1. 
   ratchet wheel
   [n] - toothed wheel held in place by a pawl or detent and turned by a lever
   Found op http://www.webdictionary.co.uk/definition.php?query=ratchet%20wheel
   
   
2. 
   ratchet wheel
   noun toothed wheel held in place by a pawl or detent and turned by a lever
   Found op http://wordnetweb.princeton.edu/perl/webwn?s=ratchet%20wheel
   
   
3. 
   Ratchet-Wheel
   A ratchet-wheel is a circular wheel having angular teeth , into which it may be moved forward, as by lever and catch into which a pawl may drop to prevent the wheel from running back.
   Found op http://www.probertencyclopaedia.com/browse/GR.HTM
   
   

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