Keith Alexander: Inventor + Engineer + Dad. He made the Springfree Trampoline.

Keith Alexander: Inventor + Engineer + Dad. He made the Springfree Trampoline.



Who knew the original metal-spring-wedgie generation of trampolines could be improved? What makes Springfree so different?

The Springfree Trampoline is different because it has been redesigned from the ground up with the intent of making it safer. The dangerous features of traditional trampolines have been designed out of the equation. It is built like a rubber room. There are no springs to fall between, no steel bar to fall on. It has a net that stops you falling off; the net is flexible and supported by flexible poles so if you do completely lose control, you are caught softly and deflected back on the trampoline mat. The whole unit is built to last, with those features essential to safety remaining in place for the life of the trampoline.

How long has Springfree been around?

Springfree started selling in Australia in 2004, so it has been around now for nearly 14 years.

You are an inventor and a Professor of Mechanical Engineering – some serious credentials! Why the trampoline?

Two reasons.

First: I loved trampolines when I was a kid, but you couldn’t buy them then. When I became a Dad, I told my wife we should get one for our daughter. But she said “No, they are too dangerous”. When I researched it I found out she was right, and being an engineer I thought I might be able to solve that problem.

Second: At University we have “academic freedom” meaning we can research whatever we are interested in. My belief was that research should be for people’s benefit. These two things allowed me to work on improving trampoline safety as part of my job.

We’re fascinated by the path that led you to the life of ‘inventor’. Was there a definitive experience or event that kicked off your love of engineering and experimenting?

I think my father always encouraged and supported my curiosity and got me a Meccano set when I was pretty young, 4 or 5. When my sister came along about that time, I spent a lot of my time ‘out of the way’. Unlike my new sister, my Meccano set played by understandable rules and allowed me to become absorbed in building things.

What was the first thing you ever invented big or small?

One of the early designs was a perpetual motion machine that my father said would not work. I found he was right, but the gearbox I had made in the process was ideal for accelerating a flywheel which stored a surprising amount of energy and let my little vehicle travel a long way without stopping. It probably wasn’t my first invention, but it was a step on the way to developing an interest in research.

If the trampoline didn’t capture your creative imagination, what other possibilities were on the cards?

Well there are a lot of things that are more in the realm of art rather than useful objects, and I have done a couple of kinetic sculpture exhibitions. These have included walk-on-water shoes, a two metre mouse trap (for very big mice), a bald patch inspector (for people who might be going bald but cannot tell), a self-discipline machine that will wack your finger if you press the button by the sign that says you shouldn’t press the button. But at University I have been working on more theoretically useful ideas like the vacuum balloon, a car that runs on top of the water, an oscillating hydrofoil for lift and boat propulsion, a tower made of airbags…

Your trampoline is a nice looking piece of equipment. What was the process that led to the final design?

That design was one of many concepts, several of which were built. I was always aware of the idea of using rods, like fishing rods, to apply the “spring” force to the edge. The problem with rods around the edge is that they needed to be vertical at the edge to make the most compact design – and this lead to the risk of impalement. The trick came in laying them over in a circular direction so that they would make a safe, soft edge. This was not a symmetrical design and that worried me. It seemed it would twist rather than bounce. After building one, we found that this was not a problem at all, and we were able to effectively get all the rods almost vertically below the edge in quite a tidy pattern. So it is a case of form following function quite satisfactorily.

Are you still involved with the company today?

Yes, I continue to work there one day a week as the ‘engineering fellow’.

Are there any plans to evolve the product further?

Yes there are, and an example of this is the Tagoma product that adds a unique dimension to the backyard trampoline using sensors in the mat to create an interactive play-space via Bluetooth.

How would you like Springfree to be remembered?

Good question. I would like it to be seen as an honest company, providing a long-lasting safe product, standing behind what it says, and being very supportive and responsive to its customer community.

Head to the Springfree Trampoline website.

Check out their Instagram here.

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