Planetary inertial seat belt retractor

Claim 1

A seat belt retractor comprising: a seat belt reel rotatable about an axis in belt retraction and belt withdrawal directions; a locking pawl movable between a lock position preventing rotation of said reel in said belt withdrawal direction and a release position allowing rotation of said reel in said belt withdrawal direction; a planetary gear system including a sun gear, a planet gear, and a ring gear, said planet gear meshing with said sun gear and ring gear; one of said sun and ring gears being connected to rotate about its axis as a function of the rotation of said reel and the other of said sun and ring gears being journaled for free rotation about its axis; connecting means between said planet gear and pawl for moving said pawl to said lock position in response to bodily movement of said planet gear to an operative position and for moving said pawl to said release position in response to bodily movement of said planet gear to a non-operative position; and spring means for biasing said pawl toward said release position; said planet gear and said other of said sun and ring gears having a predetermined inertia such that said planet gear remains in said non-operative position when said reel rotates in said belt withdrawal direction at a rate of acceleration less than a predetermined rate and moves to said operative position and causes said pawl to lock said reel when said reel rotates in said belt withdrawal direction at a rate of acceleration greater than said predetermined rate; said connecting means comprising a part projecting axially of said planet gear and connected to said pawl and operable to move said pawl from said release position to said lock position in response to movement of said planet gear to said operative position; said pawl being radially spaced from the axis of said reel beyond said ring gear; and said part being a shaped wire extending from said planet gear to said pawl.