Patent sheet: figures 1 to 5 of the steering servo-control device (1958)

In this document

This sheet constitutes the graphic annex to the patent's descriptive memorandum: it presents five numbered figures (Fig.1 to Fig.5) illustrating a servo-control device for vehicle steering.

Fig.1 — Overview

The main figure occupies the entire upper width of the page. One can distinguish a hatched reservoir (reference 17) connected by piping (16, 18, 21) to a circular element (19) and a rectangular housing (20). A vertical axis X-X1 passes through a set of cylindrical parts (15, 6, 8, 7). On the right, a horizontal tubular assembly (1, 5, 3, 4, 27, 26, 2) featuring a zigzag spring is surmounted by a long articulated lever crossing the figure diagonally. Piping (22, 23) connects the assembly to a device featuring an oblique lever (24, 28) p. 8.

Fig.2 and Fig.3 — Sections of the cylindrical mechanism

Fig.2 shows an axial section along the X-X axis, with an intersecting vertical axis Y-Y1, revealing hatched metal parts, springs, and rods (references 10, 8, 6, 5, 7, 9, 11, 13, 1, 14, 18, 16, 22, 23, 15, 12). Fig.3 presents a front view of a circular part (ring) with references 9, 9', 10, 11, 12 p. 8.

Fig.4 and Fig.5 — Details of the cylinder

These two diagrams, very similar to each other, represent a hatched rectangular cylinder or piston, equipped with vertical (24, 25) and lateral (22, 23) rods, connected to an articulated lever (28) p. 8.

The sheet bears traces of partially legible stamps and a handwritten inscription at the top of the page, almost erased, the content of which cannot be restored p. 8.

Context

This type of annexed sheet is the usual form for French patent filings of the time: the textual descriptive memorandum is systematically accompanied by numbered figures, with each numerical reference referring to a part named in the patent text.

The general context — that of research conducted at Citroën in the 1950s on steering servo-control — allows this piece to be situated within a family of inventions related to the control of vehicle road behavior. This 1958 patent is part of Paul Magès' career at the Citroën design office, which he joined after his initial work on hydropneumatic suspension — plans as early as 17 February 1944 (Hydropneumatic suspension plans with differential interaction), first 2 CV tests in 1946 (Notebook of the first 2 CV tests), then DS presented in 1955 — and where he would remain until his retirement in September 1974, after a 49-year career (autobiographical notes).

Archivist's perspective

This sheet is only fully understood when associated with its descriptive memorandum, of which it repeats and illustrates every numerical reference. Taken in isolation, it remains an essentially visual document: the technical diagrams (Fig.1 to 5) provide a concrete image of the servo-control device — reservoir, piping, cylinders, articulated levers — but without an autonomous legend.

It seems that the richness of the references (28 numbers plus the X, X1, Y, Y1 axes) reflects the mechanical complexity of the invention, probably revealing the care taken by Magès in the exhaustive description of the system's hydraulic and mechanical connections. The stamps and the handwritten annotation, illegible, suggest an administrative use (filing registration) that cannot be specified further from this single sheet alone p. 8.