A patent is a grant by the United States government through the Patent and Trademark Office (hereafter U.S. Patent Office) to an inventor of the right to exclude others from making, using, or selling his patented invention for a period of 17 years (in all but design patents, for which the period is 14 years). The patent does not carry with it the right to manufacture the patented invention free from infringement. This sentence holds a concept which some people have had difficulty understanding, and so let us give you an example. Let us assume that the Ajax Stool Company has obtained a patent on a four-legged stool consisting of a seat and four legs. That structure will be considered to be the pioneer patent.