Abstract: A lift platform has a retention ramp whose forward edge is pivotally connected to a rear edge of the platform by a hinge that permits inversion of the retention ramp to a stowed position overlying the platform. A latch member is mounted on a lateral edge of the retention ramp in operative alignment with a detent block secured to the rear edge of the platform, the detent block having a center on the axis of the hinge. The latch member is pivotally mounted and torsionally biased to press the nose portion into engagement with the periphery of the detent block, the latter having detent notches angularly spaced apart relative to its center for defining intermediate and stowed positions of the retention ramp. During movement of the retention ramp between extended and intermediate positions the nose of the latch engages a convex portion of the detent block periphery of a radius to depress the latch against the biasing force of the torsion spring.

Abstract: In a parallelogram linkage system whose swingable outer end supports a platform turnable between horizontal and vertical positions, the parallel arm has a hub to rotatably support a crank member. The companion lift arm of the linkage carries an actuator pin engaged with a cam surface of the crank member. The cam surface is disposed generally radially with respect to the hub and oppositely to a pin carried at the other side of the crank member. One end of the drive link is pivotally connected to the crank member pin with the opposite end pivotally connected to a short link whose upper end is coaxially pivotally connected at the pivot axis of the load platform. The platform mounts a stop member that is movable between active and inactive positions. In the active position, the stop member abuts the outer end of the drive link whereby upon cammed rotation of the crank member the platform is turned between horizontal and vertical positions.