Escalator with step levelers

Claim 1

An escalator comprising: steps connected with each other in an endless fashion; front wheels and rear wheels rotatably supported by each of said steps through a front shaft and a rear shaft, respectively; a first pair of guide rails on which said front wheels roll, and a second pair of guide rails on which said rear wheels roll; projections extending coaxially outwardly from the ends of said rear shaft; and a pair of upthrust rails disposed in a juxtaposed relation to said projections and adapted to engage with said projections, upon the upward pivotal movement of the step, to prevent the further upward pivotal movement of the step, wherein each of said second pair of guide rails includes a horizontal section defining a rolling surface for said rear wheel, and a vertical section on the edge of said horizontal section at the side where said projection is located, and wherein each of said pair of upthrust rails includes a horizontal section disposed above said projection, and wherein a clearance between the tip of the projection and the vertical section of said upthrust rail and a clearance between the rear wheel and the edge of the horizontal section of said upthrust rail are greater than that between the rear wheel and the vertical section of said second guide rail, whereby damage to said projection and upthrust rail can be prevented upon lateral shifting of said steps.