Patent ID: 6049189
Filing Date: 2000-04-11
Classification: B66B,Y02B

Abstract:
A method to operate a passenger conveyor, the passenger conveyor having a platform moveable between a pair of landings, a passenger sensor, a drive for providing actuation of the moving platform, a source of power for the drive, and a frequency converter, the frequency converter disposed between the power source and the drive, the method including the steps of:sensing a passenger entering the passenger conveyor;transitioning the speed of the platform to a nominal speed by increasing the frequency generated by the frequency converter;switching the drive to be directly powered by the power source after the platform speed reaches the nominal speed,switching the drive to frequency control if it is determined that no passengers remain on the passenger conveyor;transitioning the platform speed to a stand-by speed by decreasing the frequency generated by the frequency converter, the stand-by speed being less than the nominal speed; andtransitioning the passenger conveyor from the stand-by speed to a ready-to-operate condition if a predetermined amount of time elapses without a passenger entering the passenger conveyor, wherein in the ready-to-operate condition the platform is stopped.