The basic principle.
An overspeed governor detects speed beyond its designed operating threshold. In a common arrangement, a governor rope and mechanical linkage initiate operation of safety gear on the moving frame.
Safety gear acts against the guide rails to arrest and hold the moving assembly according to its design. It is distinct from the machine brake used in normal coordinated operation.
Two related functions.
The governor provides the triggering function; the safety gear provides the rail-engaging action. Their compatibility and the connecting mechanism are part of the system.
Follow the relationship.
- DetectGovernor responds to the relevant overspeed.
- InitiateThe linkage transfers the triggering action.
- ArrestSafety gear engages the rails.
Connect it to the lift.
Direction of operation and applicable protections vary by design. Unintended Car Movement Protection (UCMP) is a related protection topic but is not simply another name for every governor-and-safety-gear arrangement.
A closer look
Buffers at the ends of travel serve another distinct function. A lift uses several protective provisions; no single component should be described as handling every possible event.
Check your understanding
Are the machine brake and the safety gear the same component?
Reveal the explanation
No. They act through different mechanisms and have different roles.