Seat weight sensor having fluid filled bladder

US5957491A · kind A · utility

Assignee

• Automotive Systems Laboratory, Inc. · US

Inventors

• Leonard Cech · Brighton, US
• Michael R. Sewell · Blenheim, CA
• Edward J. Gillis · South Lyon, US
• Dennis E. Palmer · South Lyon, US
• James G. Stanley · Novi, US
• Vinh Tran · North Andover, US
• Todd Bowman · Grand Blanc, US

Key dates

• Filing date: Dec 18, 1997
• Grant date: Sep 28, 1999
• Expiry date: Dec 18, 2017

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S297/03
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

A seat weight sensor incorporates a fluid containing bladder placed in series with the load path in the seat, whereby a load applied to and distributed across the bladder increases the pressure of the fluid therein. The pressure of the fluid is measured by a pressure sensor and is substantially proportional to the magnitude of the applied load, and substantially inversely proportional to the supported area of the bladder. The output signal is substantially linear with respect to weight. Preferably, the amount of fluid in the bladder should be less than the capacity of the bladder when the bladder is unloaded. The seat weight sensor is incorporated into an occupant restraint system for controlling the safety restraint system responsive to the weight of the occupant.