This ‘modernised’ version of the traditional triangular Simplex trademark was filed in the US in 1960. It refers to an earlier French trademark of 1957 - although, confusingly, it does not acknowledge 1957 as the priority date. My guess is that this logo does date from 1957.

• Publisher: US Patent and Trademark Office
• Inventor: Lucien Juy
• Country: USA
• Date: application filed September 1960
• Derailleur brands: Simplex
• Derailleurs: nothing specific