His most notable invention is the Springfree Trampoline .
Dr. Keith Vivian Alexander , a New Zealand inventor , is Professor of Mechanical Engineering at the University of Canterbury , in Christchurch , New Zealand .
Keith Vivian Alexander 's most notable invention is the Springfree Trampoline .
Dr. Keith Vivian Alexander , a New Zealand inventor , is Professor of Mechanical Engineering at the University of Canterbury , in Christchurch , New Zealand .