Patent ID: 7568649

Claim:
A vehicle sensitive seat belt retractor control system for a vehicle for locking a vehicle seat belt retractor in the event of acceleration loads acting on the retractor in a horizontal plane while having a reduced sensitivity to acceleration loads acting in a Z-axis direction, perpendicular to the horizontal plane, the control system engaging with a toothed ratchet wheel to lock a spool of the retractor, the control system comprising: a locking lever pivotable about a pivot, the locking lever having an engagement finger engageable with the ratchet wheel, the locking lever having a center of gravity positioned relative to the pivot such that in a non-inverted orientation of the vehicle, gravity acts on the locking lever to urge the locking lever to pivot from an engaged position with the ratchet wheel to a disengaged position from the ratchet wheel, and a spring acting to urge the locking lever into the disengaged position, and a moveable mass displaceable from a resting position to a displaced position in response to acceleration loads in the horizontal plane acting in the horizontal plane and in the Z-axis direction, the moveable mass separated from the locking lever while in the resting position allowing the locking lever to remain in the disengaged position, wherein when acceleration loads act on the moveable mass, the moveable mass moves to the displaced position, contacting the locking lever and moving the locking lever to the engaged position, and a stationary restrictor, provided above a center of gravity of the moveable mass while in the resting position, restricts the moveable mass from moving to the displaced position and contacting the locking lever in response to acceleration loads acting in the Z-axis direction.