Searching patents and published applications by classification usually results in a more comprehensive search than one done by word and phrases (keyword searching).Use this process to find a classification that matches your interest:
Find a few similar patents
Note the classifications assigned to those patents
Search the classes in different patent search tools (Patent Lens, Espacenet, USPTO, etc)
Read the definitions of those classes
Search on the relevant classification codes
Repeat the process until you are satisfied you have found patents to suit your purpose
University of Central Florida Libraries offers this quick and helpful video explaining patent classification and how to conduct a search in Espacenet.
Covers the entire collection of granted patents and published patent applications from the USPTO, EPO, and WIPO. US patent documents date back to 1790, EPO and WIPO to 1978.
Offers free access to information about inventions and technical developments from 1782-present for European countries as well as other countries. Full-text access varies based on country.
This page has TWO options:
Patent Database - Search for U.S. patents 1790-present (1790-1975 searchable only by Issue Date, Patent Number, and Current US Classification).
Application Database - Published applications from 2001-present
