By an odd quirk of the law, companies at times go into court to argue that the products they turn out--or at least their key features--serve no useful purpose whatsoever. Outfits that are successful with that argument end up winning substantial protection for their designs.

The peculiar situation stems from the two methods for protecting industrial designs. One is to obtain a design patent, the other is to copyright the item. "The main consideration in determining which way to go is whether you're looking at something that is likely to survive," explained Mary Helen Sears, a veteran Washington patent lawyer. "Maybe it's going to be a very nice fad for a while, but you don't think it's going to be around for a very long time."

For a design that's transitory, companies will usually opt for a patent. A design patent gives its owner the exclusive right to make that item, and even items that look much like it. To stop an infringer of a valid design patent, all a company has to do is prove that the imitation is very close to the original. To stop an infringer of a design copyright, "You really have to prove that somebody copied from you," Sears said. "If they can show for sure that they had never heard of you and never seen anything you did, they're not violating your copyright."

But a copyright offers one big plus: Its protection runs for a long time. When a designer applies for a patent, he or she picks either a 3 1/2-year, 7-year, or 14-year term, with the cost rising with the length of the patent. But a copyright is good for 75 years. That's the reason a lot of manufacturers want to copyright styles they think will sell over the long run.

Copyright protection, however, is available only to artistic creations, and the regulations of the Copyright Office say clearly that "productions of the industrial arts utilitarian in purpose and character are not subject to copyright registration, even if artistically made or ornamented."

The U.S. Supreme Court suggested in 1954 that that regulation may be a little too harsh, and ruled that a work of art may be part of an industrial design and still have copyright protection, but only if the artistic element is separable from the utilitarian one. That case involved statuettes of dancing figures, which then were wired and fitted with sockets and sold as lamps. The statuettes by themselves could enjoy copyright protection, the justices said.

The issue gets dicier when the artistic portion of a product and the useful portion cannot be separated. The legal test is whether the useful part of the design and the artistic part are "conceptually separable." Court rulings have found just that kind of separability between a blouse and the design printed on it and between dinnerware and the patterns painted on them. In both those cases, a copyright for the design was upheld. But in other cases, judges rejected attempts to protect through copyrights distinctive treads on shoe soles and ornamental watch faces. Three years ago, the U.S. Court of Appeals in New York upheld copyright protection for some sculptured belt buckles, but warned that protecting their design was "on a razor's edge of copyright law."

These fine distinctions came up most recently in a case involving wire wheel covers. Norris Industries had gotten copyright registration for the designs in 1976, and in 1980 sued International Telephone & Telegraph Corp., claiming that some similar wheel covers being turned out by an arm of that conglomerate plagiarized the Norris design. Earlier this year, the U.S. Court of Appeals in Atlanta found for ITT, calling the Norris designs useful and with no separable artistic element.

As is typical of such cases, ITT's arguments about how useful the Norris design is were countered by Norris' arguments that it really isn't so good after all. For instance, the utility of the wheel covers was held to be their ability to protect wheels from damage, but Norris introduced evidence that some of the designs allowed road debris to pass through and hit the wheels. The evidence wasn't convincing because "the efficiency of a utilitarian article is irrelevant for copyright purposes," Judge Paul H. Roney explained. And the wire spokes--whose particular arrangement Norris tried to call an artistic accomplishment--serve such a basic structural function that they cannot be considered on their own, Roney ruled.

Norris had the disadvantage in the ITT case of having the Copyright Office on the other side. Even though the federal agency had registered the Norris designs, it later argued that they should have no protection. Actually, the Copyright Office never wanted to register the wheel cover designs. But at the time Norris pressed for registration, the U.S. District Court here in Washington had okayed a copyright for a lighting fixture, and the office felt it had to follow that lead. But before the ITT case began, the Court of Appeals had reversed the District Court--and the Supreme Court had refused to review the controversy--leaving the Copyright Office free to urge the courts to undo its own decision.