Worm drive
Appearance
A worm drive is a special gear arrangement. A worm (which looks like a screw) matches up with a gearwheel. Technically, the worm transmits the motion to the gearwheel. A transmission of the motion the other way is not feasible. The design is very old. Either Archytas (5th century BC), Apollonius of Perga (3rd cenrury BC) or Archimedes (3rd century BC) invented it.[1] The worm drive later appeared in the Indian subcontinent, for use in roller cotton gins, during the Delhi Sultanate in the thirteenth or fourteenth centuries.[2]