A clock spring or clockspring is a spiral-wound torsion spring used to mediate a spring force between two or more coaxial shafts. The number of revolutions in the spiral geometry is positively correlated to the spring rate. This makes the clockspring a suitable choice when selecting a spring system where a low spring rate is desired between two relatively rotating shafts.
In Automotive Systems
In vehicle steering systems a clockspring is a special rotary electrical connector which allows a vehicle's steering wheel to turn while still making an electrical connection between the steering wheel airbag and/or the vehicle's horn and other devices and the vehicle's electrical systems. The clockspring is located between the steering wheel and the steering column.
Clocksprings generally consist of a flat multicore cable wound in a spiral shape similar to a clock spring, hence the name, but the name is also given to devices fulfilling the same purpose but which use spring-loaded brushes contacting concentric slip rings.