Raketa 2627.H

Description

With a diameter or 26mm (11 1/2 lignes), the Raketa 2627.H is a rather large, rugged constructed selfwinding movement from the USSR.

It is, as the base plate with its bearing jewels everywhere (except for the mainspring barrel bearing) shows it, of a good quality.

The three, apparently random placed bearing jewels (they are indeed real bearing rubies!) on the positions 11:30, 3:30 and 7 o’lock are noteworthy; they will be discussed later.

Like many conventionally constructed movement, the Raketa 2627.H too uses a directoy driven center minute wheel, It is quite large and has got on its dial side pinion a bearing jewel on the inner side, through which the center seconds pinion will go and will be beared.

The rest of the gear train follows the conventional construction scheme with third wheel, directly driven center seconds wheel and escape wheel.

The center seconds wheel and third wheel have got a large diameter, too.

The Raketa 2627.H uses a four-leg anular balance, which is beared in two russian Poljot shock protections bearings.

It beats slowly with 18000 A/h and can be regulated at the hairspring key only.

As escapement, a classical swiss pallet lever escapement is used.

It is nice to see, that the escape wheel is beared in a double bearing with bearing jewel and cap jewel, even secured by an inhouse shock protection. The same double bearing is on the dial side, too.

Compared to its windup relatives, you can see, how much space was saved for the selfwinding mechanism.

The selfwinding mechanism is an own module, which is put onto the movement. Its gear train uses only little space.

The gear train for the selfwinding mechanism consists of a double roller changer, where the upper gear engages with the oscillating weight, the lower one acts as a the other rectifier part, then the first reduction wheel is used, and finally, the second reduction wheel with its roller lock engages with the ratchet wheel and decouples the selfwinding mechanism during manual winding.

The ratchet pawl engages with the first reduction wheel and ensures, that the winding always happens in the same direction, regardless of the rotation of the oscillating weight.

The selfwinding module is attached with three screws on the base plate and on the gear train bridge.

The Raketa 2627.H uses a ball beared oscillating weight.

On the dial side, you see the yoke winding system.

The three bearing jewels on position 0:30, 5:00 and 8:30 o’clock, which were mentioned at the beginning have their purpose to bear the metal calendar ring and to avoid, that metal shaves on metal.

The date switching wheel revolves once per day and has got a moveable middle part, against which a spring presses.

This spring is responsible, that until midnight enough power is built up, so that the date change happens instantly at midnight. Both indications, date and weekday are advanced at once.

At position 1 o’clock, there’s another oddity: When the crown is pulled over and beyond the hands setting position and afterwards pushed into, the lever mechanism advances the date disc one position. This is a simple, but very efficient date correcting mechanism.

The weekday disc with its inner switching star is driven by another switching wheel at position 12 o’clock, which is advanced by a pin on the date switching wheel.

The lever down locks the weekday disc into its correct positions.

The Raketa 2627.H uses a fourteen positions weekday disc, but not for displaying two languages. The weekday abbreviations are repeated after seven positions.

Since the oscillating weight overlaps the movement, the Raketa 2627.H is used with a retaining ring, whose inner side gives the oscillating weight the space, it requires.

Timegrapher result

The tested specimen from Hans-Georg perfomed not bad on the timegrapher, even a little bit better than the NOS watch of Jake R.Kaywell, which was gummed and got a little service and whose rates are not shown.

Technical data

Usage gallery