To Be Or Not To Be a true IWC?

David Boettcher is a well known author of watch articles. He has published also on early IWC watches ( Stauffer, Borgel cases, several IWC patents and more). Recently he has sent me this picture with the question : is this an IWC?
I have immediately answered him : yes, it is a forerunner of cal. 52/53.
I based my opinion on the semi-circular threequarter plate and the way the watch movement was built up. The watch has been issued in 1893. This is one year before ( as far as we know) Stauffer in Great Britain had imported watches made by IWC. The movement was anti-magnetic, had a patented safety pin and bow and a special double click. But then I compared the movement with the fore runners of cal. 52/53 and saw minor differences. There is a straight gap between the balance cock and the threequarter plate, while the gap on IWC's is slightly curved. So we needed more expertise and this came from Ralph Ehrismann, the authority on early IWC calibres (and others).
Ralph was very clear : it is not an IWC. He had seen these watches and knew that they were sold "as IWC".
However, the arrangement of the wheels is different from IWC and also the click. Most probably it is a pillar movement ( as cal. 28 is). The watch has been developed by Stauffer in Great Britain and it was marketed by him.
Maybe interesting for pocket watch freaks?
Kind regards,
Adrian,
(alwaysiwc).

Another example of why this is such a special place for we amateurs in such things. Thanks for posting and for Adrian's response.

Close, but not close enough!

I too would have initially believed it to be an IWC calibre. As you write Adrian there are so many similarities - but that's why we have the panel of wise men out there, that help us keep the knowledge alive and the watches genuine.

Thanks for posting an interesting article - maybe you may care to explain to those like me with less technical understanding Adrian, what exactly is a "double roller"?

Hi Mark,
I doubt this is interesting for many collectors and I doubt even more that I can explain what a double roller is.
But I try.....

....If you look to the drawing, you may see how the energy from the escape wheel , via the pallet fork (ancre) is transferred to the balance weel. The balance wheel is not depicted but should be imagined on the right sight of the picture. However, the "seat" of the balance wheel has been depicted and is called the roller. From the roller a pin is rising up : the impulse pin.
In the pallet fork is a horizotal pin : the guard pin. Because during action the pallet fork is sweeping and because there is only minimal contact between the escape wheel and the ruby (2,3) for a very short moment in time followed by contact between the the second ruby stone and the escape wheel, the fixing of the pallet fork is very vulnerable : it can dislocate easily by a shock. In contrast with a single roller the double roller has guard pin and the impulse pin to keep the pallet fork in position during action. All modern mechanical watches have a double roller. I doubt whether my explanation is useful but more technically skilled collectors might help...
Kind regards,
Adrian,
(alwaysiwc).

Thanks Adrian, really interesting stuff and always a good lesson to see how even experts like yourself can not always be sure!

Best regards,

Bob

Bertrand Russell Quote On The Paradox of Fools And Wise Men
“The whole problem with the world is that fools and fanatics are always so certain of themselves, and wise people so full of doubts.”

Yes Thank you Adrian, this is very clear.

For those who need some more visual explanations, I found these technical drawings in one of my favorite books:

Figure 6-6 shows a typical Swiss lever escapement, with double roller (plateau).

Part 16 is the upper roller and part 17 the lower roller. The purpose of the upper roller is to support the impulse pin (18), and the one of the lower roller is to prevent the movement from stopping with the help from the guard pin (13) (see below).

One can see that the lower roller has a semi-circular indent (19).

A transversal cut (Fig. 6-7) shows the position of the lower roller vs. the guard pin (13)

In slim (or cheaper) movements, the lower roller may be missing (Fig 6-14 & 6-15):

In the single roller, only the upper roller with the impulse pin is present, of course (Fig. 6-15).

The absence of the lower roller & guard pin may lead to a “renversement” or reversal, a problem that puts the watch to a halt (Fig 6-57).

This may happen as a result of a shock that puts the fork (ancre) on the opposite side in the cycle. In that case, the impulse pin, instead of freeing up the fork will hit it on the wrong side.

With the guard pin and lower roller, there is added security, as it will forbid such an abnormal situation.

Best regards,
Zoltan

Very interesting, thanks for posting Adrian. Lookimg forward for tomorow. :)

Best
Hajo