DISRAELI DOCUMENTS
see also French Patent # 796,583 - Spirax 1935
see also French Patent # 796,583 - Spirax 1935
see also French Patent # 849,729 - Chaluret 1939
see also French Patent # 849,729 - Chaluret 1939
see also L'Auto 18/04/1944 - Chaluret ad
see also L'Auto 18/04/1944 - Chaluret ad
see also French Patent # 934,933 - Spirax 1946
see also French Patent # 934,933 - Spirax 1946
see also Le Cycle 12/1946 - image of Le Spirax Cyclo-Tourisme
see also Le Cycle 12/1946 - image of Le Spirax Cyclo-Tourisme
see also Chaluret flyer - 1949
see also Chaluret flyer - 1949
see also French Patent # 1,020,378 - Spirax 1950
see also French Patent # 1,020,378 - Spirax 1950
see also Chaluret flyer - 1950?
see also Chaluret flyer - 1950?
see also Unknown French magazine - 1950? Après le 37e Salon de l'Automobile et du Cycle
see also Unknown French magazine - 1950? Après le 37e Salon de l'Automobile et du Cycle
see also Le Cycliste 1952 - Spirax ad
see also Le Cycliste 1952 - Spirax ad
see also Cyclo - Origine du dérailleur 1959
see also Cyclo - Origine du dérailleur 1959
see also French Trademark # 1,168,023 - Spirax 1981
see also French Trademark # 1,168,023 - Spirax 1981
see also New Cycling 05/1981 - Derailleur Collection
see also New Cycling 05/1981 - Derailleur Collection
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 trademark was last renewed in 1981, but I would be surprised if the derailleurs were manufactured much after 1960.
