United States Patent

United States patent is the grant of a property right to the inventor, issued by the United States Patent and Trademark Office. Generally, the term of a new United States patent is 20 years from the date on which the application for the patent was filed in the United States or, in special cases, from the date an earlier related application was filed, subject to the payment of maintenance fees. United States patent grants are effective only within the United States, U.S. territories, and U.S. possessions. Under certain circumstances, United States patent term extensions or adjustments may be available. 

A United States Patent gives an inventor the right to exclude all others from making, using, importing, selling or offering to sell the invention for up to 20 years without the inventor's permission. This gives the inventor the opportunity to produce and market the invention himself, or license others to do so, and to make a profit. What is granted is not the right to make, use, offer for sale, sell or import, but the right to exclude others from making, using, offering for sale, selling or importing the invention. Once a patent is issued, the patentee must enforce the patent without aid of the USPTO. 

In discharging its patent related duties, the United States Patent and Trademark Office or USPTO examines applications and grants patents on inventions when applicants are entitled to them; it publishes and disseminates United States patent information, records assignments of patents, maintains search files of foreign and United States patents, and maintains a search room for public use in examining issued patents and records.

There are three types of United States patents granted by the United States Patent Office, http://www.uspto.gov.
1. Utility patents may be granted to anyone who invents or discovers any new and useful process, machine, article of manufacture, or compositions of matters, or any new useful improvement thereof;
2. Design patents may be granted to anyone who invents a new, original, and ornamental design for an article of manufacture; and
3. Plant patents may be granted to anyone who invents or discovers and asexually reproduces any distinct and new variety of plants.

A utility patent covers what an invention is or how it functions. A utility patent is effective from the date it is issued and lasts for 20 years from the date it was applied for. A design patent covers the ornamental features of a manufactured item. Design patents cover only how something looks, not how it works. A design patent lasts for 14 years from the date it is issued. Plant patents cover asexually reproduced plants. Fruit trees and other flowering plants are the most common subjects for plant patents.