Rack-pinion jack 1

Turn pink crank clockwise to move blue rack up.
Pink ratchet wheel and yellow pawl prevent the rack from falling down.
Push the pawl to bring it out of contact with the ratchet wheel and let the rack move down slowly by holding the crank.
Inventor files of this video:
http://www.mediafire.com/file/nfs81gz888f2e7f/RackPinionJackInv.zip

Видео Rack-pinion jack 1 канала thang010146