Patent · US Expired

Seat belt tension sensor

US6081759A · kind A · utility

67Cited by
10References
15Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 24, 1998
Grant dateJun 27, 2000
Priority date
Expiry dateApr 24, 2018

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB60R22/1952
  • WIPO fieldTransport
  • WIPO sectorMechanical engineering

Abstract

A sensor of Giant magneto-resistive (GMR) type is attached to a seat belt anchor bracket. A seat belt passes through an opening in the bracket and is doubled back and sewn to form a loop. A magnet positioned on a sliding carriage is biased away from the sensor by springs. A seat belt loops around the carriage, and when tension is applied to the belt, the carriage with the magnet is drawn against the springs toward the GMR sensor. The GMR sensor measures the magnetic field present at the sensor and a microprocessor determines belt tension based on the known spring constants and the strength of measured magnetic field which is correlated with displacement of the magnet.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.