Hierarchy/Derived subclasses
| 331 / 154 | -> 156 |
uspto searches
Patent Apps in 331/156Granted Patents in 331/156
Use the links above or do an advanced search in ppubs for:
(331/156.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.