DISRAELI DOCUMENTS

USSR Patent # 850,485

USSR Patent 850,485 - Perm main image

This is the first of three derailleur patents filed by the ‘Perm Machinery Factory named for the October Revolution’ in Perm, Russia. These patents have some notable features:

  • The first two have one adjustment screw on the centre line of each knuckle, in the style of a Gian Robert.
  • All three use aluminium castings for the parallelogram plates (rather than the steel pressings more characterisitic of Kharkov designs of the period).
  • They feature a parallelogram spring that is not attached to either knuckle but sits in the centre of the parallelgram, acting between the parallelogram plates.

This particular patent features a rather odd parallelogram spring arrangement using a flat strip of spring steel formed into the shape of the letter ‘S’.

As an aside, the derailleur in this collection that I have called Kharkov 4th style shares the first two of the ‘notable features’ listed above. It also features Gian Robert’s idiosyncratic (and possibly expensive) twin parallelogram spring design - that could be seen as the inspiration for the third ‘notable feature’. Finally it sports a logo that could be seen as В for Велта (Velta) - a brand used by Perm. However I have only ever seen this derailleur fitted on Kharkov bikes and featured in Kharkov literature - so I will continue to consider it a Kharkov product - at least for now.


  • Publisher: Rospatent
  • Inventor: Yuri Petrovich Potekhin, Valery P. Kartashev & Leonid I. Arhalovich
  • Country: Russia
  • Date: USSR application filed September 1979
  • Derailleur brands: Perm
  • Derailleurs: unknown
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