Should I include a patent in my cumulative PhD thesis?
This is something you really need to discuss with your advisor. Personally I think it may be very reasonable to include the patent application as an appendix (and the fact that you are a named inventor on a patent application is by itself quite impressive and likely to add some cachet to your thesis), but that's just my highly uninformed opinion. I don't think anyone not familiar with specific details of the patent application and how it relates to the rest of your work could give you very authoritative advice on such a question.

Another thing to keep in mind is that most patent applications are not really "authored" by the inventor. Large parts (if not the entire thing) are usually written by lawyers. So (except in the unlikely event where you actually wrote the whole thing yourself) there would be an interesting question of how to properly present/credit the patent application, and whether it would be covered by any copyright laws (I suspect patent applications are considered to belong to the public domain once they are made public, but that's just a guess). These sorts of issues are some of the reasons why inclusion as an appendix seems more appropriate to me than in the main body of the thesis.