Poljot 2415A

Description

In 1955, the first Moscow watch factory, later known as “Poljot,” launched its first automatic movement, the caliber Rodina, also known as the Poljot 2415A.

At over 6 mm thick, it was still quite bulky and was replaced in 1962 by the caliber Poljot 2415.

The mainplate shows a neatly crafted movement, in which all important bearings are equipped with jewels.

Since a classic gear train design from the 1950s was used, there is a central minute wheel, which is mounted under its own cock and is driven directly by the mainspring barrel.

The rest of the gear train is also up to contemporary standards: The minute wheel drives the third wheel, followed by the central seconds wheel and finally the escape wheel.

It’s easy to imagine that this design results in a rather tall movement. The successor features a more modern design with a height of under 4 mm, which is of course also due to a different automatic movement design.

With 18,000 A/h by the shock-protected screw balance, it is a contemporary slow-beat movement. A very positive feature is the regulation with the aid of a regulator arm, albeit a short one, and the hairspring’s Breguet terminal curve.

A Swiss pallet fork escapement is used.

To decouple the automatic winding mechanism during manual winding, a lamellar clutch is used on the ratchet wheel, just as various other manufacturers did at that time.

The automatic mechanism extends over a large part of the movement; among other things, the penultimate reduction wheel is located near the crown wheel. The bearing is accessible through a cutout in the crown wheel cover, and the crown wheel is hollow.

The selfwinding gear train consists of a rocking bar switch that acts on the first reduction wheel, followed by another reduction wheel and finally the double ratchet wheel with multi-plate clutch.

Rectifying the direction of rotation is achieved by a pawl that acts on the first reduction gear and ensures that the rocking bar switch reverses the rotor’s direction of rotation. The rotor can thus be wound in both directions.

The oscillating weight is mounted on an axle.

The rotor’s axle bearing is lined with a ruby.

It is easy to see that the rotor has a larger diameter than the movement itself, and therefore shall only be mounted once the movement is already installed.

The dial side is quite unremarkable. One can see Poljot’s proprietary “Kirowskie” shock protection system, and on the opposite side, the yoke winding mechanism.

To conceal a little of the overall height, the dial-side base plate is beveled at the edge.

In the lab

Timegrapher result

Technical data

Usage gallery

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