Constant pivot mechanism for variable height radial stacking conveyors

Claim 1

A variable height radial stacking conveyor for transporting material from a location at a lower level and discharging the material at a higher level, said conveyor comprising a conveyor frame having a tail end and a head end, a material conveying means carried by the conveyor frame for moving material from the tail end and discharging the material at a higher elevation from the head end, an undercarriage combined with the conveyor frame to support the frame, means for raising and lowering the head end of the conveyor frame relative to the tail end, power-driven running gear having ground engaging wheels operatively connected to the undercarriage for moving the head end of the conveyor frame along a arcuate path, the pivot point of the arcuate path being at the tail end of the conveyor with a fixed radius of curvature between the pivot point and the wheels, a rear support arm of a fixed length forming a part of the undercarriage and having a lower end pivotly connected to the running gear and an upper end operatively connected to the conveyor frame near the tail end of the frame, a lever arm having one end pivotly connected to the conveyor frame and the other end pivotly connected to the rear support arm near its upper end, and a cam follower on the upper end of the rear support arm, the conveyor frame having a curved cam slot for receiving the cam follower for limited slidable movement in the cam slot, the curvature of the cam slot substantially following the actual path travelled by the cam follower as the conveyor frame is raised and lowered.