AUTOMATIC WATCH
A watch whose movement is fitted with a rotor which automatically winds the spring through the movement of the wrist
BRIDGES AND PLATE
The plate supports the various parts of the movement and the bridges. The latter are metallic pieces wich support one of the two pivots of the moving parts of a watch: the second pivot is supported by the plate. In fine mechanical watches, the bridge and plate are often engraved, gilded and polished: in skeleton watches, they are pierced as well
CHAMFERING
Bevelling the edges of bridges, screws
CHRONOMETER
An extremely accurate watch, with or without a chronograph mechanism, which has obtained an official chronometer certificate
CHRONOMETER CERTIFICATE
A certificate of precision issued by qualified observatories, of which the most famous in Switzerland are in Neuchatel and Geneva, or by one of the C.O.S.C. centres (Swiss Official Chronometer Testing Institute). Delivered with chronometer watches.
The c.o.s.c. chronometer certificate (collective) is given to the watch, only if provided with the seconds hand, which regularity rate has been demonstrated during a 15 days check, in 5 different positions at 3 different temperatures (8°C, 23°C, 38°C) and which daily average is including within -4 and + 6 seconds.
All of this is demonstrated by the watch rate certificate (individual) that accompany every watch certified like chronometer.
The cost for every certificate issued (individual) is about 50.00 US Dollars per watch
CHRONOSCOPE (OR CHRONOGRAPH)
A watch with an additional mechanism operating a direct-drive seconds hand at the centre of the dial to measure intermediary times
COLUMN-WHEEL
A wheel in high quality chronoscopes which coordinates the phases of the chronograph function: start, stop, return to zero of the centre-seconds hand. In more recent upmarket chronographs this wheel is replaced by a lever system
COMPLICATION
Additional functions to those indicating the hours, minutes and seconds
COTES DE GENEVE (OR GENEVA WAVE PATTERNS)
A guillochè wave-like pattern frequently used to decorate quality movements
ESCAPEMENT
Mechanism fitted between the train and the regulating organ (i. e. the balance) for:
- interrumping the undwinding of the spring at regulars intervals;
- distributing energy periodically in balancia.
The main kinds of watch escapments are:
- recoil escapment (verge and crown-wheel);
- frictional-rest escapment (cylinder, virgule and double virgule);
- detached escapment (lever, detent).
Nowadays, the lever escapment is often used: detent, virgule, etc.
FINISHING
All the adjustments and checks carried out during the final manufacturing phase
FLINQUE (OR GUILLOCHE')
Hand or machine engraving with many lines or curves intersecting at regular intervals
FLY-BACK (OR TAYLOR FUNCTION OR "RETOUR EN VOL")
A mechanism which allow the stop, the return to zero and the restart of the centre-seconds hand by
pressing only one time, instead of three times, the button of the watch
JUMPING-DIAL WATCH
Watch on which the hours are shown though a window in the dial, or on a graduated section on the dial. The change of hours occours as the result of a sudden jump
LUMINESCENCE
Is the property of some substances (i. e. the phosphoruses) of receiving energy under various shapes (i. e. the electricity and sunbeams) and of changing it in visible light. This transformation may be happen in simultaneousness with the absorption of energy (fluorescence) or may be happen after a certain time-interval (phosphorescence).
In the watches, they use like phosphoruses the zinc (Zn) salts (Zn sulphides and silicates). All the same, whereas the Zn sulphides have a weak phosphorescence, the Zn silicates don't have any phosphorescence and so to obtain it we resort to an irradiation system from a radioactive material (radioluminescence); in the past, radium (Ra) and now tritium (T).
The T is the most heavy hydrogen isotope and it is also the only one radioactive, beta less type (electron).
The use, in the watches, of the special tritium varnishes is prescribed by the international rules (ISO) to which also the swiss industries (NIHS) adjust.
For example, the max authorized value of max radioactive activity for every "standard" (wrist) watch is fixed at 7.5/1,000 curie, while for the "special" ones, like the watches certified underwater (atm. => 10 and singly tested) is fixed at 25/1,000 curie. In fact, in some "special" watches, like the Rolex Submariner mod., is written on the dial "T - < 25", while in the "standard" ones is facultative only the written "T".
The application of the T on the index may be made by serial writting or by hand application, with a special "fountain pen".
Considered that the bright intensity of the index reduce of 1/8 after 12-15 years, we must establish that the initial bright intensity must be almost 8 times the min one admitted and however included into the max.
But what happens when the T activity finish?
If it was utilized the Zn sulphide, the brightness let down very quickly, while if it was utilized the Zn silicate, we have the complete exhaustion of the brightness. In any case it is possible to renew the T deposits on the index or to renew the whole dial.
The international rules (ISO) provide that in the watches certified underwater, almost three index are realized with luminescent material, as well the index at 12 o' clock must be different from the others
PERPETUAL DATE CALENDAR
A mechanism which automatically displays the days of the month, adjusted for the varying number of days, and for leap years
POLISHING
Finishing operation consisting of bevelling the edges of the bars and polishing, satin-finishing or burnishing the surfaces of the plates and bridges
POWER RESERVE
A mechanism on certain watches to indicate the running time left before the watch needs rewinding
REFINING
Eliminating all impurities in noble metals
REPEATER WATCH
A watch whose strinking-mechanism is activated automatically on the hour, or manually. According to the model, it strikes the hours, quarters, half-quarters or minutes
RETROGRADE HANDS
Hands on fine mechanical watches that move backwards when measuring a new lapse of time
RHODIUM-PLATING
A thin lever of rhodium deposited on the plate and bridges of high quality movements to prevent oxidization
SHAPED WATCH
A watch that is any shape but round
SPLIT-SECONDS CHRONOGRAPH
A chronograph with two centre seconds hands for measuring events of different durations, but beginning at the same time
SWISS MADE
At present a watch is defined "Swiss Made" when the mechanism is of swiss origin and the assemblage and the final check happen in Switzerland.
Instead, in the past, the watches "Swiss Made" were the ones those parts, come from Swiss industries, make up almost the 50% of the value of the watch, but without consider the costs of the assemblage and of the final check
TOURBILLON WATCH
A watch in which the entire escapment is fitted in a mobile cage, with the balance in the centre. The rotation of the cage on its axis compensates for, and thus eliminates, errors of rate in vertical positions
WINDOW
Small opening in the dial through which various indications appear: date, day, month, moon phase, etc.
Stampa
