http://www.freepatentsonline.com/20050263979.html

However, I find a type of brake used on low-grade city bikes or folding bikes that the principle of it is similar to the semi circular band brake used on A-bike.


This picture showing a loosened brake band

This picture showing a tightened brake band

I'm just curious that what is this type of brake called? Is it a kind of drum brake?
I can't find it on the "Bicycle brake system" page of Wikipedia at all.

http://en.wikipedia.org/wiki/Bicycle_brake_systems