I have an idea for an invention that focuses on a spring that supports weight. Is there a way to manually make a spring vary how much weight it supports? Or is there maybe something else other than a spring that could do the same thing I need the spring to do, but could vary how much weight it supports? I thought about having a lever hooked up to the bottom end of the spring (the actual metal tip end) that pulls it apart, causing it to sort of unravel a little bit. Does that cause springs to lose compression strength? Thank you.