Inventors: Kyoji Hayashi and Takehiko Kimura

Assigned to: Shimano

US application filed: March 1966

Japanese application filed: March 1965

Relates to: Shimano Archery

As with US patent # 3,394,604, a couple of things interest me about this patent. Firstly the drawing looks like a picture of a Shimano Archery running an 1/8” chain over a three speed block. Those meaty cogs do not look like they are expecting a 3/32” chain!

Secondly the indexing system (the real subject of the patent) is entirely contained in the lever - unlike Shimano’s Positron system and very like SIS.