Improved feed mixer apparatus, wherein interconnected, auger mixing conveyors are operatively connected to a crank arm driven by a pair of pivotably mounted hydraulic cylinders which are in turn driven by a hydraulic power source providing for smooth and timed transition from low pressure to high pressure...http://www.google.es/patents/US4153376?utm_source=gb-gplus-sharePatente US4153376 - Feed mixer apparatus
