Method for producing contoured holes

1. A method for manufacturing a contoured hole, the hole being manufactured in a wall, the wall comprising a first surface and a second surface, the method comprising:

manufacturing a first non-penetrating hole extending from the first surface and into the wall, wherein a distal end of the first hole is located within the wall such that the first hole does not penetrate the wall second surface;

manufacturing a through hole, wherein the through hole is fluidly connected with the first hole and penetrates the second surface of the wall; and

manufacturing a second non-penetrating hole, the second hole being fluidly connected with the first hole and comprising a second hole distal end located within the wall such that the second hole does not penetrate the second surface of the wall, the second hole being fluidly connected with the through hole.

2. The method according to claim 1 , comprising:

manufacturing the first hole with a first cross sectional area;

manufacturing the through hole with a through hole cross sectional area; and

choosing the through hole cross sectional area to be smaller than the first cross sectional area.

3. The method according to claim 1 , comprising:

manufacturing the first hole with a first cross sectional area;

manufacturing the second hole with a second hole cross sectional area; and

manufacturing the through hole with a through hole cross sectional area, wherein the through hole cross sectional area is smaller than at least one of the first and second cross sectional areas.

4. The method according to claim 3 , wherein the through hole cross sectional area is smaller than both the first and the second cross sectional area.

5. The method according to claim 3 , wherein the through hole cross sectional area is smaller than the second cross sectional area and the second cross sectional area is smaller than the first cross sectional area.

6. The method according to claim 1 , comprising:

manufacturing the first hole comprises penetrating the first surface at a first entry location and forming a first entry opening, and advancing a tool into the wall along a first hole axis, and stopping advancing before reaching the wall second surface, thus producing a first hole distal end; and

manufacturing the second hole comprises penetrating the first surface at a second entry location and forming a second entry opening, and advancing a tool into the wall along a second hole axis, and stopping tool advancement before reaching the wall second surface, thus producing a second hole distal end.

7. The method according to claim 6 , comprising:

arranging the first and second entry openings in a non-overlapping manner.

8. The method according to claim 6 , comprising:

removing material between the first and second hole and the through hole.

9. The method according to claim 6 , wherein the manufacturing of the through hole comprises:

penetrating the first surface at a through hole entry location different from the first and second entry locations and forming a through hole entry opening;

advancing a tool into the wall along a through hole axis; and

continuing tool advancement until the wall second surface is penetrated thus producing the through hole.

10. The method according to claim 9 , further comprising:

choosing the through hole axis such as to include a main tilt angle with the wall first surface normal at the through hole entry location and defining a main plane spanned up by the through hole axis and the wall first surface normal at the through hole entry location;

choosing the first and second hole axes such as to include first and second tilt angles with the wall first surface normal at the respective entry locations, wherein the first and second hole axis, when projected onto the main plane, include first and second projected tilt angles with the surface normal at the through hole entry location; and

choosing said respective first and second projected tilt angles larger than the main tilt angle.

11. The method according to claim 9 , further comprising:

choosing the through hole axis such as to include a main tilt angle with the wall first surface normal at the through hole entry location and defining a main plane spanned up by the through hole axis and the wall first surface normal at the through hole entry location; and

choosing the first and second hole entry locations to be laterally offset from the main plane.

12. The method according to claim 11 , further comprising:

choosing the first and second hole entry locations on different sides of the main plane.

13. The method according to claim 9 , further comprising:

choosing the first, second and through hole axis such that each hole intersects with at least one other hole and wherein in particular all three holes intersect at a common intersection location.

14. The method according to claim 13 , wherein the through hole intersects the first and second holes at a common first and second hole distal end location.

15. The method according to claim 1 , further comprising:

laterally offsetting at least one of a through hole axis and a second hole axis from and at least essentially parallel to a first hole axis.

16. The method according to claim 15 , comprising:

offsetting the axes such that the hole perimeters are tangent with each other.

17. The method according to claim 15 , comprising:

smoothening the transitions between the holes thus producing a fan-shaped hole with a continuous inner surface.

18. The method according to claim 1 , further comprising:

laterally offsetting a second hole axis from and at least essentially parallel to a first hole axis and laterally offsetting a through hole axis from and at least essentially parallel to the second hole axis.

19. The method according to claim 1 , further comprising:

laterally offsetting a second hole axis from a first hole axis by a first offset;

laterally offsetting a through hole axis from the second hole axis by a second offset; and

choosing the first offset and the second offset to be at least essentially aligned with each other.

20. The method according to claim 1 , wherein manufacturing a hole comprises drilling.