Gizmag has an article on the new Ryno self-balancing unicycle which has apparently been a big hit on the Web (although I missed it). It will soon be shipping, at a price of $5250.
The story includes an interview with Chris Hoffmann, the inventor, who attributes the idea to his then 13-year old daughter, Lauren's, question. She had seen a one-wheeled motorcycle on a video, and drew a sketch of what she had in mind. Why weren't they around ? She reminded Dad that he was an engineer.
Hoffmann began to work on the idea, incorporating a gyroscope to maintain balance for the vehicle. When the Segway(R) came out gyroscopes cost $500, now they are just $10. Bringing the costs down was crucial. Seven years on, he is almost there with the product launch at the Ryno company website. By the way, their application for Ryno as a US trade mark was made in August 2013 and is pending registration.
I have found two patent applications by Christopher Hoffmann.
In August 2012 there was published a US patent application by Hoffmann and Anthony Ozrelic, Electric-powered self-balancing unicycle with steering linkage between handlebars and wheel forks. Below is one of its drawings.
The crucial patent document, though, is one that was published as both a US patent application and as a "World Patent" application on the 27 February 2014, the Electric-powered self-balancing unicycle. It was made by the same two men on behalf of Ryno Motors of Beaverton, Oregon. It is an A2 document, meaning that it is without a search report at the end listing prior art that might invalidate the concept. That might be published weeks, months or even a year or two from now, as an A3 on Espacenet's bibliographic entry for that invention.
There are 11 drawing pages -- here are three of them, which are full of interest.
I look forward to seeing the Ryno racing past me on the road. Being electric, it appears to be rather silent in comparison with normal motorcycles. I regard that as a Good Thing.