Model: C09 Endless Screw or Worm Drive Mechanism
Willis (1841) credits Pappus of Alexandria (3rd century AD) a Greek mathematician, for an early version of the endless screw. In this model, the rotation of the horizontal screw turns a gear about an axis perpendicular to the screw axis. This mechanism was also used by Leonardo da Vinci as a component in many of his designs for machines.

Francis Moon 2001-00-00