Stroke of Genius Leads to 'Smart' Fastener

 - November 2, 2006, 6:00 AM

Consider the lowly fastener, an object guaranteed to induce acute boredom in the mind of the average man, a cure for insomnia perhaps. They’re hidden away in corners, under seats and floors and behind panels, rarely seen but so necessary.

Wherever two or more parts are joined together in structural matrimony, you will find a fastener, or two, or hundreds. No matter how simple or sophisticated, products of multiple parts are held together by fasteners– nails, screws, bolts, clips, rivets, pins, glue. And the installation and removal of those fasteners has always been a labor-intensive process that required tools, time and muscle, accompanied by considerable sweat and the kind of language that sends mothers rushing to cover their children’s ears.

All that is about to change.

At last month’s Aircraft Interiors Expo 2005 in Hamburg, Germany, Textron Fastening Systems announced that it was going to reveal a new and exciting fastener system. News of the impending announcement was met with something less than excitement, with yawns, even. But as the morning passed, there were whispers that what Textron was about to reveal was worth seeing.

And by all accounts, it was, thanks to the team of Dickory Rudduck, John Wilson and Chris Kelliher, who invented the smart fastener, moved the company from Australia to Chicago, renamed it TZ Ltd. and cut a $10 million deal with Textron that included “other renumeration” as well as royalties.

What Textron introduced at Hamburg was Intevia, the “smart” fastener. At the company’s exhibit, an executive demonstrated the removal of a typical business-jet seat attached with four Intevia fasteners. When the executive pressed the remote unlocking device, all four fasteners released in the time it took to blink, and with no further ado the seat was lifted neatly from its track.

Described simply, manipulation of the fastening or locking mechanism is done using a “smart materials” actuator. So-called smart materials change shape or change their material properties with the application of stimuli such as heat or electric current. This change in properties is used to operate the fastening mechanism. An embedded microchip manages and controls the supply of energy to the smart materials actuator to ensure reliability and longevity of operation. The integrated circuit consists of a control device, sensors and the intelligence system.

Power is required. It can come in the form of a built-in battery, but in most cases the fasteners draw on power that is resident in the network system of which they are part. In the absence of power, they typically default to a locked position. All have a manual override system to allow release if power is not present.

According to Chris Marx, v-p of aerospace sales for Textron Fastening Systems, Intevia is application-specific and not limited to existing fastener sizes or functions. “Imagination is the limit,” he said, adding that at this point, “our initial fastener configurations relate to point fastening or locking applications with fasteners: stud, latch, clip-and-beam.”

The advantages, said Marx, are obvious immediately, particularly in terms of time saved. “In a business jet, it can take up to 40 minutes to remove a seat with fixed-bolted floor mountings.”

He declined to compare the cost of the Intevia fastener with current fasteners, but he said that the Intevia-based latch is “competitive with the existing solution it replaces.”

The Intevia latch is the first commercial application of Intevia technology. The slim profile allows it to mount flush into the aircraft; it weighs less than current electro-mechanical devices, operates silently and is controlled through a touch-sensitive cabinet door handle on which an LED light indicates lock/unlock status.

One of the advantages of the Intevia latch is enhanced security, said Marx. “The embedded electronics allow us to use a hierarchy of security options from a range of control devices–push-button, access key pad–to use encrypted digital message or software code.”

Responding to a question as to whether someone remotely opening the door to his BMW might result in an unfortunate release of “not-so-smart” fasteners on a jet passing overhead, Marx chuckled and emphasized that flight-critical systems can be designed to operate only under ground power. In addition, he explained, “Intevia fasteners can be designed to stay in default locked state in a ‘power-off’ situation and can use intelligence through the embedded microprocessor to interrogate an instruction to confirm whether the release command is valid.” Finally, he said, “We can encrypt the application to be unique, limiting what type of signal can activate the device.”