How does a 1/4 elliptical rear suspension work?

[SuperEx91]

Before anybody bites my head off, i ran numerous searches and came up with nothing useful or explanatory.
I am always reading about people doing this on their rig but never explaining how it works. Can anybody explain it and maybe post some pictures as well. how bout advantages/disadvantages. Thanks-Tom

 

[IZwack]

A quarter elliptical, in principle, is just a normal leaf spring cut in half (or close to the half-way point) and flipped upside down. I don't have any experience with quarter ellipticals personally but IMO, their design is the cheapest approach to having a suspension that flexes very well depending of course on the spring rate of the leaves themselves -- but is also typically a few pennies cheaper than running coils. The axle is still typically "located" using links but the mechanism to suspend the axle is merely a leaf spring cut in half. If the suspension design is a triangulated 3-link (or a so called upper "wishbone" type), or a triangulated 4-link - in other words if no panhard use, then the suspension allows the axle to be located way beyond the end of the frame rails. There are/were a few rigs on Priate4x4 that use the quarter elliptical suspension -- the one that comes to mind the most is the "Wolf" rig owned by Bill Vista -- altho that rig now runs Fox Air-Shocks. Quarter ellipticals are slowly fading as its design is rather "crude" and most serious trail rigs have moved on to either coil springs or air-shocks just because its often easier to tune coil-overs/air-shocks than a leaf pack.

This image shows the flipped leaf-spring on this rig - although you can't really see how its mounted on both ends:

These two images show a better shot of how a 1/4 is mounted:

 

[BrooklynBay]

http://www.carbibles.com/suspension_bible.html