Magès' proposal to simplify the gearbox fork control (1935)

In this document

This is a sheet signed by Magès, within the Machining-Assembly Methods department (Mechanical Manufacturing Detection section), dated 3 March 1935 p. 2.

Purpose of the proposal

The document concerns the "Gearbox" component and more specifically the Fork control. It is a "Modification proposal", the motive for which is explicitly twofold: "Reduction of Cost Price" and "Quality Improvement" p. 2.

Technical principle

The text explains that "the position of the levers being able to be raised to the maximum, the engagement of these levers will be done in a more correct way, hence a reduction in the operating effort" p. 2. The associated sketch details a mechanism with a 2nd and Reverse gear lever, a 1st and Reverse gear lever, a splined spring-loaded shaft, a flywheel housing equipped with a ball and spherical bushings tightened in their housing, as well as a cross-section of the water pump in the upper part of the drawing p. 2.

Tabulated summary of operations

The handwritten table details the savings and additional costs in time related to the modification:

The document mentions a "Total gain" of 5*70, as well as additional savings of "3 studs - 2 screws - 3 nuts & washers - 1 key", a "time saving during assembly", a "saving of one Técalémit grease nipple" and a "material saving" p. 2.

Context

This piece is part of the engineering work carried out at Citroën in the mid-1930s, a period marked by the launch of the Traction Avant and a constant concern for the industrial rationalisation of cost prices — a logic typical of the work organisation methods (time and motion) then booming in the automotive industry.

This work is situated in the very first years of Magès' career at Citroën, which he joined in August 1925 at 17 and a half years old and where he would remain for 49 years, first as a self-taught technical writer before climbing the ranks (autobiographical notes); he would enter the design office on the occasion of the braking limiter for the TUB van in 1939-1940, before designing the hydropneumatic suspension.

The mention "PV 11 cv" in the file title likely refers to a project for direct gear control for this model, without this link being made explicit in the present sheet itself.

Archivist's perspective

This document illustrates the methods/manufacturing side of Magès' work, before he became the famous inventor of the hydropneumatic suspension: here, it is a classic workshop engineer's exercise, seeking to simplify a mechanical part to reduce costs and machining time.

The meticulous costing, minute by minute, operation by operation p. 2, testifies to a very rigorous and quantitative approach, characteristic of Magès' self-taught background and his gradual ascent within Citroën, from technical writer to deputy head of Super-Control.

This sheet seems directly linked to the sketch plate from the same file, dated the same day, which undoubtedly details the technical solutions sketched here further.