How did McCoy's first steam lubricator work?

Factual Questions
1

I’m helping my son do a report on Elijah McCoy, and while there’s tons of information on his life and the fact that he made improvements to steam engine lubricators, created the first automatic steam oiler and/or “invented the oil cup” :dubious:, I have yet to find a functional description of how any of his lubricators worked.

Here is his first patent. Obviously, rising steam pressure works on the lower disk d, causing the rod to move up and down, but I don’t see any means for positive displacement for the oil. It appears that the oiler works more by creating a high pressure oil rich atmosphere inside the cup–mist transfers to the tube D when steam is cycled off, condenses on the tube walls and/or transfers to the steam passage as the disk d moves up and down.

Am I missing something here? This seems like a pretty haphazard way to meter oil. Was the volume required small enough that a splash system did the trick?

2

I am not sure of the picture, so I am not sure how it works. But here is what it looks like to me.

The cup is filled with oil. When steam is applied sone steam will rise into the cup and pressurize the cup. with the cup and the steam line at equal pressure the oil will run down the tube. The steam in the cup condenses. The water will drop to the bottom raising the oil level. The thumb screw set the rate of oiling. When the cup is empty of oil. shut oiler off, drain water and refill with oil.

I am getting this from a poor drawing so I may have missed something.

3

Thanks. I think that you’re right; the oil level is maintained at or slightly above the level of the valve.