Tandem flail type material unloaders

Claim 1

MATERIAL SPREADING APPARATUS COMPRISING: A PLURALITY OF SPREADER UNITS EACH OF WHICH INCLUDES A WHEELED CARRIAGE AND A MATERIAL CONTAINER ON THE CARRIAGE, EACH CONTAINER HAVING FRONT AND REAR END WALLS CONNECTED BY A BOTTOM WALL; HITCH MEANS SECURED TO THE FRONT OF EACH UNIT SUBSTANTIALLY ON THE LONGITUDINALLY MEDIAN PLANE OF THE UNIT; A COUPLER SECURED TO THE RAR OF EACH UNIT SUBSTANTIALLY ON THE LONGITUDINAL MEDIAN PLANE OF THE UNIT, THE COUPLER OF A FIRST UNIT BEING ENGAGED BY THE HITCH MEANS OF A SECOND UNIT SO THE UNITS ARE CONNECTED IN TANDEM; DRIVE SHAFT MEANS WITHIN EACH CONTAINER AND ON THE LONGITUDINAL MEDIAN PLANE THEREOF, SAID DRIVE SHAFT MEANS BEING SUPPORTED ON AND EXTENDING OUTWARDLY BEYOND BOTH CONTAINER END WALLS; MEANS MOUNTING A PLURALITY OF FLEXIBLE FLAIL MEMBERS ON THE DRIVE SHAFT MEANS OF EACH CONTAINER SO SAID FLAIL MEMBERS ARE ROTATABLE WITH SAID DRIVE SHAFT MEANS; MEANS ON THE FRONT OF THE FIRST CARRIAGE FOR PULLING IT BEHIND A PRIME MOVER; MEANS FOR DRIVING THE DRIVE SHAFT MEANS IN THE FIRST CONTAINER FROM A POWER SOURCE ON THE PRIME MOVER; SHAFT MEANS PROVIDING THE SOLE DRIVING CONNECTION BETWEEN THE LEADING DRIVE SHAFT AND THE NEXT SUCCEEDING DRIVE SHAFT, SAID SHAFT MEANS BEING ALIGNED WITH EACH SAID DRIVE SHAFT MEANS; AND MEANS FOR SELECTIVELY BREAKING OR MAKING SAID DRIVING CONNECTION, WHEREBY SAID CONTAINERS MAY BE UNLOADED ONE AT A TIME BEGINNING WITH THE FIRST CONTAINER BY SELECTIVELY BREAKING AND MAKING SAID DRIVING CONNECTIONS.