Strip springs

Two out of three cars produced worldwide are fitted with parts produced in KERN-LIEBERS group. Over 90% of the cars produced in India are fitted with our parts.

Constant force springs

Constant force springs are used in many industries as a resetting element that provides a uniform force.

Constant force springs are characterized by a very uniform force-displacement curve. This curve can be adjusted within defined limits to the specific application. The machinery for production is developed and manufactured internally by KERN-LIEBERS.

  • Spring width: 1.8 - 100 mm
  • Spring thickness: 0.05 – 1.00mm
  • Material: Textured carbon and stainless steels
  • Service life: Up to 50,000 load cycles
    (typical applications require 5,000 – 20,000 cycles)
  • Minimum hysteresis.

Typical applications of constant force springs for tension and compression forces include:

  • Window Balance Systems
  • Spring balance systems

We manufacture these springs with cut and deburred edges or rounded edges.
Multiple constant force springs are used in a range of different applications: as pressure springs for carbon brushes in electric motors, as safety switches for low-voltage applications, and as respirator valves for patients in hospitals. They provide indispensable services in many areas. The springs are available in natural temper colors (yellow, brown) and as bare metal hardened in protective glass.

  • Spring width: 1.5 – 10.0 mm
  • Spring thickness: 0.03 – 0.15 mm
  • Material: Stainless "Superflex®" spring steel strip

Constant force springs in a biaxial arrangement – work roll and storage roll – are used as a generator of constant torque. In retractors, the special torque characteristics assure uniformity across many winding rotations.

Cable retractors for electrical appliances and constant force spring drives also take advantage of the fact that the characteristic curve of the spring can be adjusted to the specific needs of an application. This can be defined as:
  
POGRA – rising (POsitive GRAdient)
MIGRA – flat (MInimum GRAdient)
NEGRA – falling (NEgative GRAdient)

  • Spring width: 1.8 - 50 mm
  • Spring thickness: 0.05 – 1.00 mm
  • Material: Textured carbon and stainless steels
  • Service life: Up to 50,000 load cycles
    (typical applications require 5,000 – 15,000 cycles)
  • Up to 100 working rotations
  • Small to medium torque range, minimum hysteresis, biaxial system with work roll and storage roll

Typical applications of constant force springs as a torque generator include:

  • Cable retractors

Telescopic springs are used as protective covers against dirt,
shavings or oils on shafts or spindles in machines.

  • Telescoping lengths of up to 4 m
  • Spring width: 5 – 120 mm
  • Spring thickness: 0.20 – 0.80 mm
  • Material: Stainless spring steel and C70S

Contact

Product group: Constant force springs

Phone: +91 816 2213130
E-Mail: kl-india@kern-liebers.com

Industry applications

Automotive

Mechanical engineering and equipment manufacturing