| 摘要 |
The ratchet mechanism has a wheel with one or more notches in which a pawl, pressed against it, engages, to prevent rotation in one direction. The wheel (1) is equipped with means which, on rotation in this direction, move the pawl (2) away from the notches (11). The force acting on the pawl to press it against the wheel is insufficient to bring it into engagement with a notch when the rotational speed of the wheel exceeds a predetermined value. The wheel can have a ramp surface (a-b) against which the pawl bears, forcing the latter radially outwards before it reaches the notch. |
