In case of an invalidated independent claim, does the dependent claim survive if the added limitation to the now dead independent claim is not inventive? If yes, does that mean that in a long chain of progressively dependent claims every single dependent claim must introduce something novel?
First, a small note about terminology: the word "limitation" is almost a synonym for "feature."
To answer the questions, I'll come up with a simple example. Let's say your invention is a chair that levitates. You submit only three claims, and they read:
A chair comprising: a stool and at least three legs.
The chair of claim 1, further comprising a magnetic levitation device attached below each of the three legs.
The chair of claim 2, further comprising a cushion seat.
The first claim is not patentable because it has been invented before. So the independent claim 1 would be rejected. Let's pretend the second claim passes all tests for patentability. The second claim would then allowable even though it depends from a rejected independent claim. The third claim would be allowable because, in its entirety, it reads:
A chair comprising: a stool and at least three legs [A], further comprising a magnetic levitation device attached below each of the three legs [B], further comprising a cushion seat [C].
If an invention made from A + B is novel and nonobvious, then an invention made from A + B + C will, by extension, be novel and nonobvious too. Claim 3 merely adds another limitation/feature to the already-allowable claim 2. Another way to say it is that claim 3 further narrows the scope of an invention that is already deemed patentable. So for these reasons, claim 3 is allowable, too, even though claim 3 doesn't introduce a separate novel feature from the original novelty of magnetic levitation.
However, the Patent Office would not permit a patent to issue until you: (a) amended claim 1 to include the limitation/feature of claim 2, (b) canceled claim 2, and (c) amended claim 3 so that it refers to claim 1:
(Amended) A chair comprising: a stool
and at, at least three legs, and a magnetic levitation device attached below each of the three legs.
(Canceled) The chair of claim 1, further comprising a magnetic levitation device attached below each of the three legs.
(Amended) The chair of
claim 2claim 1, further comprising a cushion seat.
I am no expert, and this response is for informational purposes only and not for the purpose of providing legal advice. You should contact your attorney or legal expert to obtain advice with respect to any particular issue or problem. Laws can differ dramatically from country to country, state to state, and technology field to technology field.
No and no. If the independent claim ist not novel and the added limitation does not make it inventive, that claim won't survive neither.
Does that mean that all dependent claims should introduce something novel? No. The combination of two known components can be inventive.
Try looking at this from another angle - if you have a broad independent claim and it turns out, one aspect of this is not novel (or inventive), other aspects could still be, but because you claim all at one, you lose the whole thing. And thats what dependent claims are for, they allow you to differentiate your dependent claims, leaving aspects out by adding limitations.