Ulysse Valentin - Originele technische tekening – “Diagramme de distribution – Arbres à cames et engrenages” c1910/20

Original technical drawing – 'Distribution diagram – Camshafts and gears' – Ulysse Valentin, École Professionnelle de Mécanique, Huy (Belgium), circa 1910–1920

Very beautiful and rare original hand-drawn lesson plate from the early 20th century, originating from the École Professionnelle de Mécanique – Section Automobile in Huy (Belgium), and signed by Ulysse Valentin, professor of auto mechanics and head of service in Marchin.

This diagram illustrates in detail the operation of the camshaft, the transmission via gears, and the valve timing diagram of a four-stroke engine.
It systematically demonstrates how the rotation of the crankshaft synchronizes the valve operation via gear pairs and the camshaft.

The illustration consists of:

At the top: three consecutive diagrams of the camshaft with cam profiles (A = Admission / E = Échappement)

Right: cross-section of gears with rotation angles of 90° and 180°.

At the bottom: timing diagrams with arrow directions and phases of valve opening and closing.

bottom left: signature and stamp of the professor

The entire drawing is hand-colored with watercolor in soft shades of yellow, blue, purple, red, and green, using East Indian ink. The combination of technical precision and aesthetic finishing makes this a masterpiece of technical education.

Distribution diagrams – Camshafts and gears
Period: ca. 1910–1920
Origin: École Professionnelle de Mécanique – Section Automobile, Huy (Belgium)
Author: Ulysse Valentin, Professor of Automotive Mechanics
Technique: East Indian ink and watercolor on drawing cardboard.
Dimensions: approximately 70 × 50 cm
Numbering: red stamp 'No 31'.
Condition: very good – some small age spots, light edge traces, no tears (see photos).

Details

Original, hand-drawn technical educational material

Signed and stamped by Ulysse Valentin

Beautiful diagram of clock timing and gear transmission.

Decorative and historically valuable – ideal for framing.

This diagram was used in automotive education to give students insight into the operation of the camshaft and valve timing in four-stroke engines.
Precision and visual clarity demonstrate the high level of technical drawing education in Belgium around 1910–1920, when mechanical principles were still explained without digital or photographic aids.

A rare and aesthetic document that connects technology, art, and the beginning of automotive history.


Short biography of Ulysse Valentin

Ulysse Valentin (active from the early 20th century) was a professor of automotive engineering in Hoei and Marchin (Liège province, Belgium). He trained young technicians and driver-mechanics during a time when the automobile was still in full development. Valentin was known for his didactic approach, producing large and precise diagrams that helped students understand the workings of engines and vehicles.

His education reflects the transition from horse-drawn carriages to cars. The signatures and stamps on his students' drawings and diplomas make these documents valuable testimonies of the early history of motorsport in Wallonia.