Highway/rail trailer axle/suspension lift assembly
US6752406B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 16, 2002 |
| Grant date | Jun 22, 2004 |
| Priority date | — |
| Expiry date | Jul 7, 2022 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB60G2204/47
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.