Glossary · Guards and machine motion
Oscillating motion
In machine safety, oscillating motion is repeated angular movement around a pivot that can create trapping or impact hazards, for example where a swinging arm passes close to a fixed part.
- Machine safety
- Risk assessment
In one sentence
Oscillating motion of swinging arms, levers and pendulums creates trapping and impact hazards at the ends of travel and between the arm and fixed parts.
Example
The swinging transfer arm of a bottle-labeling machine sweeps through an arc and can trap a hand between the arm and the machine frame at its end position.
How it applies
- Risk assessment: Map the full swept area of the moving part and every place where it closes a gap with a fixed or moving part. Those places are hazard points for trapping and crushing.
- Machine safety: Oscillating parts often move fast and change direction abruptly, which adds an impact hazard inside the swept area. Guard the whole swept area where possible rather than individual points.
- Technical documentation: Show the swept area in layout drawings and in the operating manual, especially where it extends beyond the machine frame.
Oscillating motion vs. rotary motion
Rotary motion is continuous rotation around an axis. Oscillating motion swings back and forth through a limited angle and reverses direction at each end.