[GeeTwo]

My guess would have been that it's a translator for a limit switch, but that's just me taking a Rorschach test (my current project is a translator for a limit switch).

OK, by shaft do you mean that it rotates? The clue that the square is necessary implies that it engages with something that you're getting off the shelf, or perhaps off the field. I don't see how this would engage with litter or a tote, so I'm going to guess that it's something to engage the lip of a recycle container and tilt it for easier human player loading of litter.