Having done considerable research into patents concerning knives, all the following are true....
-Its a LONG process (usually 2-3 years)
-Its an EXPENSIVE process ($10,000 to start is about right, then add another 5,000-10,000 by the time its done)
-The most important part from my standpoint....there is a little known clause that says if someone changes ANY dimension on the patented item by as little as 1/64", then its NOT patent infringement.
-And finally, there is no organization that enforces patent infringement...its up to the patent holder. Which means that the patent holder is the one who must go after the offending party, with no help from anyone.
All in all, unless your a large company, with lots of lawyers on retainer who need something to do, then its just not worth it.