One of the most rare Timex quartz movements is the caliber M272, which was launched in the early 1980ies and was built for ultra flat watches. It has got a size of 18.7 x 22.4mm (approx. 8 1/2 x 10 lignes) and is directly integrated (and fixed with an adhesive pad) into the case back. Because of the filigree wires, which connect the electronics block with the coil of the stepper motor, it is risky to separate it from the case back.
The movement is a multi-national development, assembled in France, the stepper motor was licensed from the swiss Portescap, and there was also some developement from Germany.
The still empty base plate shows the small electronics block and the Lavet stepper motor, which uses stators in an 60° angle, so that for a full rotation, six steps are required. The electronics ensured, that only every 20 seconds, there’s a step, which means, that there’s a full rotation every two minutes. The only exception is on the setting, done by a button on the base back: In the first ten seconds, there’s a step every second and afterwards, the speed increases to about ten steps per second.
The electronics block offers no possibility for adjustments.
The gear train is as simple as unusual: The rotor of the lavet stepper motor drives the large center minute wheel, below(!) there’s the changing wheel and the hour wheel. This means, that the hour wheel (and hour hand) is really below the minute wheel!
The stator is beared in metal bushings, the upper housing with its two flaps prevents the large minute wheel from tilting.
In total, there are only four wheels in the whole movement: Stepper-rotor, minute wheel, changing wheel and hour wheel. Quite impossible to construct a movement with fewer gears, and of course, such a movement cannot offer a seconds indication.
The three wheels for the time indication are beared on two thornes of the base plate, only the lavet stepper motor has got two bearings, one on each side.
You also see the two bushings, in which the two feet of the dial are put into. So the dial also acts as upper bearing for the two time indication wheels.
On the bottom of the minute wheel, you can see the gearing the for change gear, which drives the hour wheel.
In the side view, you can see the arrangements of the hands again: On the bottom there’s the minute hand and above the hour hand.
The Times M272 is backed by a number of patents: Most important is the german Patent DE 3214683 A1 (Dünne Armbanduhr mit Schrittschaltmotor), which was released in the USA in 1983 as Patent US 4376996A (Thin stepping motor watch). Another patent of the year 1983, which was published in 1984 is the US Patent US 4472068A (“Watch movement with a rotating minute disc”), which describes the usage of the large center minute wheel. The adhesive pad, which fixes the movement on the case back is described in the US Patent US 4603978A (“Laminated base element for a wristwatch using hot melt adhesive foil”) in detaul, and finally, the US Patent US 4400095A (“Push button assembly for a watch”), specifies the push button mechanism on the case back for setting the time, since there’s no crown on this movement.
This movement was also available with a date indication mechanism (caliber number not yet known), which is specified in the US Patent US 4443112A (“Planetary gear for date mechanism in a wristwatch”).
|Construction type:||solid construction|
|Size:||8 1/2 x 10''' (measured: 18,7 x 22,4mm)|