Scrool jaw ring for hydraulic soft jaws.

Hi,
I am trying to source a ring that is used for taking up the tension on a 3 jaw hydraulic jaw set up in the u.k.
It uses the holes in the soft jaws to locate itself after being sized by hand then chuck pressure apllied.
Similar items below
http://www.tradekey.com/product_view/id/82266.htm
Am reallly interestested in the Dorlan ring.
http://www.usshoptools.com/current_y...pdf/PGS_10.pdf
Any information would be welcomed.

Regards Phill

is this used to hold the jaws while they are machined? Is there a specific reason for using this tool rather than the old fashioned method detailed here followed by here

Yes these are used to machine the jaws prior to machining
With the hydraulic chuck it has a tendency to splay due to workholding pressure.
I have found that by turning a bung to the middle diameter of the jaw stroke and placing it at back of chuck then turning a counter bore in the front face of the jaws then removing
the first bung and placing the larger disc with a hole for clearance of the bored jaws diameter will
counteract the splayed jaws .This also loses some of the clamping area of the jaw to the workpiece.
Very labour intensive requiring some large rings for large diameters you can see why these tools would be a labour saving device.

Regards Phill

You could probably knock up one of those Dorian adjustable rings from a cheap chuck - i.e. bore out the middle of the chuck to the scroll bore diameter. Face off the access material from the front and back. Grind down the jaws and drill them for the jaw locking pins. :)

Interesting ptetty ingenious
Thanks for your ideas.