Expert: George H. Morgan, P.E., Patent Agent - 12/1/2010

Question
I am looking at making a product that I later found out there is a patent on, I think.  Are the "claims" the binding part of the patent document?  This patented item says in claim 1 that it is to be used "on a polluted pond".  The product I would like to make is very similar to the wording in the rest of the patent but I don't want to use it "on a polluted pond".  My product would be for fish ponds and land-based applications, not a "polluted pond".    Would I be in violation of the patent?
Thanks....John

Answer
Mr. Cole, the short answer is: Probably.

The long answer:
Prior to a Supreme Court decision known as "Festo", the doctrine of equivalence probably favored the patent holder, in this case.

However, the Festo decision some 10 years ago or so, narrowed the coverage of the doctrine of equivalence if the claim was amended to gain acceptance of the claim.

So, you need an "infringement opinion" from a patent attorney (not a patent agent, as it is a tort matter for the courts to decide) who will probably get a copy of the patent prosecution file to dig into the matter. This is expensive, probably five or ten thousand or more.

However, before that, take a closer look at the patent. Has it expired, either because the application date is more than 20 years ago (unless the time was extended for some reason), or the maintenance fees were not paid?  Did it ever go into production?

If it did not go into production, and the inventor is sitting there with a patent, but no income from it, you might approach him and see if you can cut a deal. This often happens. Co-operation often works better than adversarial proceedings.

Even if you had an infringement opinion, the inventor, who may well have his ego wrapped around his "baby" might still sue. That can get expensive.

I hope this helps. Best wishes on you projects!

George H. Morgan
Professional Engineer (since 1958)
Patent Agent (since 1973)