These overspeed governors aactivate on opening their levers, by the effect of centrifugal force, when there is an overspeed of the car in both ascent and descent.
The roller rotates in the same direction as the lift moves until it touches the blocking disc and is braked between this disc and the wedge of the pulley, producing the mechanical tripping of the overspeed governor. This system allows infinate tripping points because they happen on any position of the roller surrounding the disc.
These overspeed governors are valid for activating instantaneous safety gears with rollers, instantaneous with shock absorption effect and progressives.