Engineering:Clockspring

Short description: Car component

In order to make reliable electrical connections to the steering wheel mounted air bag and other electrical controls there is a device known as a 'clock spring'. Clocksprings generally consist of a flat multicore cable wound in a spiral shape similar to a clock spring, hence the name. The part gets its name as it resembles the spiral wound main spring of a clock however its function is to be a flexible electrical connector; not to be a spring to store energy. Note; for many years there was only the horn that required a single wire/conductor from the steering wheel to the stationary parts of the car. that connection was made either by allowing the wire to twist / untwist as the steering wheel turned or possibly a commutator and brush arrangement would be used. The advent of air bags necessitated very high reliability connections in addition to the horn, and once there was a clock spring device to make those connections to the rotating wheel it was easy to add various other electrical functions to the steering wheel including control of the radio, cruise control and gear shifting by paddle shifters. The coiled up 'spring' is contained in a plastic housing. When it fails, most likely all the electrical functions carried on the steering wheel will stop operating- That is the check a mechanic would use to identify the clock spring failure. In other words if the horn fails to work there could be many possible causes to investigate; but if at the same time the cruise control or other steering wheel mounted items do not work one can expect to find the clock spring is at fault.

In automotive systems

Steering column. The clockspring is the small black drum with yellow wires at the front end.

In vehicle steering systems a clock spring or clockspring is a spiral-wound special rotary electrical conductor 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.