Electrically adjusted safety restraint system

An electrically actuated safety restraint system for restraining the occupant in a vehicle's seat during a crash comprising:

• a seat belt;
• a seat belt retractor attached to one end of said seat belt, said retractor having an electric motor for actuating said retractor to retract and pay out said seat belt, and a lock means for inhibiting the extraction of said seat belt under crash conditions;
• means for securing the other end of said seat belt to the structural member of the vehicle,
• switch means having a first state signifying said other end of said seat belt is secured and a second state signifying said other end of said seat belt is not secured;
• first sensor means responsive to the tension on said seat belt to generate a snugged-up signal when said seat belt is exerting a predetermined force against the occupant;
• and
• motor control means for energizing said electric motor to actuate said retractor to snug up said seat belt against the occupant in response to said first state, for de-energizing said electrical motor in response to said snugged-up signal, for energizing said electric motor to actuate said retractor to stow said seat belt in response to said second state, and for de-energizing the electric motor in response to said snugged-up signal to energize said motor to rotate in the opposite direction to pay out a predetermined length of said seat belt to relieve the tension of said seat belt of the occupant.

An electrically adjusted safety restraint system for restraining an occupant in a vehicle's seat comprising:

• a seat belt having one end attached to a structural member of the vehicle;
• a retractor attached to a structural member of the vehicle, said retractor having a take-up spool attached to the other end of said seat belt, a reversible electric motor for rotating said take-up spool in either direction, and means for inhibiting the extraction of the seat belt from the retractor in response to a first predetermined rate of change in the velocity of the vehicle;
• an adjustable tongue slidably coupled to said seat belt between said one end and said retractor dividing said seat belt into a lap portion and a shoulder portion;
• a buckle for securing said adjustable tongue, said buckle attached to a structural member of the vehicle on the other side of the vehicle's seat, said buckle including a buckle switch having a first state signifying that said adjustable tongue is secured in said buckle and a second state signifying that the adjustable tongue is not secured in said buckle;
• a snugged-up sensor for generating a snugged-up signal in response to said first state and the current of said motor exceeding a predetermined value when said shoulder portion of said seat belt is snugged up against the occupant's shoulder with a predetermined force;
• a crash sensor for generating a crash signal in response to a second predetermined rate of change in the velocity of the vehicle;
• logic means for generating a first signal in response to said buckle switch assuming said first state, for generating said first signal in response to said buckle switch switching from said first state to said second state, for terminating said first signal in response to said snugged-up signal, for generating a second signal having a first fixed duration in response to the termination of said first signal, and for generating a third signal having a second fixed time duration in response to said crash signal;
• motor control means for energizing said motor to rotate said take-up spool in a direction to retract said seat belt in response to said first signal, for energizing said motor to rotate said take-up spool in the opposite direction paying out a predetermined length of seat belt in response to said second signal, and for energizing said motor in response to said third signal to rotate said take-up spool to retract said seat belt.

A method for electrically adjusting the tension of a safety restraint system about an occupant of a vehicle's seat, the safety restraint having a seat belt, a motor driven retractor, buckle and a tongue connected to the seat belt received in said buckle, the method comprising the steps of:

• detecting the latching of the tongue in the buckle to generate a latched signal;
• activating a first timer with said latched signal to generate a first mode signal having a maximum first time duration;
• energizing the retractor's motor in response to said first mode signal to snug up the seat belt against the occupant's shoulder;
• sensing a predetermined tension on the seat belt to generate a snugged-up signal;
• resetting said first timer in response to said snugged-up signal terminating said first mode signal;
• detecting the termination of said latched signal to activate said first timer to generate said first mode signal;
• detecting excessive slack in the seat belt to generate a slack signal;
• sensing the simultaneous occurence of said latch signal and said slack signal to start a second timer to generate a second mode signal having a second time duration;
• activating said first timer in response to the termination of said second mode signal to generate said first mode signal;
• sensing the occurence of said slack signal in the absence of said latch signal to start a third timer to generate a third mode signal having a third time duration;
• and
• activating said first timer in response to the termination of said third mode signal to generate said first mode signal.