Fall protection
Fall protection systems are usually mechanical components that are intended to stop the uncontrolled falling .
They are used where other protective measures are no longer possible. The best-known example is the elevator where the rope broke. The elevator car then falls so quickly that the fall protection is triggered and the car wedges into the guide rails.
Such fall protection is required in many areas by the accident prevention regulations. Approved, component-tested devices are available on the market. In the event of a trip, most of the safety catches must be replaced. They are then no longer functional and certainly no longer permitted.
In the case of presses, there is also talk of shaft breakage protection.
Simple safety ropes are also referred to as fall protection. These are beyond the scope of this article.
Trigger principle
- Centrifugal force: The fall protection is triggered by the centrifugal force . The falling movement is transferred to a rotating component. Moving parts (balls, bolts) are thrown outwards. This unlocks the wedge mechanism. The wedging (in the guide construction) brakes the fall movement "with force".
- Weight power: Falling bodies (apparently) lose their weight power. A bolt rests on a spring and thus locks the clamping mechanism. If the spring is relieved because the bolt becomes lighter, it is unlocked. Such devices can be found as fall protection on ladders. The person must click into place with the seat belt. Physically correct, one speaks of inertia protection.
- Friction: Such devices are directional. The upward movement is allowed. The device jams when it moves downwards. There is something like this, for example, as an ascender on ropes.
Trivia
The dramatic highlights that are occasionally used in action films and depict the crash of an elevator are inconceivable in a technically perfect condition. The situation is dangerous for the fitters who have to remove the fall arrest device for repairs.