These are definitely not lightning arresters. If they are, they're naked and missing their sleeves. Long lightning arresters are supposed to have insulating rings around the outside, and these are smooth. There are a few large ridge-less lightning arresters, but they look more complex and nothing like this.
They might be rollers, but then again, why would one of them have that odd bracket thing? That bracket could be some sort of crank coupling to move the roller back an forth, perhaps to eject the paper or other material. I don't know why they'd be glass either, maybe for cleaning or chemical resistance.