Handwritten comparative table on the clutch: freewheel, synchronisation, stopping

In this document

This handwritten working sheet, which is difficult to decipher, bears a reference "A - 8 - 1.55" (uncertain figures) in the top right corner p. 36.

It is presented in the form of a two-column table, the headings of which remain barely legible p. 36.

1st Removal of the freewheel

The first line mentions the "danger of over-revving" on descents and a "difficulty of re-engaging in [free?] wheel at full speed", compared with a solution consisting of shifting to neutral and then performing a "synchronous clutch" at the desired moment p. 36.

2nd Clutching during gear change assembly

This section contrasts the obligation to "feel by sound" the moment when the disc is in phase with the flywheel, with a simultaneous manoeuvre of the clutch pedal and the accelerator, with the idea of an "automatic synchronisation" which would only require a single action on the clutch pedal p. 36.

3rd Clutch at a standstill

The last part mentions disengaging via a "progressive and auxiliary clutch", as well as the need to "maintain" a minimum engine speed to "avoid stalling" during engine braking; a "flap" and a "regulator" are also mentioned, but their precise function remains unspecified due to numerous erasures p. 36.

Context

The vocabulary used — freewheel, synchronous clutch, automatic synchronisation — refers to the technical debates on automotive transmissions of the 1930s-1950s, a period during which manufacturers sought to simplify driving (elimination of double-declutching, partial automation of the clutch).

At Citroën, these reflections are part of the broader search for semi-automatic transmission solutions, a field where Paul Magès conducted several studies in parallel with his work on hydropneumatic suspension. However, nothing in the document allows this sheet to be linked to a specifically named or dated project.

Archivist's perspective

This is likely a draft of personal reflection, where Magès confronts, in the form of an "advantages/disadvantages" table, several competing avenues for improving clutch operation: removal of the freewheel, automatic synchronisation, clutch at a standstill p. 36.

The handwritten reference "A - 8 - 1.55" could indicate an internal classification or an abbreviated date, but its interpretation remains uncertain and does not allow for a more precise dating of the document.

This sheet illustrates the engineer's working method, who records his technical hypotheses in comparative form before developing them. It can be compared to other items in the same collection concerning auxiliary mechanical devices, such as the Handwritten folder "1933": list of studies (gears, injection, carburettor, synchroniser), which also mentions a "synchroniser" among the study subjects of the period.