Consider a patent with broad specification and claims. Would it be considered infringement if one then practices the invention in a way that was not PHOSITA-enabled by the spec/claims at the effective filing date?

As an example, consider an issued patent that claims a method for cutting down trees with a wooden-handled instrument, and describes an example using an ax. If a rogue wizard escaped from Hogwarts to become a lumberjack (bear with me), would using his (wooden) wand with an incantation to cut down trees constitute infringement? Presumably, the original patentee would not have considered this future improvement, but it technically is a subset of the claims.

  • Wouldn't the claimed method of "cutting down trees with a wooden-handled instrument" presumably incorporate teaching of an element of a sharp blade or other cutting surface? In theory, severing trees from the earth by other means (pulling, pushing over, using fire, trained beavers) would effectively "engineer around" the claimed "cutting instrument".
    – Upnorth
    Aug 13, 2017 at 21:20
  • @Upnorth The point I was trying to convey is claiming a superset that includes an unforeseen subset.
    – user132162
    Aug 13, 2017 at 23:46

1 Answer 1


You are conflating two different questions.

A person infringes a claim if they perform all the steps of it. It generally doesn't matter whether the original inventors foresaw the particular details of that infringement.

Enablement affects the validity of a claim. That is, a claim may be invalid if it is not suitably enabled, independently of whether it is infringed.

The only place in which the inventors' intentions might matter for infringement is in the interpretation of terms in the claims where there is some ambiguity. In your example, the argument may well be that the inventors did not use the term "instrument" with a view to including a wand, and so “instrument” should be interpreted to exclude wands. This sort of thing quickly becomes complicated.

  • Okay, thanks for clarifying. So is it fairly common that one infringes by using a method not envisioned by the original inventor? Or are such scenarios litigated with the argument that the claim contains certain embodiments not supported by the specification (and thus the claim was not enabled)? Something just seems unequitable about getting ownership to something one didn't invent, but I realize there is a gray line between what is explicitly specified and what could be inferred from that specification.
    – user132162
    Aug 14, 2017 at 15:57
  • 1
    @user132162 It's entirely common, and indeed there is a large industry built around pre-modern-web patents being enforced against modern implementations of web technologies. It's a policy decision by the architects of the modern patent system: it is seen as appropriate that an inventor should be entitled to protect the full scope of their invention, even if it encompasses implementations they didn't turn their mind to, since the alternative would result in patents which are extremely narrow and easy to design around, and which do not keep up with the march of technology.
    – Maca
    Aug 14, 2017 at 23:30
  • I would just like to add that there does seem to be a threshold beyond which one could be considered to 'over-claim'. This relates to the 'written description' requirement of 35 USC 112 (which is distinct from enablement per case law). See the following for further discussion: en.wikipedia.org/wiki/…
    – user132162
    Aug 15, 2017 at 18:02

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