Combination of Dependent Claims Infringement

Question

I have a question regarding dependent claim combinations and the infringement of them.

Lets say I have these claims:

1. A + B
2. Claim 1 + C
3. Claim 1 + D

If someone has an apparatus A + B + C + D, would they be infringing implicitly on claims 2 and 3 or is this not the case? What are the conditions for this kind of infringement (must the combination be trivial in order to infringe)? If not, what are strategies to restructure the claims such that the combinations of the dependent claims are part of the claimed invention, without necessarily having many dependent claims with repeated content?

Really appreciate any advice you can give me.

Answer 1

For infringing a claim, all elements of a claim need to be infringed.

A claim a + b can either be “at least and b“ (typically) or “exactly a and b“ (for example exactly 40% sparkling water and 60% apple juice, very rare).

In your example, at least claim 1 must be “at least a and b“ because else a+b+c would not be a dependent claim as dependent claims are always more narrow and something infringing a dependent claim always infringes the independent claim too. If claim 1 were “exactly a and b“, claims 2 and 3 wouldn't fall into it and that cannot be. I suppose the other claims then follow the same logic.

So a+b+c+d infringes all of “at least a and b“, “at least a and b and c“ and “at least a and b and d“.