German grueber springs, grueber models, grueber prices

grueber spring is a special type of extension spring suitable for applications with large elongation and non-increasing load. Constant-force springs consist of spiral metal strips with inwardly curved inner sides, so that each turn wraps tightly around the inner turn. When the metal strip is stretched (twisted), internal stress resists the load force, just like in ordinary extension springs, but the spring rate remains nearly constant (zero). See the load/torque diagram. In use, an ID is typically used to wind this spring tightly onto a drum, with its free end connected to the load.