Patent ID: 8132998

Claim:
A ramp system for a flat bed trailer having a deck frame, the ramp comprising; a ramp member; a hinge pivotally coupling the ramp member to the trailer for pivotal movement about a hinge axis between a loading position in which the ramp member extends between the deck frame and the ground and a storage position in which the ramp member is raised upwardly in relation to the loading position, through an intermediate position in which the ramp member is between the loading position and the storage position; at least one torsion member having a respective torsion axis extending in a longitudinal direction of the torsion member between opposed ends of the torsion member; said at least one torsion member being arranged to be supported such that the torsion axis of said at least one torsion member extends generally in a direction of the hinge axis; and said at least one torsion member being coupled between the deck frame and the ramp member such that the ramp member is biased from at least one of the loading position and the storage position towards the intermediate position; wherein said at least one torsion member comprises a torsion member anchored at one end relative to one of the deck frame and the ramp member; and wherein there is provided: a first crank member supported on the other end of the torsion member at the torsion axis for rotation with the other end of the torsion member relative to said one end which is anchored to one of the deck frame and the ramp member, the first crank member comprising a lever arm projecting radially outward in relation to the torsion axis of the torsion member; a second crank member anchored relative to the other one of the deck frame and the ramp member at the hinge axis in fixed relation with the other one of the deck frame and the ramp member, the second crank member comprising a lever arm extending outwardly from the hinge axis; and a connecting member separate and independent from the torsion member which is connected between respective free ends of the lever arms forming the first and second crank members.