Seat belt retractor
First Claim
1. A seat belt retractor comprising:
- a motor for rotating a spool to wind up a seat belt;
a power transmission switching mechanism which, in a connected state, allows the spool to rotate only in a seat belt winding direction and which, in a disconnected state, allows the spool to rotate in both directions;
a force limiter mechanism which allows the spool to rotate in a seat belt withdrawing direction against a rotation limiting force when a force to rapidly withdraw the seat belt is applied; and
a pyrotechnic pretensioner which forces to wind up the seat belt at the time of detection of a collision, wherein the power transmission switching mechanism is set into the disconnected state by the movement of a mechanical portion of the pyrotechnic pretensioner which moves when the pyrotechnic pretensioner is activated, thereby disconnecting the mechanical connection of the motor and the spool.
5 Assignments
0 Petitions
Accused Products
Abstract
A seat belt retractor having a force limiter mechanism that can be stably operated when a pyrotechnic pretensioner is activated. As a pyrotechnic pretensioner is activated, a ring gear rotates in the counter-clockwise direction. Accordingly, an external tooth holding an end portion of a stopper is moved, whereby the end portion of the stopper becomes free. Therefore, the stopper expands because of its biasing force. Then, a release spring is released from the restriction of the stopper and thus pivots in the clockwise direction because of its biasing force. The release spring collides with a pin of the clutch pawl to press down the pin. Therefore, the clutch pawl is rotated about a clutch pawl pin in the clockwise direction, thereby canceling the mechanical connection between the motor and the spool.
32 Citations
9 Claims
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1. A seat belt retractor comprising:
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a motor for rotating a spool to wind up a seat belt;
a power transmission switching mechanism which, in a connected state, allows the spool to rotate only in a seat belt winding direction and which, in a disconnected state, allows the spool to rotate in both directions;
a force limiter mechanism which allows the spool to rotate in a seat belt withdrawing direction against a rotation limiting force when a force to rapidly withdraw the seat belt is applied; and
a pyrotechnic pretensioner which forces to wind up the seat belt at the time of detection of a collision, wherein the power transmission switching mechanism is set into the disconnected state by the movement of a mechanical portion of the pyrotechnic pretensioner which moves when the pyrotechnic pretensioner is activated, thereby disconnecting the mechanical connection of the motor and the spool. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification