Unable to duplicate a rig

Hi guys.

I may be incredibly stupid, but how do I duplicate the spring in the blend bellow? The spring is grouped, and if I add the spring group with shift+a, the duplicated follows the movement of the original. One way is to open another .blend file and append the spring group various times, but that’s a horrible way to do it.
If I use dupligroups the duplicates follow the original, and if I apply the dupligroups the parent-children hierarchy is destroyed, and the spring stops working. Please help me:(

PS: just to be clear, what I want is to get various springs, each one independent of the other.

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Bump. Please help!;_;

Bump, please read this;_;

Bump Please, no one even reads this thread;; Has it a ugly title? ;;