|D19 / 920|
uspto searchesPatent Apps in D19/920
Granted Patents in D19/920
Advanced search in patft or appft for the hierarchy would be:
Press the Search button below to send the query to the USPTO site. (Granted patents search)
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.