Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B64—AIRCRAFT; AVIATION; COSMONAUTICS
  • B64D—EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT
  • B64D25/00—Emergency apparatus or devices, not otherwise provided for
  • B64D25/02—Supports or holding means for living bodies
  • B64D25/04—Seat modifications

Definitions

• a seat leg in particular for an aircraft, intended to connect a seat foundation to a floor, characterized in that it comprises: - a monolithic structure comprising two zones upper anchoring, respectively front and rear, intended to be connected to the seat, two lower anchoring zones, respectively front and rear, intended to be connected to the floor, and at least one central recess, said monolithic structure being produced a composite material including fibers embedded in a matrix; and
• the monolithic realization of the structure of the base in composite material makes it possible to limit the metal inserts to the anchoring zones of this structure on the floor and on the seat. This limits the mass of the structure of the seat leg to a value substantially lower than that of the metal structures of the existing seat legs, without the mechanical strength being penalized.
• the mounting of an energy absorption body in the central recess of the monolithic structure, during the manufacture of this structure, makes it possible to meet the requirements in force in the event of an accident, while preserving the overall gain in mass of the seat leg, obtained thanks to the monolithic production of the structure in composite material.
• the lower end of the fourth branch is advantageously connected to the lower front anchoring zone.
• other recesses are preferably formed in at least some of the branches of the monolithic structure, taking care to preserve the mechanical strength of this structure.
• the ring may in particular have a thickness less than the monolithic structure, so that the ends of the ring are in abutment against the sides of the monolithic structure, in the trapped parts of the ring.
• a first imprisoned part of the ring is advantageously placed in a rounded angle of the curvilinear triangle, turned towards the branch whose end has the lower front anchoring zone, and a second trapped part of the ring is placed in a convex side, facing said angle, of the curvilinear triangle, this convex side being located between the two other branches which radiate from the central part.
• the first and second trapped parts of the ring then extend respectively over approximately half and one sixth of its perimeter.
• the light alloy in which the ring is made can in particular be an aluminum alloy.
• FIG. 1 is a perspective view which schematically shows an aircraft seat whose feet are made according to the invention
• FIG. 3 is a section along line III-III of Figure 2.
• the reference 10 designates the floor of an aircraft.
• Rails 12 are fixed on the floor 10, so as to allow the mounting of the passenger seats, one of which is shown at 14.
• the rails 12 extend parallel to each other, along the longitudinal axis of the aircraft.
• Each of the seats 14 comprises a seat base 16, as well as two feet 18, by which the seat 16 is mounted on two consecutive rails 12. More specifically, each of the seat legs 18 is placed in a vertical plane, oriented in the longitudinal direction of the aircraft, between one of the rails 12 and one of the lateral edges of the seat 16 of the seat.
• the monolithic structure 20 has a lower front anchoring zone 22 and a rear lower anchoring zone 24, by which the structure can be fixed to one of the rails 12 mounted on the floor 10 of the aircraft.
• the fixing is ensured by two metallic intermediate pieces (not shown) of conventional design. These intermediate parts can take, for example, the form described in document US-A-4,911,381.
• the monolithic structure 20 preferably incorporates, in these zones 22 and 24, suitable metal inserts (not shown).
• suitable metal inserts not shown. The presence of these inserts, which are integrated into the structure 20 during its manufacture, makes it possible to avoid any risk of tearing of the fibers in the anchoring zones, in the case of long fibers.
• the monolithic structure 20 also includes an upper front anchoring zone 26 and a rear upper anchoring zone 28, provided for carrying the seat 16 of the seat. More specifically, each of the upper front 26 and rear 28 anchoring zones is in the form of a yoke, in which can be received a transverse tube 27, 29 respectively, belonging to the chassis (not shown) of the seat 16 from the headquarters. Tubular metal inserts (not shown) are preferably integrated into the monolithic structure 20, during its manufacture, in these upper anchoring zones 26 and 28.
• tubular metal inserts Like the inserts placed in the lower anchoring zones 22 and 24, these tubular metal inserts have the function of providing the desired mechanical characteristics, avoiding any risk of the fibers being torn from the composite material, in the case of long fibers.
• the monolithic structure 20 has a central part 30, of approximately triangular shape, from which radiate three branches 32, 34 and 36.
• each of the branches 32, 34 and 36 extends, without discontinuity, one of the vertices of the curvilinear triangle formed by the central part 30.
• the branch 32 extends the summit of this triangle facing the lower front anchoring zone 22, so as to present this anchoring zone at its end.
• the branch 34 extends the top of the curvilinear triangle facing the rear lower anchoring zone 24 and has this anchoring zone at its end.
• the branch 36 extends the upper vertex of the curvilinear triangle and has the rear upper anchoring zone 28 at its end.
• the monolithic structure 20 further comprises a fourth branch 38, oriented vertically, and having the upper front anchoring zone 26 at its upper end. The lower end of this fourth branch 38 is connected to the lower front anchoring zone 22, so as to extend the branch 32 without discontinuity.
• the energy absorption body consists of a metal ring 42, partially trapped in the monolithic structure 20, around the central recess 40.
• the ring 42 is a cylindrical ring, centered on an axis perpendicular to the plane of the foot 18 and crossing the curvilinear triangle formed by the central recess 40 approximately at its center.
• the ring 42 has a relatively limited thickness in the radial direction, which allows it to be trapped completely in the monolithic structure 20 over two parts of its circumference.
• the two remaining parts of the ring 42 located between the imprisoned parts 42a and 42b, pass through the central recess 40, near the rounded tops situated opposite the branches 34 and 36.
• the ring 42 which constitutes the energy absorbing body of the seat base 18 in the embodiment described, is integrated into the monolithic structure 20 during its manufacture, in the same way as the inserts which are placed in the anchoring zones 22, 24, 26 and 28.
• the ring 42 does not fulfill any particular function.
• the ring 42 absorbs the energy resulting from the excessive force then applied between the upper anchoring zones 26, 28 and lower 22, 24 of foot. More specifically, the force applied between these anchoring zones then exceeds a predetermined threshold, beyond which the monolithic structure 20 of composite material deforms significantly.
• the upper anchoring zones 26 and 28 then move forwards, that is to say to the right when considering FIG. 2, relative to the lower anchoring zones 22 and 24. This results in deformation. elastic of the composite structure, in particular in the branches 36 and 38 and in the central part 30.
• the ring 42 Under the effect of the deformation of the branch 36 and of the central part 30, the ring 42 is in turn deformed, such so that its initial circular shape approximates roughly the triangular shape of the central recess 40. During this deformation, the ring 42 absorbs the energy induced by the accident and avoids an oscillation movement of the seat of the seat, under the effect of the elasticity of the composite structure.
• the branch 32 In order to optimize the gain in mass, other recesses are advantageously made in some of the branches of the monolithic structure 20.
• the branch 32 in the embodiment illustrated in FIG. 2, the branch 32, of relatively large width, has two circular recesses 46, the branch 36 has an elongated recess 48 and the branch 38 has a recess 50 which extends practically over its entire length.
• the monolithic structure 20 can take approximately the shape of an X joining the four anchoring points, the central recess then having approximately the shape of a curvilinear square.

Landscapes

• Business, Economics & Management (AREA)
• Emergency Management (AREA)
• Engineering & Computer Science (AREA)
• Aviation & Aerospace Engineering (AREA)
• Seats For Vehicles (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=9511779

Family Applications (1)

Country Status (3)

Families Citing this family (3)

Family Cites Families (5)

• 1997
  • 1997-10-03 FR FR9712331A patent/FR2769191B1/fr not_active Expired - Fee Related
• 1998
  • 1998-10-02 WO PCT/FR1998/002110 patent/WO1999017987A1/fr not_active Application Discontinuation
  • 1998-10-02 EP EP98946549A patent/EP1019286A1/de not_active Ceased

Non-Patent Citations (1)

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