Citroën Plan E833 2704 — Hydraulic gear and clutch control (17 Nov. 1955)

In this document

Handwritten sheet (page 1)

A note dated "17-11-55" p. 1 bears the mention "Ancien bloc Ch'V[uncertain] DS" p. 1, with a word surrounded by a curved line. A technical drawing appears as a watermark under the text, as well as a partially legible stamp at the bottom of the page p. 1. The precise content of the central handwritten text remains uncertain to read.

Bobelin technical plan (page 2)

The official title block identifies the document as a plan of the Société Anonyme André Citroën, bearing the mention "REPRODUCTION INTERDITE" p. 2. The designation inscribed in the title block is: "Schéma de fonctionnement de la cde hydraulique de vitesses et d'embr.ge" p. 2. The plan is referenced N° E833 2704 p. 2, with no launch note or replaced plan indicated.

The handwritten mention "Bobelin 17.11.55" appears in the "VALABLE POUR" box p. 2, alongside an illegible initial.

The main drawing represents a longitudinal section of a mechanical assembly composed of several vertical cylinders or spools, with springs, balls and internal piping p. 2. A reference diagram in the title block identifies four points A, B, C, D arranged in a square p. 2, repeated as five markers (D, A, B, C, D) aligned under the main drawing, each corresponding to a vertical axis of the mechanism p. 2. Two additional sectional views appear at the top of the page: an elongated cylindrical organ equipped with a spring (possible distributor or hydraulic spool) and a second cylindrical element connected to a toothed part p. 2.

Context

Generally speaking, it is known that the DS presented by Citroën in 1955 integrated an assisted hydraulic control for gears and clutch, a system on which Paul Magès was then working as an engineer in charge of hydraulics. The term "old block" suggests, in the workshop vocabulary of the time, an earlier version of a component destined to evolve — but this interpretation is based on general knowledge of Citroën development methods, not on the document itself.

Archivist's perspective

This diptych associates a handwritten work note p. 1 with an official technical plan signed "Bobelin" p. 2, both dated the same day, 17 November 1955. It seems that the handwritten note serves as a commentary or personal aide-memoire attached to the formal plan, perhaps written by Paul Magès himself, although this is not explicitly attested in the transcribed pages.

The reference to an "old block" p. 1 suggests that this document records an intermediate stage in the design of the DS hydraulic gear and clutch control, probably to be compared with other plans in the same series bearing neighboring numbers (E833...), if they are preserved in the collection.