German engelhardt springs, engelhardt models, engelhardt prices

engelhardt 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; the inner side of the strip is curved so that each turn wraps tightly around the inner turn. When the metal strip is stretched (twisted), internal stress resists the load force, exactly like a standard extension spring, but the spring rate is nearly constant (zero). See the load/torsion diagram. In use, an ID is typically used to wind this spring tightly onto a drum, with its free end connected to the load.