Abstract: An escalator drive assembly (30) includes a sensor that facilitates detecting when the normal drive assembly operation is interrupted, such that a brake should be activated. In one example, a sensor member (40) in the form of a flange (42) is associated with a drive pulley (34) and normally rotates in unison with the drive pulley. When there is a failure in the normal operation of the drive mechanism, however, there is a resulting relative movement between the sensor member (40) and the drive pulley (34). Such relative motion preferably activates a switch (80) that provides a signal that indicates a failure of the normal operation of the drive mechanism (30). Another example sensor includes a sensor member (202, 212) that engages a drive belt (35). If the belt (35) breaks, the sensor member (202, 212) moves to provide an indication of the broken belt condition. Various braking application modes are possible using the invention.

Abstract: A passenger conveyor drive assembly (40) includes drive members such as belts (42) that engage a step chain (30). A monitoring device (50) provides an indication of a damaged or broken drive member (42) by monitoring the relative rotations between wheels (44, 46). In one example, relative rotation between deflection wheels (46) provides an indication that one of the drive members (42) is not performing as well as the other. In another example, a comparison between the speed of rotation of the drive wheels (44) on the one hand and the deflection wheels (46) on the other hand allows for independently monitoring each of the drive members (42) of the drive assembly. In a disclosed embodiment, the monitoring device includes rotating members (52, 56) that normally rotate in unison and move into another position when there is relative rotation between the selected wheels. Such movement provides an indication of a malfunction of the drive system and may actuate the brake as needed.

Abstract: An escalator drive assembly (30) includes a sensor that facilitates detecting when the normal drive assembly operation is interrupted, such that a brake should be activated. In one example, a sensor member (40) in the form of a flange (42) is associated with a drive pulley (34) and normally rotates in unison with the drive pulley. When there is a failure in the normal operation of the drive mechanism, however, there is a resulting relative movement between the sensor member (40) and the drive pulley (34). Such relative motion preferably activates a switch (80) that provides a signal that indicates a failure of the normal operation of the drive mechanism (30). Another example sensor includes a sensor member (202, 212) that engages a drive belt (35). If the belt (35) breaks, the sensor member (202, 212) moves to provide an indication of the broken belt condition. Various braking application modes are possible using the invention.