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Disclaimer: 

While the Library reference service staff is happy to provide assistance with your search, we cannot perform searches, evaluate searches, assist with your application or dispense legal advice.

The University of Washington and its employees are providing a service of an informational nature with no express or implied warranty for results and assume no obligation or liability for damage arising out of the use, or inability to use, the information provided.  Every effort is made to keep this information up to date. However, errors and omissions may occur.

For the most up-to-date information or legal advice, please contact a patent or trademark attorney.

Patent Searching at the University of Washington Engineering Library

What is a patent and what is patentable?
A patent gives its owner the right to exclude others from making, using, and selling the patented invention. To be patentable an invention must meet three criteria.

  • Useful. Virtually any usefulness will suffice, provided that it is functional and not aesthetic.
  • Novel. It must differ physically in some way from all prior art. The physical hardware must be different, there must be a new combination of hardware, or there must be new use.
  • Nonobvious. The differences between your invention and prior art must not be obvious to one with ordinary skill in the field.

Patent searching is a time consuming enterprise.
You cannot simply see if something has been patented. You have to make sure the item has not been patented. Hence, it is a process of elimination. This means that you must examine each patent in your subject area to determine if there is prior claim to your ideas.

You must search as far back in time as your invention has been technologically possible.
Anything that has previously been patented cannot be re-patented, even though that patent may have expired. Once a patent expires, the invention becomes part of the public domain, meaning that anyone may be able to use or manufacture the invention listed within.

Patent searching is a step by step process.

There are no shortcuts to doing a complete patent search.
Although there is a keyword searching feature in the USPTO database, keyword searching is generally not the most thorough way to conduct a patent search. There is no controlled terminology or vocabulary; patentees can use a wide variety of words to express their ideas. This is the reason the Classification system is in use. It groups all of the patents in a specific subject area together for the purposes of examination.

Just because you have not seen a product on the market does not mean that there is not a patent on that item. Obtaining a patent and marketing an invention are two completely different tasks. There are countless products that have been patented but have never been commercially marketed, either nationwide or locally.

If you have an invention, you should plan to do a patent search for three main reasons:

  • To help determine whether your invention is new. Even if you invented it on your own, someone somewhere may already have the same invention. You cannot assume your invention has never been patented even if you have never seen it on the market.
  • To document your invention's relationship to other inventions in the same field (the prior art). Almost all patents refer to earlier patents.
  • To familiarize yourself with patents. Reading a number of patents on similar inventions is a good way to learn how successful patents are written.

The United States Patent and Trademark Office (USPTO)
http://www.uspto.gov
The USPTO is the Federal agency responsible for issuing U.S. patents. The USPTO website provides access to information about the patent process, including patent searching and the patent application process:

  • Patents: The main patent information portal.
    http://www.uspto.gov/patents/index.jsp
  • Patents Process
    http://www.uspto.gov/patents/process/index.jsp
  • Search for Patents
    http://www.uspto.gov/patents/process/search/index.jsp

Be Prepared.
The process of patent searching is not overly difficult, but it does require significant amounts of time, concentration, and patience. Budget enough time to complete your tasks, but also take into consideration that the USPTO Website, the Patent and Trademark Resource Center Research Area, the Engineering Library Reference Area computers, and/or Information Desk might be crowded and busy on the day you choose to come. Sometimes you will need to share materials with others or wait to ask questions or use the computers.


The following is a step-by-step guide for searching patents by subject or by kind of invention. The steps shown here are typical, but some may not apply to your search. Please ask at the Information Desk if you have questions.


STEP 1 : Identify Your Class and Subclass Numbers

The United States Patent and Trademark Office (USPTO) maintains a classification manual which organizes patents by subject. Use the Index to the U.S. Patent Classification to find class and subclass numbers alphabetically by subject.

The Index to the U.S. Patent Classification is available online at the U.S. Patent and Trademark Office Website.

From the main USPTO webpage: Look for the "Patents" column on the left side of the screen. Click on option number 2 "Search." On the "Search for Patents" page, scroll down until you see the "Links" information box on the left side of the screen. Click on the "Tools to Help in Searching by Patent Classification" link. Use the A-Z list under section B. "Classification Information" ("Index to the U.S. Patent Classification System") or click on the link to the Index to the U.S. Patent Classification (USPC) System near the top center of the page.

Note: You may need to try several alternative terms or synonyms to find your subject in the keyword index; look for all the terms you can think of that describe the invention. Look up what your invention is, as well as what it does.

For example, to find patents related to aluminum baseball bats, look up the index heading Baseball and find the subheading Bats:

BASEBALL
. . BALLS
 . . BASES
 . . BATS
. . CARD OR TITLE GAMES
 . . COVER SEWING MACHINE
 . . GAME BOARD
. . . . . DESIGN
 . . GLOVE

Write down the index headings and subheadings that best describe your invention (for example, "Baseball-Bats"). Because few inventions fit perfectly into one classification, we usually recommend that searchers identify several relevant headings and subheadings.

__________________________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

Each index heading is followed by its class number and subclass number. Write down the class and subclass numbers from your index headings (for example, "473/564+"). Include any letters or punctuation.

STEP 2 : Narrow Down Your Class and Subclass Numbers

The index to the classification manual presents classifications in alphabetical order without showing related classifications. You should not rely on the index alone to identify your classes and subclasses.

The The Manual of Classification is available online at the U.S. Patent and Trademark Office Website.

  • From the main USPTO webpage: Look for the "Patents" column on the left side of the screen. Click on option number 2 "Search." On the "Search for Patents" page, scroll down until you see the "Links" information box on the left side of the screen. Click on the "Tools to Help in Searching by Patent Classification" link. This link leads to the Patent Classification Home/Classification Main Menu. Enter your classification and subclassification numbers under option "A. Access Classification Info by Class/Subclass." ("Enter a US Patent Classification...")
  • The Manual of Classification is also directly accessible from the Classification Index described in STEP 1. Click on the suggested starting subclassification or classification number for your term. This will link to the corresponding Classification Manual page.

The Manual of Classificationlists subclassifications from more general to more specific. To determine whether more specific subclassifications are available, take the most relevant number you found in the index and look it up in the manual.

For example, in the search for baseball bats, you would look up class 473 and find subclass 564. Immediately below 564 is subclass 566, which specifically covers baseball bats with metal shells.

564 . Bat (e.g., baseball bat, etc.) 
565 . . Having elongated blade (e.g., cricket bat, etc.) 
566 . . Of metallic-shell structure 
567 . . Of plastic composition 
568 . . Grip 

Notice that some entries in the manual begin with one or more periods. The number of periods provides a subject hierarchy, like the outline for a term paper: an entry with two periods is a more specific subset of the entry with one period above it, but less specific than the entry with three periods below it, for example. Subclass names written in capital letters are the most general.

Write down your revised class and subclass numbers.

You should also browse the entire hierarchy, starting at the top of the class and looking at all the capitalized subclasses. You may find additional subclasses that pertain to your search.

Is the meaning of your class and subclass numbers clear to you?. Do you need more information about the class or subclass? If you need more information continue with step 3. If not, go to step 4.

STEP 3 : Consult the Classification Definitions

The Classification Definitions are available:

  • In microfiche in the Patent and Trademark Research Area.
  • Online at the U.S. Patent and Trademark Office Website.
    From the main USPTO webpage: Look for the "Patents" column on the left side of the screen. Click on option number 2 "Search." On the "Search for Patents" page, scroll down until you see the "Links" information box on the left side of the screen. Click on the "Tools to Help in Searching by Patent Classification." link. Enter your class and subclass under Section A, number 1. and click the radio button next to "Class Definition (HTML)." Click "Submit" to retrieve the definition.
  • Alternately, you may read the definition for your subclass by clicking on the number(s) within the online Manual of Classification.

When reading the definitions, you should start by reading the definition for the class as a whole, for example:

Class 473 
GAMES USING TANGIBLE PROJECTILE 

Class Definition:
This class includes: 
Apparatus or means relating to the type of amusement, recreational, or play activities commonly known as games or sports (a) in which one or more players or participants use a ball, missile, stream of water, or any other such body which occupies physical space and can be touched and thereby felt by the one or more players or participants (i.e., a tangible body) such that, during play of a game or sport, the ball, missile, or other such tangible body is thrown, rolled, shoved, impelled, propelled, projected, or otherwise put into motion ...

(Then continue to main heading)

Subclass: 516
PLAYER HELD AND POWERED, NONMECHANICAL PROJECTOR, PER SE, FOR PROJECTING AERIAL PROJECTILE BY STRIKING; PART THEREOF OR ACCESSORY THEREFOR: 
(under the class definition) Subject matter (a) comprising an implement, per se, which is held and used by, or worn on the body of and used by, a player during play of a game or sport in which a game projectile is intended to move through the air during play ....

(Then continue to next specific heading(s))

Subclass: 564
Bat (e.g., baseball bat, etc.): 
(under subclass 516) Subject matter wherein the projecting implement comprises a shaft and a striking head which (a) is located at one end of the shaft, (b) is formed by a continuation of the shaft, or (c) constitutes the shaft and wherein the shaft and head are both elongated members having a length substantially greater than the width, thickness, or diameter thereof. 

(Then continue to most specific heading)

Subclass: 566
Of metallic-shell structure: 
(under subclass 564) Subject matter wherein the bat is a generally hollow body formed from a metallic material. 

STEP 4 : Search For Patent Numbers and Published Patent Application Numbers That Match Your Class and Subclass Numbers

Links from the Online Manual of Classification and the Classification Definitions

Within the online Manual of Classification and the Classification Definitionsfrom STEPS 2 and 3, you will notice a red "P" next to the subclasses. Clicking on the "P" initiates a classification search in the Issued Patents (PatFT) database, 1790 to the present. The blue "A" next to the subclasses connects to published applications. Clicking on the "A" initiates a classification search in the the Published Applications (AppFT) database, March 2001 to the present.

Online at the USPTO Website

A COMPLETE PATENT SEARCH CANNOT BE DONE VIA THE INTERNET USING KEYWORDS
Although some files of patent information are available, the information only goes back to the 1970s. At the USPTO website, images of patents are available back to 1790. However, the full-text is only searchable back to 1976. This means that searching for patents via keyword will only retrieve patents issued since the 1970s. Using class/subclass numbers you can search for patent numbers at the USPTO site. You can search all the way back to 1790 using classes and subclasses. The classification information for each patent in the USPTO database is updated if the classification numbers for the subject of the patent have changed. [Note:Please be aware that classification information on other patent searching websites may not reflect classification changes made since the date of issue. Be sure to read any available online documentation or help screens.]


USPTO Patent Full-Text and Full-Page Image Databases
http://patft.uspto.gov/
The Issued Patents (PatFT) database covers 1790 to the present. However, the database is only searchable by patent number or current US classification prior to 1976. The database is updated weekly. The Published Applications (AppFT) database can also be searched by current US classfication, as well with keywords. The AppFT database covers published patent applications (pre-grant publications) from March 15, 2001 to the present. You must search each database separately. Please read "Operational Notices and Status" for each database, as well as the "Important Notices!" Also, there is extensive online help available for searching the databases. "Help" links are present on all the USPTO web database screens.

  • To search by classification number, in the Issued Patents database, click on "Quick Search." Enter your class and subclass numbers in the Term 1 box using the format class/subclass (Our aluminum bat example would look like this - 473/566). Using the drop down menu next to Field 1, change the field to "Current US Classification." The default search is 1976 to the present. To search the entire database, select "1790 to the present" from the drop-down menu under "Select Years." You may also choose 1790-1975 if you wish. Click on "Search" to initiate.
  • To search by classification number in the "Advanced Search" mode, and use the search string CCL/[class]/[subclass]. Our aluminum bat example would look like this - CCL/473/566. The default search is 1976 to the present. To search the entire database, select "1790 to the present" from the drop-down menu under "Select Years." You may also choose 1790-1975 if you wish. Click on "Search" to initiate.
  • The same classification search methods are true for the Published Applications database, however only 2001 to the present is an option, since applications have only been published since March 15, 2001.

STEP 5: Expand Your Search to Earlier Patents

Online at the USPTO Website

You may have already searched earlier patents through your classification search online at the USPTO website as described in STEP 4. If not, please review STEP 4 for instructions concerning searching for pre-1976 patents. The USPTO Issued Patents database on the web covers back to the 1790, if you are searching by patent number or by class and subclass number.

STEP 6 : Find Patent Abstracts

Abstracts (summaries) of each patent are published in the weekly Official Gazette of the United States Patent and Trademark Office, also known as the Patent Official Gazette, or the OG. Each issue of the gazette lists the patents issued that week, in patent number order. Find the abstract (the exemplary claim) for each patent number you retrieved from the USPTO Issued Patent database on the web In addition to the brief description, each patent entry usually includes one drawing.

When using the Issued Patent database on the web, abstracts are available for each patent issued from 1976 to the present. Click on the patent number or the title of the patent to retrieve the full-text of the patent, including an abstract. For patents issued before 1976, you will have to retrieve the full-image of the patent or use the Official Gazette.

There is no Official Gazette for published patent applications (also known as pre-grant publications). You must use the Published Applications (AppFT) database to retrieve abstracts and other information concerning published applications.

In the Engineering Library, Patent Official Gazettes (in printed form) from February 2, 1971 (Patent numbers: 3,559,209- present and D219,801-present) are shelved in the Reference Area. They are the beige colored volumes in the shelving area. Earlier gazettes going back to 1872 are also shelved in the first floor Reference Stacks (call number T223 .A2b).

The Patent Official Gazette is available in electronic form on the USPTO website for the most recent fifty two issues.

Are these the patents that you are looking for? Do they describe inventions similar to yours? If no, return to STEP 1, or ask at the Information Desk for help. If yes, continue with STEP 7.

STEP 7 : Find Complete Patents

Patents are available in full-text and full-image formats in the Issued Patents (PatFT) database on the USPTO website at http://patft.uspto.gov/. Enter your patent number using the "Patent Number Search" option. Full-text (without images) is available for patents issued from 1976 to the present. Full-images (which look like actual copies of the issued patents, including the drawings) are available in pdf format for patents issued from 1790 to the present.

Published patent applications are available in full-text and full-image formats in the Published Applications (AppFT) database on the USPTO website at http://patft.uspto.gov/. Enter the application number using the "Publication Number Search" option. Full-text (without images) and full-images (with drawings) are available for applications published at the 18th month mark since March 15, 2001.

The Engineering Library has microfilm copies of issued patents from 1966-1999 (Patent numbers: 3,226,729- and D203,379-). They are filed in patent number order in filing cabinets on the third floor.   Please ask for assistance at the Information Desk.  You may read the microfilms on any microfilm reader in the library. To make paper copies, you may use the self-service reader/printer/scanner in the patent research area.