BRIDGEPORT, Conn.-A Stamford, Conn., company is suing General Motors Corp., claiming the automaker used its technology in an antilock braking system in many GM cars. In a lawsuit filed in April in U.S. District Court in Bridgeport, General Clutch Corp. alleged that the Detroit-based automaker, without its permission, incorporated a mechanical brake it developed into GM's antilock braking system. General Clutch holds two patents on the brake, known as the ``expansion spring brake.''
General Clutch does not ask for a specific amount of damages in the suit, but believes it is entitled to at least $500 million, said company attorney John Chapman.
It charged GM with patent infringement, misappropriating its trade secrets and breaching an implied contract between the firms.
A 14-year-old engineering firm specializing in wrap spring clutch technology, General Clutch develops and produces hardware for window coverings and friction hinges used in laptop computers.
In the lawsuit, it said GM approached company officials in April 1987 about using its expansion spring and clutch technology to solve problems GM was having with its ABS system, which was in development at that time.
General Clutch claims it worked with GM's Delco Products Division for the next two years, preparing engineering sketches, building demonstration models and educating GM's engineers on the expansion spring brake system.
The company said its technology developments were disclosed to GM on a confidential basis.
``General Clutch developed, designed and built a prototype, and proved through testing over two years with (GM) that the expanded spring brake was a solution to the problems it was having developing an antilock braking system,'' Mr. Chapman said.
``After General Clutch figured out the solution to the problem and that its own technology could be an integral part of this module, GM is now using the General Clutch development.''
In the lawsuit, General Clutch said its expanded spring brake technology offered several advantages over the electromagnetic brake previously designed by GM, including its low cost of manufacture, low maintenance and a reduced possibility of failure.
Eventually, Delco informed General Clutch that the ABS manufacturing contract had been awarded to Associated Spring Corp., a longtime Delco supplier.
General Clutch said it did not realize GM had used its technology until late 1992, when a General Clutch engineer saw the expansion spring brake design in a diagram in an internal 1992 Delco Products service manual.