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Vehicle: Car: Safety: Crash
New Windscreen Design   (+4, -5)  [vote for, against]
In the event of a crash, why keep the windscreen?

In the event of a crash, children/adults are often not buckled up. This is a fact we must deal with.

The effect of this is that the people go flying throught the windscreen into the road/car in front. This idea would be simple, take the windscreen with you as a buffer.

The windscreen design would be changed in 2 key ways:

1. The windscreen would be designed to detach from the car when hit by a large force from the inside. 2. The outer layer of the windscreen would be a very tough plastic, not designed to shatter or break into bits.

When a person flew into the windscreen, it would detach and they would carry on flying, now with this plastic to shield them. In the event of hitting a car this may not help much, but the plastic may shield you a bit.

However, when hitting the road the plastice may help more notably. Being fairly smooth and curved, the angle it hits the road on may be far less harsh than the angle you alone would. With luck and maybe design, the windscreen could even be made to slide on tarmac, allowing you to 'sled' for a second or so, losing kinetic energy all the time.

Only problem I can see is hitting the windscreen and it not moving, but how can that be worse than hitting a car or the road?
-- Germanicus, Nov 30 2005

Safety glass http://computer.how...com/question508.htm
Windshields DO have plastic in them. [5th Earth, Dec 02 2005]

The trouble is that the windscreen is a stressed, structural part of the body. If the car were to roll over, the roof would be more likely to collapse if the screen were not in place.
-- angel, Nov 30 2005


The idea would be that it is fitted so that it is strong from outside blows but will break off from the car if hit from the inside. Think of a windscreen slightly too and on the outside, if hit from the outside it will hold firm, but the inside will lift it off.

Though obviously it would be more complex than that, I am not sure how it would be engieniered (sp).
-- Germanicus, Nov 30 2005


And I only now re-read your post. You meant in the event of a crash not in general. Good point but I think that the benifits would out way it.
-- Germanicus, Nov 30 2005


//strong from outside blows but will break off from the car if hit from the inside.// oh, come now! we're struggling.

<throws life belt>

//Think of a windscreen slightly too and on the outside, if hit from the outside it will hold firm, but the inside will lift it off.// wonderful stuff - must remember...
-- po, Nov 30 2005


Fair point, but surely a windscreen that did what I want in the description could be made?

And my design stated was a simplifyed idea, it was not meant to be used.

And it was meant to say too big...
-- Germanicus, Nov 30 2005


I tend to think with the forces involved, I would slip right off the windshield... how do you (or could you) hold on at those speeds?
-- Zuzu, Nov 30 2005


I was assuming that the slightly curved shape of the windscreen would help slightly, besides, any amount of force absorbed by it and not you when you hit the road cannot be bad.
-- Germanicus, Nov 30 2005


I remember that in the past some reasearch went in to making inflatable windshields out of two layers of clear plastic. I'm not sure why it never caught on though.

If you wanted to use the windshield as a "sled," you would need something on the inside to keep broken glass from cutting up the crash victim.

I think that seatbelts, airbags, and safety cages would work better than anything meant to protect the crash victim after he or she is ejected from the car.
-- discontinuuity, Nov 30 2005


Thats true but we still have people who don't use them. For example didn't some people disable their airbags after rumours that they had suffocated a person?
-- Germanicus, Dec 01 2005


They have tried all sorts of windscreen designs. The main screen must be glass, for structrual reasons. Attempts have been made to incorparate plastic layers.The problem is that all plastics scratch and discolor over time. The most important property of a windscreen is its optical properties, and the best material is glass alone.
-- Minimal, Dec 01 2005


...but all (modern) windscreens DO have a plastic layer in them, which is why they are referred to as "safety glass" and is why, when broken, they DON"T shatter into a million pieces but do, in fact, stay together surprisingly well. True, they are still mostly glass, but saying they are glass alone is patently false.

That said, having a windscreen only pop out from inside force is problematic, not because it's structurally difficult (because IMO it really isn't despite what people are saying), but because the air pressure outside of a car is lower than the pressure inside of it (insert lecture on Bernoulli here). If you drove too fast the windshield might blow out.
-- 5th Earth, Dec 02 2005


Whilst I accept your last point. I would like to say that though all modern windscreen have a plastic layer so they don't shatter, they do still break up into far too small piece for humans to use as a shield.
-- Germanicus, Dec 02 2005


Hmm, good point, I guess some kind of security mechanism could be made?

Though, I stress this is a halfbaked idea.
-- Germanicus, Dec 02 2005


I thought windscreens were already designed to shatter if hit from the inside (to absorb impact of crash) but stay stable if broken from the outside?

Maybe I'm just making crap up.
-- shapu, Dec 02 2005


I suspect that that is simply a function of the screen's curvature. Pressure from outside is similar to the weight on an arch.
-- angel, Dec 02 2005


Or you could protect the screen from the pavement with your body.
-- Antegrity, Dec 03 2005



random, halfbakery