摘要 |
A pulley for guiding a suspension traction device of an elevator has a central portion for contacting the suspension traction device. The central portion has at least one of a protrusion and a marking for detecting whether the suspension traction device is positioned correctly on the pulley. A method for monitoring the elevator system utilizes a noise detector for detecting noise generated by contact between the suspension traction device and the protrusion and an optical detector for detecting when the marking is covered by the suspension traction device. |