Self adjustable escalator handrail drive

Abstract

The handrail drive is a mangle-type drive wherein the handrail passes through the nip of a pair of opposed drive rollers. A plurality of drive roller pairs may be used. The drive rollers are keyed to rotatable shafts to which drive sprockets are also keyed. The drive sprockets are rotated by an endless chain which in turn is driven by one or more powered sprockets. The drive roller shafts are journaled in rotatable bearings which are mounted in a mechanism housing with the bearings being eccentrically mounted in the housing with respect to the drive roller shafts. When the drive rollers are rotated, friction between the handrail and the drive rollers, and between the roller shafts and eccentric bearings will cause the bearings to rotate about their axes thereby tightening the drive rollers about the handrail. As handrail drive roller friction increases, the tightening effect also increases. The rollers will only tighten on the extent needed to overcome the friction between the handrail and its guide rail. When the drive mechanism is turned off, the drive rollers only lightly engage the handrail.

Dependencies are inferred from the claim text.