The Reason

This is a classic example of a 1950's triple date JLC with steel case, tear drop lugs. Entirely made by JLC the same design and mechanism was reproduced by Cartier and Vacheron Constantin in the same period by JLC for these houses. It is a historical representation of JLC's design and manufacturing expertise.

There is an extraordinary array of classic calibers in watchmaking, by numerous watch houses that have been developed, executed and found their way into history. This JLC is one of them, it is a work-horse of a caliber and with the exceptions created because of an early case which is not moisture resistant, could effectively live for ever. The over all movement design and proportions are perfect for classical chronometry and longevity.

The conical case back integrates a substantial mechanism and renders the case elegant and relatively slim. The overall design is complex and indicative of JLC from the early 1950's and late 1940's.

Profile of the case between the shoulders

Outer case reference, below it is the lip used to open the case with a case knife

Bezel removed. The case was never water resistant, though time the dial has tarnished and the sections covered by the bezel have discoloured.

Either side of the winding crown are 2 of the correctors for the calendar mechanism

The captive barrel under the barrel bridge. This construction would wear less than alternatives where the ratchet wheel would be placed above the barrel bridge.

The central screw holds the movement into the movement ring and the movement ring pushes tight into the case back

The fourth wheel pivot upon which the seconds hand is pushed

Triangular stud holding the balance spring

The copper coloured spacer between the balance screw and balance wheel is a timing washer often made in gold or platinum. The timing washer adding weight to the balance effectively slowing the rate

Under the balance is the calibre reference

The roller assembly, made in steel and stronger and more robust than most contemporary pieces

The principle train bridge removed, which holds the centre, 3rd and 4th wheels

The Swiss lever and its cock

The escape wheel and its cock

The train bridge removed, showing the centre, 3rd and 4th wheels

3rd and 4th wheels, the 4th wheel has the extended pivot which holds the seconds hand

Partially dismantelled, only the centre wheel and the barrel remain in place

The captive barrel held entirely under the barrel bridge, reduces the amount of wear on the barrel pivots over extended periods of time with out lubrication

The names were machine milled into the bridge

Case clamp screw removed

Barrel bridge removed

The upper screw in view holds in place the setting lever and in turn the stem, to remove the stem this screw is loosened.

The barrel ratchet wheel is held in place by being sandwiched between the barrel arbour and the under side of the barrel bridge

Profile of the Swiss lever. Solid and heavier in proportions than modern counterparts.

The upper crown wheel which connects the winding via the winding pinion on the stem directly to the ratchet wheel to wind up the mainspring

The raised inner circular section is the bearing surface for the ratchet wheel

The small inclined milling is to aid the watchmaker when levering off the bridge

The long steel spring is the click which allows the ratchet wheel to be wound in wound direction and not unwind when released.

The screw holding the click spring in place

The lower level of the hour wheel links with the motion work driving the hands

Full view of the caliber in its movement ring which in turn pushes with a friction fit into the case back followed by the case bezel which clips onto the back.

The balance pivot shock protection closed

The balance pivot shock protection open to access the jewel setting

The jewel setting, chaton and end stone removed

The full calendar mechanism, the discs in Spanish.

The pushers protrude through the movement ring and are apparent on the other surface of the case

In the centre is the date disc, held in place by the neighbouring discs

The large brass pin level with the month disc is a security to avoid the dial touching it

The three levels in the centre are for the date, hour and minute hands

The lower wheel indexes both the day and date

The pusher for the rapid month adjustment

The pawl for indexing the day sits on a second layer to align it with the star wheel.

The rhodium plating surrounding the pusher has been worn during its life

The hidden sides of the two discs showing the indexing star wheels

The day disc upside down showing its star wheel

The dial side viewed with out the calendar discs

The virtical pin on the steel wheel turns the date, the lower finger turns the day

The large steel lever is for the rapid date adjustement

The pawl that indexes the date wheel, guided by the large flat headed screw underneath it and limited in vertical movement by the dial

The date wheel

The finger which is underneath the date wheel which indexes the month disc every 31 days.

Pusher for rapid date correction flush with the outer surface of the case

The tear drop lugs are brazed (with yellow gold) in place

The empty bezel

Case reference stamped into the inside of the bezel

Full inner case back with references and cut outs for the crown and pushers

The cut outs for the pushers were finished by hand and the file marks remain

Full inner bezel

The case back was made in several pieces and brazed together with yellow gold which can be seen on the inside of the case back around the joins.

Various images of the dial showing the volume of the gold hands and indexes as well as the riveting of the indexes from the back of the dial.

Diverse images of the assembled watch

To learn more about JLC click on www.jaeger-lecoultre.com

Watch lent for deconstruction by

Somlo Antiques

masterclass courses

Deconstruction Vintage Jaeger Le Coultre

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