Suspension operating diagram with lightening — plate no. 6046

In this document

The plate bears the number 6046 and a title in capital letters: "SCHEMA DE FONCTIONNEMENT DE SUSPENSION AVEC [uncertain: "ALLEGEMENT"]" p. 4.

The circuit diagram

The document presents a technical diagram oriented at 90°, showing two helical springs in cross-section (top and bottom of the plate), connected by piping to a central mechanical assembly. This central device includes points marked A, A', B, B', C, associated with a diamond-shaped symbol with a cross p. 4.

A handwritten note "VERS L'OUVERTURE" (TOWARDS THE OPENING) accompanies this central device, and piping lines lead to an element noted "DU RESERVOIR D'AIR COMPRIME" (FROM THE COMPRESSED AIR TANK) p. 4.

The load/deflection graph

At the bottom of the plate is a graph drawn freehand or with instruments, with graduated axes (marks 1, 2, 3, 4). Three quantities are named: "CHARGE MAXI STATIQUE" (MAX STATIC LOAD), "CHARGE MOYENNE" (AVERAGE LOAD), and "CHARGE" (LOAD), along the axes; a mention at the end of the horizontal axis, difficult to read, seems to indicate "[uncertain: "FLECHE"]" (DEFLECTION) p. 4.

A technical cartouche, at the bottom left, contains a tabular frame whose handwritten content remains largely illegible p. 4.

Context

This type of plate evokes, by its form, the studies conducted at Citroën on the hydropneumatic suspension, a system where a volume of compressed air replaces the classic metal spring to carry the vehicle's load while ensuring progressive damping.

The notion of "deflection" (deformation of a spring under load) and load/deflection curves are classic suspension engineering tools, allowing the comparison of the behavior of a metal spring to that of a pneumatic system — a comparison that would become central in the patents and tests associated with this type of suspension.

This contextualization remains external to the document: nothing in the plate itself mentions Citroën, the DS, or a precise date.

Archivist's perspective

The number 6046 suggests that this plate belongs to a numbered series of technical diagrams, probably linked to the development work on suspension systems mentioned elsewhere in the collection. The combination of a pneumatic circuit diagram and a load/deflection graph suggests that this document aimed to illustrate, for the same device, both its mechanical operation and its behavior under load p. 4.

It seems relevant to compare this piece with the Comparative load/deflection chart: metal spring vs air cushion, which deals with the same type of load/deflection comparison, as well as the Dimensioned plans in Italian of a suspension element (SACA), which could document a part of the same mechanical assembly.

The absence of a date and the difficulty in reading several handwritten notes invite caution regarding the precise interpretation of the A, A', B, B', C device, whose exact function is not explained in the visible text.