An characteristic curve almost free of hysteresis is often required.
Although the working range for a spiral spring is in most cases limited to two revolutions, the coils do come into contact with each other after only a small angle of twist, so that the curve for spring extraction is no longer in line with the curve for retraction.
To compensate for this difference, a support is used. This support, which is in the outer hook area, can significantly reduce contact
between the coils when running. The spring support therefore has a positive influence on running behavior and thus on the service life of the spring.
A special design used in watchmaking is the sliding support, which makes it possible to shorten or lengthen the spiral spring by moving the support.
