| 摘要 |
An escalator step having a tread and a convex riser, the riser being provided on its convex surface with a number of alternating first and second grooves which are shallow and deep respectively. The tread is provided on the surface with a number of first and second alternating cleats corresponding to the first and second grooves of the riser, the ends of the first and second cleats projecting from the side opposite to the riser a short and a long distance, respectively, corresponding to the depths of the first and second grooves of the riser. The end of the tread at the side adjacent the riser is constituted by recesses conforming to the first and second grooves of the riser.
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