Seat belt retractor

A seat belt retractor comprising a spool for carrying seat belt webbing rotatably mounted about a longitudinal axis and biased in a seat belt webbing rewinding direction, a toothed ratchet wheel mounted to rotate with the spool, a sensor for detecting an emergency condition, a vehicle acceleration sensor lever responsive to the sensor to engage the ratchet wheel in the event of an emergency condition, means for locking the spool against pay-out of seat belt webbing in response to the vehicle acceleration sensor lever engaging the ratchet wheel, the retractor being adapted to operate in a first, emergency locking mode in which the spool is not locked and can rotate to pay-out and to rewind seat belt webbing and in a second, automatic locking mode in which the spool is locked against pay-out of the seat belt webbing and means for switching between the first mode and the second mode, wherein the switching means comprises a cam connected to the spool via a step-down gearing arrangement and having a cam surface and an actuating lever having a cam follower resiliently biased against the cam surface, the actuating lever being pivotally mounted and movable from a first position in which the actuating lever does not actuate the vehicle acceleration sensor lever and the retractor is in the first mode, against the action of the resilient bias to a second position in which it actuates the vehicle acceleration sensor lever and the retractor is in the second mode, the vehicle acceleration sensor lever and the means for switching between the first mode and the second mode are both located between the spool and the sensor for detecting an emergency condition.