This is something that would be easy to graph with a parametric equation. You can find a parametric equation plotter I made for illustrator here:
I quickly tested with following parameters:
X: 2.2*(t+3*PI) * sin(t) + 300
Y: 1*(t+3*PI)* cos(t) - 200 + 6/4*PI*t
Step: PI/8 (or PI/4)
Image 1: Graphing of a suitable parametric equation yields.
You may want to adjust the numeric values of the equation a bit to suit your needs. This is quickly done after all.
For finishing touches. Use the cut tool to cut the shape up and delete segments at overlapping joins.
Image 2: After twaking a bit more Result after making raise a bit bigger (the term 6/4*PI*t).