Walking-beam conveyor

A walking-beam conveyor comprising:

• a pair of longitudinally extending, parallel, and transversely spaced fixed support rails;
• at least one walking beam between and generally parallel to the rails;
• at least two lifters underneath the walking beam and operable to raise the walking beam from a return position generally below the rails to a conveying position generally above the rails;
• a first longitudinally extensible hydraulic actuator having opposite longitudinal ends;
• means anchoring one of the longitudinal ends relative to the rails;
• a second longitudinally extensible hydraulic actuator having opposite longitudinal;
• first means securing one of the ends of the second actuator to the other end of the first actuator;
• and
• second means securing the other end of the second actuator to the walking beam;
• and
• control means connected to the lifters and actuators for, starting from a condition with the actuators both contracted longitudinally, raising the walking beam with the lifters to the conveying position and extending both the actuators to shift the walking beam downstream, and then lowering the walking beam with the lifters and contracting both of the actuators to shift the walking beam upstream.