CANNON-PINION
Cannon-pinion is a cylindrical pinion maintained on the centre wheel thanks to a friction called indenting. The minute hand is fixed on the carriage.
The correct adjustment of this indenting is very important. It should be strong enough to stop the movement when the hands go backwards when setting the time, so that the watch can be set to the exact second, but it should not be too strong either.
The correct lubrication of this friction point is also very important. In the long run, when the lubrication is no longer good, the indenting is a point that can seize up and then require the overhaul of the movement.
The ancestor of the “chaussée lanternée”, which is the modern “chaussée” found on almost all mechanical watches since the beginning of the 20th century, is the “chaussée à chevillot”. Its configuration was somewhat different. The center axis was drilled and a chevillot, a conical pin slightly roughened and lubricated, crossed the axis and maintained the pavement on the dial side. This system worked relatively well, but the arrival of the lantern pavement was an improvement. The “chaussées à chevillot” are typically found on 19th century cylinder escapement pocket watches.