The government's free, searchable database of United States patents, patent applications, and trademarks. It provides coverage of patent materials from 1790 to the present.
Provided by a specialized agency of the United Nations. See the Knowledge tab to access resources such as PATENTSCOPE database to access to "...international Patent Cooperation Treaty (PCT) applications in full text format on the day of publication, as well as to patent documents of participating national and regional patent offices."