What is the name for the type of locking mechanizum used in our cars? I know its not a traditional yank hard on the belt type and seems to work with the cars momentum.
I just found this and they are calling it a "Vehicle-sensitive lock" So I guess thats it. Heres how they discribe how it works. = It is based on a pendulum swung away from its plumb position by rapid deceleration or rollover of the vehicle. In the absence of rapid deceleration or rollover, the reel is unlocked and the belt strap may be pulled from the reel against the spring tension of the reel. The vehicle occupant can move around with relative freedom while the spring tension of the reel keeps the belt taut against the occupant. When the pendulum swings away from its normal plumb position due to sudden deceleration or rollover, a pawl is engaged, the reel locks and the strap restrains the belted occupant in position.
OK,then that means that as long as the car is stopped or driving normally you can yank on the belt a dozen times and it still will not lock.

 

I think it's called Inertia