TRESSA AS5008 ALARME AUTOMATIQUE remises ET MONTRE TOUTE ALARME MÉCANIQUE ORIGINALE ENTRETENUE

A. Schild Cal. 5008 is an automatic movement with alarm function produced between 1973 and 1977. It found wide use in the 1970s, offering a function then unavailable in quartz models, and again in the 2000s as mechanical watches were once again prized. It is said that 175,891 examples were produced but only a small number were used in the 1970s. This is one reason that so many watches were produced in the 2000s with new old stock movements.

As is typical with many alarm watches, Cal. AS 5008 is a double-barrel movement. One barrel powers the timekeeping functions while a second powers the alarm chime. Unusually, the central automatic rotor winds both barrels, one in each direction. Most other automatic alarm movements, particularly the popular Jaeger-LeCoultre Memovox, require hand winding of the alarm. The A. Schild “Maximatic” uni-directional winding system is duplicated, with one operating in each direction for each barrel.

Another unusual element of the AS 5008 is the location of the gong. Rather than affix it to the back of the watch case, interfering with the winding rotor and access to the movement through the case back, it is placed between the movement and the dial of the watch. A. Schild recommended attaching one end of the gong to the outer case, below the bezel, to amplify the sound. The company claimed that a fully-wound alarm barrel would produce a 57 decibel alarm for 8 seconds.

A central hand is used to set the alarm on a 12-hour scale. A. Schild advised applying 144 marks to the dial, each indicating a 5-minute interval, to facilitate setting the alarm. The alarm is activated when the second crown is pulled out and silenced when it is pushed in, opposite the Jaeger-LeCoultre Memovox.

The basic movement had 17 jewels. A. Schild also supplied bridges for the automatic winding system and the alarm system, each with four additional jewels. This is the reason that the hand-winding AS 5001 movement was available in 17 or 21 jewel versions and the automatic movements with 17, 21, or 25 jewels.

Notable technical features include 28,800 A/h operation, direct center seconds, hacking seconds, hand winding, and the AS-3 indexed regulator. The regulator is of the classic A. Schild design, with a C-shaped device attached to a moving indicator and index. A. Schild designed the movements with modern manufacturing in mind, using the same screws for most components and supplying a special plate to facilitate working and finishing.