The United States Patent and Trademark Office is the federal agency (and only agency) for granting U.S. patents and registering trademarks. The USPTO fulfills the mandate of Article I, Section 8, Clause 8, of the Constitution that the legislative branch "promote the Progress of Science and useful Arts, by securing for limited Times to Authors and Inventors the exclusive Right to their respective Writings and Discoveries." The USPTO registers trademarks based on the commerce clause of the Constitution (Article I, Section 8, Clause 3).
Patents date from 1790 and are searchable by patent number of issue of date. Most patents are utility in nature (compared to design or plants). One easy way to search is also by classification, which is simply a hierarchical way to organize "things" by characteristics and relationships.
Examples of classifications that the USPTC uses (called CPC since 2013, or Cooperative Patent Classification in conjunction with the European Patent Office) are grouped by a symbol that shows broad group, subgroup, alpha/numeric symbol as the first part and contain words that are legal or technical by nature and not commonly used words.
Broken down:
Keyword Search Terms: Tips and Things to Avoid
As in all searches using databases, keyword searching can lead to misleading results. Why? Patents can be listed using vague or inconsistent or even outdated terminology. (examples: hi-fi, laser-disc, water closet, rodent extermination device). Words also can mean different things in different industries (example: mouse).
To avoid pitfalls, a good tip is to start with a classification search. On the USPTO home page, click on "Find It Fast"
Option 1 Search:
Option 2 Search:
Use this direct link to Google Patents, a Google search engine that indexes over 87 million patent and patent applications (public domaine) that date back to 1790.