Abstract: A speed responsive coupling device for locking a first member with respect to a second against relative rotation in at least one direction, which device comprises a ratchet wheel carried by said first member which is engageable by a pawl carried by the second member, and in which the pawl is arranged as a mechanical toggle switch which is biased to flip between a “free” condition in which such relative rotation is permitted and a “lock” condition in which the pawl engages the ratchet wheel to disallow such relative rotation, said pawl being linked to a rocker which is so shaped and disposed that when the pawl is in the free condition, such relative rotation causes the rocker to rock and that when the speed of such relative rotation exceeds a threshold value, the strength of the rocking motion imparted causes the rocker to flip the pawl to the lock condition.

Abstract: A speed-sensitive clutch device incorporates at least one drive-transmitting coupling element (17) which is connected to a safety line drum (1) so that it bodily rotates with the drum (1) about its axis of rotation and is displaceable from an inactive position (FIG. 1) into a drive-transmitting position (FIG. 2) in which it transmits drive. And the speed-sensitive clutch device also incorporates an inertia member (20) which is freely rotatable about the axis of drum rotation and yet is free to move in rotation relative to the drum itself. The inertia member (20) is formed and disposed so that on rapid acceleration of the drum (1) it exerts pressure, due to its inertia, against a said coupling element (17) thereby to cause or assist movement of the coupling element from its inactive position into its drive-transmitting position.