PUW 1564T

Description

The PUW caliber 1564T was from its diameter and from its features the maximum version of the caliber series 560/1560. This series was launched in 1971 and was replaced in 1977 by the series 660/1660.

The diameter of this movement is 12 3/4 lignes, that’s 28.9mm. Its smaller twin with a diameter of only 11 1/2 lignes (25.6mm) is the otherwise technically identidical caliber PUW 1563T.

All important bearings contain rubies, even for the mainspring barrel. Only the center minute wheel on the dial side is not ruby-beared.

On the dial side the center minute wheel is ruby beared.

Even though the construction with center minute wheel was a bit outdated that time, it was proven forever since.

The gear train is very compact and so, there’s lot of space for a large mainspring barrel and a large balance.

The mainspring barrel drives the center minute wheel, followed by third wheel, center seconds wheel and escape wheel.

As escapement, a swiss pallet lever escapement is used, controlled by a three-leg nickel balance. The balance beats rather slow with 21600 A/h and is beared in two Incabloc shock protections.
Unfortunately, it can be adjusted only directly at the hairspring, instead of a long regulator arm or a fine adjustment.

An oddity of the PUW selfwinding movements is, that the ratchet is located on the inner side of the gear train bridge, which also houses the mainspring barrel - of course ruby-beared.

When the selfwinding mechanism is not yet mounted, you can see the slipping wheel at 5:30, which decouples the selfwinding mechanism, when the movement is manually wound.

At 12 o’clock, you can also see the rectangular cap jewel for the escape wheel bearing, whose shape allows easily oiling from the sides.

Although the suffix “T” should indicate a modified selfwinding gear train bridge, there’s no way of finding any difference to the “former” version.

The oscillating weight drives a changer wheel, which is sliding-beared and engages with either of the two large exchange wheels. Since the left one is blocked by a ratched when it tries to turn in the wrong direction, the selfwinding mechanism can ensure, that the right exchange wheel always turns in the same direction, regardless of the direction of the oscillating weight.

The right exchange wheel is followed by a reduction gear, which drives the slipping wheel, which then engages with the mainspring barrel and winds it up.

As usual for PUW movements, the oscillating weight is axle beared and held into position by a slider.

Here you see the gear of the oscillating weight.

The empty dial side already shows, where the calendar mechanism will be located.

A spring, mounted at position 12 o’clock ensured, that the crown can be pushed in, even in winding position, and let the date advance one day.

For this quickset mechanism, the snake-shaped spring at position 5 o’clock is reponsible. It engages with the switching lever at position 6 o’clock, which itself engages into the date ring and let it jump forward one position.

Normally, the switching lever is tightened by the switching disc at position 7 o’clock, which is responsible for the regular date jump at midnight.

Unlike the date ring, the weekday disc advances slowly.

This is done by the switching star at position 8:30, which is turned by the date switching wheel. A quickset mechanism for the weekday is not offered.

The weekday disc has got seven teeth on its lower side, one for each weekday.

Since the switching time for the weekday is so long, every weekday is printed twicem so that one can see the current weekday, even during the transision.

In the lab

Timegrapher result

If you take into account, that this movement was already damaged and wasn’t constructed as a chronometer, the rates are really impressive. All deviations are in the single-digit range, and they even neutralize each other in the different positions.

Technical data

Usage gallery