It is already standard equipment in some middle and luxury class cars: the electric parking brake. Besides extra security, this alternative to the conventional manual brake offers greater comfort through ease of operation and takes up considerably less space. In short, it precisely fulfills the key requirements that automakers place on passenger vehicle components today.

By now a great number of Audi, Bentley, Lancia, Bugatti and VW drivers have learned to appreciate the high performance engineering tucked away behind these little levers. In lieu of the customary actuation by pulling the classical handle of the conventional hand brake, they use a switch to send an electrical impulse that activates the so-called actuators in the calipers of the rear brake assemblies. The force generated there can be used for a variety of purposes: it keeps the automobile from rolling away, even at inclinations of 30 percent. When starting out from a standstill, the brakes remain active until the car is actually moving forward without jerking or rolling backward. And also in an emergency braking situation – in the event of a failure of the foot brake system, for example – the car can be stopped by simply pulling the lever.

PPS is the key

This clever system relies on sophisticated engineering and glass-fiber-reinforced Fortron® PPS from Ticona. Both the housing and a gear wheel within the electric parking brake are made from this polyphenylene sulfide, which features exceptionally low flash formation. This eliminates the need for extensive finishing operations, above all, in the manufacture of the gear wheels. Moreover, the high performance polymer offers high temperature resistance with peaks of up to 180  C, as well as excellent dimensional stability and chemical resistance. Ultrasonic welding is used to attach the cover to the housing of the parking brake along a 250-mm welded seam. This housing assembly protects the heart of the innovative brake, withstanding extreme stresses such as stone impacts when driving on gravel surfaces.

The electric parking brake also improves the quality of life in the passenger compartment: the need for bulky cable harnesses running through the vehicle is eliminated, leaving more room for other accessory elements. And when it comes to stopping and staying put, the electromechanical parking brake system clearly outperforms its purely mechanical counterpart ...