Method of controlling a retractable stairway assembly

US6178364A · kind A · utility

Assignee

• Freightliner LLC · US

Inventors

• Paul J. Delurey · Beaverton, US
• David Johnston · Chelmsford, US
• Michael K. Smith · Beaverton, US
• Nasser Zamani · Lake Oswego, US
• William G. Massey, III · Portland, US
• Luis A. Novoa · Portland, US
• Michael von Mayenburg · Lake Oswego, US
• Charles H. Blakewood, Jr. · Vancouver, US
• Paul M. Menig · Tigard, US

Key dates

• Filing date: Feb 25, 1999
• Grant date: Jan 23, 2001
• Expiry date: Feb 25, 2019

Classification

• Technology area (CPC E): Fixed Constructions
• CPC primary: E06C7/003
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

A method of controlling a retractable stairway assembly for a vehicle includes monitoring at least one vehicle status condition such as (a) whether the vehicle is stopped, (b) whether the parking brake is set, (c) whether the cab is tilted in excess of a threshold, and (d) whether excess current is being required by a motor used to shift the stairway between stowed and deployed positions in the event an electric motor is used for this purpose. In the event any of these monitored conditions are not in a predetermined state, deployment of the stairway from a stowed position is blocked. Deployment and stowing of the stairway may also be interrupted depending upon vehicle status and other conditions. Interior and exterior vehicle alarms may be activated depending on vehicle status conditions and the mode of operation of the stairway.