brainwave?

[Roger A]

Had a sudden thought today
Rather than a HANS device, would it be feasible to attach an ordinary inertia-reel belt(or cable on an inertia-reel) to a helmet to arrest violent forward motion in the event of hitting something hard.The advantages of this would be that you would not have the restriction of movement unless you needed it. You could attach a quick-release behind your head for hasty escape and it would be ludicrously cheap.Obviously you would retain racing harness belts and probably use a headrest to avoid the whiplash of the violent backwards collision. How you would effectively attach the belt to the helmet may take some thought, but not too much.
Is this as obvious as it seems to me or am I missing something???-I am aware that I have NO mechanical expertise
What think you, techy types??

[Esprit]

Certainly feasible... I think the case against is one of quick egress should you need to get out... that's the reason why it's not done like this in high-profile motorsports (I eblieve) The HANS device is not ideal from a head-restraint point of view, just distributes the force down onto the shoulders.... don't see any major case against your proposal though.

[Roger A]

I think I covered that above. again it would be existing,freely available stuff (ordinary, push-button seatbelt release)

[htsd]

And if you're unconscious? I think the main advantage of the HANS system is that it keeps your head in a suitable position relative to your spine regardless of the mass of your head plus helmet. An inertial reel has that bit of lag then a bite which could wrench your spine. It also wouldn't protect you when getting hit from behind like HANS can. I think I'd leave the safety systems to the experts!

[Roger A]

Thanks Mr UNDISCLOSED. I guess if you're unconscious you're unlikely to be climbing out of the car anyway. I take your point re lag then jolt, but this would surely still be better than nothing- ie no HANS which some people are choosing due to cost, or feeling of constriction.
As for being hit from behind -headrest + belted helmet thingy? (as we say in the trade)

[jamieheasman]

I seem to remember that in the early days of the HANS system that the boys in IRL used to fasten their helmets to their car (that's made me go cold!) perhaps only on one side to aid the g-force on the ovals.

Some movement of your head in an accident is good to avoid your brain from exiting out of your eye-sockets.

[speedy_thrills]

Roger A said:

What think you, techy types??

Part of the idea behind the HANS system is surely that it keeps your head straight when you are involved in an accident to prevent your head from twisting and your neck/body from being out of alignment upon impact. I would be very worried that the shear force acting through the top of your spinal column due to the relative difference in motion of your head/body would allow the disks to separate more easily if you get caught with your head twisted during an accident.

If the system could correct your head relative to the vector of acceleration the system would work. The only problem is that an accident happens so fast that correcting your head may cause serious injury in itself without a damper mechanism, I cant think of a damping mechanism that would work in this time frame. You may be on to something however…

[Roger A]

point taken, thanks.Back to the drawing board. Where are my crayons?

[Esprit]

If I were you, I'd have a google and pull-down ALL the literature you can on the HANS device and how it works... as in how it works biomechanically... then you can think about designing something to replicate it.... it's the way I'd do it

[speedy_thrills]

Roger A said:

point taken, thanks.Back to the drawing board. Where are my crayons?

Haven said that it would probably work if you limited the range of movement to just a few degrees.

How about safety belts that is like a jacket front sewed into the seat? Any one who has been in a car accident or raced a car with good breaks knows how much it hurts when the belts dig into you. A safety system like this would help by not places excess force on the areas that where restrained.

Seats that allowed forward movement upon impact to slow deceleration? Of course the steering wheel would have to pull forwards as well. A neck protection system to guard against whiplash?

If you are a bit board and looking for an idea you could design a steel jacket system for the ends of wooden beams that would prevent them from cracking under the tensile/compressive loads they are subjected to. I would envision a hollow tube system with nice strong welded joints to carry the loads. The jackets or sleeves would have many small bolts to take the load from the wood, through the steel jacket transfer casing and into another beam of wood. Brilliant for New Zealand where wood is often used as a major structural member and can be subjected to reparative overloading during earthquakes.

I’m sure you will find something to make your millions on…

[Roger A]

I already have my way of making millions-this was just an idea that I thought had merit, and maybe could get a safety system out to those who, because of light wallets (through having thrown so much money at cars?) or objections to restriction of movement,don't see HANs or similar restraints as an option.
By the way, thanks for the input from you all, which has been interesting and mostly positive.
Gob less (not that any of you gob at all, of course)