Hello Jerry,

A normal screen door spring is a "zero lenght spring" it is made be twisting the wire as the spring is wound.  The screen door spring would be shorter if it's own coils didn't get in the way.

Zero lenght = constant force = Its force is proportional to its entire length, not just the stretched length, and its force is therefore constant over the range of flexures in which the spring is elastic

Angel



Wednesday, August 1, 2007, 1:28:49 PM, you wrote:

> Gentlemen:
>  
> With ALL due respect for each of you, I sincerely appreciate the
> replies that I received from each of you regarding the Zero Length Spring question.  I really do!
>  
> HOWEVER, I thought this was an AMATEUR seismology discussion net,
> not a scientific symposium.  I depend upon the threads on this net to learn, at least try.
>  
> Am I to repeat your answers to a minimum wage clerk at the local
> hardware store that might not even speak English?  It's like asking
> what time is it and being told how a watch works.  I feel like the
> guy in the Caveman Commercial on TV............HUH?
>  
> Respectfully,
> Jerry
>  
>  
>  



-- 
Best regards,
 Angel

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