On Thu, 11 Aug 2011 14:41:06 -0700 (PDT), wrote:



Look up "volute spring", have been around for hundreds of years. Kind
of a specialty item these days with coiled wire springs readily
available, but were used in a lot of places like in British railway
car buffers.. Probably was easier to roll up a sheet of steel than to
hammer or roll out round bar stock and coil it up.

Stan


Volute springs can be wound so there's tight contact between the
turns. The resulting friction is what makes them better dampers than
coil springs. "Friction springs" are an interesting alternative to
volute springs, or hydraulic shocks, and also use friction to absorb
kinetic energy.
http://www.ringfeder.com/en/america/...NGFEDER/?p=742

--
Ned Simmons