Patent Publication Number: US-2023141505-A1

Title: Aircraft comprising articulated rails integrated into the floor of a cabin

Description:
TECHNICAL FIELD 
     The subject matter herein relates to an aircraft comprising articulated rails integrated into the floor of a cabin. 
     BACKGROUND 
     According to one embodiment, an aircraft comprises a fuselage, wings and a central wing box that is positioned in the lower part of the fuselage and connects the wings to the fuselage. In the case of an aircraft intended to transport cargo, the fuselage comprises a cabin which is positioned above the central wing box and in which the containers can be stored. This cabin may comprise a floor equipped with rails on which the containers can roll. For the present application, a cabin is understood to be a cabin or a hold. 
     According to one embodiment, the floor is a load-bearing structure configured to adapt to the movements and/or deformations between the central wing box and the fuselage portion situated in front of the central wing box. The rails are attached to the floor. This configuration is not satisfactory since it tends to reduce the available height between the rails and the ceiling of the cabin. 
     SUMMARY 
     The disclosure herein aims to overcome all or some of the drawbacks of the prior art. 
     To this end, the subject of the disclosure herein is an aircraft comprising a floor positioned above a central wing box and in a front fuselage portion positioned, along a longitudinal direction, in front of the central wing box, the floor comprising at least one rail which extends along the longitudinal direction and has at least one core. 
     According to the disclosure herein, the rail comprises at least first and second rail portions, at least one articulation connecting a first end of the core of the first rail portion and a second end of the core of the second rail portion, the articulation comprising at least one splice plate which has first and second ends, a pivot pin oriented perpendicularly to the longitudinal direction, passing through the first end of the core of the first rail portion and the first end of the splice plate, and at least one first complete link connecting the second end of the core of the second rail portion and the second end of the splice plate. 
     This solution allows the rails to adapt to the movements and/or deformations between the different portions of the fuselage. Consequently, the rail can be integrated into the floor, making it possible, in the case of a floor of a cabin, to optimize the available height between the rails and the ceiling of the cabin. 
     According to another feature, each articulation comprises first and second splice plates positioned on either side of the core of each of the first and second ends of the first and second rail portions, the first and second splice plates having first ends through which the pivot pin passes and second ends connected by at least one complete link to the second end of the core of the second rail portion. 
     According to another feature, the core of each of the first and second ends of the first and second rail portions comprises first and second faces. In addition, each articulation comprises a backplate pressed against the first face of the first end of the core of the first rail portion and connected to this first end by a complete link; the first end of the first splice plate being pressed against the backplate; the second end of the first splice plate being pressed against the first face of the second end of the core of the second rail portion and connected to this second end by a complete link; the first end of the second splice plate being pressed against the second face of the first end of the core of the first rail portion; the second end of the second splice plate being pressed against the second face of the second end of the core of the second rail portion and connected to this second end by a complete link; the pivot pin passing through the first end of the core of the first rail portion, the backplate and the first ends of the first and second splice plates. 
     According to a feature, the first splice plate comprises a step between its first and second ends, in order to accommodate the backplate. 
     According to another feature, the rail comprises a horizontal plate which has an upper face on which the core is positioned. In addition, the first splice plate comprises first and second wings that form an angle of around 90° and are produced integrally, the first wing having a first end pressed against the backplate and a second end pressed against the first face of the second end of the core of the second rail portion, the second wing being pressed against the horizontal plate and connected to the latter by connecting elements. 
     According to another feature, the rail comprises two cores and first and second articulations, one for each core, which are symmetric with respect to a median plane parallel to the two cores and positioned equidistantly from the two cores. 
     According to another feature, the second wings of the first splice plates of the first and second articulations are positioned between the two cores. 
     According to another feature, the rail comprises a front rail portion, an intermediate rail portion, a rear rail portion, at least one front articulation connecting the front rail portion and the intermediate rail portion, and at least one rear articulation connecting the intermediate rail portion and the rear rail portion, the front and rear articulations being symmetric with respect to a transverse plane situated equidistantly from the front and rear rail portions. 
     According to another feature, the rail comprises a front rail portion connected to the front fuselage portion and a rear rail portion connected to the central wing box. 
     According to another feature, the floor comprises a plurality of rails spaced apart along a transverse direction perpendicular to the longitudinal direction, and horizontal panels supported by the rails, the latter delimiting between one another spaces closed off by the horizontal panels. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further features and advantages will become apparent from the following description of the disclosure herein, which is given solely by way of example, with reference to the appended drawings, in which: 
         FIG.  1    is a side view of an aircraft, 
         FIG.  2    is a longitudinal section through a part of the fuselage of the aircraft shown in  FIG.  1   , 
         FIG.  3    is a side view of a part of a floor of a cabin of an aircraft, illustrating one embodiment of the disclosure herein, 
         FIG.  4    is a cross section through a part of the floor of a cabin of an aircraft, illustrating one embodiment of the disclosure herein, 
         FIG.  5    is a perspective view of a rail of the floor shown in  FIG.  4   , 
         FIG.  6    is a cross section through the rail shown in  FIG.  5   , 
         FIG.  7    is a perspective view of an articulation connecting two rail portions, illustrating one embodiment of the disclosure herein, 
         FIG.  8    is a longitudinal and horizontal section, on the plane P in  FIG.  7   , through the articulation shown in  FIG.  7   , and 
         FIG.  9    is a longitudinal and horizontal section through an articulation connecting two rail portions, illustrating another embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     As illustrated in  FIG.  1   , an aircraft  10  comprises a fuselage  12  that extends between a nose  14  and a tail cone  16 , and wings  18  that are disposed on either side of the fuselage  12  and connected to the latter by a central wing box  20 . 
     For the remainder of the description, a longitudinal axis  22  ( FIG.  2   ) of the aircraft  10  corresponds to the horizontal axis (when the aircraft  10  is on the ground) which extends from the nose  14  to the tail cone  16  of the aircraft  10 . A longitudinal direction is a direction parallel to the longitudinal axis  22 . A longitudinal plane is a plane comprising an axis that is parallel to the longitudinal axis  22 . A transverse plane is a plane perpendicular to the longitudinal axis  22 . 
     The concepts of front (Av) and rear (Ar) refer to the direction of flow of the air outside the aircraft in flight, which passes from the front to the rear. 
     As illustrated in  FIGS.  2  and  3   , the fuselage  12  also comprises a front fuselage portion  24  situated in front of the central wing box  20 , a main landing gear bay  26  offset towards the rear with respect to the central wing box  20 , at least one first transverse beam  28  secured to the front fuselage portion  24 , at least one second transverse beam  30  secured to the central wing box  20 , and a floor  32  that is positioned above the central wing box  20  and rests on the first and second transverse beams  28 ,  30 . 
     According to an embodiment, the first transverse beam  28  has an I-shaped cross section. Of course, the disclosure herein is not limited to this cross section. Regardless of the embodiment, the first transverse beam  28  comprises a first upper transverse flange S 28 . 
     According to an embodiment, the second transverse beam  30  comprises a lower part with a T-shaped cross section and an upper part with an I-shaped cross section. Of course, the disclosure herein is not limited to this embodiment. Regardless of the embodiment, the second transverse beam  30  comprises a second upper transverse flange S 30 . 
     In flight, the central wing box  20  tends to move with respect to the rest of the fuselage  12 , more particularly with respect to the front fuselage portion  24 . Thus, the central wing box  20  may deform or pivot somewhat about a transverse and horizontal pivot axis with respect to the front fuselage portion  24 . 
     According to an application, the region of the fuselage situated above the floor  32  forms a cabin  34  in which a load can be stored. The latter comprises at least one container  36  (represented by broken lines in  FIG.  2   ). To make it easier to move the containers in the cabin  34 , the floor  32  comprises at least one rail  38  parallel to the longitudinal direction, which extends above the central wing box  20  and in the front fuselage portion  24 . 
     According to an arrangement shown in  FIG.  4   , the floor  32  comprises at least one pair of mutually parallel rails  38 ,  38 ′. 
     According to an embodiment, each rail  38 ,  38 ′ comprises, on either side, horizontal extensions  40 . 1 ,  40 . 2  configured to support horizontal panels  42 . Thus, the floor  32  comprises a plurality of rails  38 ,  38 ′ that are spaced apart along the transverse direction, and horizontal panels  42  supported by the rails  38 ,  38 ′, the rails  38 ,  38 ′ delimiting between one another spaces closed off by the horizontal panels  42 . As a result, the rails  38 ,  38 ′ are integrated into the floor  32  and form a load-bearing structure for the horizontal panels  42 . Thus, in contrast to the prior art, which provides floor panels that support the rails, the disclosure herein provides rails that support the floor panels. 
     The horizontal panels  42  can be made of different materials, such as wood, metal, composite material or the like. 
     According to an embodiment, shown in  FIG.  4   , the rails  38 ,  38 ′ are identical. As illustrated in  FIG.  6   , each rail  38 ,  38 ′ comprises a horizontal plate  44  which has an upper face F 44  oriented towards the cabin  34 , a lower face F 44 ′ oriented towards the central wing box  20 , and lateral edges forming the horizontal extensions  40 . 1 ,  40 . 2 . According to one configuration, the horizontal plate  44  is reinforced. In this case, the rail  38 ,  38 ′ comprises at least one rib  46  positioned on the lower face F 44 ′ of the horizontal plate  44  and connected to the latter. By way of example, the rail  38 ,  38 ′ has two ribs  46  with a profile in the shape of an inverted T. Each rib  46  is parallel to the longitudinal direction. 
     According to an arrangement, each rib  46  has a cutout  48  in line with the first and second transverse beams  28  and  30  such that the horizontal plate  44  rests on the first and second upper transverse flanges S 28 , S 30 . 
     Each rail  38 ,  38 ′ has at least one core  50  that is substantially vertical and parallel to the longitudinal direction and extends from the upper face F 44  in the direction of the cabin  34 . Each core  50  has first and second faces  50 . 1 ,  50 . 2  (referenced in  FIGS.  8  and  9   ). Each core  50  may have a cross section in the shape of an I, of an inverted L, of an inverted T or any other cross section. The horizontal plate  44  extends on either side of the core  50  or of the cores  50 . 
     According to an application, the containers  36  have, in their lower part, rollers allowing them to roll. According to one arrangement, shown in  FIG.  6   , each rail  38 ,  38 ′ has two mutually parallel cores  50  that are spaced apart from one another by a determined distance depending on the width of the rollers of the container  36 . 
     According to an embodiment, the horizontal plate  44 , the ribs  46  and the cores  50  are produced integrally. Thus, each rail  38 ,  38 ′ is in the form of a profiled element with a substantially constant cross section. 
     Of course, the disclosure herein is not limited to this embodiment for the rails  38 ,  38 ′. Regardless of the embodiment, each rail  38 ,  38 ′ has at least one core  50  configured to cooperate with the containers  36 . 
     According to an embodiment, shown in  FIG.  3   , each rail  38 ,  38 ′ comprises a plurality of rail portions  52 ,  54 ,  56  positioned end to end along the longitudinal direction. According to one arrangement, each rail  38 ,  38 ′ comprises a front rail portion  52  secured to the front fuselage portion  24 , a rear rail portion  56  secured to the central wing box  20 , the front and rear rail portions being spaced apart from one another, and an intermediate rail portion  54  positioned between the front and rear rail portions  52 ,  56 . 
     The front and intermediate rail portions  52 ,  54  are spaced apart by a small distance, of the order of a few millimeters. Similarly, the intermediate and rear rail portions  54 ,  56  are spaced apart by a small distance, of the order of a few millimeters. 
     The front and intermediate rail portions  52 ,  54  are connected by at least one front articulation  58 . In parallel, the intermediate and rear rail portions  54 ,  56  are connected by at least one rear articulation  60 . According to one configuration, each of the front and rear articulations  58 ,  60  is configured to allow a pivoting movement about a transverse and horizontal pivot axis between the two connected rail portions  52 ,  54 ,  56 . 
     Of course, the disclosure herein is not limited to this embodiment. Regardless of the embodiment, the rail  38 ,  38 ′ comprises at least first and second rail portions  52 ,  54 ,  56  among the front, intermediate and rear rail positions, which are positioned end to end along the longitudinal direction, one of them being connected to the front fuselage portion  24  or to the central wing box  20 ; and at least one articulation  58 ,  60  that connects the first and second rail portions  52 ,  54 ,  56  and is configured to allow a pivoting movement about a transverse and horizontal pivot axis between the first and second connected rail portions  52 ,  54 ,  56 . 
     According to the simplified embodiment shown in  FIG.  9   , the articulation  58 ,  60  connecting a first end  62 . 1  of the core  50  of the first rail portion  52  and a second end  62 . 2  of the core  50  of the second rail portion  54  comprises at least one splice plate  64  having a first end  64 . 1  pressed against the first or second face  50 . 1 ,  50 . 2  of the first end  62 . 1  of the core  50  of the first rail portion  52  and a second end  64 . 2  pressed against the right-hand or left-hand face  50 . 1 ,  50 . 2  of the second end  62 . 2  of the core  50  of the second rail portion  54 , a pivot pin  66  that is oriented perpendicularly to the longitudinal direction and passes through the first end  62 . 1  of the core  50  of the first rail portion  52  and the first end  64 . 1  of the splice plate  64 , and at least one first complete link  68  connecting the second end  62 . 2  of the core  50  of the second rail portion  54  and the second end  64 . 2  of the splice plate  64 . 
     The pivot pin  66  comprises a cylinder  70 . 1 , a first stop  70 . 2  positioned at a first end of the cylinder  70 . 1  and a second stop  70 . 3  positioned at a second end of the cylinder  70 . 1 , the cylinder  70 . 1 , the first and second stops  70 . 2 ,  70 . 3  being configured to keep the splice plate  64  pressed against the core  50  of the first portion  52 . According to one embodiment, the pivot pin  66  is a bolt, the screw of the bolt corresponding to the cylinder  70 . 1  and to the first stop  70 . 2 , the nut of the bolt corresponding to the second stop  70 . 3 . 
     In addition, the first end  62 . 1  of the core  50  of the first rail portion  52  has a through-hole  72 . 1  configured to accommodate the pivot pin  66 . In parallel, the first end  64 . 1  of the splice plate  64  has a through-hole  72 . 2  configured to accommodate the pivot pin  66 . 
     The link  68  is a complete link obtained by adhesive bonding, bolting, crimping or any other assembly technique. 
     According to one embodiment, shown in  FIG.  9   , the articulation  58 ,  60  comprises a single splice plate  64 . According to this embodiment, at least one of the ends from among the first and second ends  62 . 1 ,  62 . 2  of the core  50  of the first and second rail portions  52 ,  54  comprises an overthickness. 
     According to another embodiment, shown in  FIGS.  7  and  8   , the articulation  58 ,  60  comprises:
         a backplate  72  pressed against the first face  50 . 1  of the first end  62 . 1  of the core  50  of the first rail portion  52 ,   a first splice plate  64  having a first end  64 . 1  pressed against the backplate  72  and a second end  64 . 2  pressed against the first face  50 . 1  of the second end  62 . 2  of the core  50  of the second rail portion  54 ,   a second splice plate  64 ′ having a first end  64 . 1 ′ pressed against the second face  50 . 2  of the first end  62 . 1  of the core  50  of the first rail portion  52  and a second end  64 . 2 ′ pressed against the second face  50 . 2  of the second end  62 . 2  of the core  50  of the second rail portion  54 ,   a pivot pin  66  passing through the first end  62 . 1  of the core  50  of the first rail portion  52 , the backplate  72  and the first ends  64 . 1 ,  64 . 1 ′ of the first and second splice plates  64 ,  64 ′,   at least one first complete link  68 , connecting the second end  62 . 2  of the core  50  of the second rail portion  54  and the second end  64 . 2  of the first splice plate  64 ,   at least one second complete link  68 ′, connecting the second end  62 . 2  of the core  50  of the second rail portion  54  and the second end  64 . 2 ′ of the second splice plate  64 ′,   at least one third complete link  68 ″, connecting the backplate  72  and the first end  62 . 1  of the core  50  of the first rail portion  52 .       

     The first and second links  68 ,  68 ′ may form only one single link comprising bolts, rivets or the like passing through the second end  62 . 2  of the core  50  of the second rail portion  54  and the second ends  64 . 2 ,  64 . 2 ′ of the first and second splice plates  64 ,  64 ′. 
     Further solutions are conceivable for the first and second links  68 ,  68 ′ in order to obtain complete links. 
     The third link  68 ″ is a complete link obtained by adhesive bonding, bolting, crimping or any other assembly technique. 
     The pivot pin  66  of the embodiment shown in  FIGS.  7  and  8    may be identical to the one in the embodiment shown in  FIG.  9   . 
     The first splice plate  64  comprises a step  74  between its first end second ends  64 . 1 ,  64 . 2 , in order to accommodate the backplate  72 . 
     According to one embodiment, the second splice plate  64 ′ is in the form of a plate. The first splice plate  64  comprises two wings  76 . 1 ,  76 . 2  that form an angle of around 90° and are produced integrally, a first wing  76 . 1  having a first end pressed against the backplate  72  and a second end pressed against the first face  50 . 1  of the second end  62 . 2  of the core  50  of the second rail portion  54 , and a second wing  76 . 2  pressed against the horizontal plate  44  and connected to the latter by connecting elements  78 . This second wing  76 . 2  is shorter than the first wing  76 . 1  so as not to extend beyond the second rail portion  54 . 
     When the rail  38 ,  38 ′ comprises two cores  50 , it comprises first and second articulations  58 ,  58 ′ (or  60 ,  60 ′), one for each core  50 . These first and second articulations are symmetric with respect to a median plane parallel to the two cores  50  and positioned equidistantly from the two cores  50 . When the first splice plate  64  of each of the first and second articulations  58 ,  58 ′ (or  60 ,  60 ′) comprises first and second wings  76 . 1 ,  76 . 2 , the second wings  76 . 2  of the first splice plates  64  of the first and second articulations are positioned between the two cores  50 . 
     When the rail  38 ,  38 ′ comprises at least one front articulation  58 ,  58 ′ and at least one rear articulation  60 ,  60 ′, the front and rear articulations  58 ,  58 ′,  60 ,  60 ′ are symmetric with respect to a transverse plane situated equidistantly from the front and rear rail portions  52 ,  56 , the backplates  72  of the front and rear articulations  58 ,  58 ′,  60 ,  60 ′ being connected by a third complete link  68 ″ to the front and rear rail portions  52 ,  56 , the first and second splice plates  64 ,  64 ′ of the front and rear articulations  58 ,  58 ′,  60 ,  60 ′ having ends  64 . 2 ,  64 . 2 ′ connected by first and second complete links  68 ,  68 ′ to the core  50  or to the cores  50  of the intermediate rail portion  54 . 
     Regardless of the embodiment, the rail  38 ,  38 ′ comprises at least one core, at least first and second rail portions, at least one articulation  58 ,  60  connecting a first end  62 . 1  of the core  50  of the first rail portion  52  and a second end  62 . 2  of the core  50  of the second rail portion  54 . This articulation  58 ,  60  comprises at least one splice plate  64  having first and second ends  64 . 1 ,  64 . 2 , a pivot pin  66  passing through the first end  62 . 1  of the core  50  of the first rail portion  52  and the first end  64 . 1  of the splice plate  64 , and at least one first complete link  68  connecting the second end  62 . 2  of the core  50  of the second rail portion  54  and the second end  64 . 2  of the splice plate  64 . 
     This solution allows the rails to adapt to the movements and/or deformations between the different portions of the fuselage. Consequently, the rail can be integrated into the floor of the cabin  34 , making it possible to optimize the available height between the rails and the ceiling of the cabin. 
     To reinforce the articulation, the latter may comprise a backplate  72  provided to reinforce the core  50  of a first rail portion and to transmit forces between the pivot pin  66  and this first rail portion. 
     It may comprise two splice plates  64 ,  64 ′ disposed on either side of the cores of the first and second rail portions, these being provided to reinforce the core  50  of the second rail portion and to transmit forces between the pivot pin  66  and this second rail portion. 
     While at least one example embodiment of the 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 example embodiment(s). In addition, in this disclosure, the terms “comprise” or “comprising” do not exclude other elements or steps, the terms “a”, “an” 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.