Patent Claim Drafting: 5 Key Points to Consider

A patent is an intellectual property (IP) right that offers legal protection to an applicant’s invention. It consists of various sections including a specification, drawing, and claim. Out of these, claims define the scope of protection granted by the patent. Given their significance, applicants must be careful while drafting them.

In this article, we discuss the points that one must bear in mind during patent claim drafting.

Components of a Patent’s Claim

  • Preamble

The preamble states the domain of the invention and the introductory statement for the claim. It also defines the scope and field of the claimed subject matter. For example, for an invention in a bicycle, a preamble that says “vehicle”, provides a broad scope than a preamble that says “bicycle”. Yet, if the invention is directed to a bicycle or a part of it, there may not be any benefit in having a preamble directed to “vehicle. However, it is preferable and generally advised to have claims having preambles towards the part of the bicycle and also the bicycle to benefit from claims of variable scopes.

  • Transition Phase

The transition word or phrase is used between the preamble and the body of the claim. Various types of transition phrases are used in the claims such as ‘comprising’, ‘including’, ‘characterized in that’, ‘comprises’, ‘consisting of’, and ‘consisting essentially of’. These phrases define whether the claim is open-ended or closed-ended.

  • Body

The body of the claim is the part that follows the preamble and the transition phrase. It includes the most important and novel elements of the invention and their relationship with each other. The body also describes how the elements cooperate structurally, and/or functionally with each other. It should be limited to a description of the technical subject matter, and surplus or laudatory statements/words such as “novel” should be avoided. It is also advised to use clear and intelligible wording, as well as avoid any ambiguities, vague expressions, and unnecessary repetition of language in the body.

Points to Keep in Mind While Drafting Patent Claims

1. Be Consistent – A claim term should be used consistently in patent claims. The use of inconsistent terms can cause unintended consequences during patent examination or later during patent litigation. For example, if a “motor” has been mentioned in the claims, it is advisable not to refer to “the motor” as “the drive” or with any other nomenclature other than the first name given to the element. Furthermore, it is improper to add more details to an element when referring back to it. For instance, if “a gear” has been stated once, it would be incorrect to refer to “the gear” as “the plastic gear” or “the worm gear” or “the drive gear”. This will add an “indirect limitation” on the claimed element.

2. Correct Antecedents – The first time an element or part is introduced in the claim, it should be preceded by an indefinite article (“a” or “an”). Thereafter, the element or part is preceded by a definite article (“the”) or by “said”. The patent drafter should be consistent in the usage and must not alternate between “said” or “the”. Sometimes, an element is preceded by a numerical adjective when it is introduced in a claim such as “two containers” or “a plurality of wires” or “at least one stand”. Lastly, avoid using the expression “the said”.

3. Avoid Means-Plus-Function Terminology –Use of means-plus-function terminology should be avoided in a U.S. patent application as it generally leads to an indefinite rejection by a U.S. Examiner. For example, instead of using “attaching means” that will attract an indefiniteness type rejection, a coupler is a better terminology. Also, contrary to the broad appearance of the means-plus-function, it does not cover every means for performing the recited function provided in the mean-plus-function terminology. Instead, the means-plus-function is limited to the specific structures, materials, or acts disclosed in the specification.

4. Focus on the Objective of Literal Infringement – Claims should be drafted to target literal infringement. So, it is advisable to avoid dependency on the doctrine of equivalents while drafting. This is because, in the first stage of patent infringement, the elements of the claim are analyzed to be present in the product/process. Then, the scope is construed in the literal language of the claim. The patent infringement analysis then proceeds to the second stage if the literal infringement is not established. The doctrine of equivalents should be applied to each claim element and not to the whole invention. It cannot remove an element completely. Further, both prior-art and the prosecution history of the patent legally limit the scope of the equivalents.

5. The Problem of Vagueness and Indefiniteness – Quite often, claims are rejected or invalidated based on their vague and indefinite nature. Use of the terms such as “thick”, “heavy”, “small”, “top”, “left”, “right”, “high”, and “low” in the claims can be considered vague by the examiner. The remedy here usually is to describe the product with reference to some other element or an external standard such as “smaller than the …” or “having a specific gravity greater than water”.


All the points mentioned above are intended to make you aware of the practical strategies and considerations while drafting patent claims. A carefully drafted claim can create a high-value patent application and become part of a valuable IP portfolio that may save millions of dollars in litigation costs for your organization.

If you are seeking support for drafting patents, Sagacious IP has got you covered. Our Patent Drafting service aims to not only draft patent applications that meet the patent office requirements but also make the draft future-proof by tweaking the ideas for ensuring the broadest possible coverage. To know more about our service, click here.

– Yojit Bhugra (Engineering Patent Drafting & Prosecution) and the Editorial Team

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