Wing having a negative dihedron for towing a load

1. Wing ( 10 ) having a negative dihedron for towing a load, comprising a flexible canopy ( 12 ) which is defined between two lateral ends ( 14 A, 14 B) which are connected to each other, at the front, by a leading edge ( 20 ) and, at the rear, by a trailing edge ( 22 ), the canopy ( 12 ) having, between those two lateral ends ( 14 A, 14 B), a propulsive central region ( 16 ) bordered at each of its lateral sides by a respective control regions ( 18 A, 18 B), the wing comprising at least a member ( 30 A, 30 B) for suspending the load adjacent to each lateral end ( 14 A, 14 B), said auxiliary maintenance means ( 32 ) which are capable of flattening the propulsive central region ( 16 ), said auxiliary maintenance means being located adjacent to the leading edge ( 20 ) during flight,—wherein the trailing edge ( 22 ) of the wing is generally concave when viewed from above.

2. Wing according to claim 1 , wherein the central region ( 60 ) is not provided, except for adjacent to the leading edge ( 20 ), with any auxiliary maintenance means which is capable of flattening the propulsive central region ( 16 ) during flight.

3. Wing according to claim 1 , wherein the aspect ratio of the wing is greater than 3.

4. Wing according to any claim 1 , wherein the thrust centre of each section of the control regions ( 18 A, 18 B) is behind the thrust centre of each section of the propulsive central region ( 16 ).

5. Wing according to claim 1 , wherein the auxiliary maintenance means ( 32 ) of the propulsive central region ( 16 ) comprise at least a line ( 34 A, 34 B) which is connected by one end to the propulsive central region ( 16 ) adjacent to the leading edge ( 20 ) and which is capable of being connected to the load at the other end thereof.

6. Wing according to claim 5 , wherein each line ( 34 A, 34 B) comprises an assembly of shroud lines ( 36 A, 34 B) which are gathered at one end at the load to be towed and the other ends of which are connected to the propulsive central region ( 16 ), being distributed over the length of the leading edge ( 20 ).

7. Wing according to claim 1 , wherein the auxiliary maintenance means ( 32 ) of the propulsive central region ( 16 ) adjacent to the leading edge ( 20 ) comprise a stiffening spar which is fixedly joined over the leading edge ( 20 ).

8. Wing according to claim 1 , wherein the line (C) of the thrust centres of the sections of the canopy ( 12 ) during flight, from one lateral end to the other ( 14 A, 14 B), describes the shape of a curve whose centre of curvature, at any location, is located at the side of the trailing edge ( 22 ).

9. Wing according to claim 1 , further comprising rear lines ( 40 A, 40 B) which are connected to the suspension members ( 30 A, 30 B) which are arranged at the lateral ends ( 14 A, 14 B) of the wing, and at least a shroud line ( 80 A, 80 B) which is connected, at one end, to the leading edge ( 20 ) and, at the other end thereof, to at least one of the rear lines ( 40 A, 40 B).

10. Wing according to claim 1 , further comprising rear lines ( 40 A, 40 B) which are connected to the suspension members ( 30 A, 30 B) which are arranged at the lateral ends ( 14 A, 14 B) of the wing, and wherein the auxiliary maintenance means ( 32 ) of the propulsive central region ( 16 ) comprise at least a front line ( 34 A, 34 B) which is connected by one end to the propulsive central region adjacent to the leading edge ( 20 ) and which is capable of being connected to the load at the other end thereof, each front line ( 34 A, 34 B) comprising an assembly of shroud lines ( 36 A, 36 B; 90 A, 90 B) which are applied to the propulsive central region ( 16 ) at locations which are distributed over the length of the leading edge ( 20 ), at least one sliding shroud line ( 90 A, 90 B) being engaged in a sliding manner in a guide ( 92 A, 92 B) which is fixedly joined to the leading edge ( 20 ), the end of the sliding shroud line ( 90 A, 90 B) being fixedly joined to at least one of the rear lines ( 40 A, 40 B).

11. Wing according to claim 9 , wherein the guide ( 92 A, 92 B) is supported in a sliding manner on a deformable loop ( 96 A, 96 B) which is connected at two locations which are spaced from the leading edge ( 20 ).

12. Wing according to claim 1 , further comprising an operating device ( 100 ) which comprises a control bar ( 102 ), the ends of which are connected to the lateral ends ( 14 A, 14 B) of the canopy ( 12 ) by rear lines ( 40 A, 40 B) and at least a towing line ( 104 ) which is connected to the canopy ( 12 ) in front of the rear lines ( 40 A, 40 B) by at least a front line ( 34 A, 34 B), which towing line ( 104 ) comprises means for connection to the body of a user during use of the wing, which connection means comprise at least a pulley ( 110 ) which is engaged in a loop of each towing line ( 104 ) whose end is fixedly joined to the control bar ( 102 ), the pulley ( 110 ) comprising means ( 112 , 114 , 116 ) for connecting the axle thereof to the body of the user.

13. Wing according to claim 12 , wherein the means for connecting the axle of the pulley ( 110 ) to the body of the user comprise a complementary pulley ( 114 ) which is engaged in a loop of a return strand ( 112 ), one end of which is fixed to the axle of the pulley ( 110 ) and the other end of which is fixed to the or each towing line ( 104 ), the complementary pulley ( 114 ) comprising means ( 116 ) for connecting the axle thereof to the body of the user.

14. Wing according to claim 1 , wherein, in longitudinal section, the canopy ( 12 ) is concave.

15. Wing according to claim 1 , wherein the auxiliary maintenance means ( 32 ) are arranged only between the leading edge ( 20 ) and the line (C) of the thrust centres of the canopy.