Applications for power springs

· Tobacco shelf pusher

· seatbelt retractors

· tape measures

· retractable dog leads

· electrical cord retractors

· hose reels

· wind-up toys

· pull start on small gas-powered engines

· tool balancers

· valves

Power Springs

Power springs are identified by the many coils of strip material stored in a case, barrel, or band, and connected to a central arbor or shaft. When this shaft is rotated, the material starts to wind flat against it. This action creates an increasing torque for as many turns as it can be wound until there is no material left.

Pre-pressed or conventional power springs

Our capabilities of power springs range from 0.002 inch to 0.125 inch material thickness and from 0.030 inch to 3 inch material widths. Power springs can be made using pre-stressed (back wound) or conventional (from flat) methods. Pre-stressed power springs are spooled to a special free diameter and back wound into a housing or keeper, while conventional wound springs are manufactured and wound in the flat state. The advantages of pre-stressed springs are that it allows maximized torque from a specific material. Conventional wound power springs, however, offer increased cycle life.

Constant force spring

The constant force spring consists of strip material, which has been shaped and pre-tensioned into a tightly wound roll. The spring is used in a linear movement and produces almost constant force throughout its deflection. Constant force springs can be fitted in a number of ways and extended partly or completely. There is practically no limit on extension speed and acceleration.

Helical torsion springs in a wide range of variations

Torsion springs can either have a left-hand or right-hand helix. They are made to give a force and torque when one leg is turned relative the other.

Our helical torsion springs are made in dimensions from 0.03- 26 millimeter and we select wire diameter, spring body diameter, length and pitch to suit your requirements.

For closed coiled helical torsion springs there will be a friction between the coils giving a hysteresis in the torque-angle performance.
There are generally two common types, single and double coil torsion springs. Normally is the coil controlled inside with a mandrel but also an outer control with a cylindrical housing is possible. With fixed assembled legs the spring type can work without a coil body control. Tangential legs give the lowest stresses but also radial and axial legs of different types are possible. In many cases the strain in the legs must be considered in the design.