Hinge system for airfoil

1. A foil hinge system for a hydrofoil or airfoil, comprising:

a main foil body, substantially extending in a longitudinal direction and a transverse direction,

a flap hinged to the main foil body arranged on a longitudinal end side of the main foil body, and

a flexible element connecting the main foil body and the flap,

wherein several rigid structures are arranged in such a manner on the flexible element, that the rigid structures provide a dead stop when the flap is in a maximum deflection with respect to the main foil body.

2. The foil hinge system according to claim 1 , wherein the rigid structures are shaped and arranged on the flexible element such that a gap is provided between the adjacent rigid structures, which enables movement of the flap relative to the main foil body.

3. The foil hinge system according to claim 2 , wherein the rigid structures substantially extend in the transversal direction and the gap is provided in the longitudinal direction.

4. The foil hinge system according to claim 1 , wherein the flexible element substantially extends in a longitudinal direction and transverse direction and connects the main foil body and flap in the longitudinal direction, wherein the rigid structures are provided in a spanwise direction on both sides of the flexible element.

5. The foil hinge system according to claim 1 , wherein the flexible element is made of a thin flexible composite sheet.

6. The foil hinge system according to claim 1 , wherein the flexible element is made of an anisotropic material.

7. The foil hinge system according to claim 1 , wherein flexible element is made of a composite sheet material, whose fiber direction orientation and/or laminate thickness is altered locally.

8. The foil hinge system according to claim 1 , wherein at least three rigid structures are arranged on the flexible element.

9. The foil hinge system according to claim 1 , wherein the rigid structures have a wedge-like form increasing the longitudinal width of the rigid structures in the spanwise direction towards the flexible element, wherein when the flap is in a central position, the adjacent surfaces of two adjacent rigid structures are arranged in an angle (a) to each other.

10. The foil hinge system according to claim 1 , wherein an elastic cover is provided between the main foil body and flap and covers the rigid structures.

11. The foil hinge system according to claim 10 , wherein the elastic cover comprises a boundary elastomer which is directly arranged on the rigid structure and an outside elastomer which is arranged on the boundary elastomer.

12. The foil hinge system according to claim 10 , wherein the elastic cover provides a continuous surface between the flap and main foil body.

13. The foil hinge system according to claim 1 , wherein chamfers are provided at the longitudinal end sides of the main foil body and/or flap, which are adjacent to the flexible element.

14. The foil hinge system according to claim 1 , wherein the rigid structures are adapted to come into contact with respective adjacent rigid structures when the flap is in a maximum deflection regarding the main foil body.

15. An airfoil or Hydrofoil comprising a foil hinge according to claim 1 , wherein the flap is a leading edge flap, trailing edge flap, aileron or trim tab.

16. The foil hinge system according to claim 1 , wherein a plurality of the several rigid structures are disposed on a first side of the flexible element and a plurality of the several rigid structures are disposed on a second side of the flexible element that is opposing the first side.

17. The foil hinge system according to claim 1 , wherein each of the several rigid structures has an elongated length that extends in the transverse direction, a width that extends in the longitudinal direction, and a height that extends normal to the transverse direction and the longitudinal direction, the length of each of the several rigid structures being greater than the width or the height.