Hi Billy,
PREVIOUS FLAT KITES
Yes, it is possible to make flat kites without sweep - obviously - but you need either spars, either bridles everywhere along the profile. The Seasmik type kites had a slack TE because of no sweep.
Just put sweep on such a kite, then you can remove all the bridles but the LE ones and the TE becomes "flat" and well tightened.
Take a C-shape kite, don't modify it except putting some bridles on the LE: you get a flatter LE but the TE is still round, so the LE and TE don't match, the tips have too much angle of attack, what is bad for efficiency (high drag/vortices)
I don't believe that the success of the bow kite is just marketing as I read it sometimes. I don't have to make unsupported statements to "sell the idea', it is already a success. I just try to explain people why and how it works.
If someone finds a way to make a flat and efficient sparless bridleless kite, it will be a bow kite competitor. For now I don't think any flat kite can compete with the bow except the ram-air kites.
KITESKI PICTURE
A patent never starts from nothing. You can always find similarities.
About the C-shape kite, there were already kites with inflated struts, kites with inflated LE, kites with C-shape (sleds), kites controled with 2 lines but there wasn't one with all of them or even 3 of them.
"Assembling" these features made an innovative kite which allowed kitesurfing to become a real sport.
Our new patent, as explained on
http://www.bowkite.com, is a mix of a classic tube kite, a concave TE and a bridled LE. Take a C-shape tube kite, add sweep to the planform and bridles to the LE, you get a flatter kite. This is just aerodynamics but it seems that nobody had the idea before us, so it was patentable.
Yes, there were other kites with concave TE but with other shapes and for other purposes, they can't be compared. And yes, there were kites with bridled LE, kites with flat shape...
I hope it makes it clearer. These matters are not easy to explain.
Bruno Legaignoux