The purpose of these gears is to control the angle produced by the gear. These systems use a knuckle gear (or pins between two gears) in combination with an angled beam that uses a rubber band to place the angle into the center part of the gear.
The purpose of these gears is to select a specific degree of rotation. This can be used to align attachments, manipulators, and clutch gears (used in multiplexer designs).
Exposed view of the gear
Exposed View of the gear