how the an oil-dripping cup for trains change the world?

Answer 1

I believe you are referring to the auto-oilier or similar device.
I'll give you a little help with your homework.
Before things like auto-oilier's or auto-greaser's, something like a train, or any needed to be lubricated device.
The operator or user would have to stop and perform the operation manually.
On a fifty car passenger train with two axle's per car, and 3 minutes per axle to do the lubrication.
Every 500 mile's.
Do the math.

Answer 2

the fellow responsible for this wonderfull invention had the last name of McCoy , there were inferior copy's of this device , leading to the saying , " the real McCoy " , by the way he was an African American , something that was not made well known during his lifetime.