Technical diagram sheet P.5043 — servo-controlled anti-roll circuit (Fig. 1)

Handwritten technical drawing sheet (Fig. 1, ref. P.5043) showing the hydraulic diagram of a servo-controlled anti-roll device, with its springs, cylinders and measurement circuits, dated 8 April 1965.

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Presentation and original captions

On 17 July 1961, Paul MAGES described in a 6-page handwritten document, a servo-controlled anti-roll device for a motor vehicle. Following this document, we publish: -The photos of two DS in the middle of a high-speed turn, the first is a production DS, the second is equipped with the servo-controlled anti-roll system, the photos are "telling" -The photos of the front left tyre of the production DS, and of the front left tyre of the DS equipped with the servo-controlled anti-roll system, on the same circuit, under the same driving conditions, notice the difference in tyre wear -Photos of the installation of the servo-controlled anti-roll system of the front and rear suspensions, it is a test prototype, it shows.

Understanding this document

In this document

This is a technical drawing sheet on a printed form "Sté Anme A. Citroën", bearing the handwritten mention "Fig.1" and referenced P.5043 p. 7.

The diagram

The handwritten pencil sketch represents a complex mechanical assembly of the suspension/anti-roll type, in perspective. One can distinguish in particular:

parallel tubes or bars;
four helical springs marked R1, R2, R3, R4;
a series of numbered cylinders and parts (from approximately 1 to 18, some with an apostrophe: 1', 2', 3', 4'…);
reference letters B, D, V, X, X' associated with arrows;
two thin-lined circles, which may represent wheels, partially superimposed on the drawing p. 7.

At the top of the diagram are two circles connected by a pipe, marked P and A, themselves connected to a reservoir drawn below — the whole evoking measuring devices (pressure, ammeter or equivalent) connected to the circuit p. 7.

Identification elements

The sheet bears the handwritten inscription "P.5043" at the bottom left, an illegible initial and the date "8.4.65" at the bottom right, as well as the printed mention "MODIF." p. 7. Print references for the form also appear at the bottom of the page: "M M 6.59 - 6000" and "1 A 4 - 2" p. 7. Traces of earlier text, very faint, are visible in the background of the page but remain illegible.

Context

The code P.5043 likely corresponds, as was the custom at Citroën at that time, to an internal project or patent file number. The date of 8 April 1965 places this document a few years after the first work on the servo-controlled anti-roll device, the principle of which had been filed as early as 1961 (reference P 2908).

This type of sheet, produced on a standardized "Citroën" form, corresponds to the routine work of design offices: translating into a dimensioned and referenced diagram the mechanical and hydraulic principles of a device intended, eventually, to equip test or production vehicles.

Archivist's view

This sheet is likely a continuation of Paul Magès' research into the hydropneumatic stabilisation of vehicles. The presence of several springs (R1 to R4) and circuits connected to measurement cells (P, A) suggests that this is a principle diagram intended to formalise an assembly already tested, rather than a first design draft p. 7.

The comparison with the Note "Servo-controlled anti-roll for motor vehicle" (ref. P 2908), which predates it by several years, suggests a direct lineage between the initial idea of 1961 and this technical formalisation of 1965. The photographic report of the installation on a test vehicle could shed light on the concrete implementation of this same device.

Finally, the mention "MODIF." suggests that this diagram may have been subject to successive revisions, without the document allowing the exact nature of these to be specified.