Patent ID: 11554933

Abstract:
An elevator includes an elevator shaft defined by surrounding walls and top and bottom end terminals; an elevator car vertically movable in the elevator shaft; elevator hoisting ropes coupled to the elevator car; an elevator hoisting machine including a traction sheave engaged with the elevator hoisting ropes; a traction monitor configured to determine traction of the hoisting machine; an electromechanical brake; a measuring apparatus adapted to provide speed data and position data of the elevator car; and a safety processor associated with the traction monitor and the measuring apparatus. The safety processor includes an ETLS threshold configured to decrease towards the top and/or bottom end terminal in accordance with the position of the elevator car. The ETSL threshold is adjusted on the basis of the traction of the hoisting machine. The safety processor is configured to determine an elevator car slowdown failure if the speed data meets or exceeds the ETSL threshold.