[Land-speed] Head Restraints...another concept.

[Ed Weldon]

Neil & Lance--

Good points here. Springs (like stretchy belts) with minimal dampening are
unable to absorb the energy that will accompany a long duration crash event.
For that you need a fluid damper that converts mechanical energy to heat an
internal fluid. This is especially true if the rate of impacts is anywhere
near one of the natural frequencies of the driver's safety constraint
system.   I think some combination of shock isolation with elastic members
and one shot energy absorbers and energy absorption with dampening members
("shock absorbers" of one type or another) is going to be the future of this
new technology.  Most of the current head-neck restraint approaches depend
on the former.  Isaacs, as far as I can tell without looking inside those
things, is all the latter.  This may prove OK, crude as it is from an
engineering standpoint.  But the Isaacs approach is going to eventually have
to ditch the idea of requiring the driver to do something else besides
unhook a multipoint harness in order to get out of the seat.  Especially
where fire or suffocation is part of the hazard menu.

Ed

----- Original Message ----- 
From: "joseph lance" <jolylance at earthlink.net>
To: "LAND-SPEED @ AUTOX.TEAM .NET" <land-speed at autox.team.net>;
<neil at dbelltech.com>
Sent: Wednesday, September 10, 2008 1:15 PM
Subject: Re: [Land-speed] Head Restraints...another concept.


> Neil;
> Thats true to a certain extent but the short duration impacts can still be
> very harmful and the harm may not be immediately apparent.
> I'm thinking that repeated NFL and boxing impacts leading to concussions,
> joint injuries, etc. may be quite similar to getting rattled around in an
> LSR roll cage during a crash even if the crash is survived.
> Maybe the sports medicine people can help with increased LSR safety.
> Lance

> ----- Original Message ----- 
> From: <neil at dbelltech.com>
> To: "'joseph lance'" <jolylance at earthlink.net>; "'Ed Weldon'"
> <23.weldon at comcast.net>; <drmayf at mayfco.com>; "'LSR'"
> <land-speed at autox.team.net>
> Sent: Wednesday, September 10, 2008 12:18 PM
> Subject: RE: [Land-speed] Head Restraints...another concept.
> > Lance;
> > The body can stand high G forces but for only a very short duration. If
> > the G forces act over a longer time then the ability to withstand them
becomes
> > greatly reduced.  Regards, Neil   Tucson, AZ