Very few watches of this type were made by Vacheron Constantin. A similar watch is illustrated in 1 ' Univers de Vacheron Constantin, Geneva, p. 372. "Montres bracelets a couvercle " Shortly after 1920, the wristwatches were selling better than the pocket watches, most eminent designers and makers were keen to find for sport and everyday wristwatches, an equivalent to the popular hunting cased pocket watches which can easily be personalised with a monogram or enamelled decoration on the cover. Cartier and Verger, in France, used imp rovements such as the guillotine with sliding shutters, already invented for dress watches, and Leon Hatot, with the Montle bracelet sevenste having a spring loaded hinged cover, presented his own solution. The latter 's solution was also adopted by most of the Swiss designers such as Wenger, Niton as well as those working for Vacheron Constantin and Patek Philippe. In this respect, one of the most successful solutions was that of the celebrated Revel so invented by Rene Chauvot (French Patent No. 712868 from March 4th, 1931), fast produced by Fontainemelon S. A., often retailed by Giibelin, was then acquired by Jaeger LeCoultre. The cases of most of the watches with concealed dial, produced between 1920 and 1935, were of high quality, often with engraved decoration on the band and bezel, the cover made sometime in two coloured gold with geometrical decoration in an Art-Deco pattern.