The Figure shows the automatic opening and closing of the grip. To couple up, the workman pushed the carriage in the direction of the arrow when the coupling lever a engaged with an inclined plane b; this lifted the lever into an upright position when the lower end c of the lever engaged with the tripper d which forced the coupling lever right over through an arc of 90° from its initial position, and secured the clamp to the rope. The uncoupling, which is shown in the same illustration, is a reversal of the action, as
may be seen in the various positions in dotted lines.