It was a powerful portable oil-press described by Heron of Alexandria which continues to be in extensive use in various forms until today.
It consisted of a powerful horizontal base inside of which two vertical worm gears were secured with wedges but could be turned freely with the help of hand levers. At their uppermost point, the screws penetrated special receptors (female screw type) inside a horizontal beam. With their rotation, the worm gears pushed a horizontal wooden plank which in turn pressed the olive pulp (which was inside a special holding ring system) so that it discharged the olive oil.