摘要 |
<p>An air-free, relatively lightweight lift assembly for an axle/suspension system of a highway/rail convertible semi-trailer, utilizes a transversely-oriented coil torsion spring having a relatively low spring rate. The torsion spring is captured between a stationary plate and a rotatable plate. A flexible link is pivotally attached at its upper end to the rotatable plate and at its lower end to the axle. This assembly results in a variable rate moment arm and continuously increasing leverage when the suspension air spring is overinflated to lower the system for transfer of the trailer from a highway tractor to a rail bogie, thus enabling use of a less robust air spring. The assembly conversely creates a decrease in leverage at the lifted rail transport position, to securely maintain the axle/suspension system in the rail position. For highway use, the lift assembly provides suspension damping without shock absorbers.</p> |