A dependent claim that modifies just one aspect of the independent claim

Question

Say there's an independent claim broken down into several steps:

1. A method for ...., comprising the steps of:

(a) ....

(b) ....

(c) ....

Now let's say that a dependent claim is to be written such that only the step (b) is modified. Would it be correct to use the term 'comprising' or 'further comprising'? The term 'further comprising' would suggest that a feature is being to the already existing step (b), rather than actually modifying it.

Would this be a correct way to express the required dependent claim?

2. The method of claim 1, wherein step (b) comprises ...

Another option could be to simply have another independent claim with all the steps in claim 1, with a modified step (b).

Answer 1

You cannot modify any feature of the independent claim in an dependent claim.

Per definition, any dependent claim implements all features of the independent claim plus something.

Therefore only “further comprising“ makes sense in your example.

If you want to modify a step, find a broader independent claim and make your current independent claim and the modification dependent on that;

Or decide which one is more important and make the other one dependent (having both features);

Or file another application (divisional, continuation, ...);

Or try two independent claims and good luck with arguing a common inventive concept. It's possible, but hard, and going into that would merit a whole new question or a bunch thereof. If you're thinking about that, please ask a new question about it.

Mostly you'll find more than one independent claim only if one is for example tires for a car and the other one a car with those tires. Almost everything else gets you an election requirement where the examiner tells you to choose one.

If your step (b) only additionally comprises something else, “further comprising“ is fine, everything that means the same is fine too, another independent claim not so much if technically its dependent anyways.

Answer 2

You can't remove anything required by a referenced claim but you can add to it or you can narrow it. For example - The method of claim 1 where the hammer used in step b is a claw hammer. Or - the method of claim 1 where the dusting is accomplished with a feather.