Patek Philippe Pocket Watch – LeCoultre Calibre 17AJ

Lately I noticed an increased interest in Patek Philippe pocket watches. Often wrist watch collectors which branch out and start to look into pocket watches. Quite natural, happen to me as well…

What I do find a bit entertaining is that often, the key point for the interest is the brand on the dial… Often followed by “look at the movement, so beautiful, true craftmanship, talk about high quality”…

I fully agree on all points!

But I would not give all the credit to brand on the dial…!

My friend who have a big variety of interesting watches from several brands, received a beautiful Patek Philippe pocket watch as a gift.

A classic beauty! Solid gold case, white enamel dial, Breguet numerals and Louis XVI hands…

Case revile that it was made by Patek Philippe for the Louis Hainz company in Prague.

When he showed me this pocket watch, I of course asked to see the movement – and I was not disappointed!

Look at this beauty!

The huge balance wheel, the beautiful curves of the bridges with perfectly bevelled edges, the frosted surface to prevent dust from going into the movement…

The saw teeth on the crown wheel and barrel… The black polished screws, the large rubies…. And the very interesting spiral regulator!

With suspicion of this being a Jaeger-LeCoultre based movement, I asked the Heritage Gallery for help.

They confirmed back – LeCoultre Calibre 17AJ from 1897 which were in production all the way into the 1940’s. Used by Patek Phillipe and Vacheron Constantin among others.

Here is a LeCoultre signed version of the Calibre 17AJ:

Now this spiral regulator made me curious as I have seen the same in other movements, after a check in my archive I found this patent from 1892: Brevete No 4750 – Spiral groove regulator for all kinds of watches

In summary – (Google translate)

We claim a regulator for watches of all kinds, characterized by:

by a dial A with narrow groove in the shape of a spiral;
by a racket with pin b at the end;
by a rod E with round head and with a body partly of square section and partly of round section,
so as to be able to turn the gimbal using this rod, without having to fear loosening.

Here a closer look at the spiral regulator: now it is hard for me to determine if this is exactly the same as in the patent as I my French is very limited, but if not, it must be using the same principals for the regulator functionality.

Looking at the dial side, I suspect we are looking at another LeCoultre patent – I say suspect, because again, my French is not enough for me to determine if this is the correct patent I show here – Jaeger-LeCoultre have many patents around the crown and winding stem functionality…

1896: Brevet 11661 – Improved time-setting mechanism for watches with a crown and crown stem movable in the direction of the pendant’s longitudinal axis.

In summary – (Google translate)

We claim as our invention, a time-setting mechanism for watches with a crown and crown stem movable in the longitudinal direction of the pendant, in which the winding stem (C) – provided with the usual winding pinion and sliding pinion and of which a square end recess must receive the internal end edge of the crown stem – is movable in the direction of its length and provided internally with a pin (i) coming integrally with it and against which the pin is pressed by a spring (l) one end of a lever (G) the other end of which is provided with a toothing gear with a toothed sector (H), integral with a finger (K) against which the spring lever (L) presses which acts on the aforementioned sliding pinion to maintain the latter normally in clutch with the winding pinion, the whole arranged so that by moving the crown stem towards the outside, the spring (l) acting on the lever (G) will make the winding stem participate in this movement of the crown stem, and will turn the lever (G) whose movement will be transmitted by the sector (H) to the finger (K) which will thus move the lever-spring (L) and by the latter the sliding pinion to make it mesh with the setting pinion on time, while moving the crown stem inward, it will push the winding stem (C) inward and cause the latter to act by its pin (i) on the lever (G) against of the spring (l), in such a way that this lever (G) oscillating in the opposite direction will move through the sector (H) the finger (K) in the desired direction to allow the spring-lever (L) to release the sliding pinion of the setting pinion. time and make it mesh with the winding pinion, in principle as described above with regard to the accompanying drawing.