Elevator system

Elevator system (2) comprising

• at least one moving object (6, 21) configured for traveling along at least one guide member (14) extending between a plurality of landings (8);
• a position sensor (18) configured for determining the current position of the moving object (6, 21) along the guide member (14);
• at least one elevator safety device (20) mounted to the moving object (6, 21) comprising:
• a safety controller (42);
• a memory (40);
• at least one engagement member (26a, 26b) movable between
• a non-actuated state in which the at least one engagement member (26a, 26b) does not contact the guide member (14);
• and
• an engaged state in which the at least one engagement member (26a, 26b) engages with the guide member (14);
• and
• at least one actuation member (30) mechanically coupled with the at least one engagement member (26a, 26b) and movable between
• a non-actuated state in which the at least one actuation member (30) does not contact the guide member (14);
• and
• a partially actuated state in which the at least one actuation member (30) contacts the guide member (14);
• wherein the safety controller (42) is configured for:
• causing the at least one actuation member (30) to move from the non-actuated state into the partially actuated state and storing within the memory (40) a position of the moving object (6, 21) detected by the position sensor (18) at a point of time within a given time frame around the moment in which the at least one actuation member (30) is caused to move from the non-actuated state into the partially actuated state as a starting position;
• detecting as a detected position the position of the moving object (6, 21) along the guide member (14) after the actuation member (30) has been moved from a non-actuated state into the partially actuated state;
• calculating the distance (d) between the detected position and the starting position;
• and
• determining that the elevator safety device (20) has entered a fully activated state configured to stop motion of the object (6, 21), in which the at least one engagement member (26a, 26b) engages with the guide member (14), when the calculated distance (d) between the detected position and the starting position reaches or exceeds a predefined limit.