Citroën Plan No. E.795.050 — Brake stop contacts (March 1951)

In this document

This technical plan bears the reference No. E.795.050, designating a brake-clutch receiver assembly (page 1, designated "Ensemble récepteur frein Embrayage. D.D.19") and, on the second plate, a brake-clutch pedal assembly ("Ensemble pédalier frein - Embrayage - D.9.0.9", p. 2). Both pages therefore belong to the same plan file, but show different sub-assemblies.

Contacts and usage

Handwritten annotations specify the function of the parts represented: "Contacts de [Sigap/Stop] pour frein seulement" appears on both pages (p. 1, p. 2), with the repeated mention "Pour Frein seulement. Pour Embrayage : Bouchon N° E.795.039" on page 1 and "N° E.735.039" on page 2 (numbering slightly different depending on the page, to be noted as such).

Material and dimensions

The sheet metal used is indicated: "Tôle 1/10" p. 1 and "Tole 12/10" p. 2. Axis dimensions also appear: "A l'axe de rotule de dr.-BO" and "A l'axe de débatage. 130" p. 1; "A l'axe d'embrayage 130" and "A l'axe du volant de 80" (p. 2, figure uncertain).

Dating and persons in charge

The red title block on page 1 bears the date "2-03-51" and the reference "N° MT (51)"; the one on page 2 bears "8-03-51" with the same reference "N° MT 51". The archive stamps mention a date ending in "1951" p. 1 and "2 mars 1951" (uncertain reading, p. 2). The title blocks are signed by Baudin P., on 2/8/51 p. 1, and by a name read as "Bacoin", on 2/9/51 (uncertain, p. 2).

Context

The early 1950s were a pivotal period at Citroën: technical teams were already preparing the major innovations of the future DS, presented on 6 October 1955, notably the hydraulic braking and suspension systems on which Paul Magès would work intensely — the first hydropneumatic suspension plans dating from 17 February 1944 (Plans de suspension hydropneumatique à interaction différentielle) and the first 2 CV tests of May-July 1946 (Cahier des premiers essais de la 2 CV) preceding this March 1951 plan, itself prior to the 15-Six H test of April 1954 (Essai de la 15-Six H).

A "brake-clutch pedal assembly" and its "stop contacts" — that is to say, the switches activating the brake lights — fall under the standard engineering for the development of a production vehicle; this type of plan is part of the daily work of the Citroën design offices of the time, where Paul Magès, who joined the design office around 1939-1940 after having designed the braking limiter for the TUB van (Brouillon de lettre de Paul Magès à M. Sarre), was then serving as deputy head of the Super-Control, without the document allowing for the identification of a specific car model here.

Archivist's perspective

This diptych of plates, dated March 1951, illustrates the detailed work carried out within the Citroën design offices on components that are seemingly minor — a set of stop contacts — but essential to the safety of the vehicle.

The plan number E.795.050 common to both pages, as well as the proximity of the dates (2 and 8 March 1951), suggests that it is the same technical file processed in a few days, between the receiver assembly p. 1 and the pedal assembly p. 2 to which it is attached.

It is not possible, from reading these plates alone, to confirm a direct link with Paul Magès' personal work on hydraulics; the document presents itself as a classic design office piece, contemporary with the hydropneumatic research already underway but prior to its public culmination with the presentation of the DS in 1955.