How to Research a

U S. Patent Number Online

If you have the number of a U.S. patent and would like to see the patent drawings or read the patent text, you can do it online.  The U.S. Patent and Trademark Office (USPTO) has a website where this information is available, and you can examine copies of documents that used to be available only in Washington or at a few large regional libraries.  The address is: 

While there are shortcuts into the system, if you start at this homepage, you may get a better idea of what other information you can find here.

1.  Click "Patents" button

2.  Under "Services", click "eSearch Patents"

3.  Click "Patent Number Search"

4.  Type your patent number in the query box - commas are not necessary, but if your patent number begins with the letter "D", indicating a design patent, include the "D" - then click on "Search"

5.  Click on the patent number (now colored "blue") in the lower left corner of the page

6.  Click on "Images"

You are now at page one of your patent, and you can navigate through the pages of the patent using the tools on the left side of the page.  Patents for inventions (or, or as USPTO calls them, Utility patents) are usually at least two pages, with the first page showing patent drawings and subsequent pages stating the Specifications and Claims.  Design patents are usually just one page.

If you go back to step 6, you will see the Current U. S. Class number (CCL) for your patent.  This information is useful if you want to search for items in the same classification, i.e. other "match safe", "snuff box" or "spoon" patents.  Since some patents will have multiple classification numbers, you can widen your net by searching with these numbers.  You can also obtain classification numbers at "Tools to Help in Searching by Patent Classification" at step 3.

Once you have a classification number and want to search for other items in that particular class, click on "Advanced Search" (at step 3) or "Advanced" (at steps 4 - 6).  Then,

    a.  In the query box, type in the class in this format:  ccl/[the class number]/[the subclass number].   For example, "ccl/206/134."

     b.  Specify a range of years in the "Select Years" box.

     c.  Click on "Search".

You now have a list of patents of a particular class for the range of years you have specified, and they will be in chronological order based on the date of the Tuesday of the week in which the patent was granted.  From here, you can access an individual patent file by following steps 5 & 6 above.

Unfortunately for those interested in historical research, pre-1976 patents are only searchable by patent number or classification.  If you only have a pre-1976 patent date, you also may be able to find the patent if you can hit upon the correct class for the item (see "Tools to Help..." above) and track the patent down, hit and miss.  You cannot "Advanced Search" by date or inventor's name, etc. as you can with post-1975 patents, so that searching for patents by an inventor named Edison before 1976 will give you "0" hits.

Other Research Links

U.S. Patent Dating Chart

English Registry Marks

Online Encyclopedia of American Silver Marks






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