A clock spring is actually a flat torsion spring. Clock springs are produced by winding strip steel or strips. The name of this type of spring derives from its most well-known application, the clock.
De Spiraal produces different types of clock springs, from relatively small material (approximately 4 mm) until larger widths (e.g., 100 mm). Manufacturing these springs concerns custom made goods and are therefore only manufactured to customer specification.
Clock springs are like many other springs used for the storage of energy. Where linear springs as compression and tension springs are able to capture movements, torsion springs are, and as well the clock springs, able to capture a rotation or to even generate it (with loss of the limit). Several examples of applications in which clock springs are used are:
• Revolving doors
• MRI scanners
• Wind-up toys and music boxes
Just like other springs, clock springs can be manufactured from several materials. However, mostly Stainless Steel-spring steel (1.4310) is chosen. Often strip steel with rounded edges is chosen since this material is better resistant against fatigue as a consequence of a number of cycles (metal fatigue). It appears to happen that, as an after-treatment, the clock springs need to be greased. This is a treatment which can be carried out at ‘De Spiraal’.
There are 2 variants of clock springs. The first type is a spring whereby, when mounted properly, the coils do not touch each other. So the spring can be unwind without friction, causing that no stored energy is lost.
The coils of the second type are laying towards each other. This spring is also called the motor spring since the spring can mimic the effect of a small motor. Thereby, you could think of the ‘wind-up’ toy car. The amount of turns the spring can generate is dependent on the number of coils of the spring. The space available for the spring to be built in, is next to that important for the power the spring will generate. The opportunity to grease the spring is with this type of major importance for reducing the friction force of the movement of the coils over each other.