RATCHET (WHEEL)
Toothed wheel prevented from moving by a click pressed down by a spring.

RATING CERTIFICATES

Chronometer and COSC.

REGULATING UNIT
Made up by balance spring, governing the division of time within the mechanical movement, assuring its regular running and abburacy. As the balance works like a pendulum, the balance sprin's function consists of its elastic return and starting of a new oscillation. This combined action determines the frequency, i.e. the number of vibrations per hour, and affects the rotation speed of the different wheels. In fact the balance, by its oscilliations, at every vibration (through the action of the pallets), frees a tooth of the escape wheel ( Escapement). From this, motion is transmitted to the fourth wheel, which makes a revolution in one minute, to the third and then the center wheel, the latter making a full rotation in one hour. However, everything is determined by the correct time interval of the oscillations of the balance.

REGULATOR
A timepiece sufficiently accurate to be used as a benchmark from which to test others. Regulates the functioning of a movement by lengthening and shortening the active section of the balance spring. It is positioned on the balance-bridge and encompasses the balance spring with its two pins near its fixing point on the bridge itself. By shifting the index, the pins also are moved and, by consequence, the portion of the balance spring capable of bringing the baalance back is lengthened or shortened by synchronozing with it, and is thus ready for another recording. Pressure on the split pusher releases the split-second hand, which instantly joins the chronograph hand if the split-second hand happens to be blocked.

RETROGRADE DISPLAY
A retrograde display shows the time linearly instead of circularly. The hand continues along an arc until it reaches the end of its scale, at which precise moment it jumps back to the beginning instantaneously.

ROTOR
The rotor is the component that keeps an automatic watch wound. The kinetic motion of this part, which contains a heavy metal weight around its outer edge, winds the mainspring. It can either wind unilaterally or bilaterally (to one or both sides) depending on the caliber.