I picked up this early type Borgel screw-in case watch with Dimier Freres movement recently. The thing that caught my eye was that it doesn't have a pin-set to set the hands. This is unusual because the screw-in design of the Borgel case means that the stem is split, with the part of it carrying the crown attached to the case by a spring so it can be withdrawn clear of the movement when the movement is screwed in or out. Because the stem is split it can't be used to pull the keyless work into the hand setting position, so normally a pin-set on the case just below the crown is used to engage the mechanism for hand setting.
The 15 jewel Swiss lever movement bears the initials D.F. & C in an oval, which Pritchard confirms was registered to Dimier Freres & Cie in 1896. There is very little in Pritchard about Dimier Freres, but the firm seems to have been founded as Georges Dimier SA in La Chaux-de-Fonds in the mid nineteenth century, and presumably became Dimier Freres & Cie when the father Georges died and his sons took over the company. In Pritchard there is also mention of another company called Dimier Freres & Cie of Fleurier, which seems to have been founded in 1738 by two Dimier brothers, but I don't think the two firms are connected except by coincidence of name.
The clues to what is going on here, and the absence of the pin-set, are contained in the case back. There are London import hallmarks for silver with the date letter "b" for 1917/18, and the sponsor's mark of "DBS" which Priestley reveals was registered from 1907 to George & Edward Dimier of Dimier Brothers & Co., Watch Importers of 46 Cannon Street, London. Why DBS? I think, because the "s" is small and in superscript, it must mean Dimier Brothers.
There is also a reference in the case back to a Swiss patent, number 69988. This patent was registered by Dimier Freres & Cie and Alfred Roth on 16 December 1914 and granted on 3rd January 1916.
The patent describes a way of applying stem setting to a Borgel cased watch. The patent doesn't actually mention Borgel by name, merely saying that the patent is "applicable to watches with hermetically closed cases for which it is necessary to avoid a lateral constraint" but I think we know what it means!
This figure from the patent shows how this was achieved. The original figure was rather hard to understand so I have moved its elements around to juxtapose them more logically without altering them in any way.
The patent shows the split stem we would expect to find in a Borgel watch. But this one has three positions, the normal one with the crown against the case, a middle position with the crown and split stem partly withdrawn, and the fully withdrawn position to enable the movement to be unscrewed from, or screwed into the case.
The split stem and crown are held in these three positions by the spring "e" which engages with grooves on the shaped split stem "f". In figure 1 the split stem f is held in engagement with the movement "g". In figure 2 the stem is held in the middle position by the spring e engaging a different groove in the shaped stem. And finally in figure 3 the split stem is fully withdrawn. The spring e does not positively locate the split stem in this position because it is only required occasionally when the movement is to be unscrewd from or screwed into the case, and the designers obviously decided that the watchmaker could simply hold onto the crown as he screwed or unscrewed the movement, the same as he would do for a conventional Borgel case.
So how does the winding and hand setting work? The movement employs a type of keyless work called "negative set". This type of keyless work is, I believe, rare in Swiss watches, but is quite common in nineteenth century American pocket watches, where the movement and case were selected separately by the customer, and the retailer would fit the movement into the case.
The secret of the negative set movement is that the keyless work is spring loaded to bias it into the hand setting position. To put it into the "normal" winding position, the stem must press the keyless work in towards the centre of the movement, against the action of the spring. This is what is happening in figure 1 of the patent. The split stem f and the element "g", which represents the part of the stem in the movement, are held by the spring e in the winding position, against the pressure of the spring in the keyless work.
In figure 2 of the patent the draftsman has made a mistake. The part of the stem g should have, under pressure from the spring in the keyless work, followed the split stem f as it was withdrawn to the middle position, putting the keyless work into the hand setting position. The fact that the draftsman has made this simple mistake tends to confirm my belief that negative set mechanisms were rare in Switzerland.
As you can see from the photographs, my watch is missing its split stem and crown. The collar "c" which should hold the spring e is present, but the spring e itself is missing. The collar is actually screwed into the setm tube rather than being retained by a screw as shown in the figure from the patent. I am not sure whether to try to get this repaired: the patent figure gives an idea of how it should work, but is not an engineering drawing from which replacement parts could be fabricated, and I am sure that a fair amount of trial and error would be required to get the mechanism to work properly.
I think this type of Borgel case without the pin-set must be pretty rare because thia is the first one that I have seen. The fact that the split stem and crown are missing perhaps indicates some weakness in the design which would explain the rarity. The words "Pat[ent] App[lied] for No. 11997/15" in the case back are interesting because they reveal that an application was lodged for a British patent, but I have not been able to find a trace of this, so perhaps problems arose fairly early on and the British patent application was abandoned.
As ever, any comments, corrections or further information greatly welcomed.
Regards - David