DISRAELI DOCUMENTS

Spirax

French Patent 796,583 - Spirax main image French Patent 849,729 - Spirax main image French Patent 1,020,378 - Le Spirax main image


see also French Patent # 796,583 1935

see also French Patent # 796,583 1935

French Patent 796,583 - Spirax thumbnail


see also French Patent # 849,729 1939

see also French Patent # 849,729 1939

French Patent 849,729 - Spirax thumbnail


see also French Patent # 934,933 1946

see also French Patent # 934,933 1946

French Patent 934,933 - Le Spirax thumbnail


see also French Patent # 1,020,378 1950

see also French Patent # 1,020,378 1950

French Patent 1,020,378 - Le Spirax thumbnail


see also Le Cycliste 1952 - Spirax ad

see also Le Cycliste 1952 - Spirax ad

Le Cycliste 1952 - Spirax advert thumbnail


see also French Trademark # 1,168,023 1981

see also French Trademark # 1,168,023 1981

French Trademark 1,168,023 - Spirax thumbnail

Spirax was the creation of Raymond Bon. I believe that the company was based in northern Paris, migrating from Courbevoie in the shadow of La Defense, to La Garenne and then to Andrésy.

Raymond Bon’s first derailleur patents, dating from 1935 and 1939, were for designs incorporating a shaft with a spiral groove it. However, in these designs, this groove was used to manage the chain gap by rotating the mounting of the guide pulley as the pulley is pulled in and out by a toggle chain.

In 1946 Raymond Bon started to develop his signature design. This also featured a shaft with a spiral groove in it - but this time it is combined with a rotating sleeve with a pin to drive the pulley cage in and out - in the style of the classic Cyclo derailleur. Spirax incorporated two innovations. The first was to substitute a single cable for the double cable used by Cyclo, and spring-load the rotating sleeve with a clock-type spring. The second was to use an enclosed spring for the pulley cage, ternsioning the chain without the need for the external spring running along the chainstay. Both were useful improvements. By 1950 Raymond Bon had perfected his design - which sold reasonably well and became an acknowledged success with French cycle tourists.

The Spirax trade mark was last renewed in 1981, but I would be surprised if the derailleurs were manufactured much after 1960.

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