EQUAL TRIANGLE TESSELLATION ON PATCH surface

Sorry in advance because probably my problem is common. but i really don't find the right way..

in attachment the file. I need to make a trangles grid on this surface (patch surface). Best would be equal trangles, or few families, or even better equal triangles with equal side lenght. I tried louchbox but the paneling tools do not reconize the patch as a trimmed surface. I know that a patch is just an "hiding" of the trimmed parts but how to solve this problem? It would be great to have the right definition file. 

Thank to all for kind cooperation.