The Flat Cable Turning Over Phenomenon in The Roll Connector for The Air Bag

The roll connector for the air bag system contains a coiled flat cable like a clockspring to allow permanent electrical contact over the complete revolution range of the steering wheel.

However such coiled construction has an serious problem that the flat cable happens to be turned over during operation. This problem is extremely vital, since it may make air bag circuits open.

We discovered that the turning over phenomenon of the flat cable was happened by various different causes which could be classified into two groups; one is consisted of what caused obstructions to the flat cable movement and the other is consisted of what was caused by the normal movement of the flat cable itself. We have analized each of them, especially the latter causes, by intensive observation and theoretical calculation and found out counter measures which were put into practical designs.