Maintenance fees

Cross-referenced

Utility patent

The most common type of US patent, covering inventions that have a useful function — how something works, how it is made, or how it is used. Utility patents account for roughly 90% of all US patents issued. They last 20 years from the filing date of the non-provisional application, subject to payment of maintenance fees. Software, medical devices, chemical processes, and mechanical inventions are all protectable as utility patents.

Cross-referenced

Patent

A government-granted right that gives an inventor the exclusive right to prevent others from making, using, selling, or importing a patented invention within the country that granted the patent, for a limited time. A patent does not give the owner the right to practice the invention — only the right to exclude others. The US issues three types: utility, design, and plant patents.

Cross-referenced

Patent expiry

The point at which a patent's term ends and the invention enters the public domain — either at full term or early, when maintenance fees go unpaid. Once a patent expires, anyone may make, use, or sell what it covered: a drug patent expiring is what lets generic versions enter the market. Expired patents amount to a free, fully documented library of proven technology.

Cross-referenced

Patent term

The length of time a patent stays in force. A U.S. utility patent's term runs 20 years from its earliest non-provisional filing date, provided maintenance fees are paid; a design patent lasts 15 years from grant. Patent Term Adjustment can add back days lost to USPTO delays, and a terminal disclaimer can shorten the term. When the term ends, the invention enters the public domain.

Markush group

A way of claiming a set of alternatives in a single claim — for example, 'selected from the group consisting of A, B, and C.' It is common in chemistry and pharmaceutical claims to cover several specific options at once.

Means-plus-function

A claim format authorized by 35 U.S.C. 112(f) that claims an element by what it does rather than what it is — for example, 'means for fastening.' Such a claim is limited to the specific structures disclosed in the specification and their equivalents, so it is narrower than it first appears.