23/05/2026
An elevator overspeed governor is a mechanical safety protection device designed to prevent an elevator car from dropping uncontrolled or exceeding its designated maximum safe operating speed. It serves as a vital fallback system, acting like an emergency brake trigger if the main hoisting cables fail or the motor traction loses control.
How It Works⚙️
The system continuously monitors the car's physical movement through a synchronized mechanism:Continuous Rotation: A dedicated steel wire rope (governor rope) attaches to the elevator car, runs up to the top of the shaft around the governor pulley wheel, and extends down to a tension pulley at the bottom pit. As the elevator travels, the rope spins the governor pulley.Centrifugal Force Detection: Inside the governor sheave, weighted flyweights are held by calibrated springs. If the car accelerates past the preset trip speed limit, centrifugal force flings these flyweights outward.Electrical Cut-off: Before mechanical intervention, the expanding weights strike an electrical safety switch, cutting off electrical power to the elevator hoist motor and engaging the primary machine brake.Mechanical Tripping: If the elevator continues to accelerate (such as in a complete free-fall scenario), the flyweights move further out and physically catch onto jaw teeth on the governor wheel casing, instantly locking the wheel and stopping the governor rope from moving.Safety Brakes Engaged: Because the elevator car is still falling but the governor rope is locked in place, the moving car pulls on the stopped rope. This physical upward yank activates a mechanical lever under the elevator car, forcing heavy steel wedges (safety gears) to clamp directly onto the building's solid steel guide rails, bringing the car to a secure halt.
™️
®️
,
