Search hints for Google Patents
First, in case you don’t know about Google Patents, it is an easy way to start searching the patent literature. The familiar Google interface, powerful keyword searching, and easy accessibility make Google Patents an appealing supplement to options from patent agencies such as the United States Patent and Trademark Office (USPTO). Patent records link to citing (and cited) documents; subject classifications connect to explanatory materials; and links are provided for patent-family documents.
Second, beyond simple keyword searching, Google Patents offers advanced search options. All but the most casual searcher should know about these. Google “google patents advanced” or go directly to: http://www.google.com/advanced_patent_search. Or, if you are in Google Patents, click on the “gear” symbol near the top right of the screen and look for the “Advanced search” option.
Advanced searching allows more effective patent-number searching, and limiting searching to such fields as inventor, classification, and assignee.
Third, after doing a search in Google Patents, notice that new options will appear below the search box. Especially interesting is the “Search tools” option.
A click on the “Search tools” button displays choices for limiting and sorting. For example:
and
Fourth, once a patent of interest has been located, notice in the full-text view the options offered near the top of the page:
Besides the options to view and download a PDF (if available) of the patent document, Google Patents makes available a “Find prior art” tool. It uses Google resources to help a searcher find sources related to the technology described in the document.
Larayne Dallas, Engineering Librarian, University of Texas at Austin
We welcome your comments and suggestions. If you have a resource that you would like to see highlighted please leave us a comment.
News Yakaja Resources 
Yes, Google Patents allows keyword searching of older patents. I think that you have in mind the 1976 date before which the U.S. Patent and Trademark Office (USPTO) did not create full-text versions of patents. USPTO search forms make a distinction between the two groups.
Another reader pointed out this helpful source: http://www.intellogist.com/wiki/Report:Google_Patent_Search/System_Data. It gives detailed information, including caveats, on Google Patents. The helpful reader noted the limitations of searching with OCR (for U.S. documents we would expect that to be pre-1976) text.
Specifically on Eli Whitney’s cotton gin patent from 1794: It can be found in Google Patents searching by patent number: x0000072. This uses the USPTO convention for searching these early patents, which were not assigned numbers when issued. I do not find this patent when searching with the words on the patent or by inventor name.
LikeLike
Does it search the really old patents that have only a number? For example, Eli Whitney’s cotton gin?
LikeLike