Patent ID: 7909158
Filing Date: 2011-03-22
Classification: B65G

Abstract:
1. A walking-beam conveyor comprising: a pair of horizontal, longitudinally extending, parallel, and transversely spaced fixed support rails; a walking beam between and generally parallel to the rails; an upper horizontally and longitudinally extending guide; at least two lifters underneath the walking beam, supported on and movable longitudinally along the upper guide, and operable to raise the entire 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 a first cylinder defining one longitudinal cylinder end and a piston slidable longitudinally in the first cylinder and defining an opposite longitudinal piston end; means anchoring the cylinder end relative to the rails; a second longitudinally extensible hydraulic actuator having a second cylinder defining one longitudinal cylinder end and a piston defining an opposite longitudinal piston end; a lower horizontally and longitudinally extending guide below the upper guide; means supported on and movable longitudinally along the lower guide for securing the cylinder end of the second actuator directly to the piston end of the first actuator; means securing the piston end of the second actuator to the walking beam, the beam extending over the actuators and longitudinally in one direction past the piston end of the second actuator and longitudinally in an opposite direction past the cylinder end of the first actuator; and control means connected to the lifters and actuators for, starting from a condition with the actuators both contracted longitudinally, raising the entire walking beam with the lifters to the conveying position and extending both the actuators to shift the entire walking beam downstream, and then lowering the entire walking beam with the lifters and contracting both of the actuators to shift the entire walking beam upstream.