Door Locks

Door locks must keep the door from opening in a crash situation and resist break-ins, but it should also be possible to open them if you lose the key. The door handle acts as a lever that pulls on a rod. The rod rotates the door latch. The various types of lock mechanisms interrupt the action of the door latch. The "striker" is a mechanism attached to the door post, or part of the car body. It holds the door shut or allows it to be opened when the door handle rotates the latch. The striker's job is to keep the door closed under normal conditions, or to hold the door closed if the door post starts to bend away from the door in a crash. Power door lock mechanisms are operated by electric solenoids. Anti-burst door locks are a relatively cheap development, that have proven to be one of the most successful but unrecognized benefits of crash protective design. Studies have shown that it is much better to remain in a car than to be thrown out, because if a person is thrown out, serious injury may result from contact with the road surface, and there is a great risk of being run over by one's own or another vehicle. It is, therefore, important that the doors should stay shut during a collision, and the design of a latch to do this has been perfected and introduced into almost all cars in the world. An anti-burst latch provides resistance to tension forces of up to 3000 lb. (1360 kg) in all directions, by having a lock striker on the door which completely encircles a ring or plate mounted on the door frame. The system is designed so that it resists the forces generated in a collision both by the occupant striking the door on the inside and by the force of the impact on the outside. The result is that ejection, which was established as a leading cause of death to car occupants in 1956, has now been reduced until it has relatively little importance.