In open coiled helical springs, spring wire is coiled in such a way that there is a gap among the two successive turns, as a result of which helix angle is large. As application of open coiled helical springs are partial, Thus our discussion shall confine to closely coiled helical springs simply.
Helical springs have the following compensation:
(a) Their characteristics can be various by change dimensions.
(b) Their performance can be predict more precisely.
(c) These are reliable.
(d) These have stable spring rate.
(e) These are presented in wide range.
(f) These are simple to manufacture. 6. Disc or bellevile springs Disc or bellevile springs consist of a number of conical discs held jointly next to slip through a central bolt or tube. These springs are use in purpose where high spring rates and compact spring units are necessary. The main stresses formed in disc or bellevile springs are tensile and compressive stresses.