Why Search Patents by Classification?
The most complete method of searching by for patents is to determine the class and subclass that apply to that subject.
When a Patent is granted, Patent Examiners review the patent and classify it based on what it does and how it does it. Patent classification is unique. For example, where one classification system might classify a drinking straw with eating utensils, and a glass tube for chemistry under laboratory equipment, the Patent Classification system puts them in the same classification. There may be multiple classifications for an invention.
On January 1, 2013, the USPTO moved from using the United States Patent Classification (USPC) system to the Cooperative Patent Classification (CPC) system, a jointly developed system with the European Patent Office (EPO). CPC has now been adopted by many countries throughout the world.
All of the instructions on this page focus on the CPC system. The search features all launch from the following UPSTO page:
Classification Text Search (aka Keyword searching)
If you aren't familiar with the classification of Patents, you can search for classification codes by keyword.
On the Classification Resources page, the "Classification Text Search" (aka keyword search) box is on the right
Note: the Classification Text Search is a text matching tool. It can be helpful to put two or more words in quotation marks so the database finds them next to each other. However, search operators like And, Or, Near do not function as operators, they will be searched as words, so leave them out when you search
Interpreting Search Results
- The number of records found appears at the top
- Right below it are the words searched, which correspond to the bold face words in the results list
- Watch for these documents:
- CPC Definition - Number: These documents define the classification and are extremely useful for figuring out if the classification is appropriate for the inventions you're researching.
- In the example below, a search was done for "artificial flies". The "CPC Definition - A01K" provides the definition for the subclass that includes fishing
- CPC Scheme - Number: These are subclass documents, detailed hierarchical documents describing a subclass
- In the image below, "CPC Scheme - A01K", is the subclass that includes fishing
- CPC Class documents display as a long title
- In the image below, the class document starts with the title "Animal Husbandry" and includes "Fishing"
- CPC Definition - Number: These documents define the classification and are extremely useful for figuring out if the classification is appropriate for the inventions you're researching.
