Abstract:
In order to simplify the connection of a door to the outer envelope of an aircraft cell, it is provided to dispose the door into a portion of the outer envelope having tilted sides, as is the case at the nose cones and the tail cones of conventional airplanes, and in various portions of blended wing body airplanes and flying wings. Thus, the door can be configured to displace, in rectilinear translation, from one of its extreme opening and closing positions to the other, without requiring that the door protrudes outside of the outer envelope in the closing position.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of the French patent application No. 1563248 filed on Dec. 23, 2015, the entire disclosures of which are incorporated herein by way of reference. 
       TECHNICAL FIELD 
       [0002]    This invention relates to the field of aircraft doors which allow access for passengers or the loading of baggage or goods. 
         [0003]    The invention applies to both aircraft of the conventional type and aircraft of the “blended wing body” type, in which the doors are incorporated in the fuselage, and flying wings, in which the doors are incorporated into the wing. 
         [0004]    As is known by the skilled person, an aircraft of the “flying wing” type the aircraft has no fuselage. In an aircraft of the “blended wing body” type there is no clear distinction between the fuselage and the wings as in a conventional aircraft. The fuselage and the wings each contribute to the bearing capacity of the aircraft. In the aircraft there is continuity in the wing box between the fuselage and each of the wings. In both these cases the aircraft has zones intended for the transport of passengers (pax) or goods (cargo), or both combined. 
         [0005]    As a consequence, the invention relates in general to an aircraft cell comprising an external envelope provided with a door, the external envelope being therefore the fuselage of a conventional aircraft or a blended wing body aircraft, or the wing of a flying wing. 
       BACKGROUND OF THE INVENTION 
       [0006]    Various types of mechanisms for connecting an aircraft door to the outer envelope of an aircraft cell are known. 
         [0007]    Such doors can, in fact, open by pivoting downwards or upwards, in which case specific means, which are generally heavy, must be provided in order to overcome the weight of the door, either as it is being closed or to keep the door in the open position. Doors of this type are used in many conventional aircraft, and they are also common in flying wings and blended wing body aircraft, such as the aircraft  10  illustrated diagrammatically in  FIGS. 1A and 1B , in which the aircraft is seen from above and below respectively, and which thus comprises three doors  12  on each side of its vertical plane of symmetry  14 . As a reminder, blended wing body (or BWB) aircraft are aircraft whose cells incorporate the characteristics of conventional fuselages and flying wings in a hybrid configuration in which the fuselage is completely incorporated into the wing, which is as a consequence thick, without any clear distinction of the connecting portion between the fuselage and the wing. 
         [0008]    In other known configurations, the door opens by moving horizontally, in which case the opening mechanism generally involves a combination of rotational and translational movements, or several rotations about different axes, in order to avoid the need for the door to protrude outside from the aircraft cell envelope in its closed position. 
         [0009]    In every case, the aircraft door opening mechanisms are relatively complex and heavy. 
       SUMMARY OF THE INVENTION 
       [0010]    An object of the invention is, in particular, to provide a simple, economical and effective solution for this problem. 
         [0011]    For this purpose, it provides an aircraft cell comprising: 
         [0012]    an outer envelope having at least one longitudinal portion, the width of which reduces in a longitudinal direction of the aircraft cell, provided with at least one opening made in the longitudinal portion, 
         [0013]    a door, and 
         [0014]    linking means connecting the door to the outer envelope, configured to move the door between two extreme positions, namely, a closed position in which the door obstructs the opening, and an open position in which the door is offset horizontally from the opening in such a way that the door covers a region of the outer envelope adjacent to the opening. 
         [0015]    In accordance with the invention, the linking means are configured in such a way that movement of the door from one to other of the two extreme positions is a rectilinear translational movement in one direction of movement. 
         [0016]    The variable width conformation of the longitudinal portion of the outer envelope, in fact, makes it possible to configure an opening perimeter such that when the door is in the closed position, the perimeter of the opening does not intercept any straight line parallel to the direction of movement passing through any point in the door. 
         [0017]    Thus, the door can move from the closed position to the open position and vice versa following a single rectilinear path, without being blocked by the perimeter of the opening in the outer envelope. 
         [0018]    The nature of the path followed by the door between its two extreme positions makes it possible to use particularly simple linking means. The invention, thus, in particular, makes it possible to avoid resort to complex articulated devices using combinations of rotational and translational movements. 
         [0019]    Preferably, the aircraft cell has one overall vertical plane of symmetry. 
         [0020]    Preferably, the direction of movement is a horizontal direction parallel to the overall vertical plane of symmetry. 
         [0021]    Preferably, the door has an outer surface that is included in the longitudinal portion of the outer envelope in the closed position and has a first lateral edge extending in a first plane parallel to the overall vertical plane of symmetry and a second lateral edge arranged in such a way that movement of the door from the closed position to the open position is orientated in a direction going from the second lateral edge towards the first lateral edge. 
         [0022]    Preferably, the outer surface of the door also has a lower edge and an upper edge, each of which connect the first lateral edge to the second lateral edge. 
         [0023]    Preferably, the second lateral edge extends in a second plane forming an angle of between 60 degrees and 120 degrees with the first plane. 
         [0024]    Preferably, the second plane is at right angles to the direction of movement. 
         [0025]    Preferably, the aircraft cell further comprises a first supporting structure extending into the aircraft cell from the outer envelope, parallel to the second plane, the door has a second supporting structure extending into the aircraft cell from the second lateral edge parallel to the second plane, and the second supporting structure bears against the first supporting structure in the closed position. 
         [0026]    Preferably, the first and second supporting structures comprise at least a first blocking device which prevents the door from moving in a first direction at right angles to the first plane. 
         [0027]    Preferably, the aircraft cell further comprises at least one support extending into the aircraft cell from the first supporting structure and parallel to the direction of movement, to which at least part of the linking means is attached. 
         [0028]    Preferably, the aircraft cell further comprises at least one lock which can be moved between a locked condition in which the lock prevents the door from being moved in the direction of movement, and an unlocked condition in which the lock allows the door to be moved. 
         [0029]    Preferably, the linking means are formed of one or more slides guiding movement of the door between the closed position and the open position. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0030]    The invention will better understood, and other details, advantages and characteristics thereof will be apparent from a reading of the following description provided by way of a non-limiting example with reference to the appended drawings in which: 
           [0031]      FIGS. 1A and 1B , already described, are diagrammatical views of a cell of a blended wing body aircraft of a known type, from above and below respectively; 
           [0032]      FIG. 2  is a diagrammatical view from above of a cell of a blended wing body aircraft according to a preferred embodiment of the invention; 
           [0033]      FIG. 3  is a diagrammatical perspective view of a fore part of the cell of a blended wing body aircraft in  FIG. 2 , illustrating a door in this fore part; 
           [0034]      FIGS. 4 and 5  are partial diagrammatical half-views from above of the fore part of the cell of a blended wing body aircraft in  FIG. 3 , illustrating the door in closed and open positions respectively; 
           [0035]      FIGS. 6 and 7  are lateral diagrammatical views of the fore part of the cell of a blended wing body aircraft in  FIG. 3 , from the outside and inside respectively; 
           [0036]      FIGS. 8 and 9  are partial diagrammatical half-views of the fore part of the blended wing body aircraft cell in  FIG. 3 , in cross-section along the horizontal plane VIII-VIII in  FIGS. 6 and 7 , illustrating the door in the closed and open positions respectively. 
       
    
    
       [0037]    In all the figures the same reference numbers identify identical or similar components. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0038]    The invention provides for making use of the inclination of the outer envelope of an aircraft cell in relation to its overall vertical plane of symmetry to offer an improved configuration for an aircraft door. Such inclination of the outer envelope is, in fact, found in the nose and tail portions of conventional aircraft, and in various portions of blended wing body aircraft and flying wings. The term “outer envelope” may therefore refer to the fuselage and/or wing of an aircraft according to circumstances. 
         [0039]    By way of example, an aircraft cell  10  illustrated in  FIGS. 2 to 9  is a cell of a blended wing body aircraft having an overall vertical plane of symmetry  14 . The term “overall” plane of symmetry should be understood to mean that the outer envelope of the cell has an overall symmetrical shape in relation to that vertical plane, independently of any differences of detail which may be present between one side and the other of the outer envelope, for example as regards the number and conformation of the doors. Furthermore, the aircraft cell  10  has a longitudinal axis  16  defined as being the intersection between the overall vertical plane of symmetry  14  and a main floor  17  of the cell, which is intended for the use of passengers and/or cargo. 
         [0040]    In this description, the X direction is the longitudinal direction of the aircraft cell, corresponding to the direction of travel of the aircraft when in flight, and is parallel to the longitudinal axis  16 , the Z direction is the vertical direction at right angles to the main floor  17 A, and the Y direction is the transverse direction at right angles to the two X and Z directions, thus defining a horizontal plane with longitudinal axis  16 . 
         [0041]      FIGS. 3-7  show more particularly a fore part of aircraft cell  10 , the outer envelope of which comprises a longitudinal portion  18 , the width W whereof reduces progressively in a rearward direction along longitudinal axis  16  (see half-width W/ 2  in  FIG. 4 ). Consequently, in the view from above as in  FIGS. 4 and 5 , sides  19  of longitudinal portion  18  of the aircraft cell are inclined in relation to the overall vertical plane of symmetry  14 . 
         [0042]    As shown in  FIG. 2 , the longitudinal portion  18  has a forward extremity  18 A corresponding to the forward extremity of the aircraft cell and a rear extremity  18 B defined as being a zone of the outer envelope of the aircraft cell from which the width of that outer envelope reduces or remains constant in a rearward direction. 
         [0043]    In general, it should also be understood that the width W of the longitudinal portion  18  of the outer envelope reduces from one of forward extremity  18 A or rear extremity  18 B to the other extremity  18 B or  18 A. 
         [0044]    In addition to this, the longitudinal portion  18  of the outer envelope has an opening  20  intended to allow passengers to pass or baggage or cargo to be loaded/unloaded. 
         [0045]    Aircraft cell  10  further comprises a door  22  which can be moved between a closed position ( FIGS. 4, 6 and 8 ) in which the door obstructs the opening  20  and an open position ( FIGS. 3, 5, 7, 9 ) in which the door  22  is horizontally offset from the opening  20  in such a way that the door covers a region  24  of the outer envelope located alongside the opening  20 . In its open position, the door  22  is thus offset from the opening  20  in such a way as to allow persons, baggage and/or cargo to pass through the opening. 
         [0046]    According to one particular feature of the invention the movement of the door  22  from the closed position to the open position is one of rectilinear translation in a direction of movement  26 . 
         [0047]    The variable width conformation of the longitudinal portion  18 , in fact, makes it possible to configure a perimeter for the opening  20  such that when the door is in the closed position, the perimeter intercepts no straight line parallel to the direction of movement  26  passing through any point in the door. 
         [0048]    Thus, the door  22  can pass from the closed position to the open position and vice versa by following a single rectilinear path, without being blocked by the perimeter of opening  20 . 
         [0049]    The door  22  is connected to the outer structure by linking means which, for example, comprise two slides  28 A and  28 B of one piece with the outer envelope which guide the movement of two slide members  29 A,  29 B respectively, which are of one piece with the door, between the door&#39;s open and closed positions ( FIGS. 3 and 7 ). 
         [0050]    As a variant, the linking means may be formed of articulated arms or any other kind of mechanism, which will allow the door  22  to move in rectilinear translation. 
         [0051]    Furthermore, the slide  28 A is, for example, housed in a space located below the floor  17 A of the cell, whereas the slide  28 B is, for example, housed in an upper housing  17 B ( FIG. 7 ). 
         [0052]    In a preferred embodiment of the invention, the direction of movement  26  is a horizontal direction parallel to the overall vertical plane of symmetry  14 , that is to say, a direction substantially parallel to the longitudinal axis  26  ( FIGS. 3-7 ). 
         [0053]    The horizontal nature of the direction of movement  26 , in particular, makes it possible to avoid movement of the door being disturbed by its weight and, thus, to avoid resorting to relatively complex and heavy means normally used to overcome such disturbance. 
         [0054]    The characteristic that the direction of movement  26  is parallel to the overall vertical plane of symmetry  14  offers many advantages which will be detailed below. 
         [0055]    As a variant, the direction of movement  26  may nevertheless be orientated otherwise without going beyond the scope of the present invention, through adapting the shape of the opening  20 . Thus, the direction of movement  26  may be a horizontal direction inclined in relation to the overall vertical plane of symmetry  14 , or even a direction at right angles to the overall vertical plane of symmetry  14 , which may, in particular, be advantageous when the sides of the longitudinal portion  18  form a relatively large angle with the overall vertical plane of symmetry  14 . The direction of the movement  26  may also not be horizontal, without going beyond the scope of the invention. 
         [0056]    In any event, the rectilinear path followed by the door  22  between its two extreme positions makes it possible to use particularly simple linking means. The invention, thus, in particular, makes it possible to avoid resort to complex articulation devices involving several rotations or a combination of rotational and translational movements. 
         [0057]    At the same time, the invention makes it possible for the door  22  to have an outer surface  30  incorporated into a longitudinal portion  18  of the outer envelope when the door is in the closed position, as shown on  FIG. 4 . 
         [0058]    This outer surface  30  has two opposite lateral edges, namely a first lateral edge  32  and a second lateral edge  34 . In the terminology of the invention, movement of the door from the closed position to the open position is orientated in a direction going from the second lateral edge  34  towards the first lateral edge  32  (that is to say, strictly speaking, a direction going from a barycenter of the second lateral edge  34  towards a barycenter of the first lateral edge  32 ). 
         [0059]    Thus, in the example illustrated, movement of the door  22  from the closed position to the open position is orientated towards the front of the aircraft cell, such that the first lateral edge  32  is a forward edge, whereas the second lateral edge  34  is an after edge. 
         [0060]    The configuration of the door  22  is compatible with the use of cover plates or other sealing systems, on the first lateral edge  32 , in particular. 
         [0061]    In the preferred embodiment of the invention, the first lateral edge  32  extends in a first plane P 1  parallel to the overall vertical plane of symmetry  14 . 
         [0062]    The orientation of the first plane P 1  parallel to the overall vertical plane of symmetry  14  offers advantages with regard to the aerodynamic performance of the aircraft cell  10 . This is particularly so when the aircraft cell is a cell of a blended wing body aircraft or flying wing, because the airflow around the outer envelope of aircraft of these types follows lines extending in planes parallel to their overall vertical plane of symmetry following the profile of the outer envelope. 
         [0063]    As a consequence, positioning the first lateral edge  32  of the door in a plane parallel to the overall vertical plane of symmetry  14  makes it possible to minimize the impact of the first lateral edge on the aerodynamic performance of the aircraft cell  10 , in particular in the situation where the opening  20  is formed in a leading edge, in the example illustrated in the figures. This, in particular, makes it possible to minimize the risks of creating turbulence at this location, which is known to increase the drag of the aircraft cell, even if there is an interstitial portion between the outer surface  30  of the door and the outer envelope of the aircraft cell, or if these two surfaces are not in perfect alignment. Such a configuration of the first lateral edge  32  thus makes it possible to reduce the drag of aircraft cell  10 . Furthermore, turbulence of this type is also generally the origin of noise nuisance, such that the preferred embodiment of the invention makes it possible to limit the level of such nuisance noise close to the aircraft cell, in particular, for passengers and crew members inside the aircraft. 
         [0064]    When in flight, the aircraft cell is subject to bird strikes. As it is not formed of one piece with the outer envelope, a conventional aircraft door is particularly sensitive to such strikes. Now the orientation of the first lateral edge  32  makes it possible to reduce the effect of bird strikes on this lateral edge, and as a consequence to increase the robustness of the aircraft cell of the invention with regard to these strikes. 
         [0065]    In the example illustrated, the outer surface of the door also has a lower edge  36  and an upper edge  38 , which each connect the first lateral edge  32  to the second lateral edge  34 . 
         [0066]    This lower edge  36  and upper edge  38  extend in respective directions which are inclined in relation to the overall vertical plane of symmetry  14  of the aircraft cell ( FIG. 3 ). 
         [0067]    As a variant, the first lateral edge  32  and the second lateral edge  34  may be directly connected to each other. 
         [0068]    Furthermore, in the preferred embodiment of the invention, the second lateral edge  34  extends in a second plane P 2  forming an angle θ of between 60 degrees and 120 degrees with first plane P 1  ( FIGS. 4 and 5 ). 
         [0069]    In the preferred example illustrated, this angle θ is substantially equal to 90 degrees. The second plane P 2  is thus at right angles to the direction of movement  26 . 
         [0070]    Thus, in the situation where the aircraft cell is a cell of a blended wing body aircraft or flying wing, the second lateral edge  34  extends substantially at right angles to the flow of air around the outer envelope. 
         [0071]    Furthermore, the aircraft cell  10  comprises a first supporting structure  40  extending into the aircraft cell from the outer envelope parallel to the second plane P 2  and the door  22  has a second supporting structure  42  extending into the aircraft cell from the second lateral edge  34  parallel to the second plane P 2  ( FIGS. 4, 5, 8 and 9 ). 
         [0072]    As shown in  FIGS. 4 and 8 , the second supporting structure  42  bears against the first supporting structure  40  when the door  22  is in the closed position. 
         [0073]    The orientation of the bearing structures  40  and  42 , corresponding to the orientation of the second plane P 2  within which the second lateral edge  34  lies, allows the aerodynamic forces applied to the door  22  during flight, which are mainly orientated in the longitudinal X direction, to be taken up in an optimum way, especially in the case of a cell of a blended wing body aircraft or a cell of a flying wing. 
         [0074]    In the example illustrated, the supporting structures  40  and  42  are flat overall and respectively take the shape of two supporting plates. 
         [0075]    In the preferred embodiment of the invention, the two slides  28 A and  28 B are respectively attached to two parts of the perimeter of the opening  20 , namely a lower part  50 A and an upper part  50 B, extending from the first supporting structure  40 , respectively opposite the lower surface  36  and the upper surface  38  of the outer surface  30  of the door  22  inside aircraft cell  10  ( FIG. 3 ). 
         [0076]    Furthermore, the first and second supporting structures  40  and  42  comprise first blocking devices  44  ( FIGS. 8 and 9 ) which prevent the door from moving in a first direction at right angles to the first point P 1  when the door  22  is in the closed position. In the example illustrated, the first direction corresponds to the transverse Y direction. 
         [0077]    The first blocking devices  44  comprise, for example, locking pins or bolts  46  of one piece with the second supporting structure  42  which engage in matching housings  48  formed in the first supporting structure  40 . Other types of locking devices which are in themselves known may be used without going beyond the scope of the invention. 
         [0078]    Furthermore, the perimeter of the door advantageously comprises second locking devices  56  ( FIGS. 8 and 9 ) preventing the door from moving in the vertical Z direction when the door  22  is in the closed position. These second locking devices, for example, take the form of hooks formed in the lower part  50 A and the upper part  50 B respectively of the perimeter of the opening  20 , and engage in notches provided for the purpose in an inner wall  58  of the door  22  (only one of these hooks may be seen in  FIGS. 8 and 9 ). 
         [0079]    The aircraft cell  10  further comprises one or more locks  52  ( FIGS. 8 and 9 ). Each of these locks  52  can be maneuvered when the door  22  is in the closed position to pass from the locked condition in which a part of the lock  52  engages a housing  54  formed in the door  22 , for example in the second supporting structure  42 , to an unlocked condition in which the part of the lock  52  is disengaged from the housing  54 . In the locked condition, the lock  52  thus immobilizes the door  22  in the direction of movement  26 , while in the unlocked condition the lock  52  allows the door  22  to be opened. 
         [0080]    Other immobilization and/or locking means may, of course, be provided without going beyond the scope of the present invention. 
         [0081]    It should be noted that in the embodiment illustrated, the door  22  comprises two inner walls connected to each other and connected to the first lateral edge  32  and the second lateral edge  34 , respectively, namely the aforesaid inner wall  58 , and the second supporting structure  42  which forms the second inner wall. 
         [0082]    While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms “comprise” or “comprising” do not exclude other elements or steps, the terms “a” or “one” do not exclude a plural number, and the term “or” means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.