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ENGR 195

Engineering Librarian & CAPLA Liaison

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Paula C Johnson
Main Library A403


What is a patent?

A patent is the intellectual property right granted by the U.S. Government to an inventor "to exclude others from making, using, offering for sale, or selling the invention throughout the U.S. or importing the invention into the U.S." for a limited time in exchange for public disclosure of the invention when the patent is granted. In most cases, this is twenty years from the date of application. In some situations, the term of the patent may be extended due to delays in the processing of the application. After the patent has expired, the invention becomes public domain. In addition, patent owners must pay a maintenance fee at 3.5, 7.5, and 11.5 years after issue or else the patent will expire.

How to Read a U.S. Patent from Queen's University Library provides a detailed description of the sections of a U.S. patent.

Patent types

Utility patent: Describes a new and useful process, machine, article of manufacture, or composition of matter, or useful improvement thereof (i.e. what something does)

Design patent: A new, original, and ornamental design for an article of manufacture (i.e. how something looks)

Plant patent: Describes an asexually reproduced distinct and new variety of plant (e.g. ‘NuMex Heritage 6-4’ New Mexican Chile Pepper)

Whys & hows of patent searching

You have an idea for an invention — or have gone so far as to create a prototype. Before marketing your invention, you will need to determine if your invention has already been patented. To do this, conduct a thorough patent search. This will usually involve searching a number of different patent sites, so it's useful to keep a log of all your search activity to avoid duplicate efforts.

See General Information Concerning Patents and Patent Process Overview for more information.

You can begin your search the following way:

1.  Brainstorm keywords to describe your invention — think of synonyms.

2.  Use your keywords to search for a similar match of your invention in Google Patents. The Advanced Search in Google Patents lets you enter phrases, exclude a word, etc.

3.  If you find a similar invention, write down its class and subclass.

4.  Use the class and subclass to search patents and patent applications at the USPTO website classification search.

[Note: The default search is CPC (Cooperative Patent Classification), which harmonizes the former European Classification (ECLA) and United States Patent Classification (USPC) systems.]

5.  Trace related patents through references.