Hi;
I bet you don't ! The term has been applied for many years, Well, actually centuries, to a piece of equipment used in maritime, construction and cargo handling applications. They were originally just called sheaves. What do they do? Well If you have a Come-Along, you have a form of one.
Now the rollers or wheels are the rolling part of the description. You will find them in many applications in life from heavy lift cranes to sail handling equipment etc. I have them now nearing a hundred for many sized scale Ship applications, Armor too!
Even a modern Tow Truck model with a boom has to have them. Otherwise if you blew it up to full size the friction of the cable over a fixed point would eat a groove in the sliding surface and the cable would be compromised by heavy wear to the point of failing.
Hence a wheel! Isn't that invention a wonderful thing? The Wheel? hmmmm; Now building them in small sized units can be a pain. Definitely DON'T try to do them out of Paper of any kind. The moisture in the glue will turn them into Paper Modeling Putty!
I use my Trusty Micro-Mark Punch set to make them. I punch maybe a hundred center discs, then the two hundred outer larger discs. Stick them in little jars labled roller Sheaves ( Small) and Large. The large is the outside parts. Glue an outside part to a inside one making sure the inside one is centered.Then add the other side, again making sure of centering. Let dry, and install on the crane or boom end that you need it for. Paint it and you're good to go.
P.S. if you are a glutton for punishment you can try to drill a hole in the center so you can let it rotate on a pin or piece of wire. Nah! I ain't doin that in 1/400 or smaller scale, Whattya think, I am nuts?