What is this for?

[SteveM]

Picked up a bunch of Pratt & Whitney mill parts.

It came with this bracket that appears to attach to the overarm.

It can clamp going up or to either side and the arm on the top in the picture can rotate 360 degrees and lock.

The washer on it is dished, but I don't think it's a bellville spring.

Any ideas?

Steve

[jcfx]

A first glance it looked like a old pistol.

I don't have any scale reference to the part you posted, looks a lot like the one in this picture from Vintage machinery.org.
http://vintagemachinery.org/photoindex/ ... x?id=16151

Nevermind, you were referring to the attached part...

[spro]

They had all kinds of attachments on the older horizontal mills. There were thin belts coming from somewhere driving grinding arbors or fixtures to hold them.

[johnfreese]

The bracket on the overarm probably held the pipe for coolant or cutting oil.

[SteveM]

The bracket on the overarm probably held the pipe for coolant or cutting oil.

That seem plausible.

Steve