Ground drive assembly for drag sled

Claim 1

THE COMBINATION OF A DRAG SLED INCLUDING A SET OF SPACED PARALLEL GROUND ENGAGING RUNNERS, AN IMPLEMENT DRIVING SHAFT EXTENDING TRANSVERSELY OF AND ROTATABLY MOUNTED ON SAID SLED AT A FIXED HEIGHT ABOVE THE GROUND, A PAIR OF TRANSVERSELY SPACED PARALLEL ARMS ROTATABLY MOUNTED AT ONE END THEREOF ON SAID DRIVING SHAFT FOR RAISING AND LOWERING MOVEMENT, A RIGID MEMBER EXTENDING BETWEEN AND SECURED TO INTERMEDIATE PORTIONS OF SAID ARMS A TRANSVERSE SLEEVE ROTATABLY MOUNTED BETWEEN SAID ARMS AT THE OTHER END THEREOF, A GROUND ENGAGING WHEEL AND A SPROCKET CARRIED BY AND ROTATABLE WITH SAID SLEEVE BETWEEN SAID ARMS, A SECOND SPROCKET SECURED TO SAID DRIVING SHAFT, AN ENDLESS CHAIN PASSING OVER THE FIRST AND SECOND MENTIONED SPROCKETS WHEREBY SAID DRIVING SHAFT MAY BE ROTATED BY ROTATION OF SAID WHEEL, A TENSION SPRING CONNECTED AT ONE END THEREOF TO ONE OF SAID ARMS AND ANCHORED AT ITS OTHER END TO SAID SLED FOR URGING SAID ARMS AND SAID WHEEL DOWNWARDLY, AND MEANS FOR LIMITING THE EXTENT OF DOWNWARD MOVEMENT OF SAID ARMS UNDER THE ACTION OF SAID SPRING, ONE OF SAID RUNNERS HAVING AN OPENING, SAID SLEEVE EXTENDING FREELY THERETHROUGH, SAID ARMS BEING DISPOSED AT OPPOSITE SIDES OF SAID ONE RUNNER AND SAID RIGID MEMBER EXTENDING BETWEEN SAID ARMS ABOVE SAID ONE RUNNER, SAID RIGID MEMBER BEING ENGAGEABLE BY TO PROVIDE SAID MEANS FOR LIMITING THE EXTENT OF DOWNWARD MOVEMENT OF SAID ARMS.