Gravity Remontoire

The word remontoire comes from the french word ‘remonter’ meaning “to wind” and describes mechanisms that provide near-constant driving force by isolating and regulating the power from the primary power source. The gravity remontoire was invented by Swiss clockmaker Jost Burgi around 1595. The “Kalenderuhr” (three months running, spring-driven, calendar-desk-clock) Burgi made for William IV, Landgrave of Hesse-Kassel (or Hesse-Cassel) (now Inventory No. U 47 at the Naturwissenschaftlich-Technische Sammlung in Kassel) is widely considered the oldest surviving clock with a remontoire, even if it does not provide power to the escapement during the few seconds of the daily cycle where the remontoire weight gets wound up by the spring.[2] Today remontoire mechanisms are all designed to deliver power to the escapement during the remontoire reset cycle.

With reference to the diagram attached. During normal operation wheel ‘C’ remains stationary and weight ‘P’ falls gradually under the influence of gravity, pivoting about the center of wheel ‘C’ while delivering power to the mechanism.

As weight ‘P’ falls it causes the rotation of pinion ‘d’ against the fixed teeth of wheel ‘C’.

Wheel ‘D’ rotates clockwise with pinion ‘d’ while driving pinion ‘e’ and the coupled escapement ‘E’ counter-clockwise.

Flyback. Soon after the bar supporting weight ‘P’ passes the horizontal wheel ‘G’ is released and it begins transferring power from the main weight or spring to the attached pinion ‘g’ causing it to rotate clockwise. The rotation of pinion r causes wheel ‘C’ to rotate counter-clockwise raising weight ‘P’ back to its initial position. Flyback motion is damped by an air vane connected to pinion ‘f’.

Learn more at: My time machines – Remontoire