Constant force springs
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 - 1,0 mm
- 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:
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.
- Spring width: 1,5 - 10,00 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 - 1,0 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:
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