If you have a product patent in the U.S. doesn't matter if copies made in China get imported here.
Unless the copies have some major changes they would be considered conterfeit products which U.S. Customs and FTC Agents can sieze it if you file a complaint.
Whatever you do DON'T use those guys that advertise on TV and the Internet about using their company to patent your product .... they are ALL rip offs. They make you sign agreements with alot of fine print and rush you along and say "Don't worry about that you don't need to read it, just sign here". They are the used car salemen for patent filing and by the time you fiqure out what happened you will be lucky if you don't end up owing them money every time your product is sold.
Find a local patent attorney and in most cases they will advise you on the costs involved before you get in to deep. You must make sure you find one that specializes in the field your product is in to get the best advice.
Last edited by Gunsmith Dan; 01-21-2013 at 2:08 AM..