Using multiple dependent claims of multiple dependent claims of multiple dependent claims

Question

I'm filing a patent application in the UK covering 10 or so linked inventions spanning various industries. I plan to use multiple dependent claims to link the various inventions. I believe the number of independent and dependent claims is effectively unlimited in the UK, with no charge for excess.

What are the benefits and risks of listing many permutations of claims? For example, consider the following:

Claims 1-10 are related to invention A
Claims 11-20 are related to invention B
Claims 21-30 are related to invention C
Claims 31-40 are related to invention D
41) The systems of claims 1-10 in conjunction with the method of claims 11-20.
42) The systems and methods of claim 41 in conjunction with the method of claims 21-30
43) The systems and methods of claims 41 and 42 in conjunction with the method of claims 31-40
44) etc, etc..

Potentially thousands of theoretical claims are claimed. Am I likely to fall foul of the IPO rejecting them on the grounds that they are

... of a total number or complexity not justified by the nature of the invention
... in principle unsearchable by reason of the number of alternatives embraced, or the choice of characterizing parameters or desiderata

Taken from the code of practice here.

If they decide there are multiple inventions, what happens? If the application is divided, how do claims reference claims in the other applications?

Say invention A was deemed obvious over another patent. Are my claims of invention A in conjunction with inventions B, C and D still potentially valid?

Answer 1

Clearly non-unitary, as you state yourself. I am not acquainted with the specific procedures in the UK, but normally a request for additional fees or a request to excise the additional inventions (potentially from the claims AND description) will result.

If inventions B-D are to be excised, the dependent claims can only depend from the independent claims relating to A for obvious reasons. They will then have to be adapted accordingly.

Submitting clearly non-unitary subject-matter may also induce the examiner to look more closely and find more non-unitary inventions than you assume in the first place.

You will have to pick ONE category for each claim. Either you claim an apparatus OR a method OR a system OR .... . Claiming "The systems AND methods of...." should normally not be accepted.

You may also potentially run into problems concerning basis in the description / sufficiency of disclosure. Simply offering a "pool of features" and then trying to come up with the actual invention later in the procedure sounds tempting (and is sometimes tried), but can cause all sorts of problems.

Try at your own risk, irreversible loss of rights included.