Technical sketches on blank Citroën "Service Modifications" forms

In this document

These two pages are pre-printed forms from the Service Modifications department of the André Citroën public limited company, whose administrative tables ("Reference / Date / Replaces No." p. 29, "Replaced / Date / Part No." p. 30) remain entirely blank. They were reused as simple scrap paper for pencil sketches, with the overall legibility described as difficult.

Page 29

Several mechanical sketches can be distinguished: a cylindrical object topped with a fitting evoking a reservoir, a large central cross-section diagram showing nested cylindrical parts with springs or rods, "evoking a hydraulic part or a cylinder/distributor in cross-section" p. 29. At the bottom of the page, there is an articulated linkage mechanism with a movement arrow, as well as a small simplified electrical diagram featuring a "+" symbol p. 29. A cursive handwritten annotation at the bottom right remains illegible.

Page 30

The form, oriented upside down, also bears sketches: a round part with two concentric circles "evoking a roller or an eccentric" p. 30, a square stepped part, a rounded reservoir equipped with a fitting, and a large central longitudinal cross-section sketch of a complex cylindrical part with partial dimension lines. In the lower part, a linear diagram connects a circle marked "C" to a system of linkages forming an angled dimension ("18°" uncertain), leading to a part annotated "steel". A housing with a fitting marked "F" evokes a hydraulic cylinder or ram. A handwritten annotation in the margin mentions "cam of", and uncertain words including "Ch°. vites" p. 30.

Context

During the interwar period and beyond, Citroën's Service Modifications department managed the tracking of part evolutions on production lines: these forms were normally used to trace the replacement of one part with another. Their repurposing as scrap paper, common in the Magès archives, shows a practice frequent among engineers of the time, who used any paper available in the workshop to quickly sketch a mechanical or hydraulic idea.

Archivist's perspective

These sketches, undated and not legibly captioned, clearly illustrate Paul Magès' informal research work: reservoir shapes, cross-section parts evoking cylinders or distributors, linkage, and even a summary electrical diagram coexist on the same sheet p. 29-30.

It seems that these sketches belong to an exploratory phase, similar in nature to other repurposed sheets from the same file, such as the "Tooling sheet for the part" (B. No. 103) forms repurposed as sketch supports or the K 39-31 "Status of Standard Components Retouched during Assembly" forms. In the absence of usable inscriptions in the printed tables, the precise dating and the exact object of the drawn mechanisms remain unspecified.