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New designs are always popping up

NEW YORK - As a child of the 1970s, I have a distinct and curious memory about the landscapes I inhabited: They glittered with glinting metal, not the gold of El Dorado but the effluvia of the consumer society. I am talking about aluminum can tabs.
If, as the saying goes, we are never more than three (or five, or 10) feet from a spider, so too did those little trinkets - a sturdy ring pull attached to a curled, wedge-shaped "tear strip," the disposable remnant of the mechanism then used to open cans of beer or soda - rarely seem out of range.
There was an inherent problem in multipart portable consumer packaging: What to do with the sealing mechanism, once so vital and now so worthless (and dangerous), after you had opened the can? Often, it seemed, the answer was to simply chuck it. Another solution was to deposit the pulled tab in the can. While this may have been less environmentally injurious, it was not without its dangers. As an article in the Journal of the American Medical Association noted, at least seven children over a period of a little more than three years had "been treated for complications of ingestion or aspiration of pull tabs from aluminum beverage cans." One particularly pernicious problem is that aluminum often does not show up on X-rays.
Indeed, it was at a radiology conference in 1974 that a physician named Lee Rogers - who had inadvertently swallowed a can tab during a basketball game - broached the idea of the can tab hazard to the medical community. And it was this single panel at a medical conference that helped launch a revolution in the design of our aluminum cans.
Can tabs were an ecological disgrace and a threat to children: Is there a more potent nexus for citizen outrage? The hunt for a new and better design was on. But the irony is that the pull-tab, unveiled just more than a decade before, had been hailed as a remarkable solution to an age-old problem. As its inventor, an Ohio toolmaker named Ermal Fraze, put it, "I personally did not invent the easy-open can end. People have been working on that since 1800. What I did was develop a method of attaching a tab on the can top."
Prior to Fraze's invention, cans, both steel and aluminum, required a separate opener, the so-called "church key." As Henry Petroski notes in "The Evolution of Useful Things:" Fraze was at a family picnic in 1956, where he found "plenty of beer but no church key," and resorted to opening a brew via a car bumper. After an insomniac night and a spell at his workbench, Fraze had his concept. As Petroski describes, the actual engineering - getting a top that was easy enough to pull off but could withstand the force of the can's pressure - was tricky: "Some early pull tabs were being blown off prematurely . . . so Fraze and other inventors came up with schemes to direct benignly the first whoosh of escaping gas away from the tab itself."
But a decade later, the solution had become a problem, and the search for a better can closure began. In the early 1970s, Coors came up with its "environmental package," a curious two-opening top - the first was a small pressure-release valve, the second was a larger aperture for drinking - that some readers may recall.
But Coors wasn't the only experimenter; as the website notes: "Crown, Cork, and Seal tried a top that you pressed down then slid a tab to one side, pushing a hole into the can top.
The solution came from Daniel F. Cudzik, an engineer with Reynolds Metals, who for years had been toiling away on what would what become known as the "Sta-Tab."
As Cudzik told Studio 360, his search for a "convenience top" that was "more practical and less prone to litter" came to fruition one night when he was in living room, "half watching a movie."
While the idea might seem simple to a consumer raised on nothing but stay-on tabs, the design required some elegant engineering (and some subsequent legal battles over alleged patent infringements).
As Cudzik described the problem in his 1975 patent application: "The opening construction of the invention requires a tab which must be stiff against transverse bending and yet flexible enough and tough enough at the connection between the tab end wall to permit lifting and retracting the tab without causing a fatigue crack at the connection."
As elegantly explained in this video, the design operates both as a "second class" and as a "first class lever" at different points in the can-opening process - redirecting loads and shifting the fulcrum - using the inherent pressure from the carbonated beverage in its favor.
When the Sta-Tab launched in 1975, on Falls City beer and, quickly, other beverages, there was an initial period of consumer testing and education. But the Sta-Tab was here to stay.
NCudzik said on Studio 360 that he thought can tab design had reached a point "where I don't believe there'll be too many changes anymore." But is design ever done?
The work of design, as much as it is about eliminating obvious flaws, is also about bringing to light the things we only realize are problems the very moment we no longer have to live with them.

Tom is author of "Traffic: Why We Drive the Way We Do," now available in paperback.