Professor Keith Alexander

Mechanical engineering associate professor Keith Alexander - well-known for his “spring-free” trampoline invention which is sold around the world - has been honoured with the 2010 University of Canterbury Innovation Medal.

  • Keith Alexander receives the inaugural 2010 UC Innovation Medal

    UC Innovation Medal Winner 2010 - Professor Keith Alexander - “I made a pump system for getting gold out of rivers. I liked doing that stuff — although I only found enough gold for a filling, I think.”

Deputy Vice-Chancellor Professor Ian Town said there was very strong competition for the medal and he was “delighted to see the breadth and depth of innovation at UC as evidenced by the nominations received”. He said Alexander was a very worthy recipient of the inaugural award.

“Many people may not be aware of his many other ideas which are in various stages on the way to commercialisation. These innovations range from jet boat steering mechanisms, snow probes, ‘nifty lifters’, through to microhydro plants.

“In the case of the Springfree Trampoline, his innovation creates both wealth — selling well in a competitive international market — and beneficial value to the community by cutting down on the number of trampoline injuries. It has been estimated that if all the trampolines in the US were spring-free there would be 34,000 fewer children going to emergency departments each year,” said Town.

“Keith’s invention has created many jobs in New Zealand. All of the special rods for the trampolines are made by a firm in Gisborne that ships out more than 10 containers of product per year. Furthermore, the Chinese company which makes the trampolines has employed 10 UC graduates to help improve the design and manufacture of the product.”

Alexander said he had a rocky start to his engineering career, “failing miserably” in his first two attempts, but a trip exploring for gold in the South Island confirmed his love of the subject. “I made a pump system for getting gold out of rivers. I liked doing that stuff — although I only found enough gold for a filling, I think.” Alexander started his engineering degree at UC in 1975, during which he developed a new amphibious vehicle with bladed wheels, which later became his PhD study.

“I think the staff were somewhat bemused.” He funded much of his PhD by winning Radio Avon’s “walk on water” contests.

“They offered $1000 dollars to the person who could walk the furthest on water so I developed shoes to win the competition, won it two years running and used them to rescue prototypes of my amphibious vehicle from the middle of lakes.”

At his first job at an Auckland engineering consultancy he developed a new design for the wool dumping presses which compressed three bales into one thus enabling treble the amount of wool to be exported in one container.

Alexander then worked at Hamilton Jet and later, while teaching at UC, developed his own improved steering system for another jet company.

During a university summer break he worked in England on Alan Gibbs’ Aquada amphibious vehicle.

Alexander said one of his most enduring memories of this time was “driving around in winter, in the dark, on a little lake in England, with this incongruous feeling of sitting in an open-topped sports car. There’s the steering wheel and the dashboard. Outside is all the water going past and the headlights are pointing up into the sky.”

Many of Alexander’s ideas became final year projects for his students including a “nifty lifter”, a device to help a polio sufferer transfer from his wheelchair to his car, as well as a quieter fan for a hovercraft.

They also developed a snow probe after being approached with the original concept by Arthur Tyndall, former president of the Broken River Ski Field. The device is used to test the shear strength of snow layers, thus identifying areas prone to avalanche. Data collected is transmitted directly to a PDA enabling quick assessments and records for future use. In a recent final year project he had students working on a Martin Jetpack simulator.

Alexander’s greatest success so far is his Springfree trampoline.

The project began in 1987 when Alexander’s wife felt a backyard trampoline would be unsafe for their young daughter. He identified the main causes of trampoline-related injuries: the steel surround, the springs and the risk of falling off.

His first commercial partner required that “it could be assembled by a solo mum with no tools in half an hour”. While he never achieved this ease of assembly it has become a commercial success.

“We now have 14 patents in seven different countries.”

Alexander is on the Trampoline standards committee in the US and has contributed to the Australian standard and sees this as a career high-point.

“At the moment they are looking at mandating the standard in NSW, Australia, using a lot of my input which is hugely satisfying.”

Alexander has received numerous international awards including 2010 Product of the year USA, 2010 Product of the Year Canada, 2010 New Zealand Engineering Innovator of the Year, 2009 International Design Award Australia and the 2009 Parents’ Choice Award, USA.

He said his most meaningful was the 2010 Children’s Product of the Year, USA, for his Springfree trampoline.

“When I had originally made it, my vision was so small. I thought we would sell maybe 30 a year in New Zealand. For it to not only get to America but to win product of the year was a big boost.” Alexander played an integral part in establishing the University’s Product Innovation Centre and is the current director.

“The idea of an innovation centre has been around for a long time. It is an internal consultancy which specialises in providing services for people (both within and outside the university) developing new products they want to get to market.”

These services include mechanical engineering analysis, computer assisted design, and mechanical design. The knowledge-rich environment provides access to a huge range of expertise in one place and is particularly valuable if there is a research component to the project. One example to use the Product innovation Centre was the “instrumented climbing hold” — a training aid that identifies climbers’ hold techniques and necessary adjustments for improvement.

“Our role was to design something that would fit inside the hold and give out an electrical output that indicated what the forces were.” Currently Alexander is working on microhydro plants — small hydroelectricity systems — continuing the work of the late Peter Giddens. Power is generated from a combination of head (the height from which the water is falling) multiplied by flow. In mountainous areas such as Nepal, head is large so required flow is minimal meaning necessary pipes and turbines are small and therefore low cost. Giddens believed sites with low head while more costly were much more common, but turbines had not been designed for them. A project was started to develop suitable turbines.

Over a dozen honours students and one PhD student have worked on the project. Once the project is completed a website will be set up to provide free information. By entering specific site details, the necessary drawings and system parts lists will be provided, thus making the plant more economically available.

Alexander is also working on a patient lifter. “We need a piece of machinery that is simple, small and light — no batteries, no hydraulics, no electrics — to help carers transfer someone from one place to another so elderly people can stay at home longer. This started in 1996. “We are close to getting there. This would be my most demanding project. Prototype 16 is in my garage now!”

Keith Alexander research profile