Say goodbye to the mechanical parking brake and the levers, ratchets, cables and adjusters that go with it.
Electrically operated parking brakes are starting to replace mechanical systems, which have gone basically unchanged since the 1940s. The electric brakes are expected to be the first step to computer-controlled brake-by-wire systems, which are forecast to arrive in about a decade.
Electric parking brakes eliminate bulky hand and foot levers, and free space for the growing number of electronic devices being installed in vehicles.
"They need the space where they have the parking brake lever today," says Josef Pickenhahn, vice president of brake engineering for TRW Automotive Inc. "It's a nice feature to have. Costs have come down, and we can have some additional functionality."
Pickenhahn estimates the cost to install an electric parking brake is $50 to $60 more per vehicle than mechanical brakes.
Turning point for LS
Electric parking brakes figured prominently in the 2003 updating of the Lincoln LS interior. When the LS debuted in 1999, it came with a hand lever mounted on the left side of the center console, next to the driver's seat.
The electronic brake, made by Dura Automotive Systems Inc., allowed the LS to have an adjustable sliding armrest and a deep storage bin.
Getting rid of the brake handle also increased hip room for the driver. Electric parking brakes will simplify manufacturing efficiency by using fewer parts. Today's electric systems also will put in place some of the hardware needed for brake-by-wire systems.
In addition to the LS, cars available with electric parking brakes include the Audi A6 and A8, BMW 7 series and the Jaguar S-Type and XJ. The 2006 Volkswagen Passat also has the system.
At least six more 2006 models will have electric parking brakes.
TRW Automotive's Electric Parking Brake system is the most advanced in production. It not only eliminates the foot or hand lever but the cables, linkage and mechanical adjusters under the car.
Instead, a computer-controlled motor mounted on the brake caliper operates the parking brakes.
Other systems, such as the Dura unit on the LS and those made by Continental Teves Inc. and Siemens VDO Automotive Corp., use an electric motor to operate the parking brake cables.
The Audi A8 and A6 are equipped with TRW's Electric Parking Brake system.
Siemens also has perfected a motor-on-caliper system but does not have any customers.
Siemens equips the BMW 7 series with its cable-puller system, but company spokesman David Ladd says Siemens expects to win contracts for the more complex motor-on-caliper system.
Electrically operated parking brake systems can be programmed to:
"Eventually, electric parking brakes will lead to full electric braking," says Phil Headly, chief engineer of advanced technologies for Continental Teves.
He sees the first applications on nonconventional vehicles, though "We are going down the path of hybrid and fuel cell vehicles where you will need by-wire and regenerative braking because there is no vacuum system," he says.
"Those vehicles will have it first. Everything points to that."
You may e-mail Richard Truett at [email protected]