United States Patent Office Searching –The Way The Patent Examiners Do It
The U.S. Pat. & Tm. Off. (as officially cited), is, always has been, and is likely to be, one of the most complete and comprehensive technical libraries in the world. Since the great Patent Office fire in 1836, the library has been growing with the addition of every issued patent and, with the advent of the Patent Cooperation Treaty, with every published patent application, whether issued as a patent or not. In the 19th century, the Patent Office required models, used to illustrate and explain the invention. The hall of models, once required with every patent application, may still be seen in the top floor of old patent office building, now the Smithsonian’s Portrait Gallery.
Before computers, all searching required a reading of each printed patent. Computers have automated the process and added keyword searching, something the printed patent searches lacked. The basis of every search is the Patent Office classification system. It is organized by class designations and within each class, by separate subclasses. The system matches the known technologies, uses, and functions, of any invention, known to man. For any new invention, not squarely fitting into the existing classes and subclasses definitions, the Patent Office will add new classes or subclasses
The USPTO examination process begins by identifying each incoming patent application with a matching Class/Subclass definition and then the application is sent to the examining technical unit associated with that class/subclass. The examiner‘s review or search may be limited to the patents and patent publications, in that class/subclass.
The USPTO electronic patent library has added automation to the class/subclass search and additionally, keyword searching.
To understand the system, access the USPTO website at uspto.gov. In the drop down menu (at the top of the home page), select “Patent Classification,” revealing the entire structure of the USPTO classification.
To illustrate, try searching wood stoves. I have an inventor with a wood stove design he claims produces 99% efficiency. At this point, out of necessity, a better definition of the “wood stove,” and “efficient,” or “efficiency,” is required. Wood stove covers every known stove and efficiency is the reason for every invention. Accordingly, in this search, as in every other search, a better definition of the invention’s elements or functions is required. My inventor tells me the inventive elements are an improved flue and firebox air inlet.
With this information, I go to the Classification Index, Patents, under Patent Classification Resources. Looking in to “stoves,” “wood,” and “heating,” I realize my search should start in Class 126 because it is consistently appears under each of the above index headings. Next task is to find an appropriate subclass for Class 126 – subclass definitions: flue, firebox, air inlet. The easiest path is to enter class number 126 to obtain the all of the subclasses definitions. That would be under Classification Definitions, Patent. (Third line down). By entering “126” in the box for “Class” next appearing is the list of all subclasses under Class 126 “Stoves.”
Important in the subclass listing is the format providing for each subclass entry, subclass 290 “Draft,” for example, a link A to all of the published applications in class/subclass 126/290, a link P to all of the issued patents in class/subclass 126/290, and a link 290 to the subclass definition.
At this point, best practice is to review all of the subclasses to find those closest to the inventive elements or functions, link to those definitions and if at, or close to the invention, link to the A Published Applications or the P Issued Patents.
Keyword searching is an alternative method of finding prior art, and for locating the most likely Class/subclass definitions for searching. Readers are encouraged to try this Class/subclass method or jump ahead to the keyword search page and try their luck.
Anyone requiring assistance may call or write.
Joel I. Rosenblatt
770 645 9465.
