David Unaipon invents straight-line shearing machine without credit or compensation in 1909
David Unaipon's shearing machine (at right) is featured with him on the Australian $50 note.
The first straight-line motion shearing machine, invented in 1909, is featured on the $50 Australian note tribute to David Unaipon.
Unaipon developed and patented (provisional patent 15 624) the handpiece that became the standard in woolsheds across the country. It converted curvilineal motion into the straight-line movement that is the basis of modern mechanical shears. It was introduced without Unaipon receiving any financial return and, apart from a 1910 newspaper report acknowledging him as inventor, he received no credit.
Unaipon, a prolific inventor, has been called the Australian Leonard da Vinci for his mechanical ideas. These ideas included pre-World War I drawings for a helicopter design, based on the boomerang principle, and his research into the polarisation of light. Unaipon took out provisional patents for 19 inventions between 1909 and 1944 but was unable to afford to get any of them fully patented.
Other inventions included a centrifugal motor, a multi-radial wheel and a mechanical propulsion device. Unaipon was a recognised authority on ballistics. He also spent much of his life trying to achieve a perpetual-motion machine.
Unaipon was born at Raukkan (Point McLeay) Mission in 1872. Educated at the mission school and in Adelaide, Unaipon was particularly interested in scientific studies but also became known as a writer, musician, preacher and a spokesman for his Aboriginal people.
Unaipon was the first Aboriginal writer to publish in English. He wrote numerous articles in newspapers and magazines, including the Sydney Daily Telegraph, retelling traditional stories and arguing for Aboriginal rights and had Legendary Tales of Australian Aborigines eventually published under his name.
In his nineties, Unaipon returned to Raukkan where he continued working on inventions, convinced he was close to discovering the secret of perpetual motion.