As you know, the Cooperative Patent Classification system (CPC) replaced the US Patent Classification System (USPC). It has been a relatively slow transition period, with US patent documents first published with CPC codes in November of 2011. Since then, US patents have also included USPC codes. But, the times are not a changin’; they have now completely changed.
As of June 1st , 2015 US utility patents and applications are no longer published with USPCs. Plant patents and design patents are the exception, and they will continue to carry a USPC designation.
So even if you are an old timey patent researcher, and you love the USPC, then for better or worse, now is the time to switch to CPC.
How to Use CPC
We put a lot of work into making searching CPC classes convenient, easy and powerful. AcclaimIP includes the ability to search CPC is all possible ways, embeds fully-descriptive tooltips for all CPC codes, links to CPC class schedules, enables hierarchical CPC class searching, hierarchical class filters, and hierarchical class charting within single-series or multi-series charts.
- CPC: Searches all CPC classes
- CPCI: Searches only inventive CPC classes, which are also marked in bold text on both the patent PDF and the AcclaimIP document details window.
- CPCA: Searches only “additional” (formerly non-inventive) CPC classes. They appear in standard weight font of the patent PDF and in AcclaimIP.
- CPCF: Searches the first CPC class only
CPCF (the first code listed) is interesting. Unlike the USPC, there is a provision in the CPC rules to list CPC classes in a descending order of relevance. So the first code should be the best match, the second code the second best match, and so on. In theory, if you want to quickly map a patent portfolio by technology, you can do it by CPCF and get a nice and tidy one-to-one relationship between the best possible classes and the patents you analyze.
The usefulness of CPCF for quick technology landscapes is still in question, however. The problem is that older patents were coded in CPC with a concordance, which maps the old USPC to the new CPC. Problems arise because there is not a one-to-one correspondence between CPC and USPC codes. First, CPC has about 250K subdivisions, and the USPC has only about 150K. The result is that many USPC codes map to two or more CPC codes. You’ll notice this when you see a patent classified in both systems, with, for example, three US codes and five or six CPC codes. The second issue, is that the systems are, well, different. There is often not a perfect fit for an old USPC and the concordance is often only a best guess.
The problem will fix itself over time, since all new US patent documents are now natively classified in CPC by the examiners. But it will take another 15 or more years for the USPC-to-CPC concordance matched patents to fully age out of the system. Your young children will just love CPC when they enter the workforce. ☺
With 250K CPC codes, nobody could possibly remember all class titles. AcclaimIP has tooltips scattered throughout the application when a class code is referenced.
Just hover your mouse to see the titles and hierarchical relationship of the classification.
Right-mouse-click a class code to freeze the tooltip in a window, and click the green link to view the complete classification schedule with titles, definitions, and cross reference information. AcclaimIP provides automated links for USPC, CPC and IPC classification schedules.
Hierarchical CPC Searching
Like all patent classification systems, CPC is hierarchical in nature. This means technologies are broken down into more and more detailed descriptions the lower you go in the CPC hierarchy. View a few tooltips or examine a full patent schedule and you’ll see that CPC is divided into a high-level section, then class, sub-class, main group, then a successive number of dots from a one dot all they way to as deep as 12 dots.
Patents can be classified at any level of the CPC from the main group and lower. It is impossibly complicated to isolate patents covering a particular technology if you can’t query the CPC hierarchy. So much so, that you would probably have to revert to keyword-only searching which invites way too many errors.
Let’s look at an example. For your reference, here is the full class schedule.
Say you wanted to know the top patentees who have patents in implantable prostheses, specifically covering joints. You would use the A61F2/30 two-dot subclass. The problem is that this subclass is very detailed and includes 916 additional subclasses under it. How do you query all 916 classes without having to type 916 individual codes? Just query the hierarchy. Here’s how.
CPC:A61F2/30 → Queries just this subclass (257 deduplicated global families published in the last 20 years)
CPC:A61F2/30+ → Queries this subclass and all 916 children classes below it (13,695 deduplicated global families published in the last 20 years)
If you couldn’t query the hierarchy you would have to type in all 916 subclasses.
To illustrate the importance of querying the hierarchy, here is an example I made using AcclaimIP’s multi-series charting feature. (click to enlarge)
As you can clearly see, adding a plus sign to your CPC query expands your results over 50x.
We made it as easy as possible to analyze your search results using CPC. AcclaimIP gives you CPC filters at 5 levels of the classification hierarchy. Section, Class, Subclass, Main Group, and Complete–each analyzing your result set at a more detailed level than the previous. (click to enlarge)
The same facets that drive our hierarchical CPC filters also drive our hierarchical charting capability. (click to enlarge)
You’ll find that AcclaimIP gives you all the tools required to effectively search and analyze patents with the CPC classification system.
So, Is the US Patent Classification System Really Dead?
It’s dead as a doornail, if you consider any US utility patent or application published after June 1, 2015. However CPC has no provision for design or plant patents, so USPC will still be required for searching those.
Also, I will be using USPC for at least another year for one use case—quick technology landscaping. The benefit of USPC is that there is an Original Class, often referred to as a Primary Class, which is the first class listed on the patent, and it always appears in bold font. The original class is the most descriptive class for each patent, because examiners were forced to choose the one superlative class for each patent examined. The benefit of the one-patent to one-class relationship is that I don’t overstate my analysis, which you would do using CPC, or CPCI. Of course, if I have to analyze new utility patents, I’ll be forced to use CPC in all cases.
CPCF (first) will solve this issue, but I don’t trust it on older patents where CPC classes where mapped with a concordance. There is just no guarantee that the first listed class is the one best class.
Time marches on, things change, and we all have to adapt. That’s just life. CPC is a better, more descriptive, and more detailed classification system. It is harmonized with Europe, and is being adopted by all major patenting jurisdictions. AcclaimIP has over 34 million non-US, non-EP documents which include CPC class codes including those from all-European countries and others like CN, JP, CA, AU, KR, TW, BR, RU, MX, ZL, MZ, AR, HK, IL and many others.
With embedded concepts like “inventive,” “additional,” “first,” and descending order of relevance, CPC will eventually far surpass the functionality and power of the old-fangled US Patent Classification System.
For more information on the CPC Patent Classification System, take a look at the CPC Tutorial.