Description
The “Standard” caliber 691 of the Fabrique d’Horlogerie de Fontainemelon bases on the common FHF caliber 69 and added a center second hand to it.
Since the available space is very low on these form movements, the FHF had to use an extraordinary solution: The fourth wheel indirectly drives a wheel on the top of the main plate, which itselfs drives the center second pinion.
The rest of the caliber 691 is identical to the FHF caliber 69.
Technical data
Manufacturer: | FHF |
Caliber: | 691 (ST) |
Size: | 6 1/4 x 8''' |
A/h: | 21600 |
Number of jewels: | 17 |
Escapement: | Pallet lever |
Balance types: |
Nickel anular balance |
Shock protection(s): |
Incabloc |
Balance bearing / direction hairspring: | Counterclockwise |
Moveable stud: | yes |
Adjust mechanism: | Fonto |
Construction: |
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Winding mechanism: | yoke winding system |
Setting lever spring: | 4 hole(s) |
Features: |
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