Glossary Updates12 new terms added to the glossaries · October 2, 2026, 22:44 CEST
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Glossary · Guards and machine motion

Interlocking guard with guard locking

In machine safety, an interlocking guard with guard locking is a guard kept closed and locked until the risk from hazardous functions has ceased, for example until a spindle has run down.

  • Machine safety
  • EU

In one sentence

An interlocking guard with guard locking stays locked until hazardous motion has stopped, protecting against run-down hazards that outlast a stop command.

Example

The door of a centrifuge remains locked by a solenoid-operated guard locking device until standstill monitoring confirms that the rotor has stopped.

How it applies

  • Machine safety: Used where the stopping time is longer than the time a person needs to open the guard and reach the hazard, as with heavy flywheels, spindles or rotors with high inertia.
  • Functional safety: Unlocking must be tied to a reliable signal that the hazard has ceased, such as standstill monitoring or a timer derived from the verified run-down time. The locking function itself is a safety function with its own required Performance Level or SIL.
  • Emergency and rescue: Consider how a person trapped inside can get out and how the guard can be released after a power failure, for example by an escape release or auxiliary release. Describe this in the emergency procedure.
  • Technical documentation: Explain in the instructions why the door stays locked after the stop, so that users do not suspect a fault and force the guard.

Interlocking guard with guard locking vs. guard locking

This term names the whole guard arrangement. Guard locking is the locking function or device that it uses.

By knowledge.aitechdoc.world · Published September 25, 2026 · Last reviewed

Source: ISO 12100:2010, Safety of machinery — General principles for design — Risk assessment and risk reduction

Definitions follow the cited standards and specifications. Where a source is a copyrighted publication, such as an ISO, IEC or EN standard, the definition is a close paraphrase, not a verbatim quotation, so as not to infringe copyright. We recommend reading the original publication. The sections “How it applies” are editorial commentary by AI TechDoc Blog and are not part of any standard.

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