U.S. Patent Searching Guide

A quick guide to searching patents at United States Patent and Trademark Office.

U.S. Patent Searching:

Follow the United States Patent and Trademark Office Seven Step Search Strategy to search for patents from 1790 to the present by classification or patent number. Keyword searching is available from 1976-present. If you are having trouble coming up with search terms, try the International Patent Classification (IPC) Catchword Index. Enter this as an IPC number on Espacenet and eliminate spaces (B21F 13/00 is entered as B21F13/00).

See also a detailed handout of the Seven Step Strategy with examples and screen shots.

You will save time and search more efficiently if you first create a list of search terms (Step 1) and concepts that describe your invention and its components with details of each.  Consider the following when making your list:

  1. Function - what utilitarian purpose does your invention serve or is it simply an ornamental design?
  2. Use - how is your invention used?
  3. Structure - what is your invention or its components made out of?
  4. Effect -  what does your invention or its components do?

After you make your initial list of terms identify any synonyms for each term.  The following online resources may be useful for identifying additional search terms:

Sample Search


wheels for inline skates with improved traction

Search terms with synomyms and related terms:





wheeled vehicle








inline skate




roller skate




wheeled shoe




After identifying terms, proceed with Steps 2-7 on the Seven Step Search Strategy.

Patent Searching Tutorials:


Additional Searching Resources:

  • PubWEST web-based searching database - library use only
  • Google Patents
  • Search U.S. patents from 1790 to within the last few months. Does not include published applications.
  • Scopus 
  • Includes PatentCites which enables users to view citations from patent sources that cite Scopus articles on the Abstract and References page. Scopus Indexes over 15,000 journals, as well as several million web pages and U.S. and international patents. The database includes article citations from 1996. It offers citation tracking, saving searches, and receiving email or RSS alerts of new material. The system will export records into major citation managers and prepare a bibliography according to major formats. (1966)
  • 19th Century Masterfile 
  • Subject matter index of U.S. patents issued 1790-1873.


See also Foreign Patent Searching Resources