Patent attributes
An elevator safety arrangement and a method for implementing safety spaces in an elevator has a mechanical safety device which can be set to a working position to ensure a sufficient safety space in the elevator shaft and an electric safety system for identifying the operating state of the mechanical safety device. An electric safety controller comprises means for measuring the total resistance of a series circuit. The method includes reading the number of landing doors open by means of detectors fitted in conjunction with the landing doors, reading the number of elevator car doors open by means of detectors fitted in conjunction with the elevator car doors, and reading the position of a mechanical safety device by means of detectors fitted in conjunction with the mechanical safety device. If it is established that number of landing doors open is greater than the number of elevator car doors open, then setting the safety system into a ‘person in shaft’ state and preventing operation of the elevator. If it is established during the ‘person in shaft’ state of the safety system that the number of landing doors open is equal to the number of elevator car doors open and that the mechanical safety device has been set to a working position, then allowing maintenance operation.
