Clock Conservation Project: A.Brocot and Delletrez c.1850
By Eliott Colinge, PG/MA Conservation Studies, Clocks and Related Objects
This French clock signed A.Brocot and Delletrez presents an unusual disposition of the striking mechanism parts. The striking parts on the front plate were missing on receipt of the object in the workshop. The presence of a square section on the hammer detent indicated that there was originally a gathering mechanism working with the striking rack.
A description of the mechanism was found in Chavigny's work on the Brocot family (Les Brocot, une dynastie d'horlogers, by R. Chavigny, Editions Antoine Simonin, Neuchâtel, CH, 1991, pp. 177-181) and revealed that a patent was issued for this mechanism around 1850 by Antoine Brocot.
Following the description and the measurements available on the existing mechanism, a design was made using Autodesk® Fusion 360™, a computer assisted 2D and 3D drawing software. An animation of the mechanism shows the functionality of the missing parts (Fig.5)
This model provided a critical thought process regarding the interactions between the different components, simplifying their later making.
Figure.1 below shows the different steps of the project. On the right is the photograph of a similar mechanism found in the book by R. Chavigny, Les Brocot, une dynastie d'horlogers. In the middle is the 3D model, and on the left is a photograph of the actual mechanism with the newly made parts.