Drive system for an automatic step

Abstract

This invention relates to a drive system for an automatic step. Some embodiments include a rotary actuator for moving an automatic step, a crank arm pivotally coupled to the actuator and pivotable about a central shaft, and a first link pivotally coupled to the crank arm, the first link having first and second ends. The system has one or more force mitigation mechanisms capable of reducing forces eccentric with respect to the actuator. A first force mitigation mechanism engages when the step is deployed or nearly deployed by aligning the central shaft with the first and second ends of the first link along a first axis to generally place eccentric forces originating from the step against the central shaft of the crank arm instead of directly engaging the actuator. A second force mitigation mechanism allows the crank arm to yield without forcing the actuator by using a clutch adjacent to the central shaft.

Dependencies are inferred from the claim text.