Hierarchy/Derived subclasses
| 439 / 217 | -> 218 | -> 219 |
| -> 220 | ||
| -> 221 | ||
| -> 222 | ||
| -> 223 |
uspto searches
Patent Apps in 439/218Granted Patents in 439/218
Use the links above or do an advanced search in ppubs for:
(439/218.ccls. or 439/219.ccls. or 439/220.ccls. or 439/221.ccls. or 439/222.ccls. or 439/223.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.