| Stieber Clutch | 
Overrunning Clutches and Backstops
Overrunning clutches are directional couplings, which means they are engaged and disengaged automatically, depending on the relative direction of rotation of the driving and driven sides. Practical applications of this principle:
- OVERRUNNING CLUTCH for multiple-machine drives or to separate the inertia of masses of a driven machine from the driving machine after it has been switched off.
- INDEXING CLUTCH which turns a shaft step by step, thus achieving indexed material feed or a variable speed.
- BACKSTOP to prevent a machine shaft turning backwards. In this case the overrunning clutch acts as a brake.