Top IPC subclasses
1
|
C25C
|
2
|
processes for the electrolytic production, recovery or refining of metalsapparatus therefor
|
2
|
G09B
|
2
|
educational or demonstration appliancesappliances for teaching, or communicating with, the blind, de
|
3
|
F03D
|
1
|
Wind motors
|
4
|
C01B
|
1
|
non-metallic elementscompounds thereof
|