8 ] is a partial view from below of the mechanism of the figure 1 and illustrates a fourth step in a door unlocking sequence. DETAILED DESCRIPTION

[0041] THE figures 1 et 2 These are perspective views of a preferred embodiment of the locking / unlocking mechanism of the invention, shown alone and applied to an aircraft door with a so-called "side-exit" operating mode. This mechanism is described and illustrated in patent application WO2020 / 253986, to which the following description of the improvement according to the present invention refers.

[0042] This mechanism involves the door unlocking through lateral and rotational movements around the vertical axis of the door leaf, allowing the door stops to disengage from the stops of the fixed frame. These lateral movements are defined here as movements along a longitudinal direction parallel to the longitudinal axis of the aircraft.

[0043] The improvement according to the invention incorporates, into the kinematics of this mechanism, movements perpendicular to this axis, one of which is directed inwards to break the glass and another is directed outwards to allow the opening to come out of its frame.

[0044] THE figures 3 à 8 are figures illustrating the successive configurations of a part of the locking / unlocking mechanism according to the invention from the closed position to the fully open position of the door.

[0045] With reference to figures 1 et 2 The locking / unlocking mechanism comprises a control shaft 17 mounted on bearings (not shown) fixed to the door structure. The control shaft 17 is rotatably mounted on the door structure (not shown) around its longitudinal axis, which extends vertically.

[0046] The internal lever 15, extended by a handle 16, and the external lever 19 are directly fixed to the control shaft 17 and extend transversely to the shaft and, preferably, perpendicularly to it. The levers 15 and 19 are fixed to the control shaft 17 by any means that allows these levers to drive the control shaft 17 in rotation, for example, by screwing, keying, splined mounting, etc. The internal lever 15, the external lever 19, and the control shaft 17 are thus fixed together, without any gear reduction or transmission device. This arrangement considerably simplifies and improves the reliability of the mechanism's operation.

[0047] The external lever 19 allows the control shaft 17 to be operated in the same way as the internal lever 15, but is accessible from outside the aircraft.

[0048] The locking / unlocking mechanism further comprises, as described in WO2020253986A1, a cam 20 fixed on the control shaft 17, at its end opposite the levers 15, 19. The cam 20 is mounted on the control shaft 17 by any means enabling the cam 20 to rotate when the control shaft 17 rotates around its longitudinal axis.

[0049] The locking / unlocking mechanism also includes a fork 21 extending in a plane perpendicular to the control shaft 17. This fork 21 has a shaft 22 parallel to the control shaft 17 and rotatably mounted on the door structure. The fork 21 is driven in rotation by the shaft 22, which is itself driven in rotation by a belt 23 mounted, on one side, around the shaft 22 and, on the other side, on an intermediate mechanical drive 25 meshing with a roller associated with the cam 20. However, according to a variant of the invention not shown, it is possible to replace the belt with a connecting rod and a lever or, more generally, with a coupling between the drive shaft and the fork shaft.

[0050] The cam 20 has a cam track 26 in which the roller 25 is captive. The fork 21 has two actuating arms 34 that join in a loop 34A and an opening 35 at the end of these two arms. The loop 34A is offset transversely in the plane of the fork relative to the longitudinal axis of the arms 34, while its vertical axis is parallel to and offset inward from the shaft 22.

[0051] Furthermore, the roller's drive 25 is associated with a lever 27 that pivots about a shaft 28 parallel to the control shaft 17. The shaft 28 is connected to the belt 23 via a pulley and is also rotatably mounted on the door structure. The lever 27 extends orthogonally to the shaft 28 and is designed to restrict the movement of the roller and its drive 25 to an arc centered on the shaft 28 and to define the roller's position in the cam track 26. The roller is designed to drive the shaft 28 in rotation when the cam 20 rotates.

[0052] The locking / unlocking device further includes a guide track 29 arranged opposite the fork 21. The guide track is a part which extends in a plane perpendicular to the control shaft 17 and which includes an internal guide path adapted to guide the movement of at least one actuating finger.

[0053] Between the guide track 29 and the fork 21, extends an actuation arm (shown figures 1 et 2 ) which is fixed to a support arm (not shown for simplicity in the figures) having at its end an actuating finger which here consists of a double roller 32 (only the double roller 32 is visible) which is inserted both into the guide track 29 and into the fork 21. Thus, the double roller 32 is driven in movement by the fork 21 as it travels along the guide track 29. The double roller 32 is never positioned in the loop 34A regardless of the position of the locking / unlocking mechanism (see the figure 3 ).

[0054] THE figures 3 à 8 These are partial and bottom views of the locking / unlocking mechanism according to the invention. These figures show, in particular, the shapes of the cam track 26 and the guide track 29 (only with the actuating finger 32 on the figure 4 ). In these figures, only the internal lever 15 and the internal handle 16 have been shown, it being understood that the external lever 19 is rotationally fixed to the control shaft 17 and therefore has the same behavior.

[0055] The cam path 26 has a generally curvilinear shape with a first range 26A and a second range 26B ( figure 3 ).

[0056] The guide track 29 has a general C-shape with a first section 29A, a second section 29B, a third section 29C, and an intermediate bend 29D between the second section 29B and the third section 29C. The width of the guide track 29 is uniform across sections 29A, 29B, 29C, and in the bend 29D, and corresponds approximately to the outer diameter of the double roller 32, thus allowing its sliding movement along the track 29.

[0057] According to the invention, the closed end of the first range 29A is provided with a looped part 29E ( figures 3, 4 And 6 ) of enlarged diameter, defining with the double roller, in the closed position of the door, a set of ( figures 3 et 4 ). On the other hand, the end of the third range 29C of the guide track 29 has an opening 33 through which the double roller 32 can be positioned at the exit of the guide track 29. The opening 33 preferably has a funnel shape to facilitate the reception, during closing, of the double roller 32 in the guide track 29 and to engage the door when closing, even if the roller is not perfectly opposite the entrance of the guide track.

[0058] A procedure for unlocking the aircraft door, prior to opening this door, will now be described with reference to figures 3 à 8 on which the mechanism is illustrated in view from below, the internal lever 15 located inside the aircraft cabin being shown here on top of the figures.

[0059] In the position of figures 3 et 4 The internal lever 15 is in its locked position, which corresponds to the closed position of the door. In this position, the roller 25 is against the end of the cam track 26B. Simultaneously, the double roller 32 is positioned in the loop 29E of the closed end of the guide track 29 and is wedged at the entrance of the loop 34A of the fork 21, and therefore at a distance from its end. The offset of the double roller 32 towards the end 35 relative to the loop 34A of the fork 21, the play in the loop 29E of the track 29, and the offset of the shaft 22 relative to the vertical axis of the loop 34A, thus ensure that the door leaf is held firmly against its frame in the fuselage, thereby compressing the door seal.

[0060] From the locking position of the figure 3 The internal lever 15 is moved to its unlocked position. figure 5 This illustrates the first actuation phase during which the movement of the double roller 32 between the arms 34 of the fork 21 and the compensation of the play d in the loop 29E generate an inward movement of the door edges, thus breaking any glass that may be present at its periphery. Simultaneously, the fork 21 begins to pivot relative to the guide track 29. According to the invention, the inward movement of the door towards the fuselage is approximately 9 mm and can be adjusted as needed.

[0061] There figure 6 , illustrates a second phase in which the actuation of the lever 15 causes the rotation of the control shaft 17 and therefore of the cam 20. The rotation of the cam 20 causes the roller 25 to travel a second range.

[0062] From the position of figure 6 In a third actuation phase, the cam 20 continues its rotation and the roller 25 continues its movement in a second range. This third actuation phase results in the position illustrated in the figure 7 The fork 21, in its pivoting motion, drove the double roller 32 along the guide track 29. During this movement, the double roller 32 traveled along the first section 29A and the second section 29B and was then located in the bend 29D of the guide track 29. Since the double roller 32 is directly connected to the support arm, this movement causes the support arm to move relative to the sash. This movement drives the sash in both transverse and lateral directions.

[0063] Given the arrangement of the locking / unlocking mechanism of the invention, the movement of the double roller 32 thus allows the following movements of the opening: a movement of the double roller 32 in the range 29C towards the end 33 or in the opposite direction causes a movement of the opening parallel to the fuselage, respectively, towards the front or towards the rear of the aircraft; a movement of the double roller 32 in the range 29B towards the end 33 or in the opposite direction causes a movement of the opening in the direction perpendicular to the fuselage, respectively, towards the outside of the aircraft or towards the inside of the aircraft.

[0064] The guide track 29 allows the movements of the double roller 32, and therefore of the support arm, to be organized to cause the desired movements for the opening, among these possible movements for the opening, which can be combined according to the arrangement of the support arm, the support forearm, the pivot arm, and the pivot forearm.

[0065] In this example, with reference to the unlocking strategy illustrated in figures 3 à 8 The end of the double roller 32's path in the guide track 29 corresponds to the position illustrated in the figure 8 In this position, the opening 35 of the fork 21 is aligned with the opening 33 of the guide track 29, so that the double roller 32 can freely exit the fork 21 and the guide track 29 through their respective openings 33 and 35. The double roller 32 has traveled the entire length of the guide track 29 and is now in the release position. This position corresponds to the end of the door unlocking phase, and the door can then be operated manually.

[0066] The invention thus aims at locking / unlocking means capable of causing movement of the opening in the longitudinal and transverse directions of the aircraft, it being understood that a person skilled in the art will be able to combine these movements and transform them into rotation according to the desired opening strategy.

[0067] The door locking process follows the same sequence in reverse. The door is then manually returned to the position of the figure 8 where, the double roller 32 is then inserted into the opening 35 of the fork 21, as well as into the opening 33 of the guide track 29. The movement of one of the levers 15, 19, from its unlocked position to its locked position then entails the actuation phases corresponding, in order, to figures 7 , 6, et 5 .

[0068] The locking / unlocking mechanism thus comprises: an actuation configuration corresponding to the angular stroke of levers 15, 19 between their locked and unlocked positions, in which the rotational drive of the fork 21 causes the double roller 32 to move along the guide track 29; a release configuration in which levers 15, 19 are in the unlocked position and the fork opening is positioned opposite the opening of the guide track 29 (from the position of the figure 8 ). In this configuration, the double roller 32 is either in its position of the figure 8 , i.e. outside the guidance track 29 (position not shown).

[0069] Alternative embodiments of the aircraft door can be implemented without departing from the scope of the invention. For example, the actuating finger 32 and the roller 25 can comprise one or more rolling or friction rollers, or any other device that can be driven to travel along the guide track 29 or the cam track 26.

[0070] Furthermore, the shape of the guide track 29 can be adapted for other opening and closing strategies than the one given here as an example, by exploiting the movement possibilities of the opening caused by the possible movements of the actuating finger 32.

Claims

1. An aircraft door with lateral escape of stops equipped with a locking / unlocking mechanism for controlling the change from the closed position to the unlocking position and vice versa, said mechanism comprising: - an internal lever (15) and an external lever (19), mounted on the door by being movable between a locking position and an unlocking position; - a control shaft (17) extending along a substantially vertical axis, being mounted on the door by a pivot connection, the internal lever (15) and the external lever (19) being connected transversely to the control shaft (17) so that an action on one of the levers (15,19) causes the control shaft (17) to rotate around its axis; - a guideway (29) extending in a plane substantially orthogonal to the control shaft (17) and having an opening at its end (33); - an actuating finger (32) fixed on a support arm, said actuating finger (32) being adapted to cooperate with the guideway (29); - a mechanical transmission adapted to cause a displacement of the actuating finger (32) when the control shaft (17) is operated in rotation, said transmission comprising a fork (21) disposed opposite the guideway (29) and connected to the control shaft (17) and comprising two actuating arms (34) and an opening (35) at its end such that, in an actuation configuration corresponding to the angular travel of the levers (15,19) between their locking position and their unlocking position, the pivoting of the fork (21) causes the actuating finger (32) to move along the guideway (29) and, in a release configuration where the levers (15,19) are in the unlocking position, the opening (35) of the fork (21) is disposed facing the opening (33) of the guideway (29), characterized in that the two actuation arms (34) of the fork (21) meet opposite its opening (35) in a loop (34A) which is offset transversely with respect to the longitudinal axis of the branches (34) and in that the closed end of the guide track (29) opposite its opening (33) is provided a loop (29E) of enlarged diameter, the wall of which delimits, with the actuating finger (32) in the closing position of the door, a clearance (d) the adjustment of which makes it possible to produce an inward force exerted on the door during a preliminary phase of unlocking.

2. A door according to claim 1, characterised in that it comprises a cam (20) rotating to the control shaft (17).

3. A door according to one of the preceding claims, characterised in that the fork (21) is rotated by a shaft (22) which is itself rotated by said mechanical transmission.

4. A door according to claim 3, characterised in that the vertical axis of the loop (34A) of the fork (21) is offset with respect to the shaft axis (22) in such a way as to produce a mechanical motor effect.

5. A door according to one of claims 2 to 4, characterised in that the mechanical transmission comprises a belt (23) mounted, on the one hand, around said shaft (22) and, on the other hand, on a idler (25) engaged with a roller inserted in a path (26) provided in said cam (20).

6. A door according to one of the preceding claims, characterised in that, in its actuation configuration, the actuating pinch (32) is inserted both in the guide track (29) and in the fork (21).

7. Door according to one of the preceding claims, characterised in that the actuating finger (32) comprises a double roller.

8. A door according to one of the preceding claims, characterised in that in the release configuration the opening (35) of the fork (21) is disposed opposite the opening (33) of the guideway (29).

9. A gate according to one of the preceding claims, characterized in that the actuating finger (32) is never positioned in the loop (34A) of the fork (21) regardless of the position of the mechanism.