The springs are classified as :
- Closely coiled spring
- Open coiled spring
Difference between them are as following below :
- A helical spring is said to be closely coiled when the spring wire is coiled so close in open coiled spring wire is coiled in such a way, that there is large gap between adjacent coil.
- In closely coiled spring helix angle is very small usually less than 10 degree while in open coiled spring helix angle is large about to more than 10 degree.
- Closely coiled spring is also known as tension or extension spring while open coiled spring is known as compression spring.
- In open coiled spring both torsional and bending stresses are significant because of large helix angle while in closely coiled spring only torsional stresses are predominant.
Applications of closely coiled spring :
- Garage door assemblies
- Vise-grip pilers
- Carburetors
Applications of open coiled spring :
- Ball point pens
- Pogo sticks
- Valve assemblies in engines