Ford Belt Driven

Ford Motor Co. says it is making passenger safety an even greater priority starting with its '07 lineup.

The auto maker will make standard a bevy of safety features and currently is working on cutting-edge technology, such as 4-point and inflatable seatbelts.

Side airbags, as well as side curtain airbags, will be standard equipment on 14 '07 models, including the upcoming Ford Edge and Lincoln MKX cross/utility vehicles. However, 4-point and inflatable seatbelts still are a ways off.

To develop the 4-point technology, Ford is relying on its experience in motor sports, says Stephen Rouhana, senior technical leader-Safety Research & Advanced Engineering.

“We've had crash recorders in CART cars, so we get the crash forces during the crash,” he says at a media event in Dearborn, MI. “You've seen those collisions. At 200 mph (322 km/h), a vehicle hits the wall and there are parts flying everywhere. Very often, you see someone get up and walk out of there.”

Rouhana adds that in the history of open-wheel racing there has never been a death caused by a chest injury.

In addition to studying the benefits of 4-point safety belts in high-velocity crashes, Ford says it has conducted extensive consumer research to ascertain the comfort and acceptance levels of new seatbelt design.

In 2001, the auto maker brought car cutaways with seats equipped with 4-point belts to the North American International Auto Show in Detroit and the Frankfurt auto show in Germany.

Before attendees tried the seatbelts, they were scanned and weighed, which provided a multitude of body dimensions for Ford engineers.

“We got all that information so we could do a correlation between age, gender, weight, height — all of those things,” Rouhana says. “(We also) looked at (the showgoers') acceptability, their perception of safety, their comfort and ease of use.”

From the data, Ford found 75%-80% of those queried said they would choose a 4-point seatbelt in their next vehicle. “That's overwhelming data for a consumer clinic,” he says.

But there are obstacles to overcome before introducing the seatbelts in production vehicles. To start with, 4-point belts are illegal under National Highway Traffic Safety Admin. guidelines.

The issue is a phenomenon referred to as “submarining,” which pulls the lapbelt upwards off the pelvis during a crash, Rouhana says. In racing, submarining is overcome through the use of a crotch strap, a solution not viable for the general public.

The problem of submarining has kept 4-point belts off the road, as researchers struggled to overcome the problem.

By utilizing dual-pretensioners on the lapbelt and force-limiting retractors on the shoulder belt, Ford has been able to overcome the problem, Rouhana says.

“It allows the upper torso to come upright somewhat, in a controlled manner,” he tells Ward's. “There's also a sheet metal ramp in seats today that controls the pelvic motion. A combination of those three things enabled us to reduce the likeliness of submarining.”

Rouhana says preliminary testing shows the use of 4-point seatbelts results in a 50% reduction of the force applied to the chest by a safety belt during a crash, which reduces belt-related injuries. This is especially important for older drivers. Ford's research reveals a 65-year-old's chest has 72% less crash tolerance for safety belt forces than those 16-35 years of age.

Women, who lose bone mass more quickly than men as they age, also are at increased risk of injury due to belt forces, Rouhana says.

Ford and development-partner TRW Automotive have yet to present their 4-point technology to NHTSA for approval, Rouhana says, adding there is no timetable to do so. However, he suggests such technology could be in production vehicles by 2010.

Meanwhile, inflatable seatbelt technology is showing great promise, he says. The belts, which are essentially safety belts lined with a thin airbag, would first be used in rear seats because they act in much the same way front airbags protect occupants.

Ford's inflatable belts are connected to the same sensors as front airbags, Rouhana says. When the signal is given to deploy front airbags, the inflatable belts react at the exact same moment.

The inflatable belts look similar to normal belts, although they are thicker. The belts inflate with compressed air, funneled to the shoulder belts through the lapbelt that does not inflate.

Because compressed air is used, instead of pyrotechnic devices utilized in standard airbags, the belts are inflated at a much lower pressure.

Tests show inflatable belts are more comfortable than standard seatbelts due to their increased thickness, Rouhana says, noting the advantages of inflatable belts are many, as they essentially bring front airbag protection to rear-seat passengers that often are children.

“We get rid of a lot of the dangers for children of frontal airbags and bring a much more benign airbag into the backseat,” Rouhana says.

“There's also a tremendous increase in (belt) area, so you have a larger area on the chest that crash forces are going through. When you have a given force and you increase the area, the pressure underneath goes down.”

Ford tests also show that inflatable belts, because of their thickness, restrain the chin of an occupant during a crash, which reduce the forces on the neck. The belts also lessen the likelihood the head will hit something in front, and they are beneficial in rollovers, Ford says.

“So we have multi-mode protection with a fairly simple idea,” Rouhana says.

Ford is developing its inflatable belt system with supplier Key Safety Systems. Like the 4-point seatbelt, the inflatable belts could reach production vehicles by 2010. However, no official timetable has been set.