Stripped down

In our last episode on the Waltham 0s I made great use of my watch trays during disassembly.

Watch trays are incredibly useful for keeping parts well organized and safe.

The trays come in sets of 5 different colors and are stackable.

Keeping track and segregating parts in related sections is key to watch work.

Now back to our Waltham... while much of my focus has been on the movement I also spent time on the watch case.

Despite its missing crystal, the case of our watch is in good shape. Just a bit dirty but really looks good overall.

There is one part of the case that lives outside the moment but is critical to the function of the watch, the pendant. The pendant is comprised of the crown and neck of the watch that connects to the case.

Here's the pendant on our Waltham with it's crown at the right. 

Most watches produced in the last 140 years are wound and set by pulling / pushing and turning the crown. They are said to be "pendant set." Virtually every modern mechanical wristwatch works like this. You pull out the crown to set it and push it back down to wind it.

Here I've removed the movement and taken the crown off the case.

The crown is screwed into the stem which is a rod that extends from the crown down into the movement.

Here's the threaded tip of the stem with the crown unscrewed. There's a washer around it. Dirty but works fine.

The stem goes down through the pendant and into the movement's "keyless works" which control the setting and winding in the movement.

Take a quick look back up to the photo with the pendant circled. The keyless works live under that barrel bridge, right inline where the pendant connects to the case and movement. It's under the part that says "safety barrel" in the photo above.

In this shot the movement has been rotated a few degrees counterclockwise but you can see the keyless works still in the movement after all of the time train has been removed.

The stem extends down through those dark tubular gears that looks like a series of castle turrets. Pulling and pushing on the crown shifts the stem up and down which changes the alignment of those gears and set them to either wind or adjust the time/hands.

It is both complex and elegantly simple. Took me quite a while to understand how it works.

And now for more...

Horology history!

Prior to the mid-19th century all watches were "key wound, key set" (often shortened to as "KWKS"). In my first post about the Waltham 0s I did talk about its Hunter case and its cuvette cover but also showed an earlier watch example which is a KWKS and has the corresponding cuvette with a key winding hole. 

However in that example I didn't show the key "set" part. 

So about key setting...

The hands of a pocket watch are typically far too delicate to move by hand (versus those of a mechanical clock where moving the hands manually is expected).

In the early forms of pocket watches the key was used for winding AND setting the hands. So if you look closely at this example...

See the center arbor to which the hour and minute hands are affixed? 

There is a raised square on the top of it and that square is the same size as the winding arbor in the back.

To set the hands you open the bezel / crystal and put the winding key directly on the center arbor and gently turn it. One key, both functions.

Using a key to wind and set a watch had been the only solution for watches for roughly the first 250 years of their history. In that time no one had come up with a remotely better way to wind and set them.

Until pendant setting came along.

Pendant setting is an ingenious design from one of the most famous names in watch making, Adrien Phillipe of the renown Patek Phillipe watch company which is to this day considered perhaps the finest watch company in the world. 

Phillipe's original French patent for a keyless works is from 1845.

Here's a link to a very early example of an 1853 PP watch with a pendant setting mechanism and an excellent, brief history of pendant setting (and stunningly great photos). From that site:

"Phillipe's... invention was initially greeted with skepticism by fellow watchmakers. The breakthrough finally came at the Paris Exhibition of 1844 in form of a gold medal for his very slim stem-wound watches" 

Pendant setting has many advantages to KWKS and started to become adopted in American watches just a decade or two after watch manufacturing started in earnest in the US in the 1860's.

Those pioneer companies that became major manufacturers like Elgin, Waltham and others all started their early production of watches as KWKS. However within 10-20 years virtually all mass produced watches went to pendant set designs like our Waltham 0s.

I'm still getting my head around the specifics of the keyless works. It is truly a brilliant invention.

Back to our Waltham...

I've now removed the keyless works (a couple of the black gears on the back of the plate not shown).

And looking more closely you can see some of the intricacies of the mechanism.

And here it is with some of the other parts in the bottom unit of a watch tray.

The watch is now fully disassembled. I've got three trays worth of parts.

Ready for a bath!

That's next.