How do I create a toroidal bend?

In the "Toroidal Bend" feature the prompt asks for 2 parallel planes that define the length of the bend. The planes must be parrallel to the sketcher plane. I've tried several different plane creations and can not get the toroidal bend to perform. What are these 2 planes defining?

I've never done a toroidal bend (deliberately, anyhow). But I can offer this from the Rev20 Part Modeling User's Guide - the world's most valuable piece of Pro/E documentation. (Anyone who has extras, send them to me - I will pay the postage + ?)

Step 10. Pick two parallel planes to pull toward each other and define the radius of the bend. These parallel planes only define the radius of the toroid; all geometry will be bent, regardless of the plane location. The section that you sketch in Step 7 will be visible while you do this. For a 360 degree bend, these planes meet, In the bend used to create the tire in the illustrations, the plane at each end of the solide feature was chosen.

Also,

PTC Knowledge Base:
Example: Creating a Toroidal Bend?