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If you know the PATENT NUMBER, Skip to Step 5 below.
If you know the PATENTEE OR ASSIGNEE: Check the annual volumes of the Index of Patents for the patent number, then skip to Step 5 below.
If you know the SUBJECT OF INVENTION:
Check the Index to the U.S. Patent Classification for the classification number for the subject of the invention.
Refer to the Manual of Classification to determine the precise classification number for the subject. Where doubt exists as to the choice among several subclasses, consult the Classification Definitions.
Check the United States Patent Classification-Subclass listing for a list of patent numbers issued in the class and subclass.
For years after those included in the United States Patent Classification-Subclass listing, check the annual Index of Patents and the weekly issues of the Official Gazette.
For patent numbers 112, 304-3,778,913, check the Finding List for the volume of the Official Gazette in which that patent number will be found; then locate the volume of the Official Gazette.
For patent numbers from 3,778,914, find the microfilm reel of the Official Gazette which contains the patent number.
Additional guides for patent and trademark searching: