I believe the Adams Trail-a-bike out of Canada was the first item of this type that was openly marketed at least in the US and Canada around 1993. May have been something like it marketed in other countries before then. Guy in California had some design patents on a product he called the Alley Cat and sold rights to a number of distributors and soon after spin-offs hit the market in large numbers in 1994-5. That Yates certainly looks older than early 90's with that 600 headset.