Hierarchy/Derived subclasses
| 439 / 217 | -> 218 | -> 220 |
uspto searches
Patent Apps in 439/220Granted Patents in 439/220
Use the links above or do an advanced search in ppubs for:
(439/220.ccls.)
This will show what classes derive from the input. Ex: entering 43/42.24 shows the derived classes and the search that can be used to find patents or patent applications in those subclasses.