Device for reducing aerodynamic noise from an aircraft undercarriage
View Patent ↗In the field of aviation, a device for limiting aerodynamic noise from a deployed aircraft undercarriage during landing and/or takeoff. The device comprises two end plates ( 4 a , 4 b ) for closing respective ends ( 2 a , 2 b ) of a hollow pin ( 1 ) of the undercarriage, such as a hinge pin between two rods of the undercarriage, together with at least one tie ( 6 ) for engaging inside the hollow pin ( 1 ) to connect the two end plates ( 4 a , 4 b ) together so as to hold them pressed against the ends ( 2 a , 2 b ) of the pin ( 1 ).
1. A device for limiting aerodynamic noise from a deployed aircraft undercarriage, having a hollow pin ( 1 ), while landing and/or takeoff, the device comprising:
two end plates ( 4 a , 4 b ) for closing respective ends ( 2 a , 2 b ) of the hollow pin ( 1 ) of the undercarriage, and
at least one tie ( 6 ) disposed inside the hollow pin ( 1 ) to connect the two end plates ( 4 a , 4 b ) together so as to hold them pressed against the ends ( 2 a , 2 b ) of the hollow pin ( 1 ),
wherein the end plates ( 4 a , 4 b ) and/or the tie ( 6 ) are made of natural hemp or flax fibers agglomerated in a resin of reusable type.
2. A device according to claim 1 , wherein at least one end plate ( 4 a , 4 b ) includes a central orifice ( 9 a , 9 b ) for having the tie ( 6 ) pass therethrough in order to secure the tie ( 6 ) to the end plate ( 4 a , 4 b ) by means of the end of the tie ( 1 ) passing through the end plate.
3. A device according to claim 2 , further including at least one locking means for securing rigidly to an end of a tie ( 6 ) passing through an end plate ( 4 a , 4 b ) via its orifice ( 9 a , 9 b ), the locking means presenting a section greater than that of the orifice ( 9 a , 9 b ) so as to bear against an outer face ( 7 a , 7 b ) of the end plate ( 4 a , 4 b ).
4. A device according to claim 2 , wherein the end plate ( 4 a , 4 b ) is provided with means for locking an end of the tie ( 6 ) passing through the central orifice thereof.
5. A device according to claim 2 , wherein the material of the tie ( 6 ) is a thermoplastic for connecting said tie ( 6 ) to an end plate ( 4 a , 4 b ) with a heat flattened termination portion ( 6 a , 6 b ) of the tie passing through the central orifice ( 9 a , 9 b ) of the end plate ( 4 a , 4 b ).
6. A device according to claim 1 , wherein one of the end plates ( 4 a , 4 b ) includes centering means ( 14 a , 14 b ) whereby it is engaged in the end of the pin ( 1 ) that it is to close.
7. A device according to claim 6 , wherein the centering means are formed by a reduction in the diameter ( 14 a , 14 b ) of the outside edge of the end plate ( 4 a , 4 b ).
8. A device according to claim 1 , wherein at least one end plate includes one or more openings to avoid moist air accumulating inside the pin.