When you read patent claims you might find yourself confused, the sentences are endless and complex, hardly using any punctuation and the grammar may often seem improper. Are there any rules or guiding lines for drafting proper claims?
The main positive rule in the US requires each claim should be written as a single sentence. As inventions become more and more complex, trying to phrase them in a single sentence leads to cumbersome and surprising results. To overcome the single sentence limitation, the claim language includes many clauses fragments using keywords such as “wherein”, “whereas” etc.
The patent attorney aims to draft the claims as broad as possible, for this purpose he uses generic terms and ambiguous phrases, resulting definitions and descriptions, which are sometimes incomprehensive and even the inventor might find it hard to recognize his invention. When trying to understand the claims you may need to follow up the terms and the definition as they appear in the specification of the patent (all components of claims have to be supported in the specification of the application) . The specification must comply with an enablement requirement; hence the description should explain the implementation of the invention for people skilled in the relevant art of the invention.
The final wording of the claims is an outcome of negotiation between the inventor/patent attorney and the examiner, hence the changes in claims through the examination may reflect the distinctive features of the invention from the prior art. In the European patent system, the claims should include the clause “characterized in”, for defining the distinctive component/function of the invention in comparison with prior art. However, in the US patent system the claims include almost no clue as for which component/element of the invention have distinctive innovative features in comparison with prior art.
In software patents claims the mission of understanding the claims becomes even more complex, as software technologies have an “abstract” nature the patent attorney can describe the same invention using a verity of terms and phrases