Lightweight handcuffs. A basic time-line?

Does anyone have a very brief time-line of when lightweight metal handcuffs appeared during the 20th centuary and what prominent or note-worthy models stand out and when approx they were first made? Even if it's an uncertain general sense of what period of time?

Very good website by the way.

"Lightweight" compared to what? There are lighter versions of standard handcuffs using less metal and lighter versions using a lighter metal. What country are you talking about? Are chain cuffs included? Timeline probably starts in the late 1700s.