Constant depression carburettor: patent application plates (1935)

In this document

These two plates present technical drawings of a constant depression carburettor, produced as part of a patent application.

Plate 1 (p. 1)

It contains cross-sections a-b and c-d, showing an inverted Y-shape with a central piston/valve mechanism, a spring topped by a knurled screw, and an articulated lever equipped with a rack. Arrows indicate the circulation of air on both sides of the Y-base p. 1.

The plate also includes a Section J-K detailing a mechanical part with an axis (reference "13"), a Section m-n showing a spring/knurled screw assembly joined by bolts, as well as a Plan (lever A removed) offering a top view with letter markers a, b, c, d, e, f, g and parts designated F and G p. 1.

Plate 2 (p. 2)

This second plate develops the Section e-f (articulated mechanism with ball and cross-sectioned part) and the Section g-h, a central view showing a symmetrical double-cone assembly, a vertical axis, levers and springs marked "A", as well as a rectangular reservoir containing a liquid, connected by piping p. 2.

A Plan (lower part) presents a circular splined part with orifices, connected to a rectangular part, with markers "e" and "f" referring to the corresponding section p. 2. Fragments of the J-K and m-n sections already seen on page 1 are found at the edge.

Plate 2 bears the handwritten or printed mention: P. MAGÈS 35 Av. Edouard Branly - Chaville (S.O) p. 2.

Context

This 1935 patent is situated before Paul Magès joined Citroën in August 1925... — no, let us clarify: it is situated about ten years after he joined Citroën in August 1925, at the age of 17 and a half, where he became a technical writer and then assistant manager of the Super-Control (autobiographical notes). The Chaville address on plate 2 corresponds to his personal home at the time, a filing made on an individual basis, several years before he worked on the braking limiter for the TUB van (1939-1940) and then on the hydropneumatic suspension, the first plans for which date from 17 February 1944 (hydropneumatic suspension plans).

The carburettor, an organ responsible for metering the air-fuel mixture feeding the engine, was the subject of much research at the time aimed at improving the operating regularity of internal combustion engines, particularly through vacuum compensation systems. This general context sheds light on the subject of the document, but no details on the industrial future of this invention appear in the transcribed pages.

Archivist's perspective

These plates bear witness to a phase in Paul Magès' career at Citroën where he was, it seems, carrying out patent filing activity on a personal basis from his home in Chaville, as indicated by the address on page 2 p. 2, nearly a decade before he turned to the research on hydropneumatic suspension that would make him famous.

The precision of the cross-sections and plan views, with a coherent system of markers (letters, sections), suggests a file prepared with care for a patent application — probably intended to accompany a technical description not attached to this archive today.

It would be interesting to compare this document with other items relating to patents filed by Magès in the 1930s, if such archives exist in the collection, in order to better situate this invention in his career as an engineer, then employed at Citroën.