Conducting a Patent Search

(Before beginning your search, determine which basic patent type is appropriate)

Utility Patent - The way an invention works or functions.

Design Patents - The outer appearance of an object. The letter "D" appears before the class/subclass (D24/100) and patent number (D293, 960).

Plant Patent - a UNIQUE STRAIN OF FLOWER OR VEGETABLE. The letters "PLT" appear before the subclass (PLT/70.7), and "PP" appear before the patent number (PP09517).

Identify the Parts of the Invention. Break the invention down into its component parts, e.g., a generator-driven electric light for a bicycle would include a light, a generator and a bicycle. List all possible synonyms or related terms which identify each part of the invention.
Consult the Index to the U.S. Patent Classification (Available in paper, CASSIS or on the USPTO Web site). This alphabetical keyword Index will provide a class and subclass number for some of the terms listed in Step 1.
Consult the Manual of Classification (Available in paper, CASSIS or on the USPTO Web site). Find each set of class/subclass numbers located in Step 2. The Manual shows the relation of this invention to other inventions within the same field of technology. It provides more general and more specific aspects of the invention, which can lead to the choice of different class/subclass listings.
Consult the Classification Definitions (Available on microfiche, CASSIS or on the USPTO Web site). The Definitions cover utility patents only and state specifically what type of device fits each class/subclass. The very important search notes often suggest alternative classes/subclasses to consider.
Consult Patents BIB (Available on CASSIS or on the USPTO Web site) Check if you are on the right path; search Patents BIB (1969 to present) or USPTO Web site (1976 to present) for your particular class/subclass: retrieve results and examine titles. Try other relevant classes/subclasses and go back to 2.
Consult Patents CLASS (Available on CASSIS and on the USPTO Web site) In Patents Class choose "Classification by Subclass ." Type in your class followed by a forward slash mark and them type in your subclass. Print the list of patent numbers assigned to each class/subset set. CASSIS indexing is approximately two months prior to today's date.
Consult the Official Gazette - Patent Section (Available in paper). Find each patent number from the print-outs and lists. Mark those which have similarities to the invention being searched.
Consult the Complete Patent Document (Available in microfilm, CD-ROM, DVD-ROM, and on the USPTO Web site). View the closely related patents you have marked, paying particular attention to the claims, which are usually found at the end of the patent. The claims state specifically what is new and unique about the invention and why it is worth being granted a patent.

Last Updated: 11/06/2007