I have an invention that is the combination of components A, B, C, D, F. If I file a patent for it, what scope does it cover exactly?

Does the patent cover sub-combinations like A, B, C?

How can I write the claims so that they protect sub-parts of my invention?

2 Answers 2


To infringe on a claim, the infringer must implement each and every aspect of the claim. Thus if a claim specifies steps A, B, C, D and E and someone makes a product that utilizes A, B, C and D but not E it doesn't infringe.

As for how to write claims so that they protect sub-parts, you have to show that the sub combinations are patentable by themselves and then claim them. Truthfully, the fact you are asking these very basic questions lead me to suggest that you shouldn't be writing claims at all. You would be working with a patent attorney or agent. I have quite a few patents and have read many hundreds of patents. I wouldn't dream of writing my own claims.


A claim's scope is mostly based on simple logic. If it claims A AND B AND C AND D AND E then, as Eric said, you need to have all those to be considered inside the claim's scope.

If the claim reads (A or B) and C and (D or E) you can imagine the situation is more complicated. Sort of like searching with Boolean operators. The problem is that instead of letters A, B, C etc the claim uses words and words refer to something that might not be an object. And depending on the jurisdiction (country) you are active, the rules for interpreting claims might have their own special features.

Indeed very basic questions. Careful there, many individuals go file a PCT with a decent idea, but they try to save money by drafting themselves. Then the drafting is so poor that the damage is not repairable. And you cannot start all over again, by filing a new one (with the help of an attorney or not), because once something is published you cannot patent it anymore.

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