Door and door frame assembly for an aircraft equipped with opening assistance

Abstract

The invention relates to an aircraft door (1) equipped with an opening mechanism (2) for opening with respect to a door frame and with an assistance device (3) for assisting the opening mechanism (2) of the door (1), the assistance device (3) comprising: - an arming arm (5) with an arming finger (5c); - an assistance spring between the door (1) and the arming arm (5), this assistance spring generating a thrust force (F) on the arming arm (5); - a retractable lock (6) installed on the door (1), this retractable lock (6) being able to occupy two positions, a locking position and a retracted position, and - an assistance thrust-piece (7) transferring the thrust force (F) from the assistance spring to the opening mechanism (2).

Description

[0001] DESCRIPTION

[0002] DOOR AND DOOR FRAME SET

[0003] FOR AIRCRAFT EQUIPPED WITH AN OPENING ASSISTANCE SYSTEM

[0004] TECHNICAL FIELD

[0005] The invention relates to assisting the opening of an aircraft door or any vehicle equipped with an assisted-opening door in certain situations, such as emergencies. For aircraft, and during these emergencies—fire, emergency landing, etc.—the door must be opened quickly to allow for rapid evacuation. Furthermore, emergency systems, such as inflatable slides, are generally activated and deployed by the door when it is opened in emergency situations. The door opening assistance device therefore helps the operator to quickly open the door and deploy the emergency systems.

[0006] In the aeronautical world, the door opening assistance device is only used in emergency situations, so it may be triggered or not depending on the aircraft's situation when the doors are opened.

[0007] Traditionally, a set of locking stops arranged around the perimeter of the door and its frame are mutually engaged to close and lock the door. These stops are disengaged before the door is opened. The present invention relates more particularly to doors with vertical disengagement of the locking stops (also known as "lift" disengagement), that is, doors that are lifted to disengage the locking stops.

[0008] STATE OF THE ART

[0009] In general, aircraft door opening assistance devices are independent equipment called ejectors which include a pressurized gas, pyrotechnic or electrical energy source, this energy source being able to be triggered by a trigger.

[0010] French patent document FR 2957626 presents an emergency opening ejector comprising a pressurized gas reservoir equipped with a membrane capable of being perforated to release the gas and actuate a cylinder mounted on the door, the trigger being a perforator that pierces the membrane.

[0011] However, this membrane is fragile, and often complex and lengthy maintenance operations are required to make the ejector operational again. These operations involve replacing parts and refilling the gas reservoir. Furthermore, such an ejector is a non-standard system specific to the door on which it is installed, necessitating additional studies and different manufacturing processes for each type of door.

[0012] US patent document 5,289,615 describes a mechanism for assisting the opening of an aircraft door. The mechanism includes a spring between the door frame and the door arm. However, the spring's stiffness is high to assist the opening of the aircraft door, which has a significant mass. Thus, the high spring stiffness causes the door to open abruptly; a hydraulic cylinder is also incorporated to control and dampen this opening.

[0013] DESCRIPTION OF THE INVENTION

[0014] The main objective of the invention is to integrate into the door an operational opening assistance device without requiring maintenance operations.

[0015] In order for the assistance to be used when needed, a permanent energy source of the spring type (gas, helical, leaf, etc.) is combined with a mechanism for arming and disarming this source, this mechanism being incorporated into the kinematics of opening the door.

[0016] More specifically, the present invention relates to an aircraft door equipped with a door opening mechanism relative to a door frame and a device to assist the door opening mechanism, the opening mechanism comprising:

[0017] - a door arm connecting the door to the door frame;

[0018] - an upper lifting hinge and a lower lifting hinge between the door arm and the door, the upper lifting hinge comprising a clevis and a counter-clevis piece, the counter-clevis piece being in pivot connection with respect to the clevis and with respect to the door arm.

[0019] In addition, the door opening mechanism assistance device includes:

[0020] - a cocking arm rotating relative to the counter-piece of the clevis;

[0021] - a cocking finger at one end of the cocking arm;

[0022] - an actuation end of the cocking arm;

[0023] - an assist spring between the door and the actuation end of the cocking arm, this assist spring generating a pushing force on the cocking arm;

[0024] - a retractable bolt installed on the door, this retractable bolt being capable of occupying two positions: a locked position in which it rests on the cocking finger to lock the cocking arm in rotation, and a retracted position in which the cocking arm is free to rotate relative to the clevis counter-piece, and

[0025] - an assistance stop arranged on the door arm near the upper lifting hinge, this assistance stop transferring the pushing force from the assistance spring to the door arm.

[0026] Advantageously, the retractable lock allows the assistance provided by the door opening mechanism to be armed or disarmed. In the locked (disarmed) position, the arm is immobilized and the spring cannot transfer any assistance force to the door arm; the door then opens without assistance, and the opening assistance device is said to be disarmed. In the retracted position, the retractable lock is not in contact with the arm, which can then pivot until it reaches the assistance stop and thus transfer the pushing force from the assistance spring to the door arm, moving the door away from the arm and providing assistance for opening the door.Advantageously, the assist spring also provides a potential source of energy that is constantly available, this energy being released by assisting the opening of the door until the door is hooked onto the fuselage and regenerating when the door is closed.

[0027] Advantageously, the assist kinematics have a reduced number of parts and are therefore easily adaptable to aircraft door opening mechanisms by adjusting the spring thrust force and the dimensions of the cocking arm.

[0028] According to certain preferred embodiments:

[0029] - the assist spring is a helical spring;

[0030] - the assist spring is connected with ball joints to the door and the cocking arm;

[0031] - the retractable lock is pivotally linked to the door to pivot between its two positions;

[0032] - the opening assistance device includes a transfer rod mounted on a pivot on the door arm forming the assistance stop, the transfer rod having a stop track in which a roller of the cocking arm travels, the stop track extending over at least a portion of the transfer rod;

[0033] - the transfer connecting rod has two branches forming a bend, a guide branch and a transfer branch;

[0034] - the stop path extends along the guide branch;

[0035] - the door arm has a stop block as an assistance stop;

[0036] - the cocking arm has a transfer tab resting on the stud.

[0037] Advantageously, the helical spring allows for the storage of a source of compression energy mechanically controlled by the assist stop and the retractable lock.

[0038] Advantageously, the ball joint connections of the spring allow the kinematics of the door opening assistance device to be adapted to the disengagement of the door stops when the door is lifted.

[0039] PRESENTATION OF THE FIGURES Other features and advantages of the present invention will become apparent from the following detailed examples of embodiments, without limiting their scope, with reference to the attached figures which represent, respectively:

[0040] - Figure 1, a view from inside an aircraft of an aircraft door, of an aircraft door opening mechanism according to the invention and of a door opening assistance device comprising a transfer rod;

[0041] - Figure 2, a view from inside the aircraft of the opening mechanism and the assistance device of Figure 1 after the vertical disengagement of the locking stops, the assistance device being disarmed;

[0042] - Figure 3, a view of the interior of the aircraft during the opening of the door with the assistance device of Figure 1 in disarmed mode;

[0043] - Figure 4, a view from inside the aircraft of the opening mechanism and the assistance device of Figure 1 after the vertical disengagement of the locking stops, the assistance device being armed;

[0044] - Figure 5, a view of the interior of the aircraft during the opening of the door with the assistance device of Figure 1 in armed mode;

[0045] - Figure 6, a view from inside the aircraft of an aircraft door, an opening mechanism and a variant of the opening assistance device including an assistance stop block;

[0046] - Figure 7, a view from inside the aircraft of the opening mechanism and the assistance device of Figure 6 after the vertical disengagement of the locking stops, the assistance device being disarmed;

[0047] - Figure 8, a view of the interior of the aircraft during the opening of the door with the assistance device of Figure 6 in disarmed mode, and

[0048] - Figure 9, a view of the aircraft interior during door opening with the assistance device shown in Figure 6 in armed mode. DETAILED DESCRIPTION

[0049] Figure 1 illustrates an aircraft door 1 installed in a door frame (not shown) of the aircraft fuselage, with the door 1 in the closed position. The door 1 is formed by a door panel 1a, two circumferential frames 1b, and two transverse frames 1c; the number of circumferential and transverse frames is not limiting for the purposes of this invention.

[0050] This door 1 is equipped with an opening mechanism 2 relative to its door frame and an assistance device 3 for the door opening mechanism 2, which is described in detail later. The opening mechanism 2 comprises:

[0051] - a door arm 2a in connection between door 1 and the door frame;

[0052] - an upper lifting hinge 2b and a lower lifting hinge 2e between the door arm 2a and the door 1, the upper lifting hinge 2b comprising a clevis 2c and a counter-piece 2d of the clevis, the counter-piece 2d of the clevis being in pivot connection with respect to the clevis 2c and with respect to the door arm 2a.

[0053] Door 1 is held closed within the fuselage by a set of locking stops 1d mounted on the circumferential frames 1b and the door frame. When the aircraft is in flight, the cabin inside the aircraft is pressurized such that the cabin pressure is greater than the external pressure. This pressure difference pushes door 1 outward from the aircraft, but door 1 is held within the aircraft by the locking stops 1d, which resist its movement. The greater the pressure difference, the more the door is held within the aircraft. When door 1 is closed, the door arm 2a and the door panel 1a are substantially parallel.

[0054] Door 1 can only be opened after the locking stops 1d have been disengaged and when the internal and external pressures of the aircraft are identical. In this embodiment, the locking stops 1d are disengaged vertically as illustrated in Figure 2.

[0055] After the locking stops 1d are disengaged, the door 1 opens in a circular motion during which it remains parallel to the aircraft fuselage. This circular motion is achieved by the opening mechanism 2, assisted by guide rods 1e installed on one side at the upper edge of the door 1 and on the other side at the upper edge of the door frame. Furthermore, fasteners 2f provide the pivot connection between the door arm 2a and the door frame.

[0056] Figures 2 and 4 show the aircraft door 1 during vertical disengagement of the locking stops 1d, with the door 1 being moved vertically over a distance E. This door 1 is connected to its frame by the door opening mechanism 2, which includes the door arm 2a and the upper 2b and lower 2e lifting hinges. The door 1 is also equipped with the door opening assist device 3, which connects the door 1 to the door opening mechanism 2.

[0057] This door opening assistance device 3 comprises a cocking arm 5 rotating relative to the counter-piece 2d of the clevis and a cocking finger 5c at one cocking end 5a of the cocking arm 5 opposite to the other actuating end 5b of the cocking arm 5. An opening assistance spring is in this example a helical spring 4 working in compression disposed between the door 1 and the actuating end 5a of the cocking arm 5, this assistance spring being able to generate, when the system is cocked, a thrust force F on the cocking arm 5 from and during the opening of the door.

[0058] A retractable latch 6 is installed on the door 1. This retractable latch 6 can alternately occupy two positions: a locked position – illustrated in Figure 2 – in which it rests on the cocking finger 5c to lock the cocking arm 5 against rotation, and a retracted position – illustrated in Figure 4 – in which the cocking arm 5 is free to rotate relative to the clevis counter-piece 2d. An assist stop, here a transfer rod 7 according to a first embodiment, arranged on the door arm 2a near the upper lifting hinge 2b, allows the thrust force F from the assist spring to be transferred to the door arm 2a.

[0059] In this embodiment, the cocking finger 5c of the cocking arm 5 passes through the clevis counter-piece 2d to support the retractable latch 6 when it is in the locked position. This retractable latch 6 is pivotally connected 6a to the door 1 to pivot between the locked position and its retracted position, as illustrated respectively in Figure 2 and Figure 4.

[0060] The helical spring 4 is connected with ball joints 4a to the door 1 and to the actuation end 5b of the cocking arm 5. These ball joints 4a allow on the one hand the relative movement of the door 1 with respect to the door arm 2a and on the other hand facilitate the vertical release of the locking stops 1d by accompanying the vertical movement of the door 1 by transferring the thrust force F of the helical spring 4 to the cocking arm 5 and to the assist stop from the opening of the door.

[0061] In the first embodiment, illustrated more precisely in Figures 2, 3, 4, and 5, the transfer link 7 is pivotally mounted on the door arm 2a near the upper lifting hinge 2b. This transfer link 7 is positioned between the cocking arm 5 and the door arm 2a, thus transferring the thrust force F from the assist spring of the cocking arm 5 to the door arm 2a.

[0062] Figure 3 shows a view of the door 1 as it is being opened, with the door arm 2a perpendicular to the door panel 1a. This view also details the transfer link 7, which has two arms forming a bend 7d, a guide arm 7a, and a transfer arm 7b. A stop path 7c is included and extends along a portion of the transfer link in the guide arm 7a to the bend 7d. Furthermore, the transfer link 7 pivots relative to the door arm 2a at the pivot end 7e of the transfer arm 7b.

[0063] Furthermore, the cocking arm 5 includes a roller 5d that travels in the stop track 7c of the transfer rod 7. In Figures 2 and 3, the retractable latch 6 is in the locked position, meaning it is bearing against the cocking finger 5c of the cocking arm 5 and prevents its rotation around the upper lifting hinge 2b. Since the rotation of the cocking arm 5 is blocked, the thrust force F of the helical spring 4 cannot be transferred to the transfer rod 7 or to the door arm 2a. The roller 5d therefore travels freely in the stop track 7c, accompanying the opening of the door 1, which is referred to as the daily opening. In Figure 4 and Figure 5, the retractable lock 6 is in the retracted (armed) position and is no longer resting on the cocking finger 5c, thus freeing the cocking arm 5 from rotation around the upper lifting hinge 2b.

[0064] When the door is closed as shown in Figure 1, the helical spring 4, the cocking arm 5, the transfer arm 7b of the transfer link 7, and the clevis counter-piece 2d are aligned. Therefore, the thrust force F does not assist in opening the door 1 because this thrust force F passes through the axis D1 of rotation of the door arm 2a relative to the upper 2b and lower 2e lifting hinges.

[0065] When the door opens, door 1 pivots around the axis D1 of rotation, and the previous alignment is broken, with the transfer arm 7b then being offset relative to the axis D1 of rotation. The thrust force F of the helical spring 4 attached to door 1 is thus transmitted to the cocking arm 5, and more specifically to the roller 5d, which bears against the end of the stop track 7c at the elbow 7d of the transfer rod 7. This bearing therefore transfers the thrust force F of the helical spring 4 to the transfer arm 7b, and in particular to its pivot end 7e, causing the door 1 to rotate relative to the door arm 2a and thus assisting the door opening.

[0066] According to another embodiment illustrated in figures 6, 7, 8 and 9, the door opening mechanism 2 remains identical to that of the first embodiment but the assist stop of the assist device 3 is then made by a stud 8 fixed on a stud support 8a attached to the door arm 2a.

[0067] Figures 6 to 8 illustrate different positions of the door including the assistive stop block.

[0068] In figure 6, door 1 is closed and in this position the arming arm 5 is in contact with the stud 8.

[0069] Figures 7 and 8 depict the opening of door 1 when the retractable latch (not shown in Figure 8) is in the locked (armed) position and prevents the rotation of the cocking arm 5. In this configuration, the helical spring 4 is locked so that it cannot assist in opening the door; the door is said to be in normal opening mode. In Figure 8, it is shown that the clevis 2d of the upper lifting arm 2b has a fork 2g that allows the rotation of the cocking arm 5 to be offset relative to the clevis 2d along the axis of rotation D2, which is parallel to the axis D1.

[0070] Figure 9 shows the opening of door 1 when the retractable lock (not shown) is in the unlocked (Armed) position. As soon as the door opens, the helical spring 4 drives the transfer tab 5e of the arming arm 5, which rests on the lug 8 to push and thus move door 1 away from the door arm 2a, thereby assisting the door opening.

[0071] The invention is not limited to the embodiments described and presented. Thus, any type of spring that autonomously stores release energy can be used, such as a gas spring or a leaf spring.

[0072] Furthermore, the retractable lock can be replaced by any reversible locking mechanism for the cocking arm, such as a pin or a lock pick. The assist stop can also be implemented using a bistable mechanism, one of whose stable positions ensures contact and transfer of force from the cocking arm to the door arm (compression rod).

Claims

DEMANDS 1. Aircraft door (1) and door frame assembly, the door (1) being equipped with an opening mechanism (2) relative to the door frame and an assistance device (3) for the opening mechanism (2) of the door (1), the opening mechanism (2) comprising: - a door arm (2a) in connection between the door (1) and the door frame; - an upper lifting hinge (2b) between the door arm (2a) and the door (1), the upper lifting hinge (2b) comprising a yoke (2c) and a yoke counter-piece (2d), the yoke counter-piece (2d) being pivotally connected to the yoke (2c) and to the door arm (2a); characterized in that the assistance device (3) comprises: - a cocking arm (5) rotating relative to the counter-piece (2d) of the clevis; - a cocking finger (5c) at one cocking end (5a) of the cocking arm (5); - an actuation end (5b) of the arming arm (5); - an assist spring between the door (1) and the actuation end (5b) of the cocking arm (5), this assist spring generating a thrust force (F) on the cocking arm (5); - a retractable bolt (6) installed on the door (1), this retractable bolt (6) being capable of occupying two positions, a locked position in which it rests on the cocking finger (5c) to lock the cocking arm (5) in rotation, and a retracted position in which the cocking arm (5) is free to rotate relative to the counter-piece (2d) of the clevis, and - an assistance stop (7; 8) arranged on the door arm and transferring the thrust force (F) from the assistance spring to the door arm (2a).

2. Assembly according to claim 1 in which the assist spring is selected from a helical spring (4), a gas spring and a leaf spring.

3. Assembly according to any one of claims 1 to 2 in which the assist spring is connected with ball joints (4a) to the door (1) and to the cocking arm (5).

4. Assembly according to any one of claims 1 to 3 in which the retractable lock (6) is in pivot connection (6a) relative to the door (1) to pivot between its two positions.

5. Assembly according to any one of claims 1 to 4 in which the assistance device (3) comprises a transfer rod (7) pivotally mounted on the door arm (2a) forming the assistance stop (7; 8), the transfer rod (7) comprising a stop track (7c) in which a roller (5d) of the arming arm (5) travels, the stop track (7c) extending over at least a portion of the transfer rod (7).

6. Assembly according to claim 5, wherein the transfer link (7) comprises two arms forming a bend (7d), a guide arm (7a), and a transfer arm (7b).

7. Assembly according to claim 6, wherein the thrust bearing track (7c) extends over the guide arm (7a).

8. Any one of claims 1 to 4 in which the door arm (2a) includes a stud (8) as an assist stop (7; 8).

9. Assembly according to claim 8 in which the arming arm (5) has a transfer tab (5e) bearing on the stud (8).

Images