Cover of the archive folder "Hydrostatic transmission 59-74"

In this document

This is the spine of a red/orange cardboard binder, photographed in profile. Two handwritten labels are affixed to it: one bears the inscription "TRANSMISSION HYDROSTATIQUE", the other the mention "59-74" p. 1.

No other textual information is visible: neither author's name, nor summary, nor precise date beyond this double numerical indication. The transcription therefore does not allow for the detailed content of the folder to be specified, only its filing label.

Context

Hydrostatic transmission is one of the major research projects conducted by Paul Magès and his team at the Automotive Design Office (B.E.A.) of Citroën, in parallel with the famous hydropneumatic suspension. The principle consists of replacing the classic mechanical gearbox with a hydraulic pump/motor pair allowing for continuous variation of the gear ratio.

This research occupied Citroën over a long period, from tests on 2 CV and 3 CV models at the very beginning of the 1960s to more advanced studies, notably around the "L" vehicle project and the GS, in the mid-1970s. The range "59-74" written on the label likely corresponds, in this respect, to the chronological scope of the file rather than a production date of the document itself.

Archivist's perspective

This item is not a technical document in itself, but the cover of an archive folder — probably the physical folder that gathered, in box no. 3 of the Magès collection, all the items relating to hydrostatic transmission over nearly fifteen years p. 1.

It acts as a reference point for classification: the mention "59-74" suggests that the folder covered documents ranging from the end of the 1950s to the mid-1970s, which is confirmed by the presence, in the same file, of items dated 1962, 1964, 1968, 1973 and 1974 — for example the Handwritten notes "Presentation T.H. 50 CV" at the B.E.A. or the Presentation by P. Magès on hydrostatic transmission.

It is therefore essentially an archiving reference, valuable for situating the items it contained, but which does not provide specific technical information on the hydrostatic transmission itself.