Figure plates 1 to 5 of the automatic height adjustment device (1946)

In this document

This archive gathers five numbered plates of technical diagrams, without explanatory text accompanying the figures themselves (the legends are limited to the numerical and lettered markers visible on the drawings).

Figures 1 and 1bis — four-wheel mechanism

Fig. 1 p. 8 shows a suspension system covering the four wheels of the vehicle, designated AVG, ARG, AVD, ARD (front-left, rear-left, front-right, rear-right). Each wheel is connected to a spring, with horizontal rods connecting the elements to each other, and about fifteen parts marked with circled numbers (from 1 to 15, plus their "bis" equivalents on the right side) p. 8. Fig. 1bis details a side view of a wheel with its suspension arm and a small articulated cylinder p. 8.

Figures 2, 3 and 4 — cylinders and hydraulic circuit

Fig. 4 p. 9 presents a distribution diagram with three superimposed blocks connected to the four wheels (AVG, AVD, ARG, ARD), bearing the outputs HAV (front) and HAR (rear) as well as an IT line, all powered by a reservoir R and a pump P. Fig. 2 and Fig. 3 detail, in cross-section, cylindrical cylinders articulated to arms connected to the wheels, with series of markers numbered from (16) to (26) p. 9.

Figure 5 — circuit variant

Fig. 5 p. 10 proposes a variant of the hydraulic circuit: reservoir R and pump P feed a first distribution block towards an output IT', then a second block with inputs SG and SD (probably "left output"/"right output"), redistributed towards the four wheels AVG, ARG, AVD, ARD. Two additional sketches show, for the front wheels, a cylindrical cylinder and a spherical element evoking an accumulator p. 10.

Context

These plates accompany, in the same folder, a 1946 technical note on automatic height adjustment — the reader can refer to it for the written description of the device. Historically, this type of research at Citroën would lead a few years later to the hydropneumatic suspension, whose "spherical" element (gas accumulator) would become a technical signature, notably on the DS presented in 1955. Nothing in the diagrams themselves, however, mentions these later developments.

Archivist's perspective

These plates appear to be the technical illustrations intended to accompany the 1946 note on automatic height adjustment and transverse stabilization p. 8-10. The presence, as early as Fig. 5, of an element with a "spherical" connotation connected to the hydraulic circuit p. 10 is particularly interesting: it could constitute an early prefiguration, in Magès's work, of the principle that would later become central to the hydropneumatic suspension — but this hypothesis needs to be compared with the text of the Technical note "Device for automatic height adjustment of motor vehicles and transverse stabilization" which accompanies these figures.