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The Taubert Family - Watch Case Makers of Geneva

Copyright © David Boettcher 2005 - 2024 all rights reserved.

1924: Taubert & Fils take over The Borgel Company

This is the continuing story of the Borgel watch case making company of Geneva.

Louisa Borgel took over control of the business when her father François Borgel died in 1912, steering it through the difficult period of the First World War and the immediate post-war depression. In 1924 the business was purchased by the Taubert family of Le Locle, who continued the business of making watch cases in Geneva.

By 1924 the original screw case designed by François Borgel in 1891 needed updating and the Tauberts experimented with several existing water resistant designs such as the hermetic before producing their own phenomenally successful Decagonal waterproof screw case with its distinctive 10 flats for unscrewing and remarkably effective cork seal for the stem. They were also pioneers in the introduction for watch cases of stainless steel, which was too hard to be formed by traditional methods.

88223 Transfer to Louisa
Patent CH 88223 Transfer to Louisa Borgel
88223 Transfer to Taubert
Patent CH 88223 Transfer to Taubert et Fils

The Tauberts formed a new company to take over the Borgel company, Taubert & Fils (Taubert and Sons). In the extracts from the Fédération Horlogère Suisse reproduced here, we can see that Louisa Beauverd-Borgel first bought the rights to the Charles Rothen patent CH 88223 in February 1924, still giving her address as 10 Rue des Pecheries. Then in March, Louisa transferred the rights to the patent to Taubert et Fils, whose address is also give as 10 Rue des Pecheries.

Why Louisa or her family decided to sell the business to Taubert & Fils is not known. From the record of the transfer of patent CH 88223, first to Louisa and then from her the Tauberts, we can see that she was alive and involved at the time of the sale, so it seems likely that the family decided to cash in and retire by selling the business. Louisa Borgel lived a long life after these events, passing away in January 1980 in her 96th year, nearly 56 years after selling the company her father had founded in 1880 and which she had guided since 1912, including through the turbulent period of the First World War. Perhaps Louisa's husband was successful in his own right and wanted his wife to give up her involvement in the business.

Registration of Taubert et Fils, and
striking-off of Louisa Beauverd-Borgel

To the right we have the official announcements from La Fédération Horlogère Suisse of the registration of "Taubert et Fils, Manufacture de boîtes Borgel", and the striking off (radiation) of Louisa Beauverd Borgel. Both announcements are dated 28 April 1924, so this was the official date of the end of the Borgel family in watch case making. But it was not the end of the association of the Borgel name and the famous FB-key trademark with watch case making.

The names of the Taubert partners are given as Paul-Arthur Taubert, father, and Marcel, Paul-Emile and Bernard Taubert, sons, originally from Le Locle. Their business is given as manufacturing waterproof Borgel screw watch cases, and their address is 10, Rue des Pêcheries, Plainpalais, Geneva.

CH112153.jpg Taubert & Fils Patent
25 January 1925 Taubert & Fils First Patent

On 25 January 1925 the new firm registered patent CH 112153, the heading of which is shown to the left, proudly declaring "Manufacture Des Boîts Borgel, Taubert & Fils". This patent is noted as an additional patent, subordinate to the main patent Ch 88223 which they had acquired from Charles Rothen. The patent CH 112153 does not introduce any revolutionary invention, being confined to the addition of a screw cap over the winding crown to seal the crown and stem. It was perhaps more of a place marker to show that Taubert & Fils were serious about pushing forward the business of making waterproof watch cases.

Taubert & Fils Advertisement
April 1925 Taubert & Fils Advertisement
Journal Suisse d'Horlogerie, April 1925

In their first advertisement in the Journal Suisse d'Horlogerie in April 1925, shown here, Taubert & Fils describe themselves as "Manufacturers of Borgel cases" and "Successors of Louisa Beauverd-Borgel, a company founded in 1880."

Taubert & Fils make a big play of the Borgel name and trade mark in their advert - it appears no fewer than five times - so this business must have represented an important acquisition to them. Perhaps it transformed the fortunes of a small, previously relatively unknown case maker. The advert says they make "Borgel screw watch cases and all other screw systems". Around the FB trademark the advertisement says "Ouvrage soigné et garanti exigez notre marque de fabrique" (Properly finished and guaranteed products require our trademark).

Taubert & Fils Marque Registration
1926 Taubert & Fils Marque Registration
Archives de l'Horlogerie

The Taubert family certainly carried on using the FB trade mark into at least the late 1960s, and don't seem to have developed any other trade mark of their own. The advertisement finishes with "Seule la boîte de montre à vis Borgel protège hermétiquement le mouvement de votre montre" (Only the Borgel screw case hermetically protects the movement of your watch).

Taubert & Fils re-registered the FB-with-a-key trademark on 23rd January 1926 as shown in the picture on the left.

The firm of Taubert & Fils became known as one of the finest Geneva-based case makers, specialising in water-resistant cases and working for many firms, including Mido, Movado, The West End Watch Co., Ulysse Nardin, Patek Philippe and Vacheron Constantin and many, many others.

The firm was renamed in 1938 as Societe Anonyme Taubert Frères (Taubert brothers) or Taubert Frères SA, after the death of the father Paul Taubert.

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Early Taubert Developments

In the mid 1920s, probably as soon as they had taken over the company in 1924, the Tauberts started experimenting with new case designs. They were still manufacturing the Borgel one piece screw case, but as that design was over 30 years old when they bought the company, the time was clearly ripe for a new design to carry the firm forward for the next 30 years.

Screw Back and Bezel

Taubert screw back and bezel case
Taubert screw back and bezel case

One of the designs the Tauberts experimented with was a screw back and bezel case shown here. This watch is the only one that I have seen with this particular case design and carrying the Borgel trademark. The case has Edinburgh import hallmarks, with the date letter "Y" of 1929 to 1930. The sponsor's mark is the A·G·R of Robert Pringle and Sons.

The movement is one that I don't recognise, both the movement and the case carry a trademark of a heart under a diamond inside a rectangular surround with a pointed base which was a trademark of Courvoisier Frères of La Chaux-de-Fonds.

The screw back and bezel case design had been around for a long time, it was patented in 1872 by Aaron Dennison and the Dennison Watch Case Co. often referred to screw back and bezel cases that they made in large numbers as "the original screw case". The explorers watches made in the nineteenth century for adventurers and Royal Geographical Society travellers has this type of case, so by the 1920s the screw back and bezel case was not exactly cutting edge, and certainly not something the Taubterts could get a patent on, which explains why they did not choose continue making them – following the successful path established by François Borgel, they wanted a design of their own that could be patented to protect it from being copied, as we shall see later.

British patents have a life or "term" of 20 years. After the 1872 Dennison patent expired in 1892 anyone was free to make screw back and bezel cases, and they were produced in Switzerland as well as by Dennison's themselves. Screw back and bezel cases are occasionally called "Borgel style", but they were not produced in any quantity by the Tauberts. As they bear no resemblance to the original Borgel screw case, or to any other Borgel or Taubert case design, this is a misnomer.

In addition to experimenting with their own designs, Taubert & Fils made water resistant cases to the patent designs of others such as the hermetic case design patented by Jean Finger in 1921 and the patent Schwob Frères cushion case.

The next two sections describe two unusual designs of cases made by the Tauberts that must have been made as prototypes or small experimental production runs because neither of them are very common. They appear to be steps on a consistent path of development that culminated in Tauberts most successful Decagonal screw case design, one of the first truly modern watch cases and one of the most successful watch case designs ever produced. I have called the two prototype stages Stage 1 and Stage 2.

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Stage 1: Screw on Back

Taubert screw on back
Stage 1: Screw on back
Screw on back sleeve
Stage 1: Stem sleeve

The first Taubert development for which I have evidence is a one piece case with the movement held in a threaded carrier ring somewhat like the Borgel screw case, except that in this design it is the separate bezel rather than the separate back that is eliminated.

I have one example of this design hallmarked Edinburgh 1926/27, which is shown in the exploded view. The first stage of assembly is to drop the movement, complete with dial and hands, into the threaded carrier ring, where it is held from below by the two case screws shown in the image.

Something that is not visible in the image is that the front part of the case has a screw thread on the inside. The carrier ring with the movement, dial and hands, screws into the case from the back, or below in the image. The case back, which has a milled edge to facilitate gripping, has an internal thread which screws on to a short section of the carrier ring which remains protruding.

One item that is not shown in this picture is a sleeve that fits inside the stem tube and engages with the threaded carrier ring. This sleeve has two roles, to align the movement and carrier ring correctly before the case screws are tightened, and to form a bearing surface inside the stem tube for the stem to turn on. This sleeve is missing from my watch and I was rather puzzled by the lack of anything to register the carrier ring in position until a correspondent sent me a picture of his version of this watch, complete with the sleeve as shown in the small image.

Rolex Oyster? In the book about Rolex by Dowling and Hess, 2nd edition p75, one of these Taubert screw on back cases is described in the chapter about Oysters, said to be the earliest Rolex known with a crew on back, circa 1918. The watch is in 9 carat pink gold with luminous black and white enamel dial. The date given is most likely wrong, although the watch is most likely pre-Oyster. It is interesting to see that Rolex were using Taubert waterproof cases, as well as the Borgel screw case, before the Oyster case was patented.

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Stage 2: Screw-In Back

The next Taubert development for which I have evidence is shown in the image here. This is one of only two watches that I have seen with this case design.

The case is hallmarked with the London import mark giving a date of 1928/1929. If you look at the picture closely you will see that it has an inscription showing that it was presented to Sergeant L. Fisher by members of the sergeants mess of the Duke of Cornwall's Light Infantry in March 1937. This is rather puzzling, because the hallmarks are clear and there is no doubt that they are London import marks for the hallmarking year 1928/1929. I can only speculate that with the world still in the latter stages of the great depression, times were tough and a second hand watch was purchased for Sgt. Fisher by his comrades.

Taubert Cork Stem Seal
Taubert Patent Number CH 130942. The case is shown face down; Item 2 is the screw-in case back.
Taubert screw in back
Stage 2: Screw-In Case Back

The case has what I describe as a "screw in" back, because the back has a projecting section with an external thread that screws into an internal thread in the case, which is recessed so that when the back is screwed fully home it is nearly flush with the back of the case. This gives a very neat appearance. The case back has coin edge milling around the periphery to give a grip for unscrewing.

The middle part of the case has details which are similar to those illustrated in patent No. CH 130942 registered by the Tauberts in 1928, the figure from the patent reproduced from the section further down this page helps to understand the important features of this case, which are:

All three of these features are shown and described in patent No. CH 130942. This Stage 2 case design was the forerunner of the Taubert's Decagonal design (described later) and had all the essential features that were to make that case design an outstanding success.

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Two Important Patents

By the late 1920s the Tauberts were making progress towards a satisfactory design for a modern waterproof case. In 1928 and 1931 they registered two patents that would renew and reinforce their prominent place in the lead of waterproof watch case design, and carry the firm forward for the next 30 or more years. For the future of the firm, these were very important patents. The two patents were:

  1. The Cork Stem Seal CH 130942
  2. The Decagonal Case CH 156807

The first of these patents, granted in 1928, included a flexible seal that sealed the winding stem, a screwed back with gasket, and a plain movement carrier ring held in place by the case back. This is exactly the same design as the development stage 2 watch described above.

The 1928 design of watch case was very attractive and a distinct advance on the Borgel screw case that was still the mainstay of production, and had it entered volume production it would no doubt have been as successful as the old screw case. However, around 1930 circumstances pushed the Tauberts into a new area that brought its own problems but also opened new possibilities for the company.

The watch case that was the subject of the second of these two important patents was a screw back and bezel case with a very distinctive "Decagonal" design, 10 flats that allowed the back or bezel to be gripped for screwing and unscrewing. On the face of it this is just an incremental advance from the coin edge milling of the earlier design. But in fact it came about partly as the result of a revolution in watch case making involving a new material that was hard to shape.

The long economic depression that had started in the early 1920s and culminated in the Wall Street crash had depressed trade and watch sales around the world, so watch manufacturers were looking for a way to reduce the cost of the watches. They fastened upon stainless steel, a wonder material that was being heavily promoted as the material of the future. The only problem was that stainless steel was so much harder than the gold and silver used traditionally to make watch cases that case makers using traditional methods could not work with it. The Tauberts were leaders in the field with their factory that was equipped with powerful machinery and they developed a watch case especially to take advantage of the properties of the new material.

Watch cases made of silver or gold were too soft to be screwed together tightly to make a waterproof seal. The coin edge milling traditionally used on screw cases made of silver or gold did not permit a tight grip to be made, and the screw threads were soft and easily damaged. However, stainless steel was a different matter. The hard material would take a strong thread that could be tightened with a key or a spanner, and as the first in the field the Tauberts chose the design of a case back with 10 fine flat surfaces for a key to engage. This distinctive design of the Decagonal case enabled the Tauberts to fight off counterfeiters for the duration of the patent.

The Decagonal case with the cork stem seal based on these patents was very successful, and the Tauberts supplied them to many watch manufacturers. Almost unbelievably, One of these designs is still in use today, and the other one was used until very recently. The Decagonal case back design is still used by the West End Watch Co. The flexible seal of patent No. CH 130942 was actually made in cork. Until recently Mido were still using the cork stem seal, referring to it as "Aquadura", a name they coined for the design after the Taubert patent expired. The modern Mido seem to believe that they originated the Aquadura cork seal, but it is clear from the patents, and from Mido watch cases supplied to them by the Tauberts in the 1930s, that the cork seal was the Tauberts patented invention.

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The Cork Stem Seal

Taubert Cork Stem Seal
Taubert Patent Number CH 130942

On 18 January 1928 Taubert & Fils applied for a Swiss patent for a "Boîte de montre hermétique" or waterproof watch case. This was granted on 15 January 1929 with the number CH 130942. The patent was principally concerned with making waterproof watch cases slimmer and introduced three feature that would become very important to Taubert watch cases in the future:

  1. A screw in back, with external screw threads on an extended section that screwed into the back of the case.
  2. A plain carrier ring holding the movement, dial and hands. This ring was held in place by the screw in back.
  3. A flexible seal around the winding stem.

In the figure from the patent reproduced here, the screw in back is item 2 which engages with the carrier ring 3 at point 8. The gasket 9 seals the case back joint. In actual watches this gasket was made from lead.

The carrier ring was a vital feature of the design because with no removable bezel the movement had to be inserted from the back, which meant that the normal case screws couldn't be used to hold the movement in the case. Instead the case screws hold the movement in the carrier ring, and the carrier ring is held in place by the case back.

The flexible seal 13 is held in a cup shaped socket 10 which is soldered to the case, a bit like a pocket watch pendant. The seal is held in place in the pendant by a retaining disc 14 that clips into the end of the socket.

In actual manufacture the seal was made of cork and the stem tube was made slightly differently to the illustration in the patent. The intention of the patent is clearly that the cork seal is inserted into the socket and then the retaining disc 14 is put in place to retain it. In manufacture, a tube with a reduced opening at its outer end was welded to the watch case forming the housing for the seal. The cork seal was introduced into this housing by compressing it using a tool with a tapered tube so that it would pass through the opening at the outer end and then expand into the housing. The type of tool used is shown in the figure below.

Taubert Cork Stem Seal
Cork Stem Seals and Tool

This was very different to the screw down waterproof crown that Rolex had introduced in 1926. The cork seal prevented water passing through the opening for the winding stem without the need to unscrew the crown before winding or setting the watch. Although not ultimately as water tight as a screw down crown, it was the perfect solution for the person who wanted a waterproof watch without the additional complication of unscrewing the crown every day to wind the watch - remember that very few watches were self winding or automatic at the time. It also didn't suffer from the problem of the screw down crown threads wearing, which plagued watches with screw down crowns until automatic winding was introduced.

Taubert Cork Stem Seal
Cork seal production detail

There is a bit of a mystery surrounding this patent because the British version of it, GB 304291 "Fluid Tight Watch Case" was granted to Hans Wilsdorf, Managing Director of Rolex, describing himself as "assignee of Taubert & Fils". Why and how this came about I don't yet know, but Wilsdorf must have allowed The Taubert's to continue producing watch cases with the cork seal, because they carried on using the cork stem seal for many years. Perhaps it was another aspect of the patent that Wilsdorf was interested in.

One of the manufacturers who bought cork stem sealed watch cases from Taubert was the firm Mido. Until recently they were still using this detail in some of their watches, calling it the Aquadura stem sealing system, a name they gave to the system in 1959 after the Taubert patent had expired. The picture to the right shows a tool supplied by Mido (which would be a copy of one of the original Taubert tools) for inserting cork seals into the stem tube. The greased cork seals are loaded into the breach of the tool and pushed into the stem tube by the spring loaded plunger. The inner bore of the tool is tapered, which compresses the seal as it is pressed forward so that it will enter the small outer opening of the stem tube. Once inside the stem tube the seal expands to fill the space.

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Decagonal Case

Taubert Patent CH 156807
Taubert Patent CH 156807 / GB 385509

In the early 1930s The Tauberts designed a watch case with a screw in back and bezel that each had 10 flats around the circumference, rather like the flats on a machine screw head. By using 10 flats they could make each one quite small, making a very neat and attractive alternative to slots or notches. They protected this design by a Swiss patent. The application was deposited on 8 May 1931 and the patent granted on 31 August 1932 as CH 156807, a figure from which is reproduced here.

Early Decagonal Case
Early "Decagonal" Case

The image of a watch is an early implementation of patent CH 156807, it has a 10 sided bezel as shown in the patent. The bezel screws into the front of the case and has 10 flats for a spanner used to tighten it down against a lead gasket. The movement is fitted to the case in the usual way for the time, it drops into the middle part of the case from the front and is held in place by two case screws inserted from the back. The case also has a screw back, also with 10 sides, and also screws down onto a lead gasket.

It didn't take long for someone within the Taubert Company to decide that the 10 sided screw bezel was not an ideal feature. All previous waterproof Borgel screw cases had fluted milling around the bezel to give a better grip. But these were tightened by hand, and the necessary fluted milling added an attractive feature. The new case was designed to be more waterproof than the old ones, so needed to be tightened with a spanner, which required the 10 flats that were not so attractive. So a revised design was created, one where there was no removable front bezel and the movement was inserted from the back. This required the introduction of an inner cuvette that has over the years been called variously a "dust cover" and a "magnetic shield" by people who didn't understand its true use, which is described in the section "Inner Cover or Cuvette" below.

Dispensing with the removable front bezel left case with only the back removable, unscrewed by placing a spanner over 10 flats made for that purpose. This distinctive "Decagonal case", so called because of the 10 or "decagonal" flats on the case back, was to become an instantly recognisable case that the Tauberts supplied in huge quantities, hundreds of thousands, to many Swiss watch manufacturers for decades. Action to defend the patent resulted in two court cases in which many interesting facts were brought to light.

Taubert polygonal caseback
Taubert Patent Decagonal Case Back

The Taubert patent forced other case manufacturers to use alternative designs for screw cases such as notches cut into the circumference of the case back, and these are still used today. To open these cases requires a special tool with bits that engage with the notches or slots, and every watchmaker is familiar with gouges on case backs that come from the tool slipping when someone is trying to open one of these cases. The Taubert Decagonal case was not only elegant and simple, it was also easy and safe to open the using special keys that Taubert supplied.

Brit. Pat. 385 509

The Decagonal case patent was also registered in the UK under N° GB 385509 which was applied for on 9 May 1932 and published as complete/accepted on 29 December 1932. Reference to this patent often appears in Decagonal case backs as "Brit Pat 385 509". Reference to the Swiss patent is usually made by the Swiss federal cross and "Brevet" (patent).

The picture to the left shows the inside case back from a sterling silver watch retailed by JW Benson of London. Silver cases in the Decagonal design are relatively rare, the design was much better suited to harder stainless steel, and the flats on silver cases are often quite worn in comparison to those of steel cases. However, some high class jewellers such as Bensons must have still wanted to be able to offer the traditional silver case to their more conservative customers.

The case back is stamped with the Borgel FB trademark that the Tauberts continued to use, to the confusion of many later watch collectors. Underneath the FB mark on the left is stamped BRIT. PAT. for British patent and the number of that patent, 385 509. To the right is the Swiss Federal Cross and the word BREVET, Swiss for patent. This refers to the Taubert's Swiss patent 156807 although the number is not quoted. Beneath these marks are the two reclining opposed Fs of the Glasgow Assay Office import hallmark, the date letter "o" for 1937 / 38 and the ·925 indicating sterling silver. Beneath this is the sponsors mark SFC, entered at the Glasgow Assay Office by Schwob Freres & Co. Ltd.

Inner Cover or Cuvette

West End Watch
Exploded view of West End Sowar Prima

The exploded view here is of a West End Sowar Prima watch, one of the first watches to use the Taubert Decagonal case. There is an inner cover or cuvette between the screw in case back and the movement carrier ring. This cover is deceptively similar to the inner dust cover found in watches with jointed backs and so it is often described as a dust cover, or sometimes more imaginatively as an anti-magnetic shield. It is neither of these!

The precision machined Decagonal screw back and lead gasket form an excellent waterproof seal; a separate inner dust cover is simply not needed. The material the cuvette is made from is not ferromagnetic, so it cannot be a magnetic shield. So what is the cuvette there for? It is there to hold the movement in place.

Movements were usually fitted into the middle part of the case from the front. The edge of the movement bottom plate (the plate underneath the dial) has a widened flange which stops the movement dropping straight through the case and it is held in place by two case screws inserted from the back. The heads of these case screws either overlap the edge of the case or engage in cut outs in the case. Inserting the movement from the front of the case requires a removable bezel, and the Taubert patent shows a screw in bezel for this reason.

The separate screw in bezel added to the cost of making the case, and was a noticeable and not particularly attractive feature, and the joint between the bezel and the middle part of the case is an obvious place for dust and moisture to enter. So, following François Borgel's design principles, the Tauberts altered the design of the Decagonal case to eliminate the removable bezel. This meant that the movement had to be inserted from the back, and that the traditional case screws could not be used to hold the movement into the case.

Cross Section of Decagonal Case, Cuvette in Red

So that the movement can be inserted from the back of the case, the movement is mounted in a carrier ring, rather like the carrier ring of the original Borgel screw case but not threaded on the outside. The cross section of a Decagonal case shown here illustrates the arrangement. The carrier ring is shown cross hatched in grey. It has a smooth outside so that it can slide into the case. The cuvette, coloured red in the diagram, presses onto the end of the carrier ring and when the case back is screwed in it presses on the small nub in the centre of the cuvette so that it, and hence the movement in its carrier ring, is held in place.

The central nub or pressure point ensures that as the back is screwed in it presses on the cuvette without imparting any turning force to it. Another piece of careful and thorough Taubert design.

The use of this arrangement has a spin off benefit in that it also enables slightly different sized movements to be fitted to a standard case size, by machining the carrier rings internally to fit the movement whilst keeping their outside dimensions the same to fit the standard case. The carrier ring is made of brass which is much easier to machine than the hard stainless steel of the case.

The exploded view shows how a watch with a Decagonal case is assembled. The movement, complete with dial and hands, drops into the carrier ring and is held in place by the two case screws. The movement and carrier ring are inserted into the case from the back. The winding stem is inserted through the stem tube, the cork seal already in place, and the stem is secured into the movement by tightening the setting lever screw. The inner cuvette then fits over the lower end of the carrier ring, and the case back is screwed into place, tightening down onto a lead gasket which is not shown in the picture.

West End Watch
West End Watch Co. Sowar Prima with Decagonal Case
Decagonal keys

The picture to the right shows a West End Watch Co. watch with a Decagonal case supplied by Taubert. You can see that where the polygonal flats meet the flat part of the case back that carries the external screw thread, this is flush with the case making a very neat joint that no one would think of trying to get a knife into to lever the case back off with.

The picture to the left shows a number of Taubert keys for opening these cases. They are very light and compact, and make the job of opening a Decagonal case very easy compared to one with peripheral slots, where the tool always seems to want to jump out and scratch the case back.

The effectiveness of the Taubert Decagonal case is shown by the fact that although this West End Watch Co. watch has had a fairly tough life, probably in India because the inner cover has the mark "CS(I)" for the Civil Service in India, the movement is as clean and crisp and bright as the day it left the factory.

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Commercial Success

Taubert polygonal caseback
Patek Philippe ref. 1463 in Decagonal Case
Image by permission © Robert Maron

These two patents, CH 130942 covering the screw in back, the plain carrier ring and the cork stem seal, and CH 156807 for the distinctive and unique Decagonal case, were the foundation for the Taubert's success and their main production over decades.

For the man in the street who wanted a watch that he didn't need to worry about if it got wet, a watch with a Taubert Decagonal case was ideal, perfectly satisfactory for everyday use and without the extra cost and inconvenience of a screw down crown.

The Tauberts supplied many, many, watch manufacturers with these cases. They are very distinctive and easy to spot, even in a fuzzy eBay photograph, and I am amazed at how often they appear.

The first two manufactures to use the Decagonal case appear to have been first Mido and then West End. These were followed by many others including Vacheron Constantin and Patek Philippe.

The picture to the left shows the case back of a Patek-Philippe ref 1463J, the first water-resistant chronograph to be produced by Patek Philippe, and the case for this watch was supplied by Taubert. The polygonal facets of the Taubert patent case back are clearly visible. The image of the Patek Philippe was kindly granted to me by Robert Maron of Thousand Oaks, California who sells very fine watches. If you browse his web site you can see lots of very fine Patek Philippe watches, many with Taubert cases.

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Stainless steel

In the early 1930s, Geneva jewellery, watch bracelet and watch case manufacturers were searching for a cheaper material to use instead of the precious metals they were used to because the Great Depression, the worldwide 10 year financial slump which followed the 1929 Wall Street crash, reduced demand for expensive items, so they needed to cut costs and reduce prices. Stainless steel was an obvious material to use, but because it was much harder than the silver and gold they were used to, they found it was impossible to shape, machine and polish with their hand tools and traditional, time honoured, techniques, and required changes in the way the watch cases were made.

Silver and gold watch cases were traditionally made by forming, with simple hand tools, bar and sheet material into individual parts of the case, which were then soldered together and polished so that the joints between the component parts were invisible. This method of making watch cases developed before powered machinery was invented, but it was continued; partly out of tradition, but also because it was an economical way of handling the costly raw materials used; silver, gold and platinum. Even when powered machinery became available and it would have been possible to machine a watch case from the solid, the sheer availability and cost of blocks of silver and gold, together with the requirement to gather and reprocess large amounts of precious swarf, made this method of production economically impossible and so the old methods continued.

But the use of stainless steel for watch cases changed everything: it was not practicable to make cases from stainless steel in the traditional way, the material was much harder than gold or silver, too hard to form by hand into the individual pieces required by the old methods. And making the many welded or soldered joints required by the traditional methods was difficult in steel. Neither was it necessary economically. As a raw material, steel was cheap; so cheap that its cost could, to all intents and purposes, be ignored in watch case making. It was economic to machine away large amounts of material during the manufacturing process. But this couldn't be done on an old hand turned bow-lathe, it required powerful machines.

Swiss watch case makers working in the traditional way could not easily change over to making stainless steel cases, the material was much too hard. The School of Watchmaking in Geneva realised that they needed to be shown that it was possible to make cases in stainless steel, and the tools and techniques that were needed. Leading companies were chosen to develop the necessary processes and show others the way to make watch cases, watch bracelets and jewellery in stainless steel. The companies chosen were Taubert & Fils (watch cases), Gay Frères (watch bracelets - now part of Rolex S.A.) and Wenger (jewellery).

In an article in the Journal de Genève on 4 April 1934, Philip Werner, professor at the School of Watchmaking, reported progress that had been been made in working with the new material. After explaining the difficulties of machining and forming stainless steel, which "at the beginning made them despair", and the processes developed to overcome these difficulties.

M. Werner presented the audience with various objects from the watch bracelet makers Gay Frères, the jewellery factory of A. and E. Wenger, and the watch case factory of Taubert & Fils. Taubert & Fils had been working with stainless steel from the late 1920s and were selected to demonstrate to the rest of the watch case industry in Genev the techniques and processes necessary for making cases out of stainless steel.

The Tauberts had invested heavily in modern machinery for their factory on the Rue des Pêcheries, giving them a technical lead over other Geneva watch case makers. A Taubert advert in 1943 noted that the serial production of stainless steel watch cases was made possible by the move of the old Borgel factory to the current "spacious, light and powerfully equipped" (emphasis added) factory in Plainpalais. This ability to make watch cases from stainless steel, which most traditional watch case makers couldn't work with, gave the Tauberts an entré into two of Geneva's finest watchmakers, Patek Philippe and Vacheron Constantin.

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Patek Philippe

Patek Philippe reference 438
Image by kind permission of and ©
J&P Timepieces Inc.

Patek Philippe is one of the most illustrious watch makers in the world, tracing its roots back to Geneva in 1839. As makers of the finest watch movements, they naturally looked for watch case makers who could supply cases to match. Of course they had well established relationships with many case makers, but when they wanted in 1932 to introduce watches with stainless steel cases, their existing case makers couldn't work with the new material because it was so much harder than the gold and silver they were used to working with, so Patek Philippe approached Taubert & Fils, the leading stainless steel watch case maker in Geneva. The Tauberts made the first stainless steel pocket watch, wristwatch and desk watch cases for Patek Philippe.

The first watch cases made by the Tauberts for Patek Philippe were some pocket watch cases, made in May 1932. The Patek Philippe reference 96, which had a snap back case (later called "Calatrava") was launched in 1932. The first cases in 18k gold were made by Patek Philippe's usual suppliers, but later the same year The Tauberts made cases in for the reference 96 in stainless steel.

After making cases to Patek Philippe's existing designs for some time, the Tauberts eventually persuaded the very conservative company to try a Taubert designed case, and in 1935 the Patek Philippe reference 438 was introduced using, of course, the Taubert patent waterproof Decagonal screw case. The cases for the reference 438 were supplied by the Tauberts in both steel and gold. The picture here shows a steel reference 438 sold by J&P Timepieces Inc. of New York, who always have a wide selection of Patek Philippe and other fine watches for sale.

The reference 1463 was Patek Philippe’s first waterproof chronograph and is one of the most coveted of all Patek Philippe chronograph references because of its waterproof Taubert Decagonal case with waterproof crown and pushers. It was launched in 1941 and continued until the mid 1960s, and was available in steel or gold.

The Tauberts also made cases for Patek Philippe references 96; 437; 438; 448; 565; 608; 612; 778; 1463; 1485; 1486; 1563; 1591; 2438; 2451; 2457; 2508; 2509; 3237.

The case for the Patek Philippe Reference 1485 and 1486 was the same unusual Taubert patent clip together waterproof rectangular case as that of the Alpina watch I describe in a later section.

The Tauberts continued to supply cases to Patek Philippe until 1965.

When wealth started to return to the world economy in the 1940s, Patek Philippe didn’t need to make as many steel versions of its watches as in the lean times of the 1930s, and stainless steel was also widely used rather than being a new and cutting edge material, so Patek Philippe returned to using mainly gold cases. Ironically, this means that steel Patek Philippe watches are rare, and hence eagerly sought by collectors. This results in the topsy-turvy situation where an ounce of steel can be worth more than an ounce of gold - if it’s the steel case of a Patek Philippe watch!

Thanks to Flavia Ramelli, the Patek Philippe archivist, and John Goldberger the independent researcher, for help with this section.

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Vacheron Constantin

Like Patek Philippe, in the early 1930s Vacheron Constantin approached the Tauberts to make cases in stainless steel.

Vacheron Constantin stainless steel wristwatches are rare. Price is not something that their customers worry about, so they usually use cases made of 18 carat gold or platinum. This rarity of course means that there is a certain price to be paid, and like Patek Philiipe, an ounce of stainless steel can be worth more than an ounce of gold if it is the case of a Vacheron Constantin watch.

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A new name: Taubert Frères SA

La Fédération Horlogère Suisse, 2 August 1939

Taubert & Fils was renamed in 1938 as Societe Anonyme Tabert Frères (Taubert Brothers) or Taubert Frères SA, after the death of the father Paul Taubert. Here we have the announcement in La Fédération Horlogère Suisse of the change from Taubert & Fils to Taubert Frères. Note that this is not simply a change of name: the old company is officially struck off and a new company formed. The announcement says:

Trade Register
Social reasons:

28/1/39. - The company named Taubert & Sons, Manufacturer of Borgel Cases, manufacturer waterproof Borgel screw watch cases, in Geneva, was declared dissolved on 31 May 1938, its assets and liabilities assumed by the company Taubert Freres S.A. The reason is it was struck off.

On the date 24/12/38 was formed under the name Taubert Brothers S.A. a company with headquarters in Geneva, taking over the assets and liabilities of the company by the name of Taubert et Fils, Manufacturer of Borgel Cases. The object of the new company is the manufacture and sale of watch cases in various metals and all items related to this industry. Were elected directors: Marcel Taubert, president, Petit-Lancy, Paul and Bernhard Taubert Taubert, in Geneva, all three of Le Locle, with individual signatures. 10 Fisheries Street, Geneva.

It is interesting to note that the three brothers are listed as all being of Le Locle, an important centre of the Swiss watchmaking industry in the Jura mountains. The 1945 Directory of Swiss Manufacturers and Producers records Taubert Frères SA, Watch case factory, 10 Rue des Pêcheries, Geneva

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Two Important Court Cases

Two court cases brought by the Tauberts against companies that were infringing their patents also shed light upon the development of the Decagonal case design and the early adopters of the case with its cork stem seal.


In 1940 the Taubert company instituted proceedings before the Commercial Court of Bern against a watch case manufacturer of Bassecourt named Piquerez-Frésard, which was in the opinion of the Tauberts, imitating their Decagonal back watch cases. Piquerez then challenged the validity of the patent.

During the trial, expert opinion was sought from M. Berner, director of the School of Horology in Bienne. M. Berner concluded that some claims in the patent were not new and therefore could no be protected by patent. However, he allowed the claims on the polygonal periphery of the screwed case back, considering that they met the required characteristics of "an invention, idea, or even daring, technical progress, etc.." M. Berner maintained his view after having heard conflicting legal opinions from Blum & Co., Matter, and others.

Following the expert's report the parties agreed, on 12 November 1941, a court settlement under which the Taubert patent was limited to the following claim: "Hermetic watch case comprising a middle, and a portion (bottom or bezel) screwed therein, characterized in that the outer periphery of this section is in cross section, polygonal." So the Taubert claim to a patent on the Decagonal case, or in fact any case back with polygonal flats on the back or bezel, was upheld.


The information about the court case in the following was extracted from the judgement of the Swiss civil Court of September 14, 1948 in the case of Breguet-Bréting versus Taubert Frères S.A.

1939 Taubert Ad
1939 Taubert Advertisement

JBB: J. Breguet-Bréting

In January 1941, the partnership of Les Fils de J. Breguet-Bréting (the sons of Jules Breguet-Bréting), Bienne, manufacturers of watch cases, asked Taubert Frères S.A. for a supply of polygonal keys. As a result of this Taubert Frères realised that Breguet-Bréting were making watch cases with screwed polygonal case backs exactly the same as theirs, and pointed out the existence of their patent. Breguet-Bréting were dismissive of Taubert's patent, so Taubert sued in the Bankruptcy court of Bern for Breguet-Bréting to cease manufacture of watch cases with polygonal case backs, for any existing counterfeited or imitated products to be destroyed, damages of 8,000 Swiss francs, publication of the judgement in newspapers to be indicated by the court, and legal expenses.

The court noted that Taubert Frères had secured patent CH 156807 entitled "Boîte de montre hermétique" (Hermetic Watch Case) in 1931. Part of the patent specification was that the external circumference of the case back was made polygonal, with flats on it like a nut, instead of round. This allowed the use of an adjustable wrench, a vice, or a similar instrument for tightening and releasing the case back.

The court noted that this design of threaded or screwed polygonal case back was immediately very successful, and that Taubert Frères either supplied or licensed cases featuring it to a great number of watch manufacturers, including Mido, Movado and West End. Taubert also supplied a polygonal wrench or key that fitted the polygonal form of the case back, allowing easy screwing and unscrewing. The splendid advertisement reproduced here from La Classification Horlogere des Calibres de Montres et des Fournitures d'Horlogerie Suisse - 1939 Edition shows one of these Taubert cased watches strapped to a submarine with the headline "The waterproof watch par excellence".

The court case continued on for a number of years, during which the patent expired due to the passage of time, and in June 1945 Breguet-Bréting went into liquidation. The Journal Horlogère Suisse recorded that Bernard Breguet started a new company to make and export patented machines for making bread from wheat flour. The lawsuit was continued against the two former associates, presumably Bernard and his brother, and on November 28, 1947, the Bankruptcy court found in favour of Taubert Frères and ordered the defendants jointly to pay Taubert Frères the sum of 45,000 Swiss francs as damages and interest.

During the court case, industry experts appointed by the court were asked to comment on the Taubert design, and they remarked that it was ‘superior to the Wilsdorf design [which had the milling still seen on Rolex watch cases today] and other designs using notches or slots cut into the case back, both technically and aesthetically.’

In the next sections we will go on to look at the three watch manufacturers specifically mentioned in the court judgement as shown in the extract reproduced here.

Manufacturers Mentioned in Court Case

The extract says "The polygonal form of screwed case back was an immediate success, and a fairly large number of manufacturers used it, amongst others brands like Mido, Movado, West End, etc.".

Mido, Movado and West End were three early adopters of the Decagonal case with the cork seals in the winding stems, and all played heavily on the waterproof nature of their watches in advertising at the time. In the following sections I will look at the relationship between the Taubert company and each one of these manufacturers in turn.

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The name "Mido" comes from the Spanish "to measure". It is pronounced "Me-doe" not "My-doe".

There is a page about the history of the Mido watch company at The Mido Watch Co..

Mido Multifort

Mido Brit Pat
Mido case back marked "Brit Pat 385509"
Taubert Patent GB 385509
Taubert British Patent 385509

The Mido Multifort watch was waterproof, antimagnetic and impact resistant, one of the very first watches with these features. In 1935 the Mido Multifort Automatic was introduced, bringing together for the first time the four features of self winding, watertight, antimagnetic and impact resistant. The Multifort became the best selling Mido watch until the 1950s.

To prove that the Multifort functioned under extreme conditions, Mido had it tested by the New York Electrical Testing Laboratories Inc. Tests were conducted in freshwater and saltwater for over a thousand hours. The watches were then subjected to ten cycles of 15 minutes at 50°C followed by 15 minutes at -40°C. The winding crown was subjected to a test representing 34 years of use. Simulated tests of immersion to 13atm (120 m) and ascending to altitudes of 6,600, 13,300 and 16,600 metres were performed. One of the 6 watches tested ceased operating at 13,300 metres, but apart from that the watches seem to have passed the tests with flying colours.

Part of the success in the tests was due to the use of specially treated natural cork to seal the winding stem. In the history on their web site Mido don't exactly claim to have invented this sealing method themselves, but they do say "Because it formed such a perfect join with the winding shaft, Mido was able to guarantee absolute watertightness even when the crown is pulled out" and "In 1959, this cork system was named 'Aquadura'".

Saying that Mido was able to guarantee absolute watertightness is not the same as saying that they designed or invented the system. Mido were the company with their name on the dial and so had to take responsibility for their products. However, the way it is said implies that Mido invented the cork stem seal, and the current Mido management seem to believe this because they have refused to discuss it with me, although they have told me that they don't have any records from the time.

The cases Mido used for the Multifort were without any question the Taubert patented Decagonal cases, with the patented cork seals around the winding stem, that Bernard Taubert also supplied to the West End Watch Co., in 1934, which Taubert guaranteed as 100% waterproof.

It seems that Mido had the tests in New York carried out to substantiate Taubert's claims as to watertightness of the Decagonal before they started using them in 1935, before staking their money and the Mido name on their watertightness, so presumably Bernard Taubert called on Mido at about the same time as on West End, but West End were less cautious and had their watch on the market sooner.

No Borgel Trademark

Mido Vacuum
Mido case back marked Vacuum

The case backs of these Mido Multifort watches do not bear the FB-key Borgel trademark used by the Tauberts at the time. They were stamped "BRIT PAT 385509". British patent 385509, an extract from which is shown here, was the British version of the Swiss patent for Taubert's waterproof Decagonal case and is proof of their origin. Presumably, like many other manufacturers, Mido didn't want to reveal that the cases were not their own manufacture. Perhaps because they were an early, possibly the first, adopter of the Decagonal case, or as a quid-pro-quo for organising the New York tests, they were able to wring this concession from Taubert, who usually insisted on stamping all cases with the FB-key mark, such as those supplied to Movado and West End.


In later Mido watches, the word "Vacuum" is stamped in the watch case back, a trademark the Tauberts adopted in the mid-1950s. See the section Taubert, Manufacture Vacuum for more details.

Later Mido case backs didn't even have this explicit reference to Taubert, simply referring to "Modele Depose" (Registered Design) and "Brevet Depose" (Registered Patent) - which must be a reference to the Taubert patent, because the case backs still had the distinctive 10 flats of the Taubert Decagonal case.

Mido Ocean Star

Patent CH 346175 "Montre étanche"

Mido Ocean Star Vacuum

The relationship between the Taubert watch case company and Mido lasted at least into the 1960s. Evidence for this can be seen in a range of waterproof wristwatch cases supplied by Taubert to Mido stamped with the Taubert trademark "Vacuum" and the number "+346175". This number refers to a Swiss patent for a "Montre étanche" (waterproof watch) registered by Bernard Taubert on 16 April 1958 and published on 30 April 1960.

These Taubert "Vacuum" cases were used by Mido in the Ocean Star range of wristwatches, including a dive watch that was stamped on the outside case back with an image of a Scuba diver and the words "Guaranteed 300m / 1000 ft". Not a bad depth for a cork stem seal.

This style of waterproof case, today called "top loader" or "front loading" was very widely used in the 1960s and 1970s. I am not sure whether Mido was the first company to use this design but, given their evident close relationship with the Taubert company, it seems likely that they were.

The picture here is from the case back of one of these Mido Ocean Star watches. The Taubert trademark "Vacuum" is clearly seen above the sign of the Swiss Federal Cross, which in this case indicates a Swiss patent, followed by the patent number like this: Swiss Federal Cross 346175.

Patent CH 346175: Split Stem

Patent CH 346175 "Montre étanche" (literally a "tight watch" but translated as "waterproof watch") was registered by Bernard Taubert on 16 April 1958 and published on 15 June 1960, as shown in the extract reproduced here.

The salient features of this patent were that the case was made in one piece with no separate back, very much like the original Borgel one-piece screw case. The movement was introduced into the case through the top or front opening, hence the name "top loader" or "front loader" for this case design The movement and dial were then held in the case by the crystal through an intermediate spacer ring.

This meant that the movement had to be put into the case before the part of the winding stem that passes out through the case wall was coupled to the movement, which was exactly the same problem François Borgel had faced in 1890 when designing his one-piece screw case. Borgel overcame the problem by using a two piece winding stem, one part fixed in the movement and one part fixed to the case, and Bernard Taubert adopted a very similar solution.

Borgel's solution was to make a sliding joint between the two parts of the stem, fixing the outer part of the stem to the case with a spring so that it could be withdrawn to remove or insert the movement. However, this required a separate pin set mechanism for hand setting. For the top loader case Bernard Taubert also designed a winding stem that was in two parts, one part fixed in the movement and the outer part removable. To allow stem setting and avoid the need for a pin set mechanism, the joint allowed to two parts of the stem to separate when the movement was removed from the case, but coupled them both axially and rotationally so that the watch could be wound and set by the stem. The design of this joint can be seen in the drawing from the patent where "Fig. 3" shows a cross section of the stem.

Mido Ocean Star crystal tool

The winding stem was, of course sealed by the tried and trusted Taubert cork seal, which is not mentioned in the patent but can be clearly seen in the accompanying diagram, which Mido called the "Aquadura crown sealing system."

To facilitate removal of the crystal, Bernard designed the special tool shown here. This tool was patented in Switzerland, CH 353693, and also in Great Britain, France, Germany, and the United States. The tool has a number of exchangeable inserts to fit different size crystals, one to fit a small crystal is in place in the picture. It is a very precise and easy to use tool. The instructions printed on the tool make the operation of removing the movement clear. After removing the crystal:

Mido diver: Guaranteed 300m / 1000 ft. Image courtesy of © Jesus Manriquez Arias

"TO REMOVE MOVEMENT 1. Turn Mido name on crown horizontally – dial up – crown pushed in. 2. Invert case, movement will come out."

Inserting the movement into the case was the reverse of this. The crown was oriented so that the projection on the end of the stem lined up with the slot in the part of the stem in the movement and the movement simply dropped into the case.

This is a slightly fiddly operation and most watch repairers simply pull hard on the crown until the joint snaps apart, and all the movements I have seen in this type of case have the joint shaped to allow this, which is different to how the joints are shown in the patent. It must have been a fairly early modification. I have also seen it suggested that the crystal can be removed from of these watches by pumping air into the case once the stem has been removed, the crystal being literally blown out. Presumably not every watch repairer had access to the correct tool, or even knew of its existence.

These cases were used from 1959 in the Ocean Star range of watches by Mido, including the Mido Ocean Star diver’s watch with its amazing multicolored dial shown here. This watch is stamped on the outside case back with an image of a scuba diver and the words “Guaranteed 300m / 1000 ft,” which seems a pretty amazing depth for the cork stem seal, I wonder if there were ever any claims under the guarantee?.

Mido Aquadura

In recent years Mido advertising material claimed that the cork sealing system, which Mido call "Aquadura", was invented by Mido and patented in 1934. In fact, although there are a number of patents registered to Mido, I have found none dated between 1930 and 1940. I am certain that Mido first encountered the cork stem sealing system in 1934 when Bernard Taubert showed them the Taubert patented waterproof Decagonal case with its patented cork seal for the stem, and that over time the recollection of this has become blurred due to loss of the original records and staff through company changes.

In 2008 on the 90th anniversary of the founding of Mido, director Franz Linder introduced a new watch at Baselworld, the Mido Jubilee. This watch used the Aquadura cork stem sealing system, and so far as I am aware, Mido are still using these cork seals in watches today. Not bad for a design conceived by the Tauberts in the late 1920s!

The press report of this event said:

MIDO: Cork makes waterproof watches

Mido compete with the winemakers for cork to make waterproof watches. The system, patented in 1934, has never been matched by synthetic seals. Franz Linder, director of the Bienne brand, presents its latest creation, Jubilee, sealed with cork.

Using cork to make a waterproof watch: this invention patented in 1934 has never been matched by synthetic seals called "o-ring". The Bienne watchmaker Mido thought of using cork to seal the crown, the weak point of all dive watches. In the Aquadura system, the stem of the crown passes through a tiny cork gasket compressed in a housing, which ensures a seal even if the crown is not fully pushed-in. "Like a bottle of wine that remains sealed even if the cork is half-drawn," compares Franz Linder, Director of Mido.

Attention to defects

Compared to the vintners, the Bienne watchmaker is not a big consumer of Portuguese cork. But as its seals are tiny, they cannot bear the slightest defect of a poor quality cork. "Two thirds of the handpicked seals go in the garbage," says the director of Mido. Natural cork is heated and greased to ensure its moisture, but the real difficulty lies in the cutting of the brittle material: a small piece of cork falling into the case would be enough to stop the movement. The assembly is more difficult and more expensive than plastic seals."

Hardly anyone goes under water to a depth of 50 m. But this system, "simple but brilliant" according to Franz Linder, assured the success of Mido in Brazil, Thailand or Indonesia, wherever humidity attack the movement. And, curiously, doctors around the world are happy to wear a Mido: "Simply because they often wash their hands ..." smiles the director.

The use of cork in the watch is so efficient that Mido applied the "Aquadura" system in the chronometer "Jubilee" presented at Baselworld for the 90th anniversary of the brand. "With an automatic watch, the cork wears only during setting the time or date ..." notes Franz Linz.

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Movado was founded in 1881 by Achilles Ditesheim, a 19-year old entrepreneur who hired six watchmakers and opened a small workshop in La Chaux-de-Fonds. In 1905 the company name was changed to Movado; a word meaning always in motion international language of Esperanto.

Movado 1940 Ad
Movado 1940 Advert

In "The Movado History" Fritz von Osterhausen writes:

"The year 1935 saw the introduction of the first Movado water-resistant wristwatch, the ‘Acvatic’. This unusual spelling of the word is derived from the Latin word ‘aqua’ (water) and was first registered as a trademark on 13th February 1936.

Produced in various sizes the Acvatic had a screwed back with a lead gasket and a cork seal for the winding crown. It was developed by the case-making firm of François Borgel of Geneva, which was owned by three brothers called Tauber [sic]. They developed many other variously shaped water-resistant cases for Movado during the subsequent decades. Later a two-button chronograph called "Cronacvatic" was developed."

The screwed back case was the patent Decagonal Taubert case, complete with cork seal for the winding stem, another Taubert patent. Von Osterhausen gives the year of introduction of the Acvatic as 1935, a year later than the waterproof models using the Decagonal case back introduced by Mido and West End. So the wording of the 1940 Movado advert shown here is a little misleading, because the wording in the advert says "with the pre-tested waterproofing pioneered by Movado". It also says "Dustproof, airtight, unbreakable crystal ..." - how advertising standards have changed since 1940!

Movado became a big customer of the Taubert's and one sees many Movado watches from the 1930s to the 1960s in the distinctive Decagonal case, but unlike the Mido cases these are proudly stamped with the FB-key Borgel / Taubert trademark.

Sometimes these marks are also accompanied by the mysterious word "Vacuum", as discussed on my page about the Taubert company in the section Taubert, Manufacture Vacuum.

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West End Watch Co.

Extract M Foex Memoirs
Extract from M. Foëx Memoirs
Extract M Foex Memoirs
Extract from M. Foëx Memoirs

The West End Watch Co. was formed as a Swiss / Indian company to export Swiss watches to India, with offices in St. Imier and Bombay. It was founded in 1884 by Alcide Droz & Fils and Arnold Charpie. It was renamed as the West End Watch Co. in 1887.

In 1934 two events occurred that had a significant effect on the subsequent history of the company. Georges Braunschweig of La Chaux-de-Fonds offered the company the Incabloc shock resisting system for protecting the balance staff from breakage, and Bernard Taubert offered them the Decagonal case with cork sealing in the winding stems, which he guaranteed 100% waterproof.

The extracts reproduced here are from the memoirs of M. Foëx, who was the managing director of the West End Watch company from 1916 to 1973, and were supplied to me by M. Jérôme Monnat, the CEO of West End Watch Co. These extracts discuss the development and introduction of the Sowar Prima, shockproof thanks to the Incabloc system and waterproof thanks to Taubert's cases. Sowar means 'The one who rides' in Persian and was adopted as the name of cavalry troops in India. The Sowar Prima became West End's most successful model.

The West End Watch Co became thus one of the first company to use the Incabloc shock resisting system in their watches, and they used Taubert's waterproof watch case with the cork stem sealing and Decagonal case from 1934 until 1954, when Taubert were no longer able to keep up with West End's demand, which by then had risen to more than 2,000 case per month.

The lifetime of Swiss patents in the 1920s and 1930s was normally 15 years, so by 1954 the Taubert patents for the cork seal and Decagonal case had long since expired. West End asked the Donzé to copy Taubert's cases which, after some hesitation, they manage to do, complete with cork sealing and 10 flat screw case back. M. Foëx remarks We are saved.

There is a page about the history of the West End watch company at The West End Watch Co..

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Poinçon de Maître / Responsibility Mark

Beginning some time in the mid 1920s all precious metal (gold, platinum and palladium cases) watch cases made or imported into Switzerland were required to carry a mark to identify the maker. Makers could use their own registered mark, such as the Tauberts FB-key trade mark, but most chose to use a "collective responsibility mark". This mark consisted of a registered trademark of an association of manufacturers, with a unique number identifying the individual member. The Tauberts decided to use both methods of marking their work, the Borgel "FB and Geneva key" trademark and one of the new collective responsibility marks.

collective responsibilty marks

These collective responsibility marks are called in Swiss "Poinçon de Maître" (which translates literally as "punch of the master"). Initially the responsibility marks were filed in the Office of Control of the district of residence of the manufacturer, but since July 11, 1934, all these marks are recorded by the Swiss Central Office for Precious Metal Control in Bern. They are stamped only on watch cases, not on bracelets.

collective responsibilty mark No 5
Collective Responsibilty Mark No 5.

Collective responsibility marks for Swiss watch cases were first registered by the trade association "Fé dération Suisse des Associations de Fabricants de Boîtes de Montres Or", the Swiss Association of Gold Watch Case Makers, sometimes known by the initials "F.B."(NB: don’t confuse this F.B. with the Borgel/Taubert FB – it has been done!) Six poinçon de maître collectif or collective responsibility marks were defined as shown in the picture. From left to right they are:

  1. Hammer-Head or Hammer "without Handle" (sans manche): for gold and platinum watch cases made in Switzerland but outside Geneva.
  2. Hammer with Handle: No official description surviving.
  3. Marquee: for silver watch cases made in Switzerland.
  4. Crossbow: for silver watch cases.
  5. Geneva Key: for gold and platinum watch cases made in Geneva of thickness 0.3mm or greater.
  6. Shield: for gold and platinum watch cases made in Geneva of thickness less than 0.3mm.

The individual case makers are identified by a two or three digit registration number which is stamped where the XX or XXX is shown in the picture. There is more about this system, and tables of the lists of registrants, on my page about Swiss hallmarking.

1936 Cyma case marks

The picture to the right above shows an extract from the records held by the Swiss Central Office for Precious Metal Control for the poinçon de maître No. 5, the Geneva key. This is only a small extract, there are 45 entries in total for this one mark alone.

Manufacture Taubert were registered to use both mark number 1, the hammer head or "hammer without handle" used on watch cases made outside Geneva, and mark number 5, the Geneva key. Why did they have two registered marks? The Tauberts started out in business in La Chaux-de-Fonds, which must be why they had the hammer head registration. The Geneva Key was only for manufacturers in Geneva. In both cases their registration number was 11, so if you ever see a case with either the hammer head mark or the Geneva key mark stamped in it, and 11 where the xx are in the picture, you know it was made by the Taubert company.

Schwob Frères Cushion Case Wristwatch

You can see the Manufacture Taubert registration for the Geneva key symbol in the picture to the right. This is in a wristwatch case manufactured by the Tauberts to a patent design of Schwob Frères who together with Tavannes sold watches under the Cyma brand. You can see full details of this watch and the Schwob Frères patent case design on my Schwob Frères and Tavannes Watch Companies page.

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Taubert Patent CH 207378
(Exploded view © David Boettcher 2010)

Rectangular Watch Cases

In the 1920s and 1930s under the influence of the art deco movement, rectangular watches became fashionable. To respond to this trend, the Tauberts designed a new rectangular watch case with a twist - of course, it had to be waterproof! The patent for this new case was registered on 25th August 1938 as Swiss patent CH 207378, and published 31st October 1939.

The method of construction of this case is quite difficult to understand from the drawings in the patent, so I have made this version which shows the cross sectional drawing from the patent, and also an exploded view. The watch movement and dial, together with the winding stem (the stem opening sealed with Taubert's patent cork seal, which isn't discussed in this patent) and crown, are mounted in a rectangular inner case called a báte. The báte is open at the top and bottom.

The báte is encased in a two piece rectangular outer case. A rectangular gasket fits into a groove in the case back where it is trapped between the bottom edge of the báte and the outer case back, sealing the open bottom of the báte to the case back. Another rectangular gasket fits beneath the crystal where it is trapped between the top edge of the báte and the crystal, which is itself held in place by the top part of the outer case. This seals the open top of the báte to the crystal.

By carefully controlling the height of the báte and the dimensions of all the other components, the action of pressing the two parts of the outer case together clamps the gaskets between the inner case and the back and crystal, creating a watertight seal. The two pieces of the outer case are held together by clips which slide into grooves along the case sides.

US3791135 reference to CH207378

The pictures below are of an Alpina watch in this rectangular Taubert case. In the middle picture you can see one of the clips that holds the two parts of the outer case together slid to one side. The third picture shows all the various components, including one gasket. This gasket is made of rather hard, incompressible material, which I would have thought was not ideal for the intended use. I don't know whether it is original, but as it is the perfect size and shape it probably is original. There definitely should be two gaskets, and the watch could not be watertight without both gaskets being in place.

These cases seem to have a reputation amongst some watchmakers for not being very watertight, but they must be at least as capable of being watertight as the later 1939 Omega Marine Standard, which employs a very similar design of case with rectangular gaskets, and doesn't have such a reputation. The design is sound and they would have been assembled correctly at the factory, so there must be a problem with after sales servicing.

The problem is revealed in a later Taubert patent for another waterproof rectangular case, Swiss patent CH566048 dated 19 June 1972 "boîte de montre étanche", also registered in the USA as US 3,791,135 dated May 28, 1973, an extract from which is shown here. In this patent Bernard Taubert writes that the earlier case has ... the drawback of requiring special tools for performing the closing operation, i.e., for strongly pressing together the two case parts to enable the slide devices to be placed in a working position. [emphasis added]

The "special tools" would have been used to press the two halves of the case together, compressing the gaskets and would have been some sort of vice or clamp that enabled pressure to be applied without damaging the crystal. It wouldn't need to be anything special, even a bench vice could be used if a jig was made with a cut out for the crystal so that pressure could be applied only to the bezel, and the case and jig could then be clamped up in the vice and the slides put into place.

Many watch makers would not have possessed the necessary special tool and so, having been able to get the case apart relatively easily by sliding the clips out, they would have difficulty in properly pressing the two parts of the case together to establish the watertight seal - this can't be done by hand, you just cannot apply enough pressure by hand to compress the gaskets sufficiently. Some good watchmakers would have taken the time to make a jig and press the case together properly, but others would have simply bodged the job by leaving out one of the gaskets and handing the watch it back to its owner with the well known get-out phrase "it can't be guaranteed to be watertight".

In my Alpina, it is evident that at some stage one gasket has been left out and I can't see any good reason why this should be done except to enable the case to be assembled by hand. I have recently acquired a Movado in one of these cases, very similar to the Alpina. Again, one of the gaskets is missing and I am sure that this has been done to enable the case to be assembled by hand. It is rather disappointing that this case design has acquired a poor reputation due to the lack of care in after sales service. It is a good design and when properly assembled would be perfectly watertight.

In addition to Alpina, Taubert also supplied this case to Mido, Movado, to Patek Philippe for the References 1485 and 1486, and possibly to other manufacturers as well. If you know of one I haven't listed, please let me know.

In "The Movado History" Fritz von Osterhausen writes "The year 1935 saw the introduction of the first Movado water-resistant wristwatch, the ‘Acvatic’ . . . It was developed by the case-making firm of François Borgel of Geneva, which was owned by three brothers called Tauber [sic]. They developed many other variously shaped water-resistant cases for Movado . . ." There is an implication there that the Tauberts developed this case for Movado, one of their biggest customers at the time. Whether this is true I don't know, but certainly the majority of the watches that I have seen in one of these cases are Movados.

The Alpina came from who always have an interesting range of vintage watches for sale, and are nice people to deal with. If you are in the market for a vintage watch, I suggest you check out the Style In Time web site, or give Jonathan a call.

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Taubert, Manufacture Vacuum

Taubert, Manufacture Vacuum
Taubert Vacuum entry in Pritchard

In “Swiss Timepiece Makers 1775-1975” Kathleen Pritchard records the information shown in the image here. The details and date given of 1883 for first registration of the Borgel company name and its FB-key trademark differs from the actual date of 1880, but unfortunately, Pritchard does not explain where she got the date she quotes; the text in the image is the complete entry.

The reference to “Taubert, Manufacture Vacuum” is intriguing - what does it mean? Records from Dr. Ranfft’s website indicate that the Tauberts used the Vacuum trademark from the mid-1950s.

It seems that after some 30 years of continuing to use the Borgel FB-key trademark, to the immense confusion of those not “in the know”, the Tauberts decided that they needed a new trademark. So what did they choose? Something obvious like “TF” for Taubert Frères? No, they chose “Vacuum.” Vacuum: I ask you. This is even more anonymous and confusing than their continuing use of the FB-key trademark!

The Vacuum trademark certainly had me confused the first time I saw it; could it refer to the case being “vacuum proof”? (although such a thing is hardly needed on earth) or it could refer to vacuum testing for watertightness. But no, in this instance it is the trademark of one of the world’s finest watchcase makers. Talk about hiding your light under a bushel!

Presumably some development of case design, some new method of sealing, might have stimulated the idea to use the term vacuum as a trademark on those cases, but I don't think there are any surviving records of this. Perhaps someone might compare features of cases made around the same time by the Tauberts with and without the vacuum mark and identify a difference.

Taubert, Manufacture Vacuum
Taubert Vacuum trademark in Movado
case. Image ©

The image to the right shows the Taubert FB-with-a-key mark with the word VACUUM underneath in a Movado case back. From the mid 1950s Taubert supplied cases marked with the FB-key mark underwritten with "VACUUM"" to Movado, such as the one shown in the picture to the right. They also supplied cases without the FB-key mark but stamped "Vacuum" to Mido for the Mido Multifort range of waterproof watches. Reading the official history of Mido on their web site there is no reference to Taubert, and Mido claim to have invented the cork sealing for the winding stem themselves in 1934 and named it Aquadura. However, the first Mido Multifort cases have the very distinctive 10 flats on the case back of the Taubert patent Decagonal case, and the cork sealing is the same as in the cases supplied by Taubert to other Swiss watch manufacturers. There is no question that these cases were supplied to Mido by Taubert and that Aquadura was a Taubert, not a Mido, invention.

Thanks to John in Horsham PA who sent me an image of a Patek Philippe Ref 2508 case back with VACUUM stamped under the FB-key Borgel/Taubert trademark. John thinks this is a mid 1950’s watch, which accords with the data from Dr. Ranfft’s website. John tells me that he has seen other Patek Philippe Ref 2508 case backs online with the word PATENT in the same place under the FB-key trademark.

The Klingenberg “Vacuum” Watch

One of the red herrings I chased was that the trademark “Vacuum” could be related in some way to the evacuated “Vacuum” watch, invented around 1960 by Hans Ulrich Klingenberg.

Klingenberg was a salesman for Glycine until January 1966 when he established his own company: Vacuum Chronometer Corporation in Biel/Bienne. The watchcase was made in one piece with a flat crystal seated on an O ring gasket. The unusual feature was that an 85-90 percent vacuum inside the case held the crystal in place. The first Vacuum watch was introduced by Glycine, naturally, and then similar models followed from Longines, Waltham, and Technos. I thought that the wording “Taubert, Manufacture Vacuum” might indicate that the Tauberts made the cases for Klingenberg. However, Philip Klingenberg, son of Hans Ulrich, told me “There is no information found regarding Taubert in our company; we used to, and we are still, making most of our production ourselves.” So the two uses of the word Vacuum are not related.

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Other references to Taubert Frères

An entry in the Geneva Register of Commerce dated 15 July 1950 refers to Taubert Frères, giving the management as Marcel, Paul and Bernard Taubert of Neuchâtel. After the patent registered by the three brothers in 1940, Bernard Taubert went on from 1947 to register at least 24 Swiss patents under his own name, with no mention of his brothers, so perhaps they took something of a back seat.

The end of the line?

The Taubert company went into liquidation on 30 June 1972. The Swiss register of collective responsibility marks shows that the firm's registration was cancelled on 16 May 1974. The final patent registered under the name Bernard Taubert, CH608322, was published in 1979. The applicant for this patent was Monique Bouchet, whereas previously Bernard had applied for all his patents in his own name. Perhaps the absence of his brothers from the patents after 1940 indicates that they had left the company, and perhaps Bernard himself retired leading to the liquidation of the company, and patent CH608322 was applied for by Monique Bouchet as a mark of respect.

No, the line continues!

The reason that I headed the previous section with "The End Of The Line?" with a question mark is that the Taubert design of case with the polygonal, or more correctly decagonal for 10 sides, screw back is still in use today by the West End Watch Co.

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Taubert Patents

The table below is an incomplete list of patents by Taubert.

Date Number Title Inventor(s)
1925 CH 112153 Boîte de montre. Taubert Fils Manufacture Des Boites Borgel
1927 CH 119762 Montre. Taubert Fils Manufacture Des Boites Borgel
1929 CH 130942 Boîte de montre hermétique. Taubert Fils
1932 CH 156807 Boîte de montre hermétique. Taubert Fils
1939 CH 207232 Dispositif hermétique de poussoir au remontoir pour chronographe. Taubert Freres
1939 CH 206762 Dispositif de ressort antagoniste pour poussoir de chronographe. Taubert Freres
1939 CH 207378 Dispositif de montage hermétique pour montre à mouvement de forme. Taubert Freres
1941 CH 218691 Boîte de montre. Taubert Freres
1941 CH 217009 Boîte de montre. Taubert Freres
1942 CH 222297 Remontoir étanche. Taubert Freres
1947 CH 248901 Lien extensible. Bernard Taubert
1948 CH 257308 Lien extensible. Bernard Taubert
1948 CH 257309 Lien extensible. Bernard Taubert
1951 CH 273458 Boîte de montre. Bernard Taubert
1951 CH 274905 Boîte de montre étanche. Bernard Taubert
1951 CH 274906 Boîte étanche, notamment pour montre. Bernard Taubert
1952 CH 281492 Boîte de montre à lunette rotative. Bernard Taubert
1952 CH 287285 Montre-bracelet. Bernard Taubert
1954 CH 304087 Remontoir étanche pour pièce d'horlogerie. Bernard Taubert

While searching for records of cases made by Taubert & Fils or Taubert Frères I investigated Sotheby's Auctions. I found they had sold at least 13 watches between 2006 and 2009 where the case was attributed to Taubert. The Sotheby's watch expert obviously knows his subject very well, which I suppose is what you should expect! These were mainly watches by Patek Philippe, but there was also one by Movado. Some interesting extracts from two of the sales are noted below.

Patek Philippe 1952
Patek Philippe 1952

Sotheby's Wed 13 Jun 2007 02:00 PM New York

A Fine and Rare Patek Philippe Gold Chronograph Wristwatch with Register and Tachometer 1952, Movement No. 868505, Case No. 679108, Ref. 1463J

The following information is quoted from the Sotheby's catalogue for the sale:


Accompanied by a Patek Philippe Certificate d'Origine et de Garantie stamped Geneva 1961. Further accompanied by a Patek Philippe Extract from the Archives confirming production in 1952 and its subsequent sale on August 10th, 1961.

The inside of the case back is stamped 'FB', the maker's mark for Taubert & Fils. From the late 19th century, when it existed under the name Frères Borgel, Taubert & Fils was one of the finest Geneva-based case makers and specialized in water-resistant cases. They worked with many firms, including Patek Philippe and Vacheron Constantin.



Patek Philippe 1959
Patek Philippe 1959

Sotheby's Wed 13 Jun 2007 02:00 PM New York

A Fine and Rare Patek Philippe Stainless Steel Chronograph Wristwatch with Tachometer and Register 1959, Movement No. 869027, Case No. 2605614, Ref 1463A

The following information is quoted from the Sotheby's catalogue for the sale:


Accompanied by a Patek Philippe Extract from the Archives confirming production in 1959 and its subsequent sale on November 18, 1965.

When it made its debut in 1940, Ref. 1463 was Patek Philippe's first water resistant chronograph wristwatch, and was produced in less than 750 examples. It was the successor to Ref. 130, another iconic chronograph wristwatch with a snap back.

The inside of the case on the present example is stamped 'FB', which is the maker's mark for Taubert, the foremost supplier of waterproof cases.


  1. Dennis Harris "François Borgel: Watch Case Maker 1856 - 1912 Horological Journal November 1997
  2. Kathleen H. Pritchard: Swiss Timepiece Makers 1775-1975

If you have any comments or questions, please don't hesitate to get in touch via my Contact Me page.

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Copyright © David Boettcher 2005 - 2024 all rights reserved. This page updated June 2024. W3CMVS. Back to the top of the page.