Possible Clues:

• Bar to fit the notches of a toothed wheel
• Idle chatter has teeth on edge
• Deserter had revolutionary square toothed bar
• Sprocket
• Increase in increments, with 'up'
• Device allowing only one-way motion
• Device consisting a toothed wheel and pawl that allows movement in one direction only
• The cart's wrecked — there's no going back for it
• Increase gradually, with ''up''
• Device preventing backward motion