The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 22, 2004
Filed:
Apr. 16, 2002
Phillippi R. Pierce, Canton, OH (US);
Timothy V. Hess, Smithville, OH (US);
The Boler Company, Itasca, IL (US);
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.