Hierarchy/Derived subclasses
| 331 / 1r | -> 18 | -> 19 | |
| -> 20 | -> 21 | ||
| -> 22 | |||
| -> 23 | -> 24 | ||
| -> 25 | -> 26 | ||
| -> 27 | |||
| -> 28 | |||
| -> 29 |
uspto searches
Patent Apps in 331/18Granted Patents in 331/18
Use the links above or do an advanced search in ppubs for:
(331/18.ccls. or 331/19.ccls. or 331/20.ccls. or 331/21.ccls. or 331/22.ccls. or 331/23.ccls. or 331/24.ccls. or 331/25.ccls. or 331/26.ccls. or 331/27.ccls. or 331/28.ccls. or 331/29.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.