Patent ID: 8141806

Claim:
A seat belt apparatus for a vehicle, the apparatus comprising: a belt reel around which a webbing is wound; a driving motor which drives the belt reel to rotate; a control device which controls the driving motor; a rotational position detection device which detects a rotational position of the belt reel; a vehicle condition detection device which detects either a stable or an unstable behavior of the vehicle; an emergency locking retractor which is activated to perform a mechanical locking of the belt reel so as not to rotate in a direction of unwinding the webbing when the unstable behavior of the vehicle is detected by the vehicle condition detection device, said emergency locking retractor being operable to automatically release the locking if the belt reel rotates in a direction of winding the webbing greater than or equal to a predetermined amount; and a locking continuity determination device which determines whether or not the locking continues after the emergency locking retractor performs the locking, based on the vehicle condition detected by the vehicle condition detection device and variation of the rotational position of the belt reel detected by the rotational position detection device, wherein said locking being determined to be discontinued when said vehicle condition detection device detects the stable behavior of the vehicle and said belt reel rotational position varies in a direction of unwinding of said webbing; wherein the control device makes the driving motor rotate the belt reel in the winding direction an amount equal to or greater than the predetermined amount so as to release the locking of the emergency locking retractor when the locking continuity determination device determines that the locking continues for greater than or equal to a predetermined amount of time after detection of stable behavior by the vehicle condition detection device.