HOW WOULD YOU RECOGNIZE A REAL BOW KITE?
The BOW concept, developed by Dominique & Bruno Legaignoux since 2002, was introduced during summer 2005 by the licensed brands Cabrinha et Takoon.
What officially defines a Bow kite according to the US patent application US 2005/0230556 A1, is (page 1 [0013]) the concave trailing edge, “during flight, when viewed from above”
This concept offers many advantages compared to the C-kites:
- Huge “depower” for far more security. In case of gusts or a piloting mistake, all you have to do is to release the bar to stop the power;
- Very easy to relaunch (no need to swim)
- Very large wind range, allowing a safer and less expensive usage.
The huge success following the introduction of the BOW concept has meant all the manufacturers consider it as essential and have added it as a part of their range.
Some of them took a license (see list).
Their wings integrate all the technicalities of the Bow concept and are a guarantee of quality for the buyer since Diamond White (patent owner) helps its licensees to develop their wings.
Others market concave trailing edge wings but pretend not to depend upon the Diamond White patents and give to their models ambiguous generic terms: 100% depower, SLE, hybrid, flat, ” Bow style”.
Some brands have even developed wings that are C-kite/Bow kite hybrids. These wings generally have a smaller depower than the Bow kite, and particularly a relaunch ability closer to the one of a C-kite: It’s necessary to swim to relaunch the kite, whereas all you have to do to relaunch a Bow kite is to pull on a back line.
All wings having a large depower ability, have logically supplanted the C-kite and now make up more than 80% of the world sales.
How, to differentiate these 3 wing types?.
1/ The Bow wings respecting Diamond White’s Intellectual Property rights have a concave trailing edge, and bear an Certificate of Authenticity on one of their tips.
2/ Wings having a concave trailing edge when they are flying, seen from above, but which don’t bear a Certificate of Authenticity are probably patent infringing wings. The manufacturers, distributors, sellers and owners of such wings are likely to be prosecuted.
3/ The hybrid wings have a straight or convex trailing edge when the kite is flying, viewed from above (Diamond White will shortly publish a list of hybrid wings, i.e. that are not included in the Bow patents)
The best way to determine the trailing edge shape is to make a picture of the kite in the air seen from above. For that, the pilot places the kite at the right or left side of the wind window (close to the ground) and the photographer places himself far enough behind the kite, lined up on the lines, the pilot hidden by the kite ( we can possibly see his legs). The ideal thing would be to take pictures of the wing in the following positions: kite sheeted-in close to stalling, kite sheeted-out but without falling, and kite in intermediary position.
The only thing left to do is to draw on the picture of the normal flight wing a line parallel to the trailing edge axis.
It should be noted that pictures taken from or close to the pilot, so lined up on the lines, give the same result, and enable to determine the shape of the trailing edge too.
As an end to this topic, Diamond White owns other patents on the bow concept. Every brand marketing a hybrid kite, i.e. with a not-concave trailing edge but using other technologies patented by Diamond White must take a license for those technologies.