Are you talking about having these knives made for yourself, or are you talking about having them put into production by a knife manufacturer? Do these designs incorporate a new and unique feature that could possibly be patented?
If you just want a knife made to spec, there are more than a few makers who will make whatever you want, provided it's not an inherently weak design that they feel would harm their reputations (and there are those who'll do it anyway...). Drop me an e-mail and I'll be glad to point you to someone who will make you anything you can dream up and put to paper.
WRT manufacturers, without a reputation to your name, or a patent on a particularly appealing feature, they are probably going to trust the money they've got invested in in-house designs and collaborations with "known commodities".
Keep in mind that these are the big money deals that makers dream of, and even with original, tested designs and popular, established reputations, most makers do not have a factory collaboration with their name on it.
If you do have a new feature, PATENT IT! Do this NOW! Turn off your computer and get your patent. Then you can sell your feature.
Good luck!