Spring Info Required

Build it and see if it works...
Isn't that the whole point of a project?
Del

Here its shown that both part moves along circular arc.

But if possible 1 rod/link should move w.r.t other.

1-4 in Box shows steps of motion. Rod/Links are in Red N Green, Spring is Black in between.

Is there a practical application?

An ordinary helical spring will do the job, but if you want only 1 rod to move, then you must find some way to secure the stationary rod so that it won't move.

@DVader1000

Plss if you can elaborate little more?

What no of operation cycles can I expect by using said Spring?

Exactly what I mean, secure one rod so that it cannot move but leave the other free swinging. A torsion spring may be better since I'm no mechanical engineer.

As for how many operation cycles you can expect, honestly I don't know. That will depend on how strong the spring is, how fast the mechanism can be opened etc. What are you trying to construct anyway, a spring-loaded door closer or something? Your sketch only shows how your device is supposed to work, not what it's supposed to do or how it's supposed to be operated.

You may need a torsion spring at the pivot point, since a normal helical tension spring would go "over toggle" at 180° (somewhere between pos 3 and 4, and the two links/rods would close shut. Good luck in your project.

Please post a sketch here. Right now your description is so vague nobody can visualize just what it is you're actually trying to do, let alone answer your question.

Isn't this an assignment you should do on your own? I doubt your instructor wanted you to post your task to the Internet and submit someone else's solution.

You only need to open your eyes and look around you.
I would guess that within your home and office there are dozens of such arrangements successfully using using springs.
I sometimes think that a huge number of people have forgotten how to look and observe in a critcal manner.
The common mousetrap spings to mind... (did you see what I did there?)
Del

Del,

I'm not sure I saw what you did there. Silly me! Or should I say simile?

Silly me...simile.
Nice one made me smiley, I shall steal borrow that for use at some later date.
Del

Thanks you for the post.