History

Disclaimer: The history of crimping is a bit mired in corporate propaganda, to say the least. Also the patent situation also gets quite muddy, especially in the early part of the 20th century, but here is my best guess for a timeline of events.

• 1924
  • G.H.E. Berthold patents a Closed Frame *six* indent crimp tool for Rajah Automotive Products, it appears to be bench-mounted and is intended for automotive spark plug connectors.

• 1930
  • C.A. Rowley patents an Open Frame spark plug connector crimp tool for Rajah Automotive Products, but this time it's handheld. (AFAICT this one was actually manufactured in meaningful quantity, as it can be readily found on online auction sites)

• 1935
  • H.A. Douglas of the H.A. Douglas Manufacturing Company patents a handheld Closed Frame *four* indent crimp tool for their “snap terminal”

• 1941
  • Stephen N. Buchanan patents the modern closed barrel Ring Terminal for Aircraft Marine Products