Metron instrument variable drive

[Simon0362]

Hi All,

I have in my possession a variable speed drive manufactured by Metron instruments from Denver Colorado which adjusts the speed of the output shaft relative to the input by a variable adjustable ratio - from 0.1 to 2. The output turns in the opposite direction to the input.

The unit was given to me a number of years ago and I suspect dates from the 1970s. It is in anodised aluminium and is beautifully made. When it was given to me, I was told that it only worked 'a bit' and that it had been opened up to determine why it didn't work. My suspicion is that the very opening was the cause...



I have recently tried to see if I can make it work (again?) and have dismantled it to the limit of my capabilities and I fail to understand exactly how it works and, more importantly, how it can be returned to a functioning state.

In operation it appears to use 2 disks with a pair of wheels between them passing transmission. The variable part is obtained by adjusting the diameter at which the intermediate wheels operate (I think).



Final transmission is through a sun and planet drive.



Questions:

Is anyone familiar with this unit (verrrrrrrrrrrrrrrrrrry long shot!)

Has anyone any idea about how to setup or adjust such a unit?





Simon

 

[TroyO]

I'm not familiar with it but I've always been fascinated by constantly variable ratio drives. they are just neat, LOL.

If you can find a patent number on it somewhere maybe you can look the patent up to learn the theory of operation?

Also, I live in Denver, and I'd be willing to go knock on doors for you. Or make some calls if it's long distance for you.

 

[BillC]

That drive sounds like the vari-drive that Arens Lawn mowers used and also some railroad maintenance vehicles. The RR vehicle had a two cylinder engine that turned a large flat flywheel, and it was used as the variable speed disc. The driven wheel was adjusted across the face of the flywheel - neutral in the center and forward or reverse to each side of center, then faster toward the outside.... Arens went out of business....

BillC

 

[RICHARDDV]

THIS DRIVE SOUNDS LIKE THE ONE USED ON THE OLD SNAPPER LAWNMOWERS. THE DRIVE DISC IS RUBBER FACED AND TURNED BY THE POWER INPUT .THIS DISC CONTACTS A FLAT DISC CONNECTED TO A REDUCTION GEAR FINAL. THE DRIVE DISC OBTAINS SPEED CHANGE BY MOVING FROM THE CENTER TO THE OUTER EDGE OF THE DRIVEN DISC. NEUTRAL IS AT THE CENTER OF THE DRIVE DISC WHICH HAS A SMALL CONCAVE SPACE AT THE CENTER WHICH CAUSES THE TWO DISCS TO LOOSE CONTACT AND STOP DRIVING. FIND A REPAIR MANUAL FOR AN OLD SNAPPER RIDER LAWN MOWER OR TRACTOR AND LOOK.
ITS AN OLD DRIVE METHOD THAT ALSO WAS USED WAY BACK IN THE EARLY 1900 S TO DRIVE SOME OF THE OLD FARM TRACTORS OF THAT ERA. THEY CALLED IT FRICTION DRIVE TRANSMISSION. THEY CHANGED THE SPEED BY MOVING THE WHOLE ENGINE ---RICHARD

 

[Simon0362]

Thanks for all of the comments. Just to give everyone an idea of scale I have taken these shots - since we are in the process of moving house this is probably not the ideal time to be doing this......!

The paper is 5mm square and the rule is my Grandad's wooden folding rule marked in inches.

Simon

DSC07238 small by simon0362, on Flickr


DSC07231 small by simon0362, on Flickr


DSC07233 small by simon0362, on Flickr


DSC07232 small by simon0362, on Flickr