How does a Studio Stand lift up and down?

[kepano]

Hi,

I'm curious about how the wheels on studio stands are retracted:

http://www.bhphotovideo.com/images/images345x345/145489.jpg

Under this cast iron base are caster wheels which can be raised or lowered to secure the unit or move it around. A simple press on the foot pedal allows this action to happen.

How does this work?

Better pictures here:

https://www.image2output.com/user_resources/TextFiles/pdfs/FOBA_studio_camera_stands.pdf

[Danger]

Welcome to PF, Kepano.
Since the mechanism isn't shown, and there is very little in the way of external detail, I would surmise that it's a simple ratchet jack. That could very well be wrong, but it's the best guess that I can come up based upon the photos.