The US engine-maker Briggs & Stratton has started to mass-produce the novel DC motor developed in the UK by the inventor Cedric Lynch. Until now, Lynch`s lightweight, high-efficiency motors have been hand-assembled at his Devon factory.

The availability of the volume-produced versions will make the motors "more competitive", according to Trevor Lees, Lynch`s partner in his Lemco business.

Instead of normal windings, the Lynch motor uses stamped copper bus bars, resulting in a machine that is around 20% lighter and 50% smaller than a conventional motor. Other advantages include an efficiency of 88-91% over a wide range of loads, and a speed drop of just 10% when the motor is loaded, compared to up to 60% for standard series-wound DC motors.

At present, Briggs & Stratton is producing the motor in one size - a 10kg machine, about 15cm thick and 20cm in diameter, that develops a peak output of about 9kW and a continuous output of 2kW. Lees says that Lemco will continue to build motors in other sizes and ratings.

Briggs & Stratton`s Chinese-built motor - which it calls Etek - marks the company`s debut in the electric motors business. Initially, it plans to target OEM customers which currently use its petrol or diesel engines in golfcarts, lawnmowers and similar products. The Lynch motor will allow them to produce electrically driven vehicles with a longer range, and better hill-climbing and speed-holding abilities than would be possible using conventional motors, B&S says.

Bryan Peachey, Briggs & Stratton`s UK general manager, sees the motor as an opportunity for the company to enter new markets, such as forklifts and invalid vehicles. Another possibility is to use the motor as a generator in hybrid electric vehicles - possibly coupled to a B&S engine.

One of the first applications for the Etek motor in the US is to power a vehicle designed to retrieve supermarket trolleys. The motors have also been used by competitors in the US equivalent of the Robot Wars television programme.

Under the two companies` licencing deal, Lemco will sell the Etek motor for automotive and leisure applications.