Finger pawls, working into ratchets at the ends of the roller, serve to rotate it after each line is printed. Edward W. Byrn.十九世纪发明进展.
Bolts or ratchets are inserted through the rail, and clamp the cushion to the wall of the rail. 佚名.神奇的知识之书.
So they attached levers, pulleys, ratchets and windlasses, until at last they reached the size of the great siege cross-bows, weighing eighteen pounds. 佚名.神奇的知识之书.