What is the purpose of the ball bearing in a seat belt assembly?

Question

I replaced a rear seatbelt assembly in my wifes Mazda6 and I could see a single ball bearing about 7/16" in dia. in some sort of carriage that looks like it locks the seat belt if the car is overturned. Does anyone know if thats what that single ball bearing is intended for?

Answer 1

http://auto.howstuffworks.com/seatbelt.htm This page will answer all your seat belt questions.

Answer 2

It's a safety device to prevent slack in the seatbelt. Try pulling the seatbelt out half way, and you'll notice that you can let it retract and pull it out again.

Now pull the seatbelt out as far as it will go. Let it retract again and this time you'll notice that you can't pull the seatbelt back out until it retracts completely.

The ratcheting sound you'll hear is the ball bearing mechanism.

In the event of an accident, the mechanism prevents the passenger's body from moving forward and colliding with the seat/dash board.

Answer 3

It acts as a weight and is moved by inertia, locking the seat belt reel. Have you ever stopped quick and noticed that your seat/shoulder belt locked? That's so you don't spool out the unused portion of the belt and smack your face on the winshield or eat the steering wheel.

Answer 4

its a safety device,if the car tilts or stops suddenly it makes the belt lock in place and not move,all it has to do is get out of place and automatically the belt will no longer move,,good luck with it.

Answer 5

That's a good question, I was wondering the same thing myself

Answer 6

i would say its part of the inertia activated restraint if the belt does not lock when you tug it out sharply and just spools out slack thats your answer.