Dual-speed escalator apparatus

Abstract

A dual-speed escalator apparatus comprises a main frame defining an elongated sloped circulating path, a plurality of steps disposed along the circulating path and dual link assemblies each including a first and a second link. The first and second links each have one end pivotally connected to a front roller shaft on a step, and the other end of the first link has a link roller and is pivotally connected to the other end of the second link on a neighboring step. A front roller guide rail extends along the circulating path, a rear roller guide rail is disposed along the front roller guide rail for maintaining the steps in a predetermined position, and a folding rail is disposed along the front roller guide rail for guiding the link rollers on the dual link assembly and for folding the dual link assembly into a folded position at the end portions of the circulating path. Intermediate plates are provided each having a first end in engagement with one of the steps and a second end in slidable engagement with neighboring step. The intermediate plates are positioned between the steps when the dual link assembly is expanded in an elongated intermediate portion of the main frame. Alternatively, a step chain having a rack may be disposed along the circulating path to correct the steps in an endless loop, and a drive unit for driving the step chain may be mounted at a midpoint of the length of the main frame.