Patent ID: 7753158
Filing Date: 2010-07-13
Classification: B60R

Abstract:
1. A seat belt retractor to be installed in a vehicle comprising: an electric motor for driving a spool configured to wind and unwind a seat belt to restrain an occupant; and a control mechanism for controlling the electric motor, wherein the control mechanism is configured to control the electric motor to increase seat belt tension and wind up the seat belt and remove seat belt slack when a vehicle occupant wears the seat belt, and wherein the control mechanism controls the motor to have a tension increasing rate lower than a predetermined criterion value of restraining force until the seat belt tension reaches a target tension, wherein the control mechanism controls the motor to adapt an inclination of a rising curve of the tension increasing rate to be gentler than an inclination of the predetermined criterion value of restraining force, and wherein the predetermined criterion value of restraining force is a reference tension increasing rate indicating whether the tension increasing rate is effective for reducing a restraining feeling on the occupant.