Citroën dimensioned drawing of a cylinder body / suspension shock absorber (15-16 June 1949)

In this document

The official title block

The sheet bears the printed header of the Société Anonyme André Citroën, with the mention "REPRODUCTION INTERDITE" p. 1. The title block indicates the part designation: "Corps de cy[lindre] / [amortisseur] de suspension" p. 1, as well as the references E 651.328, E 401.818a and the drawing number E 42 401 F. p. 1. It specifies "VALABLE POUR 653" and "LANCÉ PAR NOTE N° 653", with the name Vinter and the handwritten date 15-6-49 p. 1.

The dimensional specifications

A table entitled "SPECIFICATIONS" lists seven diameters (Ø1 to Ø7) and four face dimensions (F1 to F4), with tolerances of maximum concentricity 0.05 for Ø2 and Ø4, and an indication of "maximum run-out 0.005 relative to XY" for Ø6 p. 1.

The technical views

The drawing includes a "Coupe a" (Section a) of a hollow cylindrical part, with the references F1, F2, Ø1, Ø2 and a dimension "3.5 mm", as well as an angle "Pente 5°" (5° slope) p. 1. A "Section b" details a threaded end piece with "8 equidistant holes p.3" p. 1. Another perspective view shows a part featuring the references Ø6, Ø7 and several radii (r-14, r-15, r-5) p. 1.

A handwritten annotation diagonally bears the date "16-06-49" p. 1, as well as a circular red stamp bearing the number "64" p. 1, the function of which is not specified.

Context

This type of dimensioned drawing corresponds to post-war design office practices at Citroën, where every mechanical part was subject to a standardized sheet before mass production. The mention "corps de cylindre / amortisseur de suspension" is part of the work carried out at that time in the design office on suspension systems: Paul Magès had already filed plans for hydropneumatic suspension with differential interaction as early as 17 February 1944 (Plans de suspension hydropneumatique à interaction différentielle), and the first tests on the 2 CV had taken place in May-July 1946 (Cahier des premiers essais de la 2 CV à suspension hydropneumatique), i.e., three years before this 1949 drawing. This system would lead to the presentation of the 15-Six H in April 1954 (Essai de la 15-Six H) and then to the DS in 1955. However, this connection remains a contextual association external to the document itself, which mentions neither the DS nor the hydropneumatic principle, nor the name of Paul Magès.

Archivist's perspective

This technical drawing, dated 15-16 June 1949 p. 1, constitutes a raw and anonymous manufacturing document in its content — no designer's name appears on it except for the checker "Vinter" p. 1. It is likely a production part from the design office, rather than a document directly signed by the hand of Paul Magès, who at that date held positions as a technical writer and then as deputy head of the Super-Control within the same company (Brouillon de lettre de Paul Magès à M. Sarre).

Its interest lies in the extreme precision of the required tolerances (concentricity to 0.05 mm, run-out to 0.005 mm), revealing the manufacturing requirements specific to the suspension components of the time. It appears to be a jacking or damping part, consistent with the research conducted in parallel on oleopneumatic suspension, for which Paul Magès' initial plans date back to 1944.

This document would benefit from being compared with other contemporary drawings bearing similar references (E 651.xxx), if they are preserved in the collection, in order to reconstruct the complete mechanical assembly of which this part is only one element.