Cal. JB1 from Excelsior Park was an 18 ligne stopwatch movement produced from the 1890s the 1920s. It was the first in-house patented movement from the company, which was still known as Alb. Jeanneret & Frères at the time the patent was granted in March 1891. One notable feature of Cal. JB1 is the distinctive J-shaped barrel bridge, which would be a signature of the Jeanneret family of Saint-Imier and was registered as a design trademark in 1903 and renewed in 1918.
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. Although typically shown at 18 ligne, it was also available in 20 and 22 ligne versions. The column wheel (with 5 columns) and control levers are located on the dial side of the movement.
Internal documents from the 1930s show the movement called “Cal. B”, “Cal. B No. 3364”, and simply “Compteur de sport ancre.” Similarly, Cal. JB11 is called “Cal. BR” and “Compteur de sport à rattrapante” at this time.
See Also: Patent CH3364A
Cals. JB1, JB11, and JB15 include the Jeanneret spare parts compartment embedded in the movement next to the balance. This was patented in the 1920s. The parts container included the following text in various languages:
- Dutch: “Hieronder reservedeelen”
- English: “Spare parts in here”
- French: “Ci-dessous fournitures de rechange
- German: “Hier ūnten Ersatzstücke”
- Romanian: “edesubt piese de schimb”
See Also: Patent CH100230A
