Top IPC subclasses
1
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F03D
|
4
|
Wind motors
|
2
|
H01M
|
2
|
processes or means, e.g. batteries, for the direct conversion of chemical energy into electrical ene
|
3
|
C25B
|
2
|
Electrolytic or electrophoretic processes for the production of compounds or non- metals; apparatus therefor
|
4
|
B60M
|
1
|
power supply lines, or devices along rails, for electrically-propelled vehicles
|