Tips on locating patents (when you don't have the patent number)
Additional guidance: http://www.uspto.gov/video/cbt/ptrcsearching/
The Cooperative Patent Classification (CPC) effort is a joint partnership between the United States Patent and Trademark Office (USPTO) and the European Patent Office (EPO) where the Offices have agreed to harmonize their existing classification systems (European Classification (ECLA) and United States Patent Classification (USPC) respectively) and migrate towards a common classification scheme.
View the CPC Scheme HERE
The International Patent Classification (IPC), International, common, and uniform classification of patent documents. Can be searched in English and French.
View the IPC Scheme HERE
The United States Patent Classification (USPC) System is a system for organizing all U.S. patent documents and many other technical documents into relatively small collections based on common subject matter.
New classification to the USPC was frozen as it merged and became the CPC.
View the USPC System HERE