| 74 / | HD | MACHINE ELEMENT OR MECHANISM | 
| 640 | DF | GEARING {31} | 
| 325 | DF | .~ Interchangeably locked {11} | 
| * | DD | .~.~ Slidable keys or clutches {3} | 
| * | DD | .~.~.~ Single clutch shaft {3} | 
| 376 |  | .~.~.~.~ Single speed forward and reverse {3} | 
| 377 | DF | .~.~.~.~.~> Spur gears | 
| 378 | DF | .~.~.~.~.~> Bevel gears | 
| 379 | DF | .~.~.~.~.~> Bevel and idler gears |