Skateboard inventions with a difference

Skateboards have been around for decades, with the earliest patent with the word in the title being Skate board provided with longitudinally adjustable wheel carriage units by Louis Bostick of California, filed in 1965. The sport actually goes back a few years earlier. Over 700 US patent specifications since have used that word in the title. This post is on some of the more unusual ones.

There's for example Control system for a skateboard type device by Samuel Shiber for Saroy Engineering of Illinois, filed 1975:

Combination cycle seat-skateboard by Charles Persons II and Robb Harst, both of Ohio, for Persons-Majestic Manufacturing Company of Massachusetts, filed 1978, the idea being that the seat part of the bicycle can be detached to form a skateboard (see the tiny wheels underneath the saddle):

Radio controlled skateboard with robot by Steven Derrah of Rhode Island, filed 1997:

Solar skateboard by Chien-Ching Su of Taiwan, filed 2006:

Motorized skateboard  by James Hawkins of California, filed 2009:

Self-propelled skateboard by Craig Gager of London, UK, filed 2010:

Finally, only published a few weeks ago, is Electric skateboard by Aaron King for Redrock Boardshop, both of Florida, with a very cool looking drawing showing it in action. Looks like he's on his way to work, though actually he has batteries in his backpack (which would be heavy, I think ?).