Segway owner, Jim Heselden, who died after apparently driving one of the company's vehicles of the cliff of his English estate, did not actually invent his firm's signature product. That honor goes to Dean Kamen. But with the Wikipedia has put together a list of inventors who perished using their own inventors. You can find the full list there but here is a subset.of his accidental death garnering so much attention,
Tailor Franz Reichelt designed a suit/parachute that was originally going to be tested on a dummy dropped from the Eiffel Tower in 1912. But when he showed up, Reichelt instead announced that he would perform the jump. It was not successful.
- Otto Lilienthal won international renown for building and successfully testing several hang gliders. But he died on August 9 1896 when his glider lost lift and crashed.
- Li Si, who was an adviser to the Chinese emperor, was convicted of treason and sentenced to death in 208 BCE using the so-called Five Pains method of capital punishment he reportedly invented.
- After contracting polio at age 51, Thomas Midgley, Jr. invented a pulley system to help lift disabled people out of their beds. He died after getting strangled in the device's ropes in 1944.
- William Bullock who invented the web rotary printing press, was severely injured during the installation of one of his machines. His crushed foot developed gangrene and he later died during an amputation operation in 1867.