A patent gives its owner the right to exclude others from making, using, offering to sell or selling products or performing services in the United States that would infringe claims of that patent.1 To be valid, a claim must express exactly what the inventor of the patented invention created and described in a technical disclosure part of the patent and, at the same time, avoid being readable on what already existed in the prior art. The content and wording of the claims are negotiated between the patent applicant and an examiner at the U.S. Patent and Trademark Office (USPTO) during a process termed prosecution of the patent.
A claim has a preamble that usually describes the general field of the invention, followed by the body of the claim in the form of a number of paragraphs describing elements (also called limitations) of the claim. A typical patent contains a number of claims, often 20 or more. Some of the claims, termed independent claims, express the invention in its broadest
