When the load to be weighed comes upon the platform, the end of the steelyard rises and unlocks the ratchet wheel through the pawl; the sprocket gearing is driven by the friction clutch, and drives the axle of the left-hand small pulley.
The currents actuate a ratchet-wheel mechanism at the receiving station, whereby the hand on a small dial is moved on letter by letter.
Intermittent LinkworkClick and Ratchet.A click acting opon a ratchet-wheel or rack, which it pushes or pulls through a certain arc at each forward stroke and leaves at rest at each backward stroke, is an example of intermittent linkwork.
A catch or pall, turning on a fixed axis, prevents the ratchet-wheel or rack from reversing its motion.
The brushes are carried by sleeves which run loosely on the shaft, and to each sleeve is rigidly fixed a ratchet wheel.
