Covers all US patents from 1790 onwards. Download or view high-quality images of the actual pages of the patents, including diagrams and structures from 1790 onwards. Patents from 1976 - present are available full text in an HTML text format.
Also Known as: Manual of Patent Classification , USPTO. Patents are classified in the U.S. by a system using a 3 digit class and a subclass to describe every similar grouping of patent art. A single invention may be described by multiple classification codes.