UK fastening technology could revolutionise how we interact with everyday objects
For all that fastening and joining technologies are intrinsic to so many innovative products, it is fair to say that 'innovative' is not a word that most engineers would normally associate with the technologies themselves. Fastening is generally the unsung hero of design, often taken for granted and sometimes not even considered until other aspects of the design have already been finalised.
This makes it particularly exciting when a genuinely innovative fastening technology does emerge – as it appears to have done with the British-developed Rotite system, which its inventor Stuart Burns describes as "potentially the most innovative mechanical fastener in terms of its mechanical interface since the screw thread."
This is a massive claim, of course, but Burns' excitement is perhaps understandable when one starts to appreciate the potential of his invention.
The fundamental principle of Rotite (which Burns is at pains to point out is a system rather than a product), is essentially a low-profile, helicoidal dovetail. Basically, this means that the two surfaces dovetail together and can be rotated against one another until the required tightness is achieved. Thus, the dovetail connection can be rotated 360° about an axis on a helicoidal pitch.
In the same way as a thread can have a number of starts points, so can Rotite. For every additional start point required, the number of degrees of rotation is reduced. This feature means Rotite can connect two items with 360° of rotation, 180, 120, 90, and 45° down to a minimal 10°. All variations of rotation from 10-360° provide full surface interlock between opposing connectors, which results in a low-profile, but high-surface area connector.
This confers an additional advantage in that Rotite can be 'hermaphroditic'. In other words, geometries of certain profiles can also be identical, meaning that objects can be connected without the need for A and B or 'male' and 'female' components.
Burns claims that the Rotite has has "limitless" derivatives, and literally thousands of potential uses in dozens of key industries. Possible industrial applications include domestic goods right through to aeronautical applications. It can be a connector or coupling that may be used for transmission, electrical connectivity, electrical/control sequencing, fluids or gases, and general product enclosures.
Among the key advantages of the system is its low profile, which allows it to be used in applications where aesthetics or aerodynamics are major concerns. Its geometry also means Rotite has the ability to apply high axial loads without the necessary rotation of normal screw mechanisms, saving time and effort while also simplifying mechanics.
Although the system's mechanical interface is complex, Rotite is actually very easy to grasp and use from a consumer's perspective. Indeed, Burns believes that this apparent simplicity is one of the system's greatest strengths.
He says: "It's intuitive because it uses an ergonomic twist action, so it feels familiar and this makes it is extremely simple to use and has positive benefits for everyone, regardless of their strength or dexterity. Equally, because it allows the user to choose the degree of rotation to suit the particular application, it's adaptable to any number of markets and applications."
From a manufacturer's point of view, the fact that Rotite can be easily manufactured in numerous materials, is easily scalable, easily standardised and can be easily integrated into products with minimal tooling costs should make it very attractive. All these factors, claims Burns, make its widespread adoption across a range of sectors highly likely. "Rotite technology will revolutionise how we interact with everyday objects in the future due to its limitless derivatives and applications," he claims.
Although developed over a three-year period in conjunction with some of the UK's leading professionals in the fields of additive manufacturing and structural analysis, the idea was arrived at originally as Burns was looking for a low-profile fastening system for textiles. He says: "I came up with the idea at 3am. I then 3D printed the first prototype. It didn't work, but by 5 O'Clock we had it." He was quick to realise his invention's potential far beyond the world of textiles. "I realised it had commercial value because, apart from anything else, nobody had done it before. It can attach any object to any object… you could even dock spaceships with it!"
3D printing has played a huge part in the development of the Rotite system. "Without 3D printing, we probably couldn't have 'discovered' the geometric principles that enabled us to develop the system. It has been the vehicle that has allowed us to take this step and our good contacts with the additive manufacturing community have proved absolutely invaluable to us."
Having developed the system and its variations, Burns then spent a year patenting it. "I had some great advice from an IP professional, who told me not to commercialise too early and to first get as much protection in place as I possibly can."
With this protection in place, the time has come for Rotite to find its markets. The most effective route to market, Burns believes, is via licensing the technology to companies who wish to manufacture products that use it. Thus far, he says, there has been interest from some big aerospace and automotive companies, while a leading product design company in London has expressed a desire to develop it in conjunction with Rotite. Says Burns: "Because Rotite is defined by a mathematical equation and has numerous forms, it is adaptable to any number of applications in any number of derivations. "
Currently, Rotite is planning a series of demonstrations across the UK to display the advantages of the system. Says Burns: "It's so different to anything else out there that we've almost had to write a new language for the terminology we use to describe it. Even so, as soon as you show it to people, they get it. For that reason, we want to get it into the hands of every designer in Europe."