Requirements.
S6.4.8.3 Requirements. When tested in accordance with S7.8, platform lifts must have an inner roll stop that provides a means that prevents:
(a) The front wheels of the test device specified in S7.1.2 from extending beyond a plane that is perpendicular to the platform reference plane (Figure 1) and that is tangent to the edge of the platform where the roll stop is located when the lift is at ground level loading position; and
(b) Any portion of the test device specified in S7.1.2 from being contacted simultaneously with a portion of the lift platform and any other structure, throughout the lift's range of passenger operation.