IPC 6 English version  Class F03
SECTION F– MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING

F 03

MACHINES OR ENGINES FOR LIQUIDS (for liquids and elastic fluids F 01; positive-displacement machines for liquids F 04); WIND, SPRING, WEIGHT, OR MISCELLANEOUS MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR

F 03 B

MACHINES OR ENGINES FOR LIQUIDS (machines or engines for liquids and elastic fluids F 01; positive-displacement engines for liquids F 03 C; positive-displacement machines for liquids F 04)

F 03 C

POSITIVE-DISPLACEMENT ENGINES DRIVEN BY LIQUIDS (positive-displacement engines for liquids and elastic fluids F 01; positive-displacement machines for liquids F 04; fluid-pressure actuators F 15 B; fluid gearing F 16 H)

F 03 D

WIND MOTORS

F 03 G

SPRING, WEIGHT, INERTIA, OR LIKE MOTORS; MECHANICAL-POWER-PRODUCING DEVICES OR MECHANISMS, NOT OTHERWISE PROVIDED FOR OR USING ENERGY SOURCES NOT OTHERWISE PROVIDED FOR (arrangements in connection with power supply in vehicles from force of nature B 60 K 16/00; electric propulsion with power supply in vehicles from force of nature B 60 L 8/00)

F 03 H

PRODUCING A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR (from combustion products F 02 K)
 ^