Patent ID: 7857337

Claim:
A movable step apparatus, comprising: a mounting frame; at least one step; a pivot rod mounted to the frame to pivot about an axis that is generally parallel to the frame; a linkage assembly pivotally connecting the at least one step and the frame, and the linkage assembly being connected to the pivot rod and including at least two links, each link having a longitudinal axis that extends between pivot points of the link where the link is connected to the frame and to the at least one step, and wherein the axes of the links are non-parallel when the step is in an extended position; a crank arm driven by a motor, the crank arm being rotatable about an axis of rotation to thereby cause the pivot rod to move the at least one step to the extended position from a retracted position and vice versa, whereby rotating the pivot rod in a first direction causes the at least one step to move to the extended position, and rotating the pivot rod in a second direction causes the at least one step to move to the retracted position, and wherein at least one of the links of the linkage assembly contacts a stop of the frame in the extended position, such that a gravitational force on the step rotates said at least one link further in a direction of rotation of the link that the link rotates in toward the extended position of the step, so that the at least one link is pressed against the stop and the stop reacts against the gravitational load; a transmission stop, the crank arm engaging the transmission stop in the extended position; and wherein when the step moves toward the extended position, the at least one of the links contacts the stop of the frame before the crank arm contacts the transmission stop.