To prevent any wasteful operation on a bag to bind an occupant at the time of locking a child seat by an air belt device.
A retractor 6 of an air belt device 2 is composed of making an emergency locking mode and an automatic locking mode switchable. This emergency locking mode is one that is used in the case where an occupant is fastened to a seat 1, and it is also locking a shoulder belt 7 being indrawable only at the time of a car crash, while the automatic locking mode is one that is used in the case of locking a child seat 11 by air belt device 2, and also it allows the winding of the seatbelt and regulates its drawing motion. When such a fact that the retractor 6 is the automatic locking mode is detected by a detecting means 16, a contol means 14 prohibits any operation of an inflator 13 inflating the shoulder belt 7, whereby any wasteful operation of the air belt device 2 is thus prevented from occurring.
AKAHA HIROSHI
OKAZAKI HIDETSUGU
