What are Jepson patent claims in United States patent law?

A patent is a set of exclusive rights granted to an inventor for an invention. A patent allows an inventor to prevent other people from making, using, or selling an invention. The heart of a patent is the claims of the patent. The claims of a patent describe the aspects of an invention which are protected by the patent. If an aspect of an invention is described in the patent but not listed in the claims of the patent, than that aspect of the invention is not protected by the patent.

Patent claims have a very specific style. Even people with strong English language skills have difficulty understanding patent claims, and more trouble drafting patent claims. The meaning of words in a patent claim do not always follow the ordinary English language meaning. The style used to construct patent claims has developed over the years as United States patent law has evolved. The reason that patent claims do not always follow the rules of the English language is because so many different types of inventions can be patented. While is may be easy to write patent claims for a simple machine like a bicycle, it can be challenging to write patent claims for complex chemicals. As different fields of technology evolve, patent law has evolved to allow inventors to claim their inventions with precise language.

Jepson format patent claims are a special style of drafting patent claims. Jepson claims are specifically crafted to patent an improvement to an existing invention. Jepson claims are relatively easy to write and understand. The style for Jepson claims can be found in 37 C.F.R. 1.75(e). Rule 75(e) states:

(e) Where the nature of the case admits, as in the case of an improvement, any independent claim should contain in the following order:
(1) A preamble comprising a general description of all the elements or steps of the claimed combination which are conventional or known,
(2) A phrase such as “wherein the improvement comprises,” and
(3) Those elements, steps, and/or relationships which constitute that portion of the claimed combination which the applicant considers as the new or improved portion.

The key things that distinguish a Jepson claim are a list of all the known elements of prior inventions, the phrase “wherein the improvement comprises” and then a description of the claimed invention.

Many experienced patent attorneys have the opinion that Jepson format patent claims are terrible and should only be used as a final resort. Jepson claims are easy to write, but if getting a patent is easy, then the patent probably has little value. The purpose of the patent prosecution is not to submit a patent application which is approved without question, but to submit a patent application with claims as broad as possible, and debate the patent examiner until an agreement can be reached. Jepson claims are rarely used because they raise issues of collateral estoppel and prior art.

Manual for Patent Examining Procedure section 2129 states: “Drafting a claim in Jepson format is taken as an implied admission that the subject matter of the preamble is the prior art work of another.” This means that if you file a patent application using Jepson claims, you are admitting that the elements of prior inventions are prior art, and not claiming those elements. While an applicant for a patent has an obligation to disclose all prior art known to them in the application they are not obligated to agree that it prevents them from claiming those elements.

There is one situation when Jepson claims can be valuable and that is to avoid a claim of double patenting. If a patent application is denied because the claimed invention covers part of a patent owned by the patent applicant, a Jepson format patent claim can help avoid a rejection. Because the prior art is owned by the patent applicant it does not put the applicant at a significant disadvantage.

Drafting a patent applications is a complex task, if you want to apply for a patent it is best to consult with an experienced patent attorney to help you.

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