CA is an exceptional patent database, covering 29 national patent offices and two international bodies. For US patents, the beginning year was 1967. CA can be found at STN, Dialog and Questel Orbit. Nearly 900 periodicals in more than 20 languages are screened as well as the patent gazettes of five major authorities. The content is bibliographic data.
Abstracts are also available to subscribers.
The searchable contents include bibliographic information, abstracts, indexing terms, and CAS Registry numbers, covering 1965 to date. The earliest patent found in this data was issued in 1955. IMSworld Patents International is used in Dialog. Other online services Aside to Dialog, Questel Orbit and STN that are using comprehensive databases, there are some other web-based services for searching for earlier US patents or at least for some information of earlier US patents. Besides, it also provides quick downloading as well as delivery service covering all US patents.