Grades 3–5 · Machines
How do escalator steps flatten at the landing?
An escalator seems to grow stairs from a flat moving floor. Its steps are separate rigid parts connected to moving chains. A motor drives the chains around a continuous loop, including a return route hidden beneath the visible steps.
In the diagramRigid steps change their relative heightsInclineTransitionLandingRoller guidesReturn chainHeight differences become smaller near the landing
Rollers attached to the steps follow shaped tracks. Different rollers guide the step assembly so that its upper surface, called the tread, stays level on the passenger-carrying section. The track arrangement determines where each step sits.
On the incline, neighboring treads are at different heights, making a staircase. Near a landing, the guided paths bring those treads to the same height. The staircase becomes a level row without the metal steps changing their shape.
The chains provide continuing movement while the tracks guide the arrangement. This division of jobs explains both the rising staircase and its flat ends; the illustration shows that mechanism rather than the details of a particular escalator.
About this explanation
Starting knowledge: Recognize a rigid step, a rolling wheel and a guide that constrains a path.
Sources
- KONE — KONE Escalators and Autowalks Planning Guide
- Otis — Otis Escalator Catalog: Track Sections