Abstract:
An aircraft passenger seat having a seat bottom movable between a stationary position for taxi, take-off and landing and a movable position during flight in which at least one of a leading edge and a trailing edge of the seat bottom deflects downward in response to a downward load applied thereto.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority from U.S. Application No. 62/134,111 filed Mar. 17, 2015, the entirety of which is incorporated by reference herein. 
     
    
     TECHNICAL FIELD AND BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates generally to an airliner passenger seat design, and more particularly, to a spring loaded seat bottom movable between a stationary position during taxi, take-off and landing and a freed position during flight where one or more of a leading edge and a trailing edge of the seat bottom can move up and down, deflecting to different levels according to the downward load applied thereto. 
         [0003]    The design of the seat bottom, or seat pan, of an economy class airliner seat is heavily governed by the requirement to pass a series of dynamic tests that form part of the seat certification process. The structure of the seat has to withstand extremely high loads, limit deflection under load, and do so at the minimum weight. To provide comfort, the seat bottom can be formed of a movable structure that can change position and angle according to the reclined position of the seat back. To further enhance comfort, the seat bottom can be constructed from a flexible diaphragm that is securely fastened to the seat bottom structure and covered with foam cushioning. 
         [0004]    Passengers are required to be in an upright sitting position during taxi, take-off and landing (TTOL). During flight the sitting position requirements are relaxed. As such, the seat back of most seats is able to recline to a degree to enhance comfort. In premium class seats, the seat back has a greater range of motion and the seat back and seat bottom can be linked such that reclining the seat back changes the angle and/or position of the seat bottom. In economy class seats, the seat bottom is usually fixed in one position regardless of the reclined position of the seat back. 
         [0005]    With either seat type, a fixed sitting position becomes uncomfortable over time. Therefore, what is needed is a seat bottom compatible with a reclining seat back that can be held stationary during TTOL to achieve a fixed, upright sitting position, and released during flight to increase body movement, improve blood flow and enhance cushioning. 
       BRIEF SUMMARY OF THE INVENTION 
       [0006]    It is therefore an object of the invention to provide a seat bottom assembly for an economy class passenger seat for an airliner or other conveyance. 
         [0007]    It is another object of the invention to provide a seat bottom that increases body movement and improves blood flow during flight or travel. 
         [0008]    It is yet another object of the invention to provide a seat bottom movable between a stationary position and a movable position, independent of seat back recline. 
         [0009]    It is yet another object of the invention to provide a seat bottom configured to deflect in response to a downward load applied thereto and recover upon removal of the downward load. 
         [0010]    It is yet another object of the invention to provide a seat bottom which satisfies upright sitting position requirements for TTOL and is movable during flight to enhance comfort. 
         [0011]    To achieve the foregoing and other objects and advantages, in one embodiment the present invention provides an aircraft passenger seat having a seat bottom movable between a stationary position for taxi, take-off and landing and a movable position during flight in which at least one of a leading edge and a trailing edge of the seat bottom deflects downward in response to a downward load applied thereto. 
         [0012]    In a further aspect, the seat bottom can include a seat bottom frame positioned between spaced spreaders. 
         [0013]    In a further aspect, the seat bottom frame can include spaced frame members, a front beam, a near front beam, and a rear beam interconnecting the spaced frame members, and a flexible diaphragm spanning the front beam, the near front beam and the rear beam. 
         [0014]    In a further aspect, the flexible diaphragm can be held in a tensioned state, and wherein the rear beam and the near front beam are spaced apart to allow the flexible diaphragm to deflect downward therebetween and the front beam and the near front beam are positioned close together to prevent the flexible diaphragm from deflecting near a front of the seat bottom frame. 
         [0015]    In a further aspect, each of the spaced frame members can be curved or angled. 
         [0016]    In a further aspect, the seat can further include a linkage and spring assembly packaged on an inboard side of each of the spreaders, the linkage and spring assembly including a hinge block attached to the inboard side of one of the spreaders, a link pivotably attached at one end to the hinge block, and a spring disposed between a free end of the link and a spring seat defined in the spreader, the spring arranged to bias the link upward in a direction of the seat bottom. 
         [0017]    In a further aspect, the spring can be a vertically-oriented helical spring. 
         [0018]    In a further aspect, the seat bottom frame can include a vertically-oriented roller rotatably carried on each of the frame members, the vertically-oriented rollers arranged to travel along a top of the links as the seat bottom moves horizontally between the stationary position and the movable position. 
         [0019]    In a further aspect, in the stationary position the vertically-oriented rollers can be positioned vertically above the hinge blocks such that the downward load does not act on the links, and in the movable position the vertically-oriented rollers can travel forward along the top of the links causing the free end of the links to pivot downward in response to the downward load. 
         [0020]    In a further aspect, the link can define a linear portion along which the vertically-oriented roller travels and the free end of the link can be shaped to capture the spring between a bottom of the link and the spring seat. 
         [0021]    According to another embodiment, the present invention provides an aircraft passenger seat having a seat bottom configured to translate between a first position in which the seat bottom is stationary and a second position in which at least one of a leading edge and a trailing edge of the seat bottom moves downward in response to a downward load applied thereto and recovers upward upon removal of the downward load. 
         [0022]    In a further aspect, the aircraft passenger seat can have a reclining seat back and spaced spreaders, and the seat bottom can have a seat bottom frame positioned between the spaced spreaders. 
         [0023]    In a further aspect, the seat bottom frame can include spaced left and right frame members, a front beam, a near front beam, and a rear beam interconnecting the spaced left and right frame members, and a flexible diaphragm spanning the front beam, the near front beam and the rear beam. 
         [0024]    In a further aspect, the seat can include a linkage and spring assembly packaged on an inboard side of at least one of the spreaders, the linkage and spring assembly including a hinge block attached to the inboard side of one of the spreaders, a link pivotably attached at one end to the hinge block, and a biasing member disposed between a free end of the link and a biasing member seat defined in the spreader, the biasing member arranged to bias the link upward in a direction of the seat bottom. 
         [0025]    In a further aspect, the biasing member is a vertically-oriented helical spring. 
         [0026]    In a further aspect, the seat bottom frame can include a vertically-oriented roller rotatably carried on one of the frame members, the vertically-oriented roller arranged to travel along a top of the link as the seat bottom translates between the first position and the second position, the first position for use during aircraft taxi, take-off and landing and the second position for use during flight. 
         [0027]    Embodiments of the invention can include one or more or any combination of the above features and configurations. 
         [0028]    Additional features, aspects and advantages of the invention will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the invention as described herein. It is to be understood that both the foregoing general description and the following detailed description present various embodiments of the invention, and are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed. The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0029]    Features, aspects and advantages of the present invention are better understood when the following detailed description of the invention is read with reference to the accompanying drawings, in which: 
           [0030]      FIG. 1  is a perspective view of a spring loaded seat bottom according to the present invention shown with the cushion removed; 
           [0031]      FIG. 2  is a plan view of the seat bottom shown with the cushion removed; 
           [0032]      FIG. 3  is a detailed view of the linkage and roller showing the seat bottom locked in the TTOL position; and 
           [0033]      FIG. 4  is a detailed view of the linkage and roller showing the seat bottom freed from the TTOL position. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0034]    The present invention will now be described more fully hereinafter with reference to the accompanying drawings in which exemplary embodiments of the invention are shown. However, the invention may be embodied in many different forms and should not be construed as limited to the representative embodiments set forth herein. The exemplary embodiments are provided so that this disclosure will be both thorough and complete, and will fully convey the scope of the invention and enable one of ordinary skill in the art to make, use and practice the invention. Like reference numbers refer to like elements throughout the various drawings. 
         [0035]      FIG. 1  shows the relevant portions of an aircraft or airliner passenger seat  20  necessary for a complete understanding of the present invention. The seat  20  is shown with the cushion and upholstery removed for clarity. Passenger seat  20  generally includes a recline-capable seat back  22  and sprung seat bottom  24  or seat pan. The seat back  22  and seat bottom  24  can be linked such that motion of one drives motion of the other. The seat bottom  24  is generally positioned and supported between spaced left and right spreaders  26 ,  28  in an arrangement such that the seat bottom  24  can move or translate horizontally and/or change in pitch. 
         [0036]    Front and rear transverse beam tubes  30 ,  32  are received through and support the spreaders  26 ,  28  in a generally horizontal position above the floor. The beam tubes  30 ,  32  further engage through one or more legs  34  equipped with track fasteners  36  for attaching the legs  34  to the floor. The spreaders  26 ,  28  generally support the seat bottom  24  and may further extend upward to support and/or guide the seat back  22 . The beam tubes  30 ,  32  and legs  34  may be shared by and cooperate to support a row of two, three, four, n-number of laterally adjacent seats. Laterally adjacent seats in the same row may share a single spreader positioned therebetween, or may each include their own dedicated left and right spreaders. 
         [0037]    The seat bottom  24  is positioned between the left and right spreaders  26 ,  28 . The seat bottom generally includes a seat bottom frame  38  having left and right frame members  40 ,  42  oriented longitudinally relative to the seat axis and positioned inward of the respective left and right spreaders  26 ,  28 . The left and right frame members  40 ,  42  are interconnected through a plurality of transverse beams, such as a front beam  44 , near front beam  46 , and rear beam  48  as shown. The frame members  40 ,  42  may be shaped to provide a specific curvature/angular shape to the seat bottom  24 , while the beams  44 ,  46 ,  48  are positioned and spaced according to the frame member shape. As shown, the rear beam  48  and near front beam  46  are spaced far enough apart to allow the flexible diaphragm  50  to deflect downward therebetween under an applied load from a passenger, while the front beam  44  and near front beam  46  are positioned close together to prevent the flexible diaphragm  50  from deflecting near the front of the seat pan. The flexible diaphragm  50  may attach to the front and rear beams  44 ,  48  to maintain the diaphragm in a tensioned state. Although removed for clarity, the flexible diaphragm  50  may be covered with a foam cushion and upholstery for comfort and aesthetics. 
         [0038]      FIGS. 2-4  show the linkage and spring assembly  52  by which the seat bottom  24  moves between the stationary position and the movable position, and by which the seat bottom  24  is able to deflect, when in the movable position, downward under loading and then recover in the absence or lessening of loading. The seat bottom  24  is configured to move between a first position in which the seat bottom  24  is rearward and stationary or “locked” relative to the spreaders  26 ,  28  for TTOL, and a second position moved forward relative to, or freed from, the TTOL position. In the first or TTOL position shown in  FIG. 3 , the seat bottom is stationary such that the leading edge thereof is incapable of deflecting or moving up and down. In the second or freed position shown in  FIG. 4 , the leading edge of the seat bottom is able to deflect up and down according to the downward load on the seat bottom. 
         [0039]    While the drawings show the linkage and spring assembly  52  arranged to bias the leading edge of the seat bottom  24 , it is envisioned that the same linkage and spring assembly  52  can be arranged to bias the trailing edge of the seat bottom  24  by relocating the linkage and spring assembly  52  closer to the trailing edge. Two linkage and spring assemblies  52  can also be positioned to bias both the leading and trailing edges of the seat bottom  24 , and can be used to tune the amount of deflection of each edge by changing the position of the assemblies  52  and/or front and back spring rates. 
         [0040]    Seat bottom locking and deflection is achieved using the compact linkage and spring assembly  52  packaged on the inboard side of each of the left and right spreaders  26 ,  28 . Each linkage and spring assembly  52  generally includes a hinge block  54  attached to the inboard side of the spreader, a link  56  pivotally attached at one end to the hinge block  54 , and a biasing member, for example a vertically-oriented helical spring  58 , maintained between the free end of the link  56  and a spring seat  60  on the spreader  26 . The spring  58  is arranged to bias the link  56  upward in the direction of the seat bottom, and spring force can be adjusted/customized based on the stiffness of the spring used. 
         [0041]    The linkage is sprung such that, in use, a vertically-oriented roller  62  rotatably carried on the seat bottom frame member  40  travels along a top surface of the link  56  as the seat bottom  24  moves between the first and second positions. In the first or TTOL position shown in  FIG. 3 , the roller  62  is positioned vertically above the link pivot point  64 , or just behind the link pivot point, such that the roller  62  is positioned vertically above the fixed hinge block  54  such that no downward load acts on the link  56 . 
         [0042]    In the second position shown in  FIG. 4 , in which the seat bottom  24  is freed, as the seat bottom moves horizontally forward the roller  62  travels forward along the top surface of the link  56  causing the free end of the link  56  to pivot downward in response to a downward load on the seat bottom large enough to overcome the spring force of the spring  58 . The link  56  defines a linear portion  66  along which the roller  62  travels, and the free end of the link  56  is shaped to capture the spring  58  between the bottom of the link  56  and the spring seat  60 . The amount of horizontal travel of the seat pan  24  determines the length of the link  56 . The link  56  may also have a predetermined shape and/or orientation to control the seat bottom angle as the seat bottom moves forward and backward. 
         [0043]    As best shown in  FIGS. 1 and 2 , additional vertically-oriented rollers  68  rotatably carried near the back of the frame members  40 ,  42  travel within elongate guides  70  of the left and right spreaders  26 ,  28 , which guide the trailing edge of the seat bottom as the seat bottom moves between the first and second positions. While the guides  70  shown are linear, they can have any predetermined curvature and/or orientation to control the seat bottom angle as the seat bottom moves. For example, it may be desirable for the seat bottom  24  to be farther from horizontal in the TTOL position and closer to horizontal in the freed position, or vice versa. 
         [0044]    The sprung seat bottom described herein increases comfort once the seat bottom has been moved out of, or freed from, the TTOL position. Deflection in the seat bottom increases body movement, improves blood flow and enhances cushioning, among other advantages. 
         [0045]    While the foregoing description provides embodiments of the invention by way of example only, it is envisioned that other embodiments may perform similar functions and/or achieve similar results. Any and all such equivalent embodiments and examples are within the scope of the present invention and are intended to be covered by the appended claims.