SAE better mousetraps ... New gas springs add touch of class to liftgates and hoods

First they made liftgates easier to open and close, now they're adding Fa touch of class to tailgates and hoods of sport/utility vehicles. Gas springs that hold open hoods and liftgates aren't often thought of as highly engineered products, but thanks to clever engineering, they've gone from mere widget status to true value-enhancers on a number of vehicles.

Two years ago Stabilus, a division of Fichtel and Sachs Industries Inc., introduced gas springs that provide plenty of assist when opening big minivan liftgates, but offer significantly less resistance when closing - even on hot days, when gas springs tend to be especially stiff. The latest system improvement by Stabilus is dubbed "Dynamic Damped Gas Springs," which allow automakers to tailor the opening speed of a hatch, tailgate or hood throughout its full range of motion. Most noticeably, the springs reduce annoying flutter and bobbing at the end of extension for a higher quality look and feel. Luxury automakers already are using such motion damping to lend a high-quality feel on everything from ashtray and glovebox doors to hood and deck lids. The new gas springs are expected to be shoo-in upgrades on pricier SUV's -- some of which still use gauche prop bars to hold up the hood.

PLASTIC PAINT'

3M Automotive and Rexham Performance Products plan to jointly manufacture and market a film to replace paint on plastic parts used by automakers. The new product, a modification of Rexham's Flourex surfacing film, is placed inside of a mold and applied during the molding of plastic parts. Intended to eliminate the need to paint plastic parts, the companies say the film offers improved quality, no volatile organic compounds, better color and appearance and reduced finish variation.

AIR BAG SYSTEMS IMPROVING

You'd think air bags represent a relatively static technology, but SAE reveals that major suppliers such as TRW Inc., Morton International and Takata Inc. are hard at work making them smarter, safer, more space-efficient -- and more environmentally "clean." Takata, for instance, introduces its SafetyShield, which is set to appear in '98 as the "intelligent occupant position system." The device will cost automakers approximately $25 per front seating position. Normally there would be only one - on the passenger side - but in some vehicles the air bags also cover the center position.

Via an opening in the instrument panel the system uses infrared sensors "and a proprietary algorithm" that determines occupant position and distinguishes between people, child seats and inanimate objects, and controls how quickly the air bag should deploy to minimize injury.

An optional side-impact sensor linked to the system can be adapted to door- or seat-mounted side-impact air bag modules, says Takata.

In another development, Takata says it has developed a new compact driver-side air bag module using "technically advanced" inflators, cushions, covers and overall design. President C. Reid Rundell says Takata already has signed contracts to supply several automakers with the new module starting with the 1997 model year.

The company's new "EnviroSure" inflator, which Takata claims is the first to use a non-azide (or non-toxic) propellant, is the key element of the new module. The inflator is 40% smaller and 30% lighter than current sodium azide inflators, Mr. Rundell says, giving designers greater flexibility without sacrificing performance.