Animation of the behavior of a ratchet. Before Starting, please turn up speaker volume. This ratchet operates on the principle that it is possible to drag the spring-loaded ratchet pawl over the gear teeth but it is impossible to push it over them. When engaged, the pawls are spring loaded to stay in contact with the gear. Direction of rotation of the gear is reversed by switching which pawl is disengaged. Of course, it is the gear that applies the torque to the object of interest. The learner can adjust the number of teeth of the gear. Since the pawl skips over only 3 teeth on each stroke and the gear tooth speacing remains constant, larger numbers of gear teeth result in reduced driving angle of the object (e.g. a bolt) being turned. The learner can also adjust the number of update frames per second to change the speed of the animation. And the handle length can be adjusted to alter the amount of force needed to apply a given torque.
Number of Gear Teeth
Handle Length
Frames Per Second
Counter-Clockwise Rotation
Clockwise Rotation
Single Step
This causes each press of the Start button to advance gear 1 by about 0.05 radians