Cyma 791

Description

The early past century was the climax of the development of pocket watches.

The movements became better and better, got more precise and robust until around 1920 the wrist watch became popular and demanded smaller (and unfortunately less precise) movements.

From the best time of the pocket watches, according to its serial number, from the early 1920s, is this 17 1/2 ligne Cyma 791, a movement, which is hardly documented in literature.

The base plate gives an impression of the high quality of this movement. All important bearings contain rubies, and under the balance wheel, you see the easily readable caliber number, “Ref. 791”.

Usually at this time, either no caliber number at all was marked on the plates, or only on the dial side. So, the Cyma 791 is clearly better here.

The gear train with its beautiful, filigree gears is the classical one with direcly driven center minute wheel, followed by third wheel, seconds wheel at 6 o’clock (which carries the decentral seconds hand on the prolonged axle on the dial side) and finally the escape wheel.

It also uses a swiss pallet lever escapement.

Of course, the large monometallic screw balance is not yet shock protected. It beats with 18000 A/h.

The hairspring has got a Breguet endshape, which ensures low deviations over all positions.

The fact, that not only the escape wheel is beared under its own cock, but there’s also a second cock used, which bears third and seconds wheel, makes this movement nicely serviceable.

The Cyma 791 already uses a yoke keyless works, which means, that you can just pull the crown to adjust the hands instead of pushing a lateral pin, like it was still used in most contemporary pocket watches.

This is another sign of the high quality of this swiss pocket watch movement.

Technical data

Usage gallery