HOLLIS/WorldCat Subject Terms

Guides, Indexes, and Bibliographies

Patents and Trademarks: PTRC (Linda Hall Library)

Subject-Matter Index of Patents for Inventions from 1790 to 1873, Inclusive, by M. D. Leggett. 3 v. Washington, DC: U.S. Patent Office, 1874.
Print version not at Harvard.
HathiTrust Version

Patent Classification

Search for Patents

Index to the United States Patent Classification (USPC) System

For hospital bed patents, scroll down or do screen search for Bed.  At Bed, scroll down to Invalids and hit 600+ which will take you to you Class 5 (Beds), Subclass 600 of the Manual of Classification.  The + after 600 indicates that you should scan nearby subclasses, both before and after your selected subclass. Before doing this, go to top of the page and at Select Largest Indent Level to be Displayed, select Expand All Indent Levels and Submit.  The number of dots (…) indicates the level of subdivision.


Hitting the verbal statement of the subclass opens window in which if you hit Definition View, you get a definition of the Class and of the subclass selected, along with cross-references to other possible subclasses.  If you hit the subclass number, the whole section is expanded to show the definitions of the subclasses.


Hitting P yields a list of the corresponding patents in inverse chronological order. Hitting A yields a list of patent applications.


There is also a keyword search but only for patents after 1976.



Examine individual patents to determine the originality of your invention.

  1. Click on the red P icon to the left of the blue subclass number 163. This will bring up a list of all the U.S. Patents in that particular classification code, in this case more than 1,300 patents. (You can also click on the A icon to bring up a list of published applications in a particular class.) All years have been searched, and the list displays the most recent patents first.


  1. Get a preliminary feel for the group by browsing the titles that look like they might describe your invention. Keep in mind that the titles are often short and not overly descriptive. Looking at the patent as a whole is the only way to really decide whether or not the invention is similar to your own. If you conclude that this is indeed the correct classification code, you must examine all the patents to determine if your invention is original.


To view the patent, click on the patent number. If the patent was issued after 1976 you may view the full text, without images.


If you are still having trouble finding a term that adequately matches your invention in the Index to the U.S. Classification System or can't find the right code in the Manual of Classification, you can do a keyword search. However, only patents since 1976 can be searched by keyword.