Power springs

The traditional form of the strip spring is the power spring. It was used in the early days for energy storage in pocket watches. With the energy it stores, it can power a drive or shaft – hence the name.


  1. Spring width: 1.8 - 100 mm
  2. Spring thickness: 0.05 - 3.0 mm
  3. Material: Martensitic textured carbon steels and stainless steels
  4. Service life: Up to 500,000 load cycles 
  5. Low hysteresis
  6. Flat characteristic curve in the working range


Power springs for locking systems


A MAXIMO power spring is an assembly made up of a stamped part, turned parts and a safety key.

This unit is part of an actuator for ventilation flaps. The spring return secures the emergency control function.

Textured rolled special steel PRIMAFLEX

Door closer

The spring is supplied with a retaining strip. This is not removed during assembly. It remains in the assembly.

The springs are installed in retraction systems for the automatic closing of swing doors, where a long service life is important.

Textured rolled special steel PRIMAFLEX

Power springs for return systems

Seat belt

The MAXIMO power spring is wound into a plastic housing. Other components such as axis or cover can also be installed.

The spring is used to extend and retract the seat belt strap and keeps it taut while the passenger is wearing the belt.

Textured rolled special steel PRIMAFLEX


Vacuum cleaner (cable retractor)

The MAXIMO power spring is wound into a metal or plastic housing.

Vaccuum cleaner cables can be wound up with a power spring or constant force spring. The MAXIMO power spring has a particularly long service life.

Textured rolled special steel PRIMAFLEX

Dog leash

The MAXIMO power spring is wound into a plastic coil. The coil rotates around a fixed axis to wind in the leash.

The spring mechanism keeps the leash slightly tensioned. The brake button can be used to let the dog run or reel him back in.

Textured rolled special steel PRIMAFLEX


Hose retractor

A power spring for a retractor system has a high number of working revolutions at a low material weight.

It supports the retraction of hoses mainly in industrial applications.

Textured rolled special steel PRIMAFLEX

Power springs for compensation systems

Balancer (weight compensation)

The spring is installed in a conical roller. With its reduced lever arm and rising characteristic curve, the return force of the assembly is constant.

The component supports weight balancing when working with loads.

Textured rolled special steel PRIMAFLEX

Electrified railway catenary

The spring is part of an assembly consisting of several power springs. The system has very high tensile forces and is patented.

The retractor system is used for temperature-related expansion compensation of overhead contact lines on electrified railway lines.

Textured rolled special steel PRIMAFLEX

Power springs in starter systems


The power spring is optimized for its weight and wound into a small plastic housing.

These components are used in starting systems for small motor devices and vehicles.

Textured rolled special steel PRIMAFLEX

Power springs for mechanical drive systems

Mechanical clockwork

These high-precision power springs are the reliable energy storage system in hand-wound or automatic calibers.

When watches are wound, the spring is tensioned. When it relaxes, it releases energy and powers the timepiece.

Nivaflex 45/5

Wind-up toy

The power spring here functions as a spring motor that drives a toy car.

Spring motors use the tension in an extended spring as a driving force. They do not require an external power supply.

Textured rolled special steel PRIMAFLEX

Online inquiry

Power springs tailored directly to your requirements - it’s easy to inquire online.

Guaranteed good advice

You can reach Mrs Sibel Zoroglu, your contact
for the area of power springs, at:

+49 (0) 7422 . 511 - 668


Hugo Kern und Liebers GmbH & Co. KG
Platinen- und Federnfabrik
Dr.-Kurt-Steim-Straße 35
78713 Schramberg - Germany