Retractor with pretensioner
AssigneeAutoliv ASP, Inc.
InventorGunter K. Clute
Life of this patent
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Abstract
A retractor includes a pretensioner whereby increased control and variation over the load limitation characteristics of the retractor are provided. The seat belt and spool are linked to a locking mechanism through a first force limiting element, while the pretensioner is linked to the seat belt and spool through a second force limiting element. Both the first and second force limiting elements are employed during a load limiting phase of the retractor.
Claims21
A retractor for a seat belt restraining system for restraining an occupant of an automobile having a sensor detecting an impact event, the retractor comprising:
- a spool receiving a portion of the seat belt;
- a first force limiting element connected to the spool;
- a locking mechanism operatively connected to the spool through the first force limiting element;
- a second force limiting element connected to the spool;
- a pretensioner having a drive mechanism operatively connected to the spool through the second force limiting element;
- and
- the retractor operable in at least two modes upon detection of an impact event including,
- a first load limiting mode wherein the locking mechanism is activated to limit belt force through the first force limiting element, and
- a second load limiting mode, wherein the drive mechanism of the pretensioner is activated to retract seat belt onto the spool and blocked to limit force through the second force limiting element, and wherein the locking mechanism is activated to limit belt force through the first force limiting element.
A method for restraining an occupant of an automobile having seat belt securing the occupant and a sensor detecting an impact event, and generating a pretension signal, the method comprising:
- providing a retractor having a pretensioner, a spool, a first force limiting element, a second force limiting element, and a locking mechanism, the spool receiving a portion of the seat belt, the first force limiting element operatively connecting the spool and locking mechanism, the pretensioner having a drive mechanism, the second force limiting element operatively linking the spool and drive mechanism;
- activating the drive mechanism of the pretensioner based on the pretension signal indicative of an impact event to retract seat belt onto the spool;
- and
- maintaining the position of the drive mechanism of the pretensioner throughout the impact event to provide load limitation via the second force limiting element.
A retractor for seat belt restraining system in an automobile having seat belt restraining an occupant and a sensor detecting a potential crash event, the retractor comprising:
- a spool receiving a portion of the seat belt;
- a first force limiting element connected to the spool;
- a locking mechanism operatively connected to the spool through the first force limiting element;
- a second force limiting element connected to the spool;
- a pretensioner having a drive mechanism and a driven element operatively connected to the spool through the second force limiting element and structured such that movement of the driven element causes rotation of the spool to tension the seat belt;
- and
- the pretensioner including a one-way locking element that is activated only upon initiation of the pretensioner and its drive mechanism, the one-way locking element blocking movement of the driven element of the drive mechanism to prevent rotation of the spool and pay out the seat belt.
Dependencies are inferred from the claim text.