Safety device for locking in position a longitudinally adjustable seat equiped with an integral safety belt device

The motor vehicle has longitudinal seat adjustment and a safety belt system (16) with a belt lock locking arrangement (18). The safety device (10) causes locking of the longitudinal seat adjustment device (12) when the locking device of the safety belt system is in its operating position. The belt lock locking arrangement has at least one belt lock (20) and at least one belt tongue (22).