Aircraft cabin door, and aircraft

Abstract

The present invention consists of a side door (20) for an aircraft (10), comprising at least one leaf (21) connected to the cabin structure (11) by an operating mechanism (30), said door (20) being characterized in that the operating mechanism (30) comprises a support arm (31) and a guide rod (32), both extending substantially horizontally and arranged in an articulated quadrilateral (ABCD). To this end, the support arm (31) and the guide rod (32) are articulated to the cabin structure (11) at one of their respective ends, and to the leaf (21) of the door (20) at the other of their respective ends, all axes of articulation being parallel and substantially vertical. Figure to be published with the abstract: [Figure 1]

Description

Title of the invention: Aircraft cabin door, and aircraft technical field

[0001] The present invention relates to the field of light aircraft, particularly airplanes and rotorcraft, with or without occupants, and more specifically to a swing-type side cabin door, and an aircraft equipped with such a door, offering excellent cabin accessibility while preserving the cabin's usable volume, which can be operated safely in flight and on the ground without risk of tearing, and which combines simplicity, reliability, and low cost and weight. In particular, the door must remain substantially parallel to the fuselage, even if curved, during its opening or closing movement, to limit the aerodynamic forces on the door.

[0002] Generally, the cabin of an aircraft has two distinct areas; the forward area (usually called the "cockpit" or "crew cabin"), which accommodates the crew, and the rear area (usually called the "passenger cabin"), which accommodates passengers or cargo, these two areas sometimes being separated by a partition.

[0003] On an aircraft, particularly a rotary-wing aircraft, cabin accessibility is a major concern because it must be perfectly suited to the aircraft's intended missions. Indeed, in the case of passenger transport, ease of access to the cabin directly affects passenger comfort and even their safety in the event of a rapid evacuation. In the case of medical missions, wide access to the cabin is essential for loading a stretcher and the necessary equipment. The same applies to cargo transport or winching operations. These few examples illustrate the importance of choosing the type of door(s) to adopt according to the aircraft's missions.

[0004] In all cases, the opening / closing system, and the doors themselves must encroach as little as possible on the interior space of the cabin in order to preserve the operational capability of the aircraft.

[0005] In the following text, the word "door" refers to the assembly consisting of a leaf capable of totally or partially closing the access opening to the cabin, and an "operating mechanism", intended for opening, closing and fixing the leaf to the structure of the aircraft.

[0006] Typically, the leaf of an aircraft door consists of: • either a peripheral frame, of varying thickness, ensuring the torsional and flexural rigidity of the leaf around its principal axes of inertia, said frame being covered by an external wall, with reference to the cabin, designed for aerodynamics and flush with the fuselage when the door is closed, in order to minimize the increase in aircraft drag, • either a structural, sandwich-type panel, consisting for example of a foam or honeycomb core covered with an outer skin (or wall) and an inner skin, generally made of fiber / resin composite materials, • all the components necessary for closing, locking, sealing and other possible functions, such as, for example and without limitation, an electrical control for opening / closing the door, • and possibly a lining for the inner wall of the door leaf, intended to improve aesthetics, acoustic or thermal insulation, or even comfort.

[0007] Furthermore, in the remainder of the text, the same word "opening" refers, depending on its context, either to the opening in the fuselage providing access to the cabin or to the movement of the door. In case of ambiguity, we will specify "cabin opening" (opening in the fuselage) or "door opening" (movement of the door). Previous technique

[0008] Schematically, the doors of the Prior Art installed on aerial or land vehicles belong to three main families: hinged doors, sliding doors, swing doors. • Hinged doors (automobiles, aircraft cockpits): These pivot around an axis near one of their lateral edges. Their main drawback is their limited opening, constrained by geometric limitations. For the door leaf to reach or exceed 90°, their operating mechanism becomes complex and expensive. Most importantly, a hinged door is incompatible with in-flight operation because the leaf would directly obstruct airflow and would be immediately torn off by the relative wind due to the aircraft's speed. • Sliding doors (buses, cars, trains, helicopter cabins): These are held in place by rollers that roll or slide in rails installed at the top and bottom of the opening, and sometimes behind it. The rails are generally visible and can detract from the aircraft's aesthetics and aerodynamics. Most importantly, experience shows that sliding doors can become misaligned, or even jam, if the geometry of their guiding mechanism is altered by structural deformations of the cabin and by the strong stresses they undergo during handling and closing. • Swing doors (buses, airliners): these are held and driven by a mechanical device of the articulated quadrilateral type, which generally imposes a roughly circular translational movement. Ultimately, only swing door technology is of interest to us because it does not present the drawbacks of hinged or sliding doors, considered insurmountable for our application. The following documents provide background information on the technology: • In the aeronautical field, US patent 4720065, issued on January 19, 1988, to THE BOEING COMPANY, is well-known and exemplifies the technical principle commonly adopted for cabin doors on large commercial aircraft. It describes an aircraft door supported and driven by an arm pivoting around a substantially vertical axis, and guided by a set of connecting rods mounted in a double articulated parallelogram to maintain the door leaf substantially parallel to the straight fuselage of the aircraft during opening / closing maneuvers.

[0009] More specifically, a substantially horizontal rigid arm, the first end of which is connected to one of the two lateral uprights reinforcing the opening by means of a first hinge pivoting about a substantially vertical axis, and the second end of which is connected to the door by a second hinge pivoting about said substantially vertical axis. This arm supports the door leaf and allows its swinging opening / closing movement, thus ensuring transverse contact of the leaf with its frame, and therefore perfect embedding of the leaf in the closed position, the leaf then being flush with the fuselage.

[0010] In addition, a connecting rod articulated on the leaf by one of its ends around a vertical axis and connected by its other end to a cascade of three levers articulated around vertical axes, cooperate with said arm to form an articulated parallelogram, which imposes on the leaf a quasi-circular translational movement so that its orientation remains constant and parallel to the straight fuselage of the aircraft during the entire opening / closing movement.

[0011] The door described in US patent 4720065 therefore pursues an objective incompatible with that of our present application, since it maintains the orientation of the door leaf constant and thus does not give it a slight pivoting movement to substantially accommodate the possible curvature of the fuselage behind the opening. Furthermore, the cascade of levers required for the invention according to US patent 4720065 is bulky and complex, and therefore unsuitable for a light aircraft.

[0012] Aircraft are also known whose doors use the same principle as the previous US patent 4720065, but replace the cascade of levers with a pair of connecting rods mounted in an articulated parallelogram. Since these doors also have a translational movement, they do not address our problem. • Patent application W02010001210A3, published on 08 / 04 / 2010 For EUROCOPTER DEUTSCHLAND GMBH, describes a door opening / closing device using two rigid arms mounted in an articulated parallelogram, fixed on one side to the door leaf at slightly offset points longitudinally, and on the other side to one of the two vertical uprights of the opening at two points offset by the same amount. The movement imposed on the door leaf is thus a circular translation. This patent provides for two arm configurations: either one arm supports the door leaf while the other arm actuates the door leaf, or both arms support and actuate the door leaf.

[0013] The door described in this patent application therefore pursues an objective incompatible with that of our present application, which does not aim at a translation of the door leaf but at a combination of translation and pivoting so that the trajectory of the door leaf substantially follows the curvature of the fuselage behind the opening. Furthermore, since the articulation axes of the two arms are both fixed near the rear frame of the opening, they are necessarily very close to each other. Consequently, the parallelogram is very narrow and poorly suited to withstand the forces introduced by the pivoting moments of the door leaf around its vertical axis under the effect of gusts of wind or somewhat rough handling.

[0014] These two documents from the aeronautical field therefore do not reveal a door concept that meets our problem. • In the automotive field, patent application FR2032069, published on November 9, 1970, in the name of ATELIERS DE LA MOTOBECANE, describes a motor vehicle door equipped with an articulated trapezoidal mechanism using two connecting rods. The parameters of the quadrilateral, namely the center-to-center distances of the connecting rods (distance between the two articulation axes) and the angles of the quadrilateral, are optimized to impose on the door leaf a movement combining circular translation and pivoting, which significantly reduces the lateral space required to open the door compared to a conventional hinged door. However, such a door cannot open the opening as wide as desired, due to interference between the connecting rod 10 and the front pillar of the opening, because the articulation pivot of said connecting rod 10 on the front pillar of the opening is necessarily offset towards the interior of the passenger compartment to be sufficiently The offset is positioned at a distance from the pivot point of connecting rod 4 to ensure the articulated quadrilateral is sufficiently rigid and can achieve the desired kinematics. Another consequence of this offset is an excessively large passenger compartment. For the same reason, the offset between the two pivot points on the door panel necessitates a relatively thick door panel. • US patent 6382705B1, issued on May 7, 2002, to General Motors, describes a car door attached to the body by means of a "hinge" consisting of two arms. One end of the hinge is fixed to the body, and the other end is fixed to the door leaf. The two arms of the hinge are arranged in a quadrilateral articulated around vertical axes. This quadrilateral is designed to impart a specific movement to the door. First, it pivots so that its rear edge moves apart laterally and releases the weatherstripping. Then, it translates in a circular motion towards the rear while continuing to pivot. Finally, it completes its movement by pivoting in the opposite direction to become substantially parallel to its initial orientation, and therefore parallel to the vehicle's body, which is generally straight.

[0015] The operating mechanism disclosed in this patent allows for a combination of circular translation and pivoting, but does not solve our problem since it does not keep the door substantially parallel to the fuselage during its movement in the case of a fuselage curved behind the opening. Furthermore, the size of this mechanism is quite significant because the hinge comprises two adjacent arms, whose respective pivot points on the frame must be sufficiently far apart laterally to produce the desired kinematics while ensuring good rigidity and stability of the articulated quadrilateral.

[0016] In conclusion, none of the prior art documents describe a door that: • In the open position, it almost completely clears the cabin opening. • can be opened in flight without risk of tearing (rigidity, robustness), • does not clutter the interior volume of the cabin, • can be operated manually in a simple, intuitive way and with little effort, • can be easily motorized • includes an armrest function, • offers high reliability, at minimal weight and cost • is compatible with a cabin without a central pillar between a cockpit access door and a passenger cabin access door, in order to obtain maximum accessibility. First object of the invention

[0017] To remedy the shortcomings of the Prior Art, a first object of the invention is an aircraft side door, said aircraft comprising at least one cabin intended to accommodate cargo or at least one occupant and provided with at least one floor, a ceiling, a rear bulkhead and a side opening extending substantially to said rear bulkhead and closable by said door, which comprises at least one leaf connected to the cabin structure by an operating mechanism, said door being notable in that the operating mechanism comprises a support arm and a guide rod, both extending substantially horizontally, the proximal end of the arm, with reference to the leaf, being fixed to the leaf by a pivoting means about a first axis, the distal end of said support arm being fixed to the cabin structure, near the rear edge of the opening, by a pivoting means about a second axis,the proximal end of the connecting rod, with reference to the door leaf, being fixed to the door leaf by a means of connection articulated around a third axis, the distal end of the connecting rod being fixed to the cabin structure, near any one of the lower or upper edges of the opening, by a means of connection articulated around a fourth axis, said four axes being all parallel and substantially vertical, so that their projection onto a plane perpendicular to them constitutes the vertices of an articulated quadrilateral.

[0018] A definition of the three directions horizontal, longitudinal and transverse, forming a direct orthogonal trihedron, can be found in the chapter "Description of drawings".

[0019] In order to avoid any ambiguity of vocabulary, it is specified that a pivot joint has only one degree of freedom, in rotation around its pivot axis, whereas the expression "joint articulated around an axis", used in the present application, designates a joint that can have several degrees of freedom in rotation, which is notably the case of a ball joint, which has three.

[0020] In the rest of the text, the support arm will generally be referred to as "arm", the guide rod will be referred to as "connecting rod".

[0021] Furthermore, to clarify the meaning of the expression "substantially vertical," it is specified that the invention functions even if the four respective axes of the arm and connecting rod links on the door and the structure are not perfectly vertical but are all slightly inclined at the same angle, on the order of 10° maximum in practice, relative to the vertical. If the axes are inclined towards the front of the aircraft, then the door will rise slightly during its opening movement towards the rear of the aircraft, and will descend during its closing (and vice versa if the axes are inclined towards the rear of the aircraft). Such a configuration can be advantageous to adapt to geometric or kinematic constraints specific to the aircraft. Door leaf

[0022] In one embodiment, the inner wall of the door leaf has a substantially horizontal recess extending at least the length of the arm, and the arm and its connecting means are configured such that the arm is entirely contained within the total thickness of the door leaf when the door is closed. Thus, the arm does not reduce the usable space of the cabin, that is, the space actually available for occupants or cargo, excluding inaccessible or unusable spaces between or behind equipment or structural elements. Similarly, the arm does not create any inconvenience for any occupant seated near the door.

[0023] In a particularly advantageous embodiment, the inner wall of the door leaf comprises a structural element having a substantially flat and horizontal upper surface, extending over a length of approximately 50 cm, at a height of approximately 60 cm above the floor, and positioned above the arm when the door is closed, thus enabling the inner wall of the door leaf to function as an armrest. It is considered that, in order to function as an armrest, this structural element must have a length close to that of a human forearm, approximately 50 cm, and a width close to that of a human forearm, approximately 10 cm. It should also be noted that 60 cm is the average height, relative to the floor, of the forearms, positioned horizontally, of a passenger seated in an aircraft. These values ​​may vary depending on the desired level of comfort and installation constraints.

[0024] In another embodiment, in which the leaf is provided with a stiffening frame around its perimeter, said structural element can be rigidly fixed to the front and rear uprights of said stiffening frame, so that said structural element contributes significantly to the overall rigidity of the leaf.

[0025] In another embodiment, in which the structure of the leaf is of sandwich construction, i.e. made up of two skins stabilized by a central core, the structural element intended as an armrest can advantageously be an integral part of the working structure of the leaf, thus providing significant stiffening of the leaf, which significantly reduces its warping for a minimum mass since said structural element does not require additional means of fixing to the wall of the leaf.

[0026] And in a particularly advantageous embodiment, the pivoting means for connecting the arm to the door leaf is a bracket, rigidly fixed to the door leaf, and whose upper flange has a substantially flat and horizontal upper surface intended as an armrest, extending over a length of approximately 50 cm, at a height of approximately 60 cm above the floor, and positioned above the arm when the The door is in the closed position. This embodiment minimizes the number of elements required to provide the armrest function and the articulated arm joint. Support arm

[0027] In all embodiments, the side door is connected to the structure by means of at least one substantially horizontal arm having high torsional rigidity about its three proper axes of inertia. A first end of the arm, proximal with respect to the door leaf, is fixed to the door leaf by a pivot connection means, also called a hinge, about a first substantially vertical axis, and the distal end of the arm is fixed to the cabin structure, near the rear edge of the opening, by a pivot connection means, about a second axis, substantially vertical, and parallel to said first axis.

[0028] In a preferred embodiment, the distal end of the arm is fixed to the rear partition.

[0029] The arm is dimensioned to withstand the forces and moments introduced by the weight of the complete door, the aerodynamic forces exerted on the door leaf, and the operating forces applied by an operator. The arm and its two joints therefore bear the greater part of the forces acting on the door, with the exception of the moments about the vertical direction, since the door leaf is hinged around a vertical pivot at the proximal end of the arm. The guide rod is responsible for resisting these moments about the vertical direction.

[0030] In a preferred embodiment, viewed from above and in the closed position, the arm consists of a first straight and slender section, connected to the door leaf at its proximal end, extended rearward and outward from the cabin by a second section, shorter and slightly angled relative to the first, and fixed to the cabin structure at its distal end. In other words, the arm is slightly bent near its distal end so that it can pivot relative to the cabin structure with the greatest possible angular deflection without interfering with the rear edge of the opening when the door approaches its maximum opening position. The length of the second section, the angle of the bend, and the position of the arm's pivot axis on the structure are chosen such that, when the door is in the closed position, the arm is entirely within the thickness of the door leaf.

[0031] The clearance of the door leaf, that is to say, the portion of the cabin opening not obstructed by the door leaf in the open position, depends directly on the center-to-center distance of the arm and its total pivot angle. It should be noted that a total pivot angle of 180°, which would maximize the door leaf clearance, must be avoided because it would induce instability in the articulated quadrilateral, whose sides would in this case all be aligned (complete "flattening" of the quadrilateral), said quadrilateral then being able to lock depending on the stresses it receives from the operator. In practice, a total pivot of approximately 160° allows for a large clearance of the leaf while ensuring good rigidity and stability of the operating mechanism.

[0032] In a preferred embodiment, the center distance of the arm is substantially equal to half the width of the leaf, and the total pivot angle of the arm is on the order of 160°.

[0033] The expression "nearby" should be understood as meaning "as close as technically possible," that is, within a few centimeters, generally less than 10 cm. Such a geometry minimizes the arm's center-to-center distance required for maximum door clearance, allowing access to the cabin through almost the entire fuselage opening. It should be noted that since the arm's center-to-center distance is approximately equal to half the width of the door, its pivot point on the door is located approximately halfway across the door's width, as its pivot point on the structure is fixed near the rear edge of the opening. Other values ​​are obviously possible depending on installation constraints, but will deviate from the design optimum, and therefore from the minimum mass and cost, or will limit the door clearance.Note, as an example for a small or medium tonnage aircraft, that the center-to-center distance of the arm, close to half the width of the door leaf, is in practice around 30 to 50 cm because the width of the door leaf is around 60 to 100 cm to allow comfortable access to the cabin.

[0034] In one embodiment, the arm is positioned at a height of approximately 60 cm above the floor, and said arm has a substantially flat and horizontal upper surface, making said arm suitable for providing an armrest function when the door is in the closed position.

[0035] In a preferred embodiment, the arm is a horizontally slender box with a substantially rectangular vertical cross-section, positioned at a height of approximately 60 cm above the floor, and whose upper surface is substantially flat and horizontal, making the arm directly suitable for use as an armrest when the door is closed. Such a box-shaped structure provides the arm with excellent rigidity around its three main axes of inertia, and this embodiment, in which the arm directly performs the function of an armrest, is particularly advantageous because it constitutes the lightest solution for integrating an armrest into the door.

[0036] In other embodiments, the vertical section of the arm may have another shape, in particular and without limitation, circular, elliptical or trapezoidal.

[0037] In a particular embodiment, the arm comprises at its upper part a complementary element, the upper surface of which is substantially flat and horizontal, making said arm suitable for serving as an armrest when the door is in the closed position. Such an embodiment is well suited to arm configurations that do not inherently make it suitable for the function of an armrest.

[0038] In one embodiment, the ends of said complementary element cover the two respective means of connecting the arm to the door leaf and to the cabin structure, in order to improve the aesthetics of the door and to eliminate any risk of injury in the event of possible contact of the arm of the seat occupant with said respective means of connecting the arm to the door leaf and to the cabin. guide rod

[0039] The main role of the connecting rod is to guide the pivoting of the leaf around the articulated link of the leaf with the proximal end of the arm.

[0040] In a preferred embodiment, the distal end of the connecting rod is fixed to the floor.

[0041] In another embodiment, the distal end of the connecting rod is fixed to the ceiling of the cabin.

[0042] These two methods of fixing make the connecting rod particularly discreet and allow a robust connection that does not require reinforcement of the edges of the opening.

[0043] In combination with the support arm, said connecting rod serves to prevent the door leaf from freely pivoting around its proximal articulated connection with the arm, by imposing an orientation that is substantially parallel to the fuselage throughout its opening or closing movement, the fuselage of a light aircraft, particularly a rotary-wing aircraft, generally not being straight but curved. The essential purpose of this particular arrangement is to reduce the aerodynamic drag of the door leaf by forcing the leaf to remain substantially parallel to the airflow along the aircraft fuselage, which has the effect, on the one hand, of reducing the stresses on the door leaf and therefore on the entire door, and on the other hand, of minimizing disturbances to said airflow, and thus the aerodynamic drag of the aircraft.Furthermore, the guide rod stabilizes the door leaf by limiting its deformations, particularly those caused by aerodynamic forces or forces exerted by an operator handling the door. The overall rigidity of the door is thus significantly increased, resulting in smooth operation during the various phases of opening and closing.

[0044] Thus arranged, the arm and the connecting rod function according to the principle of an articulated quadrilateral (also called a deformable quadrilateral). More precisely, in projection onto a plane perpendicular to the common direction of the pivot axes of the arm and the connecting rod, that is to say a substantially horizontal plane, the pivot axes of the arm and the connecting rod become four points, designated as articulation points, constituting the four vertices of an articulated quadrilateral.

[0045] The kinematics of the door depend directly on the construction parameters of said articulated quadrilateral.

[0046] In a particular embodiment, the respective center distances of the arm and the connecting rod are identical, and the arm and the connecting rod are parallel, so that the articulated quadrilateral is a parallelogram. In other words, the distance between the two respective articulation points of the arm and the connecting rod on the structure is equal to the distance between the two respective articulation points of the arm and the connecting rod on the door leaf. In such a configuration, the door undergoes a purely circular translational motion when the arm is rotated about its pivot point attached to the structure.The door therefore maintains the same orientation (translation) throughout its entire movement, which is particularly advantageous for a cabin and rear fuselage that are relatively straight, as the door remains substantially parallel to the structure, allowing the aircraft to fly with the door open while minimizing the risk of it being torn off by the longitudinal relative wind.

[0047] In all other embodiments, that is to say when the respective center distances of the connecting rod and the arm are different from each other, the movement of the leaf consists of a circular translation to which is added a pivoting around its axis of connection with the proximal end of the arm, the characteristics of said pivoting movement being determined by the construction parameters of the quadrilateral.

[0048] In a preferred embodiment, the respective center distances of the arm and the connecting rod are slightly different, so that the movement of the leaf is the combination of a circular translation around the axis of the pivot joint of the distal end of the arm on the structure, and a pivoting around the axis of the pivot joint of the leaf on the proximal end of the arm, the construction parameters of the quadrilateral being chosen so that the leaf remains substantially parallel to the side of the fuselage, even curved, during its opening or closing movement.

[0049] It should be noted, however, that in practice the articulated quadrilateral must be close enough to a parallelogram so that the movement of the leaf remains close to a circular translation, while including a slight oscillation component, or swaying, that is to say a small controlled rotation of the leaf around its axis of connection with the proximal end of the arm, in reference to the leaf.

[0050] In a preferred embodiment, the parameters are chosen so that the leaf remains, during its movement, substantially parallel to the adjacent portion of the fuselage, despite the possible curvature of the fuselage, in order to limit as much as possible the drag induced by the leaf, the latter then disturbing little the airflows flowing along the fuselage since it is substantially parallel to these airflows.

[0051] In a particular embodiment, the center distance of the arm is about 2% shorter than the center distance of the connecting rod, and in the closed position, the two acute angles of the quadrilateral, which are almost identical in this case, are on the order of 15°. Such The door's design allows for a movement well-suited to the fuselage of a light aircraft; the door leaf remains essentially parallel to the aircraft's sagittal plane at the beginning of the opening phase, then pivots slightly to remain essentially parallel to the fuselage, which gradually tapers from the cabin to the tail. Thus, despite the fuselage's curvature, the door leaf remains essentially parallel to the fuselage during its opening or closing movement in flight, and particularly in the fully open position. This minimizes the drag induced by the door leaf and, consequently, the aerodynamic forces on the entire door and its hinge points.

[0052] Furthermore, since it does not have to absorb the moments around the longitudinal and transverse directions, which are entirely absorbed by the arm, the guide rod can be mounted freely to rotate around these longitudinal and transverse directions, given that it is mounted pivotally around the vertical direction. The rod is then only subjected to tensile or compressive forces.

[0053] Thus, in a preferred embodiment, the articulated linkage means of the guide rod are ball joint linkage means, which facilitates their assembly by avoiding any hyperstaticity.

[0054] It should also be noted that, since it does not have to resist these significant moments about the longitudinal and transverse directions, the guide rod can be much lighter in size than the arm. Furthermore, the distance between the arm and the guide rod directly determines the level of tensile or compressive forces exerted by the guide rod on the leaf to resist the pivoting moments of the latter about its vertical axis, these moments being mainly due to relative wind and rotor wash. In other words, the greater the distance between the arm and the guide rod, the lighter the size of the guide rod and its joints can be. Moreover, the rigidity and stability of the articulated quadrilateral increase with the distance between the arm and the guide rod.They are at their maximum when the proximal end of the connecting rod is fixed closest to the front edge of the sash, while the distal end of the connecting rod, fixed to the floor or ceiling, will be positioned towards the middle of the opening.

[0055] Thus, in all embodiments, the connecting rod and its articulated joints are compact, which allows them, in the closed position, to be easily housed under the cabin floor or in its ceiling, using only the available space, without encroaching on the usable volume of the cabin and without requiring significant structural reinforcements. If installation of the guide rod under the floor is not feasible, for example due to an opening in the floor required for the installation of a winching device, it is possible to install the rod in the cabin ceiling. As the ceiling generally has a certain thickness due to the presence of mechanical, electrical or hydraulic components, which is also the case with a winch gantry, then the connecting rod can advantageously be concealed in the thickness of the ceiling, without loss of usable cabin volume, or alteration of its aesthetics.

[0056] Finally, the door assembly may, if necessary, include a stiffening element, for example, a connecting rod with ball joints at both ends, inserted between the door leaf and the structure on the side opposite the guide rod, i.e., on the ceiling if the rod is fixed to the floor and vice versa, in order to reinforce the rigidity of the door around the longitudinal direction in particular, and thus limit its deformations under the effect of aerodynamic loads, especially during flight with the door open. For the complete door assembly to be rigid without being statically indeterminate, the stiffening element must be located directly above the connecting rod, have the same center-to-center distance as the connecting rod, and the respective pivot axes of the guide rod and the stiffening element must coincide. Method of recall

[0057] In an advantageous embodiment, the door operating mechanism is provided with a means for returning the door to its extreme open or closed positions, consisting of a gas spring (known from the Prior Art) arranged substantially horizontally, the proximal end of which, with reference to the door leaf, is fixed to the distal end of the arm by a connecting means articulated about a fifth axis, parallel to the pivot axes of the arm, said articulated connecting means consisting of a lever rigidly fixed to the distal end of the arm, and configured as a yoke cooperating with the proximal end of said gas spring, while the distal end of the gas spring is fixed to the partition by a connecting means articulated about a sixth axis, parallel to the pivot axes of the arm, said fourth articulated connecting means consisting of a yoke fixed to the partition and cooperating with the distal end of the gas spring,The cylinder is roughly aligned with the arm when the door is in an intermediate open position.

[0058] In a preferred embodiment, both ends of the cylinder are provided with ball joints to facilitate their assembly.

[0059] This particular arrangement of the gas spring allows it to exert a significant restoring force on the door near its two extreme positions, open or closed, while remaining relatively neutral during a large part of the opening or closing movement. Indeed, to open the door, it is first necessary to overcome the restoring force exerted by the gas spring, which initially benefits from a favorable lever arm effect due to the misalignment between the gas spring and the arm when the door is closed. Then, as the lever arm decreases rapidly with the pivoting of the arm, the force required to open the door also decreases, until it is almost zero. Apart from frictional forces, in the vicinity of the intermediate opening position, which corresponds to the alignment of the cylinder and the arm, and finally, beyond the intermediate position, the cylinder actually assists the operator to continue the maneuver because the cylinder's line of action passes to the other side of the arm's main axis. The behavior of the return mechanism is the same from the closed position onward. The main advantage of this design is that it prevents unintentional opening in flight, since it is necessary to overcome the cylinder's return force to initiate the door opening. Furthermore, the assistance provided to the operator in the second part of the movement enhances ease of use.

[0060] In addition, in a preferred embodiment, the return means is a damped gas spring (also known from the Prior Art), ensuring damping of the door movement at the end of opening and at the end of closing, thus limiting the shocks between the leaf and the cabin structure at the end of the door operation.

[0061] A damped gas spring installed according to the invention, simultaneously exerting thrust and damping thanks to the gas and oil it contains, performs two complementary functions: • The thrust of the cylinder holds the door in both its open and closed positions, while it remains relatively neutral during much of the opening or closing movement. • The end-of-travel damping prevents the door leaf from coming into sudden contact with the cabin structure, thus avoiding damaging impacts caused by an operator or by gusts of wind.

[0062] Furthermore, in a preferred embodiment, to complement the action of the damper, at least one elastic stop is disposed either between the arm and the structure, or between the arm and the leaf, or between the leaf and the structure, to absorb the residual shocks between the leaf and the fuselage at the end of opening.

[0063] It should be noted that generally, door seals, which are essential to ensure the cabin is watertight, at least partially provide this shock absorption function when the door is closed. Controlled actuator

[0064] In a particularly advantageous embodiment, the arm is driven by a controlled actuator capable of opening and closing the door and slowing its movement at the end of its travel to prevent collisions between the door leaf and the cabin structure. Such an actuator is capable of operating the door independently, i.e., without any muscular effort from an operator. The control means for said actuator has the essential function of regulating the arm's operating speed to ensure, in particular, deceleration at the end of its travel to prevent any damaging collision between the door leaf and the cabin structure. arm on detection of abnormal forces for safety, or any other complementary function.

[0065] In a preferred embodiment, the controlled actuator is rotary and consists of an electric motor rigidly fixed by means of an articulated linkage of the arm to the cabin structure, a mechanical gearbox whose output shaft is coaxial with the articulation shaft of said linkage, and a control and servo means. This arrangement makes it possible, in particular, to fix the actuator to the lower part of the articulated linkage of the arm, thereby concealing the actuator under the arm and preventing any accidental contact between an occupant and the actuator.

[0066] Structurally different but functionally identical assemblies are obviously possible. Furthermore, it should be noted that the installation of such a motorized cylinder can be compatible with that of a damped gas spring, but the latter becomes unnecessary or even problematic when the actuator's control includes deceleration at the end of its stroke. Second object of the invention

[0067] Another object of the present invention is a light aircraft, fixed-wing or rotary-wing, piloted or unpiloted, whose cabin has, on at least one side, a single opening that can be closed by two doors joined together in the closed position, a first door providing access to the cockpit, and a second door, according to the first object of the present invention, providing access to the passenger or cargo cabin. In other words, the cabin has no central pillar separating the two doors.

[0068] Thus, in a preferred embodiment, the aircraft comprises, in addition to a door according to the invention, at least one cockpit access door, placed in front of the door according to the invention, and opening towards the front of the aircraft, the rear edge of the leaf of the cockpit access door and the front edge of the leaf of the door according to the invention being joined when the two doors are in the closed position, so that accessibility to the cabin is maximized when the two doors are in the open position. Description of the drawings

[0069] The invention, its operation, and its advantages will become apparent in greater detail in the following description, with non-limiting examples of embodiments illustrated by the accompanying figures. It should be noted that in the examples described below, the door according to the invention is located on the right side of the aircraft. A simple symmetry can be made by a person skilled in the art to apply the invention to a door located on the left side of the aircraft.

[0070] The figures show three orthogonal reference directions attached to the aircraft: • the X direction, also called longitudinal. It corresponds to the aircraft's roll axis. The terms front, rear, anterior, and posterior refer to this direction. • the Y direction, also called transverse. It corresponds to the pitch axis of the aircraft. The terms lateral, transverse, side, refer to this direction. • the Z direction, also known as the elevation direction. It corresponds to the yaw axis of the aircraft. The terms upper, lower, top, bottom, summit, base, above, below, refer to this direction.

[0071] For the sake of simplifying the description, the aircraft is represented in horizontal flight, that is to say that the elevation direction Z is vertical.

[0072] The word "occupant" refers indifferently to a crew member or a transported passenger, seated in a cabin seat.

[0073] The word "operator" means any person operating the door, whether an occupant of the aircraft or a person outside the aircraft (e.g., ground personnel).

[0074] The “direction” of an arm refers to the angle formed, in a horizontal plane XY, by the line connecting the two joints of said arm with the longitudinal direction X.

[0075] Throughout this description, a pivot joint means a cylindrical material component capable of pivoting around a geometric axis.

[0076] Reference 10 designates an aircraft, partially or sometimes not shown according to the figures, in particular a light rotary-wing aircraft in the examples chosen.

[0077] [Fig.1] shows, in a partial longitudinal elevation cross-sectional view, the different elements constituting the door which is the subject of the invention, and their means of attachment to the structure of the aircraft cabin.

[0078] [Fig.2] shows, in a partial cross-sectional elevation view, the different elements constituting the door which is the subject of the invention, and their means of fixing to the structure of the aircraft cabin, the door being in an intermediate open position.

[0079] [Fig.3] shows, in projection in a horizontal plane, the kinematics of the articulated quadrilateral formed by the arm and the connecting rod, the door being in an intermediate position.

[0080] [Fig.4] shows, in a horizontal cross-sectional view, the door in the closed position.

[0081] [Fig.5] shows, in a horizontal cross-sectional view, the door in the open position.

[0082] [Fig.6] shows, in a horizontal cross-sectional view, the details of the connections of the cylinder to gas on the arm and the partition, as well as its kinematics.

[0083] [Fig.7] shows, in a schematic longitudinal sectional elevation view, a example of an armrest integrated into the arm.

[0084] [Fig.8] shows, in a schematic longitudinal sectional elevation view, an example of an armrest integrated into the door leaf, in the closed position.

[0085] [Fig.9] shows, in a partial cross-sectional elevation view, an example rotary actuator fixed under the connecting bracket of the arm to the partition. General construction principles and kinematics

[0086] Fig. 1 illustrates an example of an embodiment of the door 20 of the invention, consisting of a leaf 21 closing the lateral opening 15 of the cabin 11 of the aircraft 10, and a maneuvering device 30, connecting the leaf 21 to the structure of the cabin 11, equipped with a seat 16 to accommodate at least one occupant.

[0087] In [Fig. 2], which shows an example of an embodiment of the invention in an intermediate open position, the relative positioning of the arm 31 and the connecting rod 32 can be seen, in substantially horizontal planes, but at different elevations. In this example, the proximal end of the arm 31, with reference to the door leaf 21, is fixed substantially at mid-height of the door leaf 21, and its distal end is fixed substantially at mid-height of the partition 14, while the connecting rod 32 is fixed, by its proximal end, to the bottom of the door leaf 21, and by its distal end, under the floor 12 of the cabin 11, which makes it particularly discreet. In other embodiments, the connecting rod 32 can be fixed, by its proximal end, at the top of the leaf if it is not possible or optimal to place it at the bottom of the leaf 21, its distal end then being fixed to the ceiling 13 of the cabin 11.

[0088] As illustrated in the [Fig.3], the proximal end of the arm 31, with reference to the leaf 21, is fixed to the leaf 21 by a pivot joint 33 about a first axis 33', the distal end of the arm 31 is fixed to the cabin structure 11, near the rear edge of the opening 15, by a pivot joint 34 about a second axis 34', the proximal end of the connecting rod 32, with reference to the leaf 21, is fixed to the leaf 21 by a hinged joint 35 about a third axis 35', the distal end of the connecting rod 32 is fixed to the cabin structure 11, near any one of the lower or upper edges of the opening 15, by a hinged joint 36 about a fourth axis 36', and the four axes 33', 34', 35', 36' are all parallel and substantially vertical, so that their projections onto a plane perpendicular to them constitute the vertices of an articulated quadrilateral ABCD, substantially horizontal in the chosen embodiment.

[0089] Figs. 3, 4, and 5 show three notable positions of the door.

[0090] In [Fig. 4], the door is completely closed; the arm 31 is then substantially parallel to the door leaf 21, which allows it to be integrated as best as possible into the thickness of the door leaf 21, while the connecting rod 32 is concealed under the floor 12. Thus, the arm 31 and the connecting rod 32 do not in any way reduce the usable volume of the cabin, that is to say, the space actually available for the occupants or the cargo, excluding the spaces inaccessible or unusable between or behind equipment or structural elements.

[0091] In [Fig. 3], the door is in an intermediate position; the arm 31 and the connecting rod 32 are Significantly extended transversely, the door leaf is then in its furthest laterally position from the aircraft fuselage 17, and therefore from the passenger occupying the seat next to the door. This position is crucial for the passenger's comfort and safety, as they should not have to lean out of the cabin to manually operate the door, which is then far from their shoulder. Therefore, consideration of this position by a person skilled in the art is important when choosing the dimensions and kinematics of the door.

[0092] In [Fig. 5], the door is in its rearmost position; the accessibility of the opening 15 is then at its maximum, for the example chosen, the front edge of the leaf 21 being moved back considerably to the level of the seat back 16, thus allowing comfortable access to the seat 16. This [Fig.5] shows the advantage of the slightly angled shape of the arm 31 in the example chosen, which allows the arm 31 to pivot towards the rear of the aircraft 10 without interfering with the rear edge of the opening 15 or with the outer edge of the partition 14. Details of the arm and its connections

[0093] In the embodiment chosen from all the figures, the arm 31 is a slender box in a horizontal plane, with a rectangular vertical cross-section. This shape provides it with high rigidity around its three principal directions of inertia. The longest dimension of the rectangular cross-section is oriented substantially vertically to maximize the horizontal bending stiffness of the arm 31, as the arm must firmly support the entire door 20. The center-to-center distance of the arm 31 is substantially equal to half the width of the door leaf 21 of the door 20, to allow ample clearance of the opening 15 of the cabin 11 when the door is in the open position. A longer center-to-center distance would allow even greater clearance, but this is unnecessary in the chosen example because access to the rear of the opening 15 remains limited by the presence of the seat back 16.Conversely, a shorter center distance would limit the clearance of opening 15 and access to seat 16 would then be uncomfortable.

[0094] In its largest dimension, oriented substantially along the longitudinal direction X, in the closed position of the leaf 21, the arm 31 adopts a generally straight shape, but slightly angled in a horizontal plane and outwards from the cabin, near its distal end, so that the arm 31 can pivot outwards and towards the rear of the aircraft 11 while avoiding contact with the rear edge of the opening 15, or with the outer edge of the partition 14. Thus, in the example chosen, the total pivot angle of the arm 31 is substantially 160°, quite close to the theoretical maximum of 180°, which would be useless in the example chosen because of the presence of the seat back 16.

[0095] If necessary, in an embodiment not shown, it is possible to slightly notch the rear edge of the opening 15, and possibly the outer edge of the partition 14, locally at the height of the arm 31, to allow the arm 31 to pivot a few additional degrees rearward. In this case, the rear of the door leaf 21 will advantageously have a rearward extension designed to close the notch in the fuselage 17 when the door is closed.

[0096] In the chosen embodiment, the pivot connection means 33 of the proximal end of the arm 31 on the leaf 21 is a clevis rigidly fixed to the leaf 21, cooperating with a pivot of axis 33' passing through the proximal end of the arm 31.

[0097] In another embodiment, not illustrated in the figures, it is the proximal end of the arm 31 which is shaped into a yoke cooperating with a pivot of axis 33' passing through a fitting rigidly fixed to the leaf 21.

[0098] In the chosen embodiment, the pivot linkage means 34 of the distal end of the arm 31 on the rear bulkhead 14 of the cabin 11 is a clevis rigidly fixed to the rear bulkhead 14, cooperating with a pivot of axis 34' parallel to the axis 33' and passing through the distal end of the arm 31, said clevis 34 being positioned as close as possible to the side of the fuselage 17, so that the distal end of the arm 31 is almost in contact with the leaf 21 when the door 20 is in the closed position, which minimizes the lateral bulk of the arm 31 and its pivot links 33, 34.

[0099] Different embodiments of the armrest function

[0100] In the embodiment illustrated in [Fig. 1] and [Fig. 2], the arm is positioned next to the seat 16 at a height of approximately 60 cm above the floor 12, therefore slightly above the seat of the seat 16, the average height of which in an aircraft is approximately 45 cm, and the upper surface 37 of the arm 31 is substantially flat, horizontal, longitudinally slender, and of a width comparable to that of a human forearm, i.e. approximately ten centimeters, so that an occupant of the seat 16 can rest their forearm on said surface 37. These average dimensions are given as an indication and may vary by approximately plus or minus 10 cm for the seat and armrest heights and by approximately plus or minus 5 cm for the armrest width. Optionally, surface 37 can be constructed or covered with a coating that improves occupant comfort.

[0101] In the embodiment illustrated in [Fig. 7], a complementary element 38, of the form of a substantially flat and horizontal plate, extending substantially over the entire length of the arm 31 and over a width close to that of a human forearm, is rigidly fixed to the upper part of the arm 31, and the ends of said complementary element 38 cover and conceal, in top view, the two means respective 33, 34 pivot linkage of the arm 31 to the leaf 21 and to the rear partition14, with the aim of improving the comfort and aesthetics of the arm with armrest function, and of eliminating any risk of injury to an occupant in contact with the respective means 33, 34 of linkage of the arm to the leaf and to the partition. Armrest variant, integrated into the door leaf

[0102] In the embodiment illustrated in [Fig. 8], it is the inner wall of the door leaf 21 that includes a structural element having a substantially flat surface 37” intended as an armrest. More precisely, said surface 37” is the upper face of the upper flange of a bracket used as a pivot connection means 33 of the arm 31 to the door leaf 21, said upper flange being substantially extended over the entire length of the arm 31 and positioned above the arm 31 when the door is closed, and said arm 31 being positioned next to a seat 16 at a height of approximately 60 cm above the floor 12, therefore slightly above the seat of the seat 16, the average height of which in an aircraft is approximately 45 cm.Furthermore, the arm 31 and its pivot connecting means 33, 34 are configured so that they fit entirely within the total thickness of the leaf 21 when the door 20 is closed, thus preserving as much of the usable volume of the cabin 11 as possible, and in no way hindering the comfort of the occupant of the seat 16. Finally, in this embodiment, the arm 31 and its connecting means 33, 34 are completely concealed under the upper wing of said bracket when the door 20 is closed. Details of the installation of the recall device

[0103] In the embodiment illustrated in [Fig. 6], the distal end, with reference to the leaf 21, of the gas spring 40 constituting the return means, whether cushioned or not, and simply designated as spring 40, is fixed to the rear partition 14, behind the seat 16, by a clevis-type articulated connecting means 41, the pivot axis of which 41' is parallel to the pivot axis 34' of the distal end of the arm 31, and the proximal end of the spring 40 is fixed to the distal end of the arm 31 by a clevis-type articulated connecting means 42, the axis of which 42' is parallel to the pivot axis 34' of the distal end of the arm 31, and the wings of which are integrated into the distal end of the arm 31, the pivot axis 42' of said clevis being positioned such that the cylinder 40 is substantially aligned with the arm 31 when the door 20 is in the intermediate open position.In other words, the length of cylinder 40 is minimal when the door is in an intermediate open position.

[0104] Figure 6 shows three key points O, I, and F, representing, in projection onto a horizontal plane, the respective positions of the pivot axis 42' of the proximal end of the cylinder 40 when the door 20 is in the fully open, partially open, and fully closed positions. Points O, I, and F Positioned on a circle centered on the pivot axis 34' of the arm 31, the lever arm of the cylinder 40 is at its maximum at the extreme points O and F, and zero at point I. This results in a greater restoring force near points O and F than at point I. In other words, the force required to operate the door 20 will be greater near its fully open or closed positions than in other positions, particularly near the intermediate opening. Actuator details

[0105] Fig. 9 schematically shows the integration of a rotary actuator 50 into the operating mechanism 30 of the door 20. The rotary actuator 50 comprises at least one electric motor 51 driving a speed reducer 52 whose output shaft 53 is rigidly linked to the pivot of rotation of the arm 31.

[0106] The fixed part, or stator, of the actuator 50 is integral with the bracket that secures the arm 31 to the partition 14. Thus, the electric motor 51 drives the arm 31 in rotation around its pivot axis 34'. Advantageously, the stator of the actuator 50 is rigidly connected to the lower flange of the bracket that forms the pivot connection means 34 of the arm 31 to the partition 14. Thus, the actuator is entirely positioned and concealed beneath the arm 31 and does not encroach in any way on the top of the arm 31, whose function as an armrest is therefore fully preserved. Advantages of the invention

[0107] The door according to the invention maximizes the available space in the cabin since the arm, which is the bulkiest element of the device, is housed within the thickness of the door leaf, while the guide rod is concealed under the floor or in the ceiling, and the gas spring is located behind a seat, in an otherwise unusable area. The overall aesthetics of this door are thus particularly advantageous and streamlined because the operating mechanism is practically invisible.

[0108] The invention allows for a wide range of adjustment during its design while ensuring a very small footprint for the operating mechanism, regardless of the center distances of the arm and connecting rod, as well as the positioning of their respective articulation points. Indeed, in the closed position, the arm is always housed within the thickness of the door leaf, and the connecting rod is always concealed under the floor or on the ceiling.

[0109] The trajectory of the leaf during the opening / closing maneuvers of the door can be precisely adjusted during development by choosing the most suitable lengths and angles of the articulated quadrilateral, in particular for precise and watertight docking of the leaf on the cabin opening, and possibly against the leaf of the front door in the case of a cabin without a central post.

[0110] The door according to the invention can be opened in flight without risk of being torn off because it moves parallel to the air currents along the fuselage, which makes it possible to carry out many specific missions, such as medical transport, winching, landing of commandos, aerial photography, air rescue, etc.

[0111] This door is particularly advantageous in the case of a cabin without an intermediate pillar, as the access door to the passenger or cargo area is directly adjacent to the cockpit access door. This allows the entire cabin opening to remain unobstructed by opening both the front and rear doors simultaneously. Such accessibility makes it particularly convenient to load long objects, such as a stretcher, after some seats have been removed.

[0112] Furthermore, on aircraft whose cabin is devoid of an intermediate lateral post between the cockpit and the passenger cabin, and whose cockpit is equipped with at least one seat without a base according to the invention described in patent application FR2303299, then a door according to the present invention allows the widest possible access to all the available volume of the cabin, in particular under the seats.

[0113] The invention can be implemented with a very small number of parts since its operating mechanism uses only a single arm and its two connecting means, as well as a single connecting rod and its two connecting means. No other known solution offers such simplicity. Moreover, the design and manufacture of the articulated quadrilateral made with these elements are perfectly understood by those skilled in the art.

[0114] Consequently, the mass and overall cost of a complete door according to the invention are low and much lower than those of most other solutions, and the reliability of its components is widely proven.

[0115] Although the door according to the invention brings together maximum advantages when installed on a conventional aircraft carrying occupants, it remains feasible and advantageous on a drone (unmanned aircraft) carrying freight because its cabin will then be usable at its maximum capacity. Limitations

[0116] For large doors, the arm spacing must be longer, and the maximum distance of the door from the fuselage during opening or closing will also be greater. With a door wider than approximately 100 cm, an occupant seated near the door will not have sufficient reach to maintain a good grip on the door handle throughout the entire operation without leaning dangerously outwards. However, this limitation inherent to a wide door can be easily eliminated by installing a motorized operating mechanism, as described above. Variants

[0117] Naturally, the present invention is subject to numerous variations in its implementation. For example, and without limitation: • The pivot joints 33, 34 of the arm can be made by clevises with the inverse conformation of those described in the drawings, i.e. with the wings arranged at the ends of the arm 31. • The arm 31 can be multiple, that is to say, made up of at least two substantially parallel elements rigidly linked to a vertical pivot ensuring their spacing, these three elements together forming a rigid fork, fulfilling exactly the same functions as the single arm according to the invention. • The rotary piloted actuator 50 according to the invention can be replaced by a functionally equivalent device, or be installed on the proximal end of the arm 31, or even on any of the ends of the guide rod 32, because from a purely kinematic point of view, the rod and the arm play equivalent roles.

[0118] Although several embodiments have been described, it is understood that it is not possible to describe all possible embodiments. Modifications may be made without departing from the invention, the invention being defined by the appended claims.

Claims

Demands

1. Aircraft (10) side door (20), said aircraft (10) comprising at least one fuselage (17), a cabin (11) intended to accommodate cargo or at least one occupant and provided with at least one floor (12), a ceiling (13), a rear bulkhead (14) and a side opening (15) extending substantially to said rear bulkhead (14) and closable by said door (20), which has at least one leaf (21) connected to the cabin structure (11) by an operating mechanism (30), said door (20) being characterized in that the operating mechanism (30) comprises a support arm (31) and a guide rod (32), both extending substantially horizontally, the proximal end of the arm (31), with reference to the leaf (21), being fixed to the leaf (21) by a pivoting means (33) about a first axis (33'), the distal end of the arm (31) being fixed to the structure of the cabin (11), near the rear edge of the opening (15),by means of a pivot joint (34) about a second axis (34'), the proximal end of the connecting rod (32), with reference to the door leaf (21), being fixed to the door leaf (21) by means of an articulated joint (35) about a third axis (35'), the distal end of the connecting rod (32) being fixed to the cabin structure (11), near any one of the lower or upper edges of the opening (15), by means of an articulated joint (36) about a fourth axis (36'), the four axes (33', 34', 35', 36') all being parallel and substantially vertical, so that their projection onto a plane perpendicular to them constitutes the vertices of an articulated quadrilateral (ABCD).

2. Aircraft side door (20) (10) according to claim 1, characterized in that the pivoting linkage means (34) of the distal end of the arm (31) is rigidly fixed to the rear bulkhead (14),

3. Aircraft side door (20) (10) according to claims 1 or 2, characterized in that the articulated connecting means (36) of the distal end of the connecting rod (32) is rigidly fixed to the floor (12),

4. Aircraft side door (20) (10) according to claims 1 or 2, characterized in that the articulated connecting means (36) of the distal end of the connecting rod (32) is rigidly fixed to the ceiling (13),

5. Aircraft side door (20) according to claims 1 to 4, characterized in that the articulated connecting means (35, 36) of the ends of the connecting rod (32) are ball joint connecting means.

6. Aircraft (10) side door (20) according to claims 1 to 4, characterized in that the inner wall of the leaf (21), with reference to the cabin (11), has in its thickness a substantially horizontal recess extending at least over the length of the arm (31), and said arm (31) and its respective means (33, 34) for connecting to the leaf (21) are shaped so that they fit entirely within the thickness of the leaf (21) when the door (20) is in the closed position.

7. Aircraft side door (20) according to claims 1 to 6, characterized in that the arm (31) is positioned at a height of approximately 60 cm above the floor (12), and said arm (31) has a substantially flat and horizontal upper surface (37), making said arm (31) suitable for providing an armrest function when the door (20) is in the closed position.

8. Aircraft side door (20) according to claims 1 to 7, characterized in that the arm (31) is a horizontally slender box with a substantially rectangular vertical section, positioned at a height of approximately 60 cm above the floor, and whose upper surface (37) is substantially flat and horizontal, making said arm (31) directly suitable for providing an armrest function when the door (20) is in the closed position.

9. Aircraft side door (20) according to claims 1 to 8, characterized in that the arm (31) has at its upper part a complementary element (38), the upper surface of which (37') is substantially flat and horizontal, making said arm (31) suitable for providing an armrest function when the door (20) is in the closed position.

10. Aircraft side door (20) according to claim 9, characterized in that the ends of the complementary element (38) cover the two respective means (33, 34) of connecting the arm (31) to the leaf (21) and to the cabin structure (11).

11. Aircraft side door (20) (10) according to claims 1 to 8, characterized in that the inner wall of the leaf (21) comprises a structural element having a substantially flat and horizontal upper surface (37”), extending over a length of the order of 50 cm, and positioned above the arm (31) when the door (20) is closed, at a height of approximately 60 cm above the floor (12), making the internal wall of the leaf (21) suitable for serving as an armrest.

12. Aircraft side door (20) according to claims 1 to 6, characterized in that the pivot connection means (33) of the arm (31) on the leaf (21) is a clevis, rigidly fixed to the leaf (21), and whose upper wing has a substantially flat and horizontal upper surface (37”), extending over a length of approximately 50 cm, at a height of approximately 60 cm above the floor (12), and disposed above the arm (31) when the door is closed, making the inner wall of the leaf (21) suitable for providing an armrest function.

13. Aircraft side door (20) according to claims 1 to 12, characterized in that the center distance of the arm (31) is substantially equal to half the width of the leaf (21), and the total pivot angle of the arm (31) is on the order of 160°.

14. Aircraft side door (20) according to claims 1 to 13, characterized in that the respective center distances of the connecting rod (32) and the arm (31) are slightly different, so that the movement of the leaf (21) is the combination of a circular translation around the axis (34') of the pivot joint of the distal end of the arm (31) on the cabin structure (11), and a pivoting around the axis (33') of the pivot joint of the leaf (21) on the proximal end of the arm (31), the construction parameters of the quadrilateral (ABCD) being chosen so that the leaf (21) remains substantially parallel to the side of the fuselage (17), even when curved, during its opening or closing movement.

15. Aircraft side door (20) according to claim 14, characterized in that the center distance of the connecting rod (32) is approximately 2% greater than the center distance of the arm (31), and the acute angles of the articulated quadrilateral are on the order of 15 degrees when the door is in the closed position.

16. Aircraft side door (20) according to claims 1 to 15, characterized in that the operating mechanism (30) is provided with a means for returning the door (20) to its extreme open or closed positions, consisting of a gas spring arranged substantially horizontally, the proximal end of which, with reference to the leaf (21), is fixed to the distal end of the arm (31) by an articulated linkage means (41) about a fifth axis (41'), parallel to the pivot axes (33', 34') of the arm (31), said articulated linkage means (41) being made up of a lever rigidly fixed to the distal end of the arm (31), and configured as a clevis cooperating with the proximal end of the cylinder, while the distal end of the cylinder is fixed to the partition (14) by an articulated linkage means (42) about a sixth axis (42'), parallel to the pivot axes (33', 34') of the arm (31), said articulated linkage means (42) being made up of a clevis fixed to the partition (14) and cooperating with the distal end of the cylinder, the cylinder being substantially aligned with the arm (31) when the door (20) is in the intermediate open position.

17. Aircraft (10) side door (20) according to claim 16, characterized in that the return means (40) is a damped gas spring, ensuring damping of the door movement at the end of opening and at the end of closing, thus limiting the shocks between the leaf (21) and the cabin structure (11) at the end of the door operation.

18. Aircraft side door (20) according to claims 1 to 17, characterized in that the arm (31) is driven by a piloted actuator (50) capable of performing the opening and closing maneuvers of the door (20) and of slowing its movement at the end of the stroke, to avoid collisions between the leaf (21) and the structure of the cabin (14).

19. Aircraft side door (20) according to claim 18, characterized in that the piloted actuator (50) is rotary, and consisting of an electric motor rigidly fixed by means of articulated linkage (34) of the arm (31) on the structure of the cabin (11), a mechanical reducer whose output axis (53) is coaxial with the articulation axis (34') of said articulated linkage means (34), and a piloting means.

20. Aircraft (10) equipped with at least one door according to claims 1 to 18, characterized in that it also comprises at least one cockpit access door (22), located forward of the door (20) according to the invention, and opening towards the front of the aircraft (10), the rear edge of the door leaf (22) and the front edge of the door leaf (20) being joined when said doors (20) and (22) are in the closed position, so that accessibility to the cabin is maximized when said doors (20) and (22) are in the open position.

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