Principle

After grant, it is not possible to broaden the scope of a patent, on pain of nullity (L613-25 CPI, d): « The patent shall be declared null and void by a court decision… if, after limitation, the extent of the protection conferred by the patent has been increased. »

Naturally, under this assumption, the limitation under Article L613-24 CPI would not have been a true limitation…

Assessment

Subject Matter Not Initially Covered by the Claims

To demonstrate an extension of scope, it is sufficient to show that the new claims cover a new element that was initially outside the scope of the patent.

In other words, if a third party becomes an infringer solely due to the limitation, the limitation must be prohibited under Article L613-25 CPI, d.

Adding New Claims During Limitation

Adding an independent claim that does not incorporate all the teachings of at least one granted independent claim clearly constitutes an extension of scope (Regional Court of Paris, 3rd Chamber, 1st Section, 21 May 2015, Case No. 2014/02007).

If the addition concerns dependent claims, this is more debatable: in my view, such an addition does not constitute an extension if and only if the claims from which these new claims depend are declared valid by the court.

Adding a Technical Effect to the Claims

Adding a technical effect to a claim does not appear to increase the scope of that claim (e.g., « so as to create a restoring moment opposing the compression of the suspension« ) (Court of Appeal of Lyon, 1st Civil Chamber, Section A, 13 July 2011, Case No. 2009/02302).

Indeed, this addition only concerns the result of technical features, not a technical feature as such (Court of Appeal of Lyon, 1st Civil Chamber, Section A, 13 July 2011, Case No. 2009/02302).