Retrofitting Old Cars With Driver’s
Auto manufacturers are luring buyers into showrooms by offering air bags. But what about people who would like air bags but are not ready to replace their cars?
A large maker of air bag components has begun offering an “after market” driver’s side air bag actually, a replacement steering wheel that contains an air bag. The company, Breed Technologies Inc. of Lakeland, Fla., says that the technology it is using in its used car version represents an advance that may eventually be adopted for new car air bags.
In new cars, the crash sensors of which Breed is already a leading supplier to Detroit are in several places under the hood. This forward placement of the sensors gives the air bag as much warning as possible that a crash is occurring, but the complex leather converse wiring needed to link the sensors to the air bag makes it difficult to install after market air bags. Available for 26 Models
That’s why the Breed air bag, which is available for 26 car models produced in 1987 or later, is self contained, with the sensor housed in the same steering wheel compartment as the bag itself.
Richard M. Stolbach, executive vice president of the company, conceded that the bag was not quite so good as the factory installed bag that comes in a new American car. Because the sensing equipment must be crammed into the steering wheel, too, the bag itself is only a little more than half the size of a factory installed bag. As a result, the use of a combination lap and seat belt is even more crucial with the after market bag than with the factory installed versions, leather converse Mr. Stolbach said. To Reduc leather converse e Facial Injuries
But even the smaller bag, when used with a seat belt, would help reduce facial injuries, Mr. Stolbach said. He expects anyone safety conscious enough to install such a bag at a cost of $700 to $900 would also wear seat belts.
The company says it has had “several thousand” orders so far through its two main distributors: Applied Safety Inc.
In a frontal collision at 35 miles an hour the driver hits the steering wheel about 100 milliseconds one tenth of a second after impact. Engineers figure they have about 50 milliseconds to get the bag inflated before the driver begins to move toward the wheel. Because inflation takes about 20 mil leather converse liseconds, the air bag system has only the first 30 milliseconds to sense the crash and decide to inflate the bag, and that is why factory installed units rely on sensors near the front of the car. Mechanical Sensor Used
Breed, however, uses a single mechanical sensor in the steering wheel that senses the abrupt stop of a head on crash. When that happens, a ball is jolted loose and rolls down a tube to trigger a firing pin, inflating the bag with the same type of mini explosion used in factory installed air bags.
Breed contends that its sensing system would be superior for original equipment, too, because there is no under hood wiring to be damaged by the heat, gravel and other insults of daily operation, and no electric signal is required for the air bag to inflate.
But auto makers still tend to favor the advance warning feature of the underhood sensors, which allows the bag to be inflated a bit more slowly, to avoid punching the driver in the face.