Found this at work

motorboy2011, Mar 7, 9:24am
Bugger if I know what it was off, Mechanical box of magic: http://youtu.be/U53cZumCNMA
intrade, Mar 7, 9:27am
lol no its a geduction gerabox. i sold one of these with a motor attached to a guy on here who wanted to make a constant rim welder.
NZTools, Mar 7, 9:55am
Look closer Intrade. The toothed pulley only turns in one direction. Clever use of a couple of sprag clutches.
jason_247, Mar 7, 10:16am
same workings as the dual drive screwdriver from supercheap.
kazz67, Mar 7, 5:12pm
From memory the can vary from 0-400 rpm with no interruption.
Amazing little transmission. The single lever moves a camshaft inside and enables the fingers inside to grab more of the output shaftusing sprag clutches on the fingers.
The fingers are only pressed steel and the unit is only rated for 1/3 hp from memory. Tehy are availabe from McMaster Carr in the USA, from their catalogue.
Without taking it apart I couldn't figure out how such a compact unit could work.
mrfxit, Mar 7, 5:38pm
Yep correct, they are a form of variable speed single direction reduction drive, (adjustable speed )

This model is marketed under the "Zero-Max" brand
http://www.zero-max.com/adjustable-speed-drives-c-21-l-en.html

Had 1 here a couple of years ago.
motorboy2011, Mar 7, 6:27pm
This one had Chinese stickers on it, though they looked old so maybe made when China had a little pride in quality
tintop, Mar 7, 6:34pm
ratzos, Mar 7, 9:07pm
I found penthouse last week in the workshop ???
tintop, Mar 7, 9:27pm
You had forgotten you had hidden it ?
motorboy2011, Apr 11, 6:12pm
Pulled it apart. It has 0 gears inside. The input shaft has a cam on the shaft inside, with about 6 lobes. Each lobe has an arm running on it, in a slightly different position. All these arms then push the output shaft a bit (a 6th of a turn I guess). This output shaft has some sort of arrangement on it so each arm only pushes the shaft and can then pull back without puling the output shaft back against whatever arm is then pushing it. The leaver on the side moves the pivot point of the arms, changing how much the arm pushes the output shaft, which in turn enables the speed of the output shaft to be altered. Be good with a clear cover on the side and filled up with some clean clear oil.
lookoutas, Apr 11, 7:58pm
I've got a ratchet that works like that. After cracking a bolt/nut, just twist the handle in either direction, and the socket drive turns in accordance to the selected rotation.
brapbrap8, Apr 11, 8:57pm
A lot of seed drills use the same system for varying the rate of seed dispensed. Driven off a wheel on the ground then it allows exactly the rate you need to set it for.
motorboy2011, Apr 12, 9:37am
Mechanical box of magic solved: https://youtu.be/g9JSM6CMd0Q
johotech, Apr 12, 9:58am
Nice vid. But let us know when you have figured out how this bit works.

Otherwise, not "solved" at all!
motorboy2011, Apr 12, 10:01am
4 arms with a variable pivot point and 4 one way clutches on the output shaft. Solved :)
purple666, Apr 12, 10:18am
A very clever bit of kit, infinitely variable drive was always the holy grail.
grangies, Apr 12, 12:00pm
I think you'll find the writing is Korean or Japanese.
grangies, Apr 12, 12:00pm
aj.2., Apr 12, 1:25pm
Sounds to me to be a ( CVT ) gearbox, it is variable speed, the input speed stays the same , but out put can vary, Do not adjust if it if not turning, as this loads it up too much.
I have used this type of gearbox, on a Lapping machine, where the warping head is needed to speed up ,or slow down due to different width of paper used to warp around cardboard tubes to form a long spiral tube.
johotech, Apr 12, 1:36pm
No, Chinese.
motorboy2011, Apr 12, 1:41pm
nah it can be adjusted when stopped, I know the cvt type talk of, we also have them on machines, they have warnings on not adjusting while stopped. They work completely differently to this type of cvt
aj.2., Mar 18, 10:07am
motorboy2011, Yes I just saw your vid post at #16.
Have read #24 post.