Technical drawing DS 314-11 — Clutch control cylinder, type T detail

In this document

This technical plate is a dimensioned drawing of the DS 314-11 clutch control cylinder, drawn at several scales with a type T detail at scale 5 p. 17.

Dimensions and reference table

A table on the left page lists references and positions: Ø3 = 25.38, F = 30.41, Ø2 = 28.49, Ø4 = 29.18, all relative to Ø1 (23.40), with form tolerances: max run-out = 0.1 and max warping = 0.2% p. 17.

The drawing also specifies two holes Ø 7.75 max centered on Ø1, as well as a thread Ø 21 pitch 1.5 centered on Ø1 p. 17.

Section views and details

Several views detail the part: Section A (Ø32, Ø27, radii r=5, sharp angles), Section C (threaded hole Ø9 pitch 1.25, chamfered angle, Ø4.6 +0.25/+0.15), Section B (angle 60°, Ø2, radii r=5 and r=8), and the Type T detail (angle 35°, dimension 0.7, Ø18.49, symbol m2) p. 17.

Dimensions of the type Ø1 = […]+0.021, 23.3, Ø3 = 23.8+0.05 appear on the right page, associated with roughness symbols (∇g) p. 17.

Title block

The title block indicates: draftsman Bourget, checker Belloncle, industrialization Guyétant, with the dates 27.12.56 and 4.1.57; on the laboratory side, the visas Pompon (Lab), Caneau (M.T.), Cadiou (B.E.A.) p. 17.

The official designation is "CYLINDRE DE COMMANDE DE DÉBRAYAGE" (Clutch control cylinder), material Cast iron CA, without treatment or coating, with weight indications (FAB 295, LIM 338). The drawing is released by note no. 28311, replaces a previous drawing, and concerns the DS 314-02 assemblies. Two handwritten modifications are noted: (m1) 33/79 28500 and (m2) 15/72 19/42 28851 p. 17. The legal notice "SOCIÉTÉ ANONYME ANDRÉ CITROËN — REPRODUCTION INTERDITE" appears at the bottom of the plate p. 17.

Context

The clutch control cylinder is a component of the DS hydraulic circuit, which used the pressure of the hydropneumatic system to actuate several mechanical functions, including the semi-automatic clutch — a notable feature of DS driving at the time.

This type of dimensioned drawing, with a title block of successive visas (drawing, verification, laboratory, B.E.A.), corresponds to the rigorous industrial manufacturing methods of Citroën in the 1950s, where every critical mechanical part was validated by several departments before mass production.

Archivist's perspective

This plate is part of a series of drawings dedicated to the same organ: the clutch cylinder of the 314 family, of which earlier and later versions can be found in the collection — notably drawing D314-02 from 1954 and drawing DS 314-02 from 1957.

The coexistence of the dates 27.12.56 and 4.1.57 in the title block p. 17 suggests that this document was likely finalized at the turn of the year 1956-1957, which is consistent with the dating retained to the day.

The level of detail of the tolerances (run-out, warping, dimensions to the hundredth of a millimeter) testifies to the care taken by Paul Magès' teams for the reliability of the hydraulic organs, essential for the proper functioning of the suspension and power-assisted controls of the DS.