Cal. JB1 from Excelsior Park was an 18 ligne stopwatch movement produced in the 1920s and 1930s and officially called “compteur de sport ancre” by the company. The crown is used for winding and can house a co-axial button in addition to the button at 11 (with the crown at 12). Excelsior Park made standard, rattrapante (Cal. JB11), and addition timing versions of Cal. JB1. A high-beat (36,000 A/h) version was also produced, with a 30-second dial. Internal documents show the movement called “Cal. B” and that it was available in 20 and 22 ligne versions in addition to 18 ligne.
One notable feature of Cal. JB1 is the distinctive J-shaped barrel bridge, a signature of the Jeanneret family of Saint-Imier. It also includes the Jeanneret spare parts compartment embedded in the movement next to the balance.
Cal. JB1 was protected by Swiss Patent CH3364A, which was published on March 21, 1891. This patent number was prominently stamped on the J-shaped bridge and appeared in advertisements for decades.
Excelsior Park introduced Cal. JB1 by the 1910s, with it appearing in a 1912 advertisement. Notably, this advertisement features the distinctive J-shaped bridge making up the “J” in Jeanneret-Brehm. The logo and movement are marked with patent number 3364, which was issued in 1891 and applied to the predecessor movements produced by Jeanneret-Brehm. It remains listed in the 1950 Excelsior Park catalog, though it was outdated by this point. Still, it is listed as a “first quality” movement compared to the Roskopf stopwatch movements also offered.
Cal. JB1 stopwatches used the “Excelsior” brand before the company took that name.
