US Patent 7681272 Counterbalance assembly for a fold out ramp

A counterbalance for a ramp assembly includes a chain assembly and a spring assembly. The spring assembly includes a spring and first and second spring fittings. The first spring fitting restrains a first end of the spring when the ramp portion is between a neutral position and the stowed position and moves the first end of the spring toward a second end of the spring when the ramp portion moves from the neutral position toward the deployed position. The second spring fitting is spaced from the first spring fitting and restrains the second end of the spring when the ramp portion is between the neutral position and the deployed position. The second spring fitting moves the second end of the spring toward the first end of the spring when the ramp portion moves from the neutral position toward the stowed position.