Tumble Bug

A Tumble Bug is an amusement park ride with a circular track.
The ride has a central axis and a circular track. The track has changes in elevation in it, and the cars, each attached by a rod to a central pivot attachment point and connected together, are propelled around the track via motors between the cars. Power is carried to the motors via slip ring brushes at the center and cables. 
Only one full-sized Tumble Bug remains operating today in the United States, in Pennsylvania: at Kennywood in West Mifflin. All full-size instances were made by Traver Engineering, and its successor, R.E.Chambers. The ride also exists in a miniature children's form. The size of the full-size Tumble Bug is 100 feet in diameter. The full-size has 5 or 6 cars, while the kiddie version has 3 to 4 cars. There are more kiddie versions operating today than there are full-sized. The one in Conneaut Lake Park has been removed as of April 2021. The future of the ride is unknown as of yet.