How Seat Belts Work
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- เผยแพร่เมื่อ 20 พ.ย. 2017
- Ever wonder how seat belts work to save your life in a crash?
Well buckle up! This video takes you through the inner mechanical workings of the seat belt mechanism, its various functions and internal components.
The three point seat belt is common on most modern passenger vehicles. Normally unlocked, seat belts give the user sufficient freedom to move around while riding in a car.
However when the vehicle undergoes heavy braking or collides with another object, the seat belts lock - and in some cases retract, pulling the occupant away from smacking their face on the dashboard causing injury.
The seat belts also sense when a vehicle is accelerating hard, on an incline, as well as stop if pulled out too far, as well as sense quick sharp tugs on the seat belt and lock it in place.
A cam gear inside controls how much seat belt webbing can be extracted without locking. A gravity ball inside a plastic casing senses the incline of the vehicle under acceleration or braking. A centrifugal ratchet engages when the seat belt is tugged on rapidly. Finally a small tooth engages to lock the seat belt when all of the webbing material has been extracted.
The front seats are a bit different, as they come with pretensioners. Working with the SRS airbag system, the pretensioners will wind up any slack in the seat belt webbing during a collision. This will hold the occupant away from hitting the dashboard and prevent injury.
Seat belt pretensioners contain an explosive because it has to react very quickly during the collision. The explosive pushes a piston that's attached to a wire. The wire is reeled around the seat belt retractor, and thus winds up the slack when fired.
The seat belts in this video were removed from a 2001 Toyota Corolla, and completely taken apart and detonated to explain what's inside and how it works.
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Reference material:
auto.howstuffworks.com/car-dr... - ยานยนต์และพาหนะ
the amount of craftsmanship and complexity in such a seemingly simple part of the car
Exactly what I was thinking as I took apart this seat belt.
Thanks for your effort making this video
+Chrismalito Terec glad you enjoyed it. Video ideas are welcome
Damn,, just stumbled across this video and ended up watching the whole thing.. You really know your stuff. Good job..
+Mike A I'm glad you enjoyed it.
Thanks brother I’m working on a new project and this really helped me narrow down what I need to emulate
What is your project with seat belts? I'm curious
Thank you for this video. I don't know anything about cars, but your explanation was very clear and easy to follow.
Thanks. Glad you enjoyed it
Love this series :) Thanks!
RIP The toothbrush. Moment of silence
+Germaine Liew Don't worry my brother has more where that came from!
Cheers for the video! Turns out the gravity ball was full of fluff, as the seatbelt was completely locked up. Works like new again!
Glad it helped. Hope to update this video soon
Very informative video. Thanks for your educational contributions to the community.
+M.I.B MEN IN BLACK your welcome and thanks for your kind comment.
Brilliant video! I was looking to find out how it all worked, expected some visual graphics, in a dry and boring presentation, but this is brilliant! Reminds me of AVE but without the swearing! Great job!
Amazing I'm glad you were impressed
Where do you get OEM spiders? My dealership doesn't supply them.
+MaximumJonathanosity I left my parts sitting for a while after pulling under my shed, I bet most of the videos youll see from now onward will have spiders.
i enjoy your videos, an easy and fun way to comprehend function principles of any car component, a big salute from Colombia
Cool, had no idea they were so complex. Thank you
Always like to watch your videos. Very comprehensive and informative.
+Mian Arshad Glad you enjoy them. Share them with your friends and feel free to che k other videos like this.
Brilliant video.. the way you explain is great with some humor too.. thank you
Excellent Job, best video describing this ever! Thanks for sharing your knowledge!
thanks for the informatic videos man!!!
+Jorge Gomez your welcome!
most intricate part of the car
Real very informative video. thank you for taking your time to make and upload this video.
+Shreedharan Vijaykumar I'm glad you enjoy it! Informative concise videos are my style.
Very Effectively explained .Thanks
+Rajan k your welcome
I love your videos keep the good work up!
+Ma Co Thanks for watching!
he knows what he is talking. Great explanation.
right on! your video was very helpful, thank you
very educative as ALWAYS . Thank you Regards
You really know your stuff! That's awesome!
Thanks. I learn as you learn, opening things up
That was a great video. Subscribed
Great vid, and great engineering.
Thanks. Allot of engineering for such an overlooked device
Love this guy!
My big fat belly and i appreciate your video
You're belly is welcome
Through this video I got some picture about seat belt ...but didn't understand, I am gonna soon disassemble seat belt and learn .thank q
Hope you learned something
Thanks for this wonderful clips learnt alot. Please can I replace the pretensioner for my 2015 Nissan versa front passenger seat belt or do I need to replace the entire seat belt?
Thank you
could you potentially use a mechanism like this for climbing gear (ignoring obvious safer precautions)? i looked up how a seat belt works because the mechanism 1: extends and retracts 2: locks up when pulled on 3: has a max distance it can extend before locking up and needing to retracts. these seemed like good features in my mind for a belt/harness attachment that could wind in your rope while climbing something. i don't know much about climbing gear or mechanics i just had always had this thought in the back of my mind and decided to learn if it was possible. thanks for any answers
Thank you ihave been looking for thise vedio all over youtupe
+mshary's garage Glad you enjoy it
Thanks! Very informational.
+Huri Bagdat your welcome!
Super cool video, thank u very much
You are welcome
Interesting video!!! Love the toothbrush pointer :) gives a little humor to a serious and informative video.
Haha thanks
Awesome video!
+Fernando Sousa thanks
Very informative video. Thanks
You are welcome
Love your videos and your brothers toothbrush trick....lol!
Haha
I love the toothbrush too
Thanks for this video! That's very clear, funny and synthetic! I could finally manage to find the problem in my seatbelt. The gravity ball might be in a slightly wrong position: this causes the belt to stuck often. How would I fix this problem? Is it dangerous to remove the gravity ball and keep driving until find a replacement?
I know this comment is over three years old, but you never know what’ll help.
Yes, it’s very dangerous because that mechanism is what causes the seatbelt to lock in high accelerations (negative or positive)
The seat belt on my old beater acts up a lot. One day I pulled on it fifty times and it wouldn't extend, so I just drove off without using it. Of course a Highway Patrol spotted me in heavy traffic and pulled me over. I demonstrated that it wasn't working that day....he could have given me a warning or a fix it ticket but he nailed me for the full fine, One Hundred Twelve Bucks! : ( Then they wonder why people hate cops : ( Later I used compressed air and blew out about a pint of sand and gravel from the mechanism. It still doesn't work very well but once I got it extended I used a vise grips to keep it there.
Now that I got that off my chest this was another fascinating video!
Awesome, glad you learned something
Unique and interesting content!
+Jim Trainor Thanks, your right there really isnt many other articles explaining how these mechanisms work.
Super cool vid, seatbelts are way more complicated than I thought they are... :) Maybe you could record something short to show how to recognize seatbelts after collision? It happens that you might have ones in a used car from a lousy seller. Sometimes torn white label on the belt may be a sign that it saw too much g-force.
+pancakewsx They are quire complex, I was surprised opening these up myself
Very very nice video
Good Video
Very interesting to see all those components for real
Sure is!
i m surprised that my life is being held by plastic gears rather than metal gears.
+superpanda 1022 that's a good thought I didn't realize that.
I'm pretty sure most modern ones are made of metal
They’re still plastic for many reasons. I know this because I’m a seat belt engineer
Sergio Gonzalez can you contact me please sir? I need your help in a design process.
Sergio Gonzalez can you contact me please sir? I need your help in a design process.
Really good
good video
Great video, very informative and entertaining 😁 👍🏼
Thanks
@@speedkar99 by the way, Thanks to your video, I was able to disassemble my seatbelt and fix it. It was locking everytime I tried to pull it out. Just needed a good clean and some lubrication.
I use to assemble the spindle part of these
Way to take one for the team, Toothbrush. Your sacrifice will result in millions of saved lives.
*trumpet taps*
*Burrr bur burrrrr, burr bur burrrrrrrrrr*
+Rob Hodge Haha! The toothbrush is like Kenny in south park....always taking one for the team :)
speedkar99
- OMG! They broke the toothbrush!
- You, bastards!!!
Good thing his brothers underwear is safe in this video
how do you put the spring back?
amazing~~~~
You should do slow mo so we can see exactly how its retracting during a collision.
+heyitschino that would be cool....if I had a high speed camera
Please make what’s inside a electronic throttle body
Ah, that signature toothbrush
Took one for the team
Good day from Kit=Waterloo Boy o boy interesting video, especially on front belts Good video Thanks
Hi from Mississauga
amazing presentation!!!
Edit, don't call me fat!
Whats the purpose of that seatbelt mechanism explosive?
It'd be interesting to see the pre-tensioner system work while the seat belts are still attached to the car.
+Mateusz Wojtkiewicz Yea that would be good. You'll see it retract a bit
Spiders xD...nice video!
Yes the parts were under the shed for a while
What will avoid pretensioners locking the retraction before it blasts off ? What will make it lock once it blasts off?
Hahaha... You're brother will have to use neem branch now. Great video by the way.
Haha poor brother.
i had... a same brush lol............... good explanation bro
Colgate? Haha
@@speedkar99 i enjoyed with useful info thnx
2:05 does it mean that if I remove this seatbelt can pop out from shaft?
That toothbrush though it’s like the staff for a wizard
Agreed haha
"Wizard "
Great stuff. Now take a car battery and melt those big springs :D
+ciprianwiner I never thought of that, I wonder if it will melt the spring or the battery catch fire.
speedkar99 After melting a ton of springs, I doubt that the battery will catch fire but, we never know until we try :)
This was an amazing video! Very informative, descriptive, and well explained!
I’m currently working on a seat-belt related project and this will help me tons!
However, I do have questions and will have lots of questions in the future. May I get your email address for easier communication?
Thanks for the feedback. Facebook
My front passenger side has locked up mostly out but it won't retract either. I'm not even going to try fix it, just replace it with one off a low mileage car I found that still works. Only new one I can buy is made up in a factory in Italy where the car comes from but the quote will be a fortune. Specially with the explosive charge.
Easy to replace. Open it up and you'll likely misplace something
plz upload about how the lever works sir
The shifter? I have 2 videos on that already
Lol @ when the spring steel flies out!!! 🤣🤣🤣
Yea it surprised me
I can relate
Did you find the seatbelt sensor that makes the light on the dash flash incessantly even though you have your belt on? I got sick of it enough in my corolla that I removed the bulb outright.
The Sensor/Switch is in the "Seatbelt Lock or Connector...i don´t know the English Word...." not on the Seatbelt-Mechanism itself! :D
I removed my seats completely from the car to clean them and there were no connectors or wires on the buckle side See the following for what I mean - th-cam.com/video/8tW6joHPQNU/w-d-xo.html The sensor is buried up inside the B pillar somewhere.
My seats were so filthy and grubby that they got removed and got a bath with hot water and dish soap.
Now I know how to fix my seat belt thanks
You are welcome
Informative and enjoyable -- loved the toothbrush pointer -- hope your brother forgave you! ;)
What he doesn't know won't hurt...
Do all modern cars have this type of seat belt with the "pre-tensioner" in the front seats? How would I know if mine has already popped in the past?
Yes. A popped seat belt won't retract
im trying to install a child car seat using the seatbelt but cant get the seatbelt to lock in place. i followed the videos online that says retract all the belt then slowly feed it back in ( should hear the ratcheting sound but i am not) to switch from emergency lock to manual lock the seatbelt but it isnt working. i tried it on 4 cars , i dont know what im doing wrong. any help will be appreciated thanks
The talking is a tad to fast but you get to the point. Thanks
They call me speedkar for a reason
Why there is a push to lock system and gravity sensor? Is one enough for locking the person moving forward??
+Yathu prem Gravity senses moderate braking forces. The force pull is much more rapid and sense sudden impact. Two separate systems.
Hi,
I could not put my car seat belt when the car is in rest. Rather I need to start and move some distance then I need to put my brake slowly and at the same i need to put seat belt at one stretch slowly. I feel now its something related to gravity ball. Can you please advise the fix. Car is Nissan Altima 2010.
Jihad vv so, did you manage to fix it?
Hello great video! My drivers seatbelt is blocked pulled out after the firing mechanism exploded after a very small hit with another car. Now the seatbelt is out and the spring cant pull it in back in place so i cant use the seatbelt at all because its stuck out. So the question is, can i unblock the seatbelt to be able to use it normally as a simple seatbelt without the firing mechanism untill i replace it, because till then i cant use the seatbelt at all. Thank you very much.
I think you'd have to disconnect it entirely
@@speedkar99 . Yes i did so and it worked. I thought in theory after i watched your video first because i had no idea how seastbelts work that the mechanism consists of 3 main parts. The part with the gravity ball that works in slower decreasings of the car, the centrifugal part that works in very hard decreasing of the car like really hard hit of the brake or crash on another car or wall for example and finaly the firing mechanism that the reason of it is actually to pull you back when u are leaned forward for some reason like to scratch your ankle for example and your back is not touching the back of the seat. If the steering wheel airbag explodes and u are leaned front it will hurt u so the firing mechanism pulls u back in place. So what i did was to open the mechanism to the side that this wire rope is, cut it and throw it away and take out a couple of parts that engage the seatbelt to wrap in when firing mechanism explodes, it was just 2 kinda gears parts and then the whole mechanism was able to work freely again. The part with gravity ball and the part with centrifugal mechanism was untouched. I repeat for anyone that reads this that the seatbelt can be unblocked and work safely like a simple seatbelt without a firing mechanism untill it will be replaced with a new one BUT WITHOUT TO TOUCH OR REMOVE THE GRAVITY BALL OR MESS WITH THE CENTRIFUGAL MECHANISM that is on the side the gravity ball is too. In few words we dont touch or open for any reason the side we see the lil bearing ball is. The wire rope we need to cut and discard is on the other side where the firing mechanism is and the wrapping spring is too like it shows on the video. My car is a Hunday Tiburon coupe 2006. Sorry for any mistakes but english isnt my language. Keep up the good videos mate ! Peace and thank you !
So when it doesn't retract, what do we need to replace? The coil of spring?
+spiritbuu Likely
we got more spiders!!!!!! haha
Whoops
Bought an 03 Sierra with the back seatbelts removed, but when fiddling with them I noticed the seatbelt won’t pull out. Anyone know why or could help thanks
It's probably this ball mechanism preventing it
hi,can the spring be repaired?.mine is stuck.it can not roll back.
+Ernesto rono If it's been in an accident and locked up then you'll need a new pretensioners assembly
Good wideo
the seatbelt really saved my life
Glad it did
hey, thanks man :D
A video idea you prob wont see it how does a steering wheel move the two front wheels?
See my steering rack and steering column video for that
Why do old seat belts retract slowly? Does the spring lose tension?
Also when dirt and grime builds up on the belt and it looses it's flexibility
Can the spring or belt be changed/cleaned?
também quero desmontar um deses
This price plese
If only there was 1 type of retractor lol....there are a ton of combinations
There sure are! It's quite complex
Cavity free video
Because toothbrush
Wanted to experiment with a seatbelt retractor for a 'simple' project... but... gosh dam bruh...
It's soooo complex eh!
I was installing a amplifier and accidentally apply power to that tetionner and it lock my seatbelt I had to take it to the mechanic
Oh my, that must have been an expensive fix!
This definitely didn't grow on tree.
Hahaha that's one way to put it
the law changed for seat belts was in 1996
Hahah the spiders 😂
Yea poor things...I took away thier home
You forgot to say, "Hey guyyz, Chris Fix here."
That's not me.
@@speedkar99 I'm kidding haha i thought you sounded a bit like him😂
After watching the HVAC video I wanna do a tag job and after this video I realized I have a big fat belly. I also stole my brothers tooth brush, he he.
+richgg2 haha
Well time for a new years resolution
that's funny for you to use a tooth brush as a pointer lol, but nice clip anyway, thanks
+Cyrus Chann the toothbrush took the hit when I exploded the retractor
absolutely lol