Door Latches

By the 1950s interlocking door latches were standard components on passenger automobiles. Door latches are found on driver and passenger doors, trunk and hood lids, and lift-gates. In addition, the door latch may be controlled manually, automatically or remotely.

During an accident, it is important for an automobile door to stay securely closed. A properly functioning door latch can make the difference between life and death. In most cases, a grouping of cables, levers, catches and pawls operate the lock from inside the vehicle’s door. The door latching system opens the vehicle from inside and outside the vehicle. In some cases, an actual key is necessary to activate the system while in others the system is operated remotely. Today, most door latch systems include a child-safety system.

Door Latch Defects

Door latch systems may fail in a variety of ways, including:  

Fail NHTSA Standards: A door latch will fail if it cannot withstand at least 30 Gs of force. This rule was initiated by the NHTSA and is credited with reducing vehicle ejections by at least 15 percent.

System Jam: As important as it is to be able to remain in your vehicle during an automobile accident, it is equally important to be able to exit the vehicle afterward. In some cases, the door latch system jams and occupants are unable to exit the vehicle.

Improper closing: If the vehicle door does not close properly, the door latch cannot close properly either. In this case, the vehicle door remains ajar. In most cases, the occupants are unaware that the door is not closing properly.

There are approximately 210 million door latching systems produced annually and several examples of defective door latch systems are detailed below.

Ford Motor Company was sued by several plaintiffs over defective door latches installed between 1997 and 2000. The issue was an inferior spring utilized in the door mechanism. Those injured due to defective door latches often seek compensation to help cover medical expenses or receive damages from pain and suffering.

In 1997, Chrysler Corporation lost a large lawsuit in the amount of $262.5 million in a defective door latch case. A defective rear-door latch was blamed on the death of a young boy.

In 2009, Mazda recalled 30,000 Mazda 6 vehicles because the door latch system would fail at higher speeds, causing the doors to fly open. The doors did not line up properly and the doors never properly latched shut.

Resources

  1. Attridge, A. (2002). Developments in car door latching systems. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automotive Engineering. 216:10. Retrieved from http://journals.pepublishing.com/content/728v458583879473/
  2. Michigan Historical Center. (2009). My dream car: Lesson plan. Department of Natural Resources. State of Michigan. Retrieved from http://www.michigan.gov/dnr/0,1607,7-153-54463_18670_18793-53601--,00.html
  3. O’Donnell, J. (2004, May 4). Ford suits raise door-latch issues. USA Today. Retrieved from http://www.usatoday.com/money/autos/2004-05-04-fordlocks_x.htm
  4. Segal, D. (1997, October 10). Ross, Dixon celebrate its victory over Chrysler. The Washington Post. Retrieved from http://pqasb.pqarchiver.com/washingtonpost/access/17594950.html?dids=175...
  5. Staff. (2008, May/June). Kiekert locks onto car door safety with realistic solution. Insights. Retrieved from http://www.simulia.com/download/calendar2009/April_Kiekert_Insights_08.pdf
  6. US News & World Report. (2009, February 17). Recall Alert: Mazda6. Retrieved from http://usnews.rankingsandreviews.com/cars-trucks/daily-news/090217-Recal...