Seat belt device

A seat belt device comprising:

• a first unit for determining a possible collision of an automobile in response to a manipulation thereof by a driver;
• a second unit for detecting the collision of the automobile;
• seat belt webbing;
• a spindle around which a portion of the seat belt webbing is wound;
• a first pretensioner having a motor to rotate in a direction to wind the seat belt webbing onto the spindle in response to a signal indicative of the possible collision determined by the first unit;
• a second pretensioner pyrotechnically driven to rotate in a direction to wind the seat belt webbing onto the spindle in response to a signal indicative of the collision detected by the second unit;
• a sensor attached to the automobile;
• and
• a controller configured to activate the first pretensioner immediately before the second pretensioner starts operating, according to at least one of a signal indicative of an activation of the second unit and a signal generated by the sensor, wherein
• the second pretensioner can release a mechanical connection between the first pretensioner and the spindle only after activation of the first pretensioner, and
• the first pretensioner includes a limiter for restricting the motor from transmitting a driving force to the spindle exceeding a predetermined threshold, while resisting the spindle rotating in a direction to unwind the seat belt webbing.