A patent dispute between a Canadian auto parts maker and the U.S. company suing it could rewrite American patent law as the U.S. Supreme Court considers what constitutes an "obvious" invention.

Teleflex, Inc., of Limerick, Pa., is suing KSR International Inc. of Ridgetown, Ont. — about 100 kilometres east of Windsor — over a claim that the Canadian company infringed on a gas pedal design that KSR says simply combines existing technologies.

The case is being closely watched by large and small technology firms that include Intel, IBM and General Electric, as well as the U.S. government, some of whom have filed briefs supporting or rejecting the claims of the companies involved in the suit before the court on Tuesday.

At issue is what constitutes an obvious invention and what kinds of innovations are eligible for a patent. A previous court ruling made it possible for combinations of existing technologies to be patented, paving the way for what some companies see as nuisance lawsuits.

Intel Corp., the world's largest computer chip-maker, and semiconductor maker Micron Technology, Inc., jointly filed a brief with the court supporting KSR's argument that combinations of previous inventions should be ineligible for a patent.

To promote innovation, "patents must be restricted to those claims that truly advance the body of relevant knowledge," Intel and Micron say in the their filing. "Claims encompassing simple combinations of the prior art that would have been apparent to anyone trained in the relevant field do not reflect innovation and do not warrant patent protection."

The companies argue that the court should strike down the section of the law that allows combinations of existing technology to be patented and set a higher standard.

The U.S. government has also weighed in on the matter, filing a brief supporting the Canadian company's position.